CCL2 Potentiates Inflammation Pain and Related Anxiety-Like Behavior Through NMDA Signaling in Anterior Cingulate Cortex.

Previous studies have shown that the C-C motif chemokine ligand 2 (CCL2) is widely expressed in the nervous system and involved in regulating the development of chronic pain and related anxiety-like behaviors, but its precise mechanism is still unclear. This paper provides an in-depth examination of the involvement of CCL2-CCR2 signaling in the anterior cingulate cortex (ACC) in intraplantar injection of complete Freund's adjuvant (CFA) leading to inflammatory pain and its concomitant anxiety-like behaviors by modulation of glutamatergic N-methyl-D-aspartate receptor (NMDAR). Our findings suggest that local bilateral injection of CCR2 antagonist in the ACC inhibits CFA-induced inflammatory pain and anxiety-like behavior. Meanwhile, the expression of CCR2 and CCL2 was significantly increased in ACC after 14 days of intraplantar injection of CFA, and CCR2 was mainly expressed in excitatory neurons. Whole-cell patch-clamp recordings showed that the CCR2 inhibitor RS504393 reduced the frequency of miniature excitatory postsynaptic currents (mEPSC) in ACC, and CCL2 was involved in the regulation of NMDAR-induced current in ACC neurons in the pathological state. In addition, local injection of the NR2B inhibitor of NMDAR subunits, Ro 25-6981, attenuated the effects of CCL2-induced hyperalgesia and anxiety-like behavior in the ACC. In summary, CCL2 acts on CCR2 in ACC excitatory neurons and participates in the regulation of CFA-induced pain and related anxiety-like behaviors through upregulation of NR2B. CCR2 in the ACC neuron may be a potential target for the treatment of chronic inflammatory pain and pain-related anxiety.

Peripheral BDNF Regulates Somatosensory-Sympathetic Coupling in Brachial Plexus Avulsion-Induced Neuropathic Pain.

Brachial plexus avulsion (BPA) is a combined injury involving the central and peripheral nervous systems. Patients with BPA often experience severe neuropathic pain (NP) in the affected limb. NP is insensitive to the existing treatments, which makes it a challenge to researchers and clinicians. Accumulated evidence shows that a BPA-induced pain state is often accompanied by sympathetic nervous dysfunction, which suggests that the excitation state of the sympathetic nervous system is correlated with the existence of NP. However, the mechanism of how somatosensory neural crosstalk with the sympathetic nerve at the peripheral level remains unclear. In this study, through using a novel BPA C7 root avulsion mouse model, we found that the expression of BDNF and its receptor TrκB in the DRGs of the BPA mice increased, and the markers of sympathetic nervous system activity including α1 and α2 adrenergic receptors (α1-AR and α2-AR) also increased after BPA. The phenomenon of superexcitation of the sympathetic nervous system, including hypothermia and edema of the affected extremity, was also observed in BPA mice by using CatWalk gait analysis, an infrared thermometer, and an edema evaluation. Genetic knockdown of BDNF in DRGs not only reversed the mechanical allodynia but also alleviated the hypothermia and edema of the affected extremity in BPA mice. Further, intraperitoneal injection of adrenergic receptor inhibitors decreased neuronal excitability in patch clamp recording and reversed the mechanical allodynia of BPA mice. In another branch experiment, we also found the elevated expression of BDNF, TrκB, TH, α1-AR, and α2-AR in DRG tissues from BPA patients compared with normal human DRGs through western blot and immunohistochemistry. Our results revealed that peripheral BDNF is a key molecule in the regulation of somatosensory-sympathetic coupling in BPA-induced NP. This study also opens a novel analgesic target (BDNF) in the treatment of this pain with fewer complications, which has great potential for clinical transformation.

Ultrasensitive Detection of Bacteria Using a 2D MOF Nanozyme-Amplified Electrochemical Detector.

Bacterial infection is one of the major causes of human death worldwide. To prevent bacterial infectious diseases from spreading, it is of critical importance to develop convenient, ultrasensitive, and cost-efficient methods for bacteria detection. Here, an electrochemical detector of a functional two-dimensional (2D) metal-organic framework (MOF) nanozyme was developed for the sensitive detection of pathogenic Staphylococcus aureus. A dual recognition strategy consisting of vancomycin and anti-S. aureus antibody was proposed to specifically anchor S. aureus. The 2D MOFs with excellent peroxidase-like activity can efficiently catalyze o-phenylenediamine to 2,2-diaminoazobenzene, which is an ideal electrochemical signal readout for monitoring the bacteria concentration. Under optimal conditions, the present bioassay provides a wide detection range of 10-7.5 × 107 colony-forming units CFU/mL with a detection limit of 6 CFU/mL, which is better than most of the previous reports. In addition, the established electrochemical sensor can selectively and accurately identify S. aureus in the presence of other bacteria. The present work provides a new pathway for sensitive and selective detection of S. aureus and presents a promising potential in the realm of clinical diagnosis.

In Situ Fabrication of Ultrasmall Gold Nanoparticles/2D MOFs Hybrid as Nanozyme for Antibacterial Therapy.

As one of the common reactive oxygen species, H2 O2 has been widely used for combating pathogenic bacterial infections. However, the high dosage of H2 O2 can induce undesired damages to normal tissues and delay wound healing. In this regard, peroxidase-like nanomaterials serve as promising nanozymes, thanks to their positive promotion toward the antibacterial performance of H2 O2 , while avoiding the toxicity caused by the high concentrations of H2 O2 . In this work, ultrasmall Au nanoparticles (UsAuNPs) are grown on ultrathin 2D metal-organic frameworks (MOFs) via in situ reduction. The formed UsAuNPs/MOFs hybrid features both the advantages of UsAuNPs and ultrathin 2D MOFs, displaying a remarkable peroxidase-like activity toward H2 O2 decomposition into toxic hydroxyl radicals (·OH). Results show that the as-prepared UsAuNPs/MOFs nanozyme exhibits excellent antibacterial properties against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria with the assistance of a low dosage of H2 O2 . Animal experiments indicate that this hybrid material can effectively facilitate wound healing with good biocompatibility. This study reveals the promising potential of a hybrid nanozyme for antibacterial therapy and holds great promise for future clinical applications.

Boosting Electrocatalytic Hydrogen Evolution over Metal-Organic Frameworks by Plasmon-Induced Hot-Electron Injection.

Efficient hydrogen evolution via electrocatalytic water splitting holds great promise in modern energy devices. Herein, we demonstrate that the localized surface plasmon resonance (LSPR) excitation of Au nanorods (NRs) dramatically improves the electrocatalytic hydrogen evolution activity of CoFe-metal-organic framework nanosheets (CoFe-MOFNs), leading to a more than 4-fold increase of current density at -0.236 V (vs. RHE) for Au/CoFe-MOFNs composite under light irradiation versus in dark. Mechanistic investigations reveal that the hydrogen evolution enhancement can be largely attributed to the injection of hot electrons from AuNRs to CoFe-MOFNs, raising the Fermi level of CoFe-MOFNs, facilitating the reduction of H2 O and affording decreased activation energy for HER. This study highlights the superiority of plasmonic excitation on improving electrocatalytic efficiency of MOFs and provides a novel avenue towards the design of highly efficient water-splitting systems under light irradiation.

Biomimetic Nanochannel-Ionchannel Hybrid for Ultrasensitive and Label-Free Detection of MicroRNA in Cells.

A biomimetic nanochannel-ionchannel hybrid coupled with electrochemical detector was developed for label-free and ultrasensitive detection of microRNA (miRNA) in cells. Probe single stranded DNA (ssDNA) was first immobilized on the outer surface of the nanochannel-ionchannel hybrid membrane, which can hybridize with the target miRNA in cells. Due to the unique mass transfer property of the hybrid, the DNA-miRNA hybridization kinetics can be sensitively monitored in real-time using the electrochemical technique. More importantly, due to the super small size of the ionchannels, the DNA probe immobilization and hybridization process can be carried out on the outer surface of the ionchannel side, which can effectively avoid the blockage and damage of channels and thus considerably enhance the reproducibility and accuracy of the method. Using this strategy, the miRNA ranging from 0.1 fM to 0.1 µM can be facilely detected with a low detection limit of 15.4 aM, which is much lower than most reported work. The present strategy provides a sensitive and label-free miRNA detection platform, which will be of great significance in biomedical research and clinical diagnosis.

Increasing on-target cleavage efficiency for CRISPR/Cas9-induced large fragment deletion in Myxococcus xanthus.

BACKGROUND: The CRISPR/Cas9 system is a powerful tool for genome editing, in which the sgRNA binds and guides the Cas9 protein for the sequence-specific cleavage. The protocol is employable in different organisms, but is often limited by cell damage due to the endonuclease activity of the introduced Cas9 and the potential off-target DNA cleavage from incorrect guide by the 20 nt spacer. RESULTS: In this study, after resolving some critical limits, we have established an efficient CRISPR/Cas9 system for the deletion of large genome fragments related to the biosynthesis of secondary metabolites in Myxococcus xanthus cells. We revealed that the high expression of a codon-optimized cas9 gene in M. xanthus was cytotoxic, and developed a temporally high expression strategy to reduce the cell damage from high expressions of Cas9. We optimized the deletion protocol by using the tRNA-sgRNA-tRNA chimeric structure to ensure correct sgRNA sequence. We found that, in addition to the position-dependent nucleotide preference, the free energy of a 20 nt spacer was a key factor for the deletion efficiency. CONCLUSIONS: By using the developed protocol, we achieved the CRISPR/Cas9-induced deletion of large biosynthetic gene clusters for secondary metabolites in M. xanthus DK1622 and its epothilone-producing mutant. The findings and the proposals described in this paper were suggested to be workable in other organisms, for example, other Gram negative bacteria with high GC content.

Increased Vitreous Chemerin Levels Are Associated with Proliferative Diabetic Retinopathy.

PURPOSE: To investigate chemerin in the vitreous bodies of patients with proliferative diabetic retinopathy (PDR) and determine the correlation between the levels of vitreous chemerin and vascular endothelial growth factor (VEGF). METHODS: This study included 17 patients suffering from PDR and vitreous hemorrhage (VH) (group A), 21 patients with PDR and tractional retinal detachment (TRD) (group B) and 25 patients with idiopathic macular holes or preretinal membranes (control group). All vitreous samples were obtained through pars plana vitrectomy. Enzyme-linked immunosorbent assay and Western blot analysis were performed to evaluate the levels of vitreous chemerin and VEGF. RESULTS: Vitreous concentrations of chemerin were significantly higher in PDR patients with VH and TRD than those in the controls [4.82 ng/ml (3.91-6.13) vs. 5.03 ng/ml (4.01-6.15) vs. 2.53 ng/ml (1.53-5.66), p = 0.025]. The ratio of vitreous chemerin to plasma chemerin concentration significantly differed between groups A and B and the control group [4.93% (4.69-5.34) vs. 4.98% (4.63-5.19) vs. 2.58% (1.78-4.58), p < 0.001]. Western blot results indicated that the levels of vitreous chemerin protein in PDR patients significantly increased compared with those in the controls. Spearman correlation analysis further showed that vitreous chemerin levels in patients with PDR were positively correlated with vitreous VEGF levels (r = -0.542, p < 0.001). CONCLUSIONS: Increased vitreous chemerin levels are associated with the development of PDR.

[Study on Flavonoids of Ophioglossum thermal].

Objective: To investigate the chemical components of Ophioglossum thermale,one of the original species of Chinese medicine "Yizhijian". Methods: The air-dried whole plant material of Ophioglossum thermale was extracted by thermal reflux with 95%Et OH,then separated and purified by joint utilization of various chromatography techniques including macroporous resin,silica gel,Sephadex LH-20 column chromatography and HPLC. Their structures were elucidated on the basis of spectroscopic methods. Results: Six flavonoids were isolated and identified as 3-O-methylquercetin( 1),ophioglonol( 2),3-O-methylquercetin 7-O-ß-D-glucopyranoside( 3),3-O-methylquercetin 7-O-ß-D-glucopyraosyl-4'-O-ß-D-glucopyranoside( 4),kaempferol 3-O-( 6-O-caffeoyl)-ß-D-glucopyranosyl-( 1 →2)-α-L-rhamnopyranosyl-7-O-α-L-rhamnopyranoside( 5) and quercetin 3-O-( 6-O-caffeoyl)-ß-D-glucopyranosyl( 1→2)-α-L-rhamnopyranosyl-7-O-α-L-rhamnopyranoside( 6). Conclusion: Compounds 2 ~ 6 are isolated from this plant for the first time,compounds 5 and 6are firstly isolated from Ophioglossaceae family.

[Population dynamics of ground carabid beetles and spiders in a wheat field along the wheat-alfalfa interface and their response to alfalfa mowing].

Taking the wheat-alfalfa and wheat-wheat interfaces as model systems, sampling points were set by the method of pitfall trapping in the wheat field at the distances of 3 m, 6 m, 9 m, 12 m, 15 m, 18 m, 21 m, 24 m, and 27 m from the interface. The species composition and abundance of ground carabid beetles and spiders captured in pitfalls were investigated. The results showed that, to some extent there was an edge effect on species diversity and abundance of ground carabid beetles and spiders along the two interfaces. A marked edge effect was observed between 15 m and 18 m along the alfalfa-wheat interface, while no edge effect was found at a distance over 20 m. The edge effect along the wheat-wheat interface was weaker in comparison to the alfalfa-wheat interface. Alfalfa mowing resulted in the migration of a large number of ground carabid beetles and spiders to the adjacent wheat filed. During ten days since mowing, both species and abundance of ground carabid beetles and spiders increased in wheat filed within the distance of 20 m along the alfalfa-wheat interface. The spatial distribution of species diversity of ground beetles and spiders, together with the population abundance of the dominant Chlaenius pallipes and Pardosa astrigera, were depicted, which could directly indicate the migrating process of natural enemy from alfalfa to wheat field.

G1359A polymorphism in the cannabinoid receptor-1 gene is associated with metabolic syndrome in the Chinese Han population.

BACKGROUND AND AIMS: Recent studies suggest that endocannabinoids modulate food intake and lipogenesis through cannabinoid receptor-1 (CNR1). This study aims to determine the association between G1359A polymorphism of CNR1 and metabolic syndrome (MetS) in the Chinese Han population. METHODS: A total of 382 subjects at risk for MetS and 136 healthy subjects from Tianjin, China were genotyped for the G1359A polymorphism of CNR1 using TaqMan assay. Anthropometric measurements and serum analyses were done for body mass index (BMI), waist circumference, blood pressure, serum triglycerides (TG), serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting plasma glucose, and plasma insulin levels. RESULTS: GG genotype of CNR1 has a higher incidence in MetS subjects than in control subjects. Logistic regression analysis shows that the GG genotype was significantly associated with the increased risk of developing MetS (OR 2.204, 95% CI 1.277-3.803, p = 0.005). Compared with CNR1 GG genotype in MetS subjects, CNR1 GA and AA genotypes in subjects with MetS had relatively lower levels of BMI, waist circumference, homeostasis model assessment of insulin resistance (HOMA-IR) and TG. CONCLUSIONS: Results suggest that the G1359A polymorphism of the CNR1 gene may contribute to MetS susceptibility in the Chinese Han population.