Sensory neuron transient receptor potential vanilloid-1 channel regulates angiogenesis through CGRP in vivo.

Angiogenesis plays a key role in bone regeneration. The role of neurons of peripheral nerves involved in angiogenesis of bone defects needs to be explored. The transient receptor potential vanilloid 1 (TRPV1), a nociceptor of noxious stimuli, is expressed on sensory neurons. Apart from nociception, little is known about the role of sensory innervation in angiogenesis. Calcitonin gene-related peptide (CGRP), a neuropeptide secreted by sensory nerve terminals, has been associated with vascular regeneration. We characterized the reinnervation of vessels in bone repair and assessed the impact of TRPV1-CGRP signaling on early vascularization. We investigated the pro-angiogenic effect of neuronal TRPV1 in the mouse model of femur defect. Micro-CT analysis with Microfil® reagent perfusion demonstrated neuronal TRPV1 activation enhanced angiogenesis by increasing vessel volume, number, and thickness. Meanwhile, TRPV1 activation upregulated the mRNA and protein expression of vascular endothelial growth factor A (VEGF-A), cell adhesion molecule-1 (CD31), and CGRP. Immunostaining revealed the co-localization of TRPV1 and CGRP in dorsal root ganglia (DRG) sensory neurons. By affecting neuronal TRPV1 channels, the release of neuronal and local CGRP was controlled. We demonstrated that TRPV1 influenced on blood vessel development by promoting CGRP release from sensory nerve terminals. Our results showed that neuronal TRPV1 played a crucial role in regulating angiogenesis during bone repair and provided important clinical implications for the development of novel therapeutic approaches for angiogenesis.

Biphasic Fermentation of Trapa bispinosa Shells by Ganoderma sinense and Characterization of Its Polysaccharides and Alcoholic Extract and Analysis of Their Bioactivity.

BACKGROUND: Trapa bispinosa shells (TBs) and its flesh (TBf) have been recognized for their medicinal properties, including antioxidant, antitumor, and immunomodulatory effects. Despite these benefits, TBs are often discarded as waste material, and their applications remain to be further explored. METHODS: In this study, we optimized the solid-state fermentation process of Ganoderma sinense (GS) with TBs using a response surface experiment methodology to obtain the fermented production with the highest water extract rate and DPPH free radical scavenging activity. We prepared and characterized pre-fermentation purified polysaccharides (P1) and post-fermentation purified polysaccharides (P2). Alcoholic extracts before (AE1) and after (AE2) fermentation were analyzed for active components such as polyphenols and flavonoids using UPLC-QTOF-MS/MS (ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry). Mouse macrophages (RAW 264.7) were employed to compare the immune-stimulating ability of polysaccharides and the antioxidant activity of AE1 and AE2. RESULTS: Optimal fermentation conditions comprised a duration of 2 days, a temperature of 14 °C, and a humidity of 77%. The peak water extract yield and DPPH free radical scavenging rate of the water extract from TBs fermented by GS were observed under these conditions. The enhanced activity may be attributed to changes in the polysaccharide structure and the components of the alcoholic extract. The P2 treatment group indicated more secretion of RAW 264.7 cells of NO, iNOS, IL-2, IL-10, and TNF-α than P1, which shows that the polysaccharides demonstrated increased immune-stimulating ability, with their effect linked to the NF-кB pathway. Moreover, the results of the AE2 treatment group indicated that secretion of RAW 264.7 cells of T-AOC and T-SOD increased and MDA decreased, which shows that the alcoholic extract demonstrated enhanced antioxidant activity, with its effect linked to the Nrf2/Keap1-ARE pathway. CONCLUSIONS: Biphasic fermentation of Trapa bispinosa shells by Ganoderma sinense could change the composition and structure of the polysaccharides and the composition of the alcoholic extract, which could increase the products' immunomodulatory and antioxidant activity.

A case of junctional epidermolysis bullosa intermediate with collagen XVII deficiency treated with dupilumab.

Inherited epidermolysis bullosa is a heterogeneous group of hereditary skin diseases characterized by skin (mucosa) fragility, which leads to blistering. Junctional epidermolysis bullosa is associated with mutations in genes expressing proteins of the dermo-epidermal junction. Dupilumab, an antibody that directly targets interleukin (IL)-4 receptor alpha, may be an effective treatment for dystrophic epidermolysis bullosa. We describe a case of junctional epidermolysis bullosa that improved with dupilumab.

The more the better: on the formation of single-phase high entropy alloy nanoparticles as catalysts for the oxygen reduction reaction.

High entropy alloys (HEAs) are an important new material class with significant application potential in catalysis and electrocatalysis. The entropy-driven formation of HEA materials requires high temperatures and controlled cooling rates. However, catalysts in general also require highly dispersed materials, i.e., nanoparticles. Only then a favorable utilization of the expensive raw materials can be achieved. Several recently reported HEA nanoparticle synthesis strategies, therefore, avoid the high-temperature regime to prevent particle growth. In our work, we investigate a system of five noble metal single-source precursors with superior catalytic activity for the oxygen reduction reaction. Combining in situ X-ray powder diffraction with multi-edge X-ray absorption spectroscopy, we address the fundamental question of how single-phase HEA nanoparticles can form at low temperatures. It is demonstrated that the formation of HEA nanoparticles is governed by stochastic principles and the inhibition of precursor mobility during the formation process favors the formation of a single phase. The proposed formation principle is supported by simulations of the nanoparticle formation in a randomized process, rationalizing the experimentally found differences between two-element and multi-element metal precursor mixtures.

Environmental concentrations of anionic surfactants in lake surface microlayers enhance the toxicity of Microcystis blooms: Insight from photosynthesis, interspecies competition, and MC production.

Anionic surfactants represented by linear alkylbenzene sulfonate (LAS) exhibit vertical heterogeneity of concentrations in aquatic environments owing to their amphiphilic structure. Field investigations showed that the concentration of anionic surfactants (mainly LAS) in the water surface microlayer (SML) of Lake Taihu reached 580 µg/L, higher than that in the lower layer. Floating Microcystis blooms overlap in space with the high concentration of anionic surfactants in SML. However, few studies have focused on the effects of anionic surfactants (e.g., LAS) on the interspecies competition between toxic and nontoxic Microcystis. In this study, coculture and monoculture experiments were conducted with both toxic and nontoxic Microcystis species to explore how the environmental concentration of LAS regulates the dominance of toxic Microcystis and toxicity from the perspective of photosynthesis, species dominance, and MC production. The results showed that LAS concentrations above 0.267 or 0.431 mg/L (depending on light conditions) selectively promoted the photosynthetic competitive advantage of toxic Microcystis, leading to its higher population proportion in the community. Additionally, LAS concentrations above 0.5 mg/L induced the synthesis and release of microcystins (MCs). The results of chlorophyll fluorescence analysis, electron microscopy and transcriptome sequencing suggested that compared with nontoxic Microcystis, toxic Microcystis can better resist LAS stress by dissipating excess light, maintaining an intact membrane structure and maintaining cellular homeostasis. Transcriptome sequencing revealed that the photosynthetic damage of nontoxic Microcystis might be attributed to the impacts of LAS on the absorption and assimilation of nitrogen, which finally resulted in the degradation of phycobilisomes. This study can provide novel insight for establishing standards and safety management of wastewater discharge.

STIM2 Suppression Blocks Glial Activation to Alleviate Brain Ischemia Reperfusion Injury via Inhibition of Inflammation and Pyroptosis.

Cerebral ischemia/reperfusion injury (CIRI) involves various pathogenic mechanisms, including cytotoxicity, apoptosis, inflammation, and pyroptosis. Stromal interactive molecule 2 (STIM2) is implicated in cerebral ischemia. Consequently, this study investigates the biological functions of STIM2 and its related mechanisms in CIRI progression. Middle cerebral artery occlusion/reperfusion (MCAO/R) mouse models and oxygen-glucose deprivation/reoxygenation (OGD/R) cellular models were established. STIM2 level was upregulated in experimental CIRI models, as shown by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting and immunofluorescence staining. Brain infarction and edema were attenuated by STIM2 knockdown, as 2,3,5-triphenyltetrazolium chloride (TTC) staining and brain water content evaluation revealed. STIM2 knockdown relieved neuronal apoptosis, microglia activation, inflammation and pyroptosis in MCAO/R mice, as detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, enzyme-linked immunosorbent assay (ELISA) and western blotting. Results of flow cytometry, ELISA, western blotting and cell counting kit-8 (CCK-8) assays also showed that STIM2 knockdown inhibited inflammation, apoptosis and pyroptosis in OGD/R-treated BV2 cells. Moreover, STIM2 knockdown inhibited apoptosis and pyroptosis in PC12 cells incubated with conditioned medium collected from OGD/R-exposed BV2 cells. Mechanistically, lncRNA Malat1 (metastasis associated lung adenocarcinoma transcript 1) positively regulated STIM2 expression by sponging miR-30d-5p. Their binding relationship was confirmed by luciferase reporter assays. Finally, lncRNA Malat1 elevation or miR-30d-5p knockdown abolished the sh-STIM2-induced inhibition in cell damage. In conclusion, STIM2 knockdown in microglia alleviates CIRI by inhibiting microglial activation, inflammation, apoptosis, and pyroptosis.

Cyanobacterial organic matter (COM) positive feedback aggravates lake eutrophication by changing the phosphorus release characteristics of sediments.

Phosphorus is a key nutrient that causes eutrophication in lakes. Our investigation of 11 eutrophic lakes found that the concentrations of soluble reactive phosphorus (SRP) in the water column and EPC0 in sediments decreased with aggravated eutrophication. There was a significant negative correlation between the SRP concentrations and eutrophication parameters such as chlorophyll a (Chl-a), total phosphorus (TP) and algal biomass (P < 0.001). In addition, SRP concentrations were significantly affected by EPC0 (P < 0.001), while EPC0 was significantly affected by the content of cyanobacterial organic matter (COM) in sediments (P < 0.001). Based on these findings, we hypothesized that COM can alter the phosphorus release characteristics of sediments, including the phosphorus adsorption parameters of sediment (PAPS) and the phosphorus release rate of sediment (PRRS), thereby stabilizing SRP concentrations at lower levels and rapidly replenishing them when depleted by phytoplankton, which in turn benefits cyanobacteria due to their low SRP adaptation strategies. Simulation experiments were conducted to confirm this hypothesis by adding higher plant OM and COM to sediments. The results showed that all types of OM could significantly increase the maximum phosphorus adsorption capacity (Qmax), but only COM could reduce sediment EPC0 and promote PRRS (P < 0.001). Changes in these parameters (i.e., Qmax, EPC0, and PRRS) resulted in a larger SRP adsorption quantity and faster SRP release rate at low SRP concentrations. This promotes the competitive edge of cyanobacteria due to they have a higher affinity for phosphorus than other algae. As an important component of cyanobacteria, EPS can change the phosphorus release characteristics (i.e., PAPS and PRRS) by reducing sediment particle size and increasing sediment surface functional groups. This study revealed the positive feedback effect of COM accumulation in sediments on lake eutrophication from the perspective of phosphorus release characteristics of sediments, which provides a basic reference for the risk assessment of lake eutrophication.

Molecular Cloning, Expression, and Functional Analysis of Glycosyltransferase (TbUGGT) Gene from Trapa bispinosa Roxb.

Trapa bispinosa Roxb. is an economical crop for medicine and food. Its roots, stems, leaves, and pulp have medicinal applications, and its shell is rich in active ingredients and is considered to have a high medicinal value. One of the main functional components of the Trapa bispinosa Roxb. shell is 1-galloyl-beta-D-glucose (ßG), which can be used in medical treatment and is also an essential substrate for synthesizing the anticancer drug beta-penta-o-Galloyl-glucosen (PGG). Furthermore, gallate 1-beta-glucosyltransferase (EC 2.4.1.136) has been found to catalyze gallic acid (GA) and uridine diphosphate glucose (UDPG) to synthesize ßG. In our previous study, significant differences in ßG content were observed in different tissues of Trapa bispinosa Roxb. In this study, Trapa bispinosa Roxb. was used to clone 1500 bp of the UGGT gene, which was named TbUGGT, to encode 499 amino acids. According to the specificity of the endogenous expression of foreign genes in Escherichia coli, the adaptation codon of the cloned original genes was optimized for improved expression. Bioinformatic and phylogenetic tree analyses revealed the high homology of TbUGGT with squalene synthases from other plants. The TbUGGT gene was constructed into a PET-28a expression vector and then transferred into Escherichia coli Transsetta (DE3) for expression. The recombinant protein had a molecular weight of 55 kDa and was detected using SDS-PAGE. The proteins were purified using multiple fermentation cultures to simulate the intracellular environment, and a substrate was added for in vitro reaction. After the enzymatic reaction, the levels of ßG in the product were analyzed using HPLC and LC-MS, indicating the catalytic activity of TbUGGT. The cloning and functional analysis of TbUGGT may lay the foundation for further study on the complete synthesis of ßG in E. coli.

Analysis on the Vulnerability of a Tunnel Entrance under Internal Explosion.

Tunnels play an essential role in the transportation network. Tunnel entrances are usually buried at a shallow depth. In the event of an internal explosion, the blast pressure will cause severe damage or even collapse of the tunnel entrance, paralyzing the traffic system. Therefore, an accurate assessment of the damage level of tunnel entrances under internal blast loading can provide effective assistance for the anti-blast design of tunnels, post-disaster emergency response, and economic damage assessment. In this paper, four tunnel entrance specimens were designed and fabricated with a scale ratio of 1/5.5, and a series of field blast tests were carried out to examine the damage pattern of the tunnel entrances under internal explosion. Subsequently, static loading tests were conducted to obtain the maximum bearing capacity of the intact specimen and residual bearing capacities of the post-blast specimens. After that, an explicit non-linear analysis was carried out and a numerical finite element (FE) model of the tunnel entrance under internal blast loading was established by adopting the arbitrary Lagrangian-Eulerian (ALE) method and validated based on the data obtained from the field blast and static loading tests. A probabilistic vulnerability analysis of a typical tunnel entrance subjected to stochastic internal explosions (assuming various charge weights and detonation points) was then carried out with the validated FE model. For the purpose of damage assessment, the residual bearing capacity of the tunnel entrance was taken as the damage criterion. The vulnerability curves corresponding to various damage levels were further developed based on the stochastic data from the probabilistic vulnerability analysis. When the charge weight was 200 kg, the tunnel entrance exhibited slight or moderate damage, while the tunnel entrance suffered severe or even complete damage as the charge weight increased to 1000 kg. However, the tunnel entrance's probability of complete damage was less than 10% when the TNT charge weight did not exceed 1000 kg.

Effect of Spraying Polyurea on the Anti-Blast Performance of the Ultra-High Performance Concrete Slab.

Recently, polyurea has been applied to improve the anti-blast performance of metal plates, masonry walls, and concrete structures. However, the strengthening effectiveness of polyurea on ultra-high performance concrete (UHPC) slabs with an overall response is still unclear. Hence, this paper examined the strengthening effectiveness of polyurea on the anti-blast performance of UHPC slabs under near-field explosion by the finite element (FE) method. First, a benchmark finite element model for UHPC and polyurea-UHPC (PUHPC) slabs under blast loading was established and validated by field blast tests, with scaled distances ranging from 0.4 m/kg1/3 to 0.8 m/kg1/3. After that, parametric analysis was conducted to fully understand the strengthening effectiveness of polyurea on the anti-blast performance of the UHPC slab. Factors including the scaled distance, polyurea thickness, span-to-depth ratio of the slab, and longitudinal reinforcement ratio were considered. The results showed that (1) spraying polyurea on the rear face of the UHPC slab can reduce the width of cracks and mitigate the damage of specimens; (2) the strengthening effectiveness of polyurea on the UHPC slab became prominent when the UHPC slab suffered a larger maximum deflection; (3) in terms of the deflection and energy absorption capacity of PUHPC slabs, the optimum thickness of sprayed polyurea was determined to be 8 mm to 12 mm; and (4) by adopting the multiple nonlinear regression method, a prediction formula was developed to quickly obtain the end rotation of the UHPC slab strengthened with polyurea under near-field explosions.

Integrative Analysis of the Transcriptome and Metabolome Reveals Genes Involved in Phenylpropanoid and Flavonoid Biosynthesis in the Trapa bispinosa Roxb.

Background: Trapa bispinosa Roxb. is grown worldwide as an important aquatic cash crop. Current research on Trapa bispinosa primarily focuses on the separation and identification of active ingredients, as well as the inhibitory effect on tumors; however, research on the molecular mechanism of secondary metabolite accumulation is rather limited. Consequently, an integrative analysis of transcriptome and metabolome is required to identify the key metabolic pathways, and key genes, and to explain the molecular mechanism of Trapa bispinosa. Results: The biosynthesis pathways of phenolics in Trapa bispinosa were examined through transcriptome and metabolome analyses. Transcriptome analysis yielded 42.76 million clean reads representing 81,417 unigenes with an average length of 1,752 bp. KEGG pathway analysis revealed that 1,623 unigenes, including 88 candidate unigenes related to phenolics biosynthesis, were up-regulated in Trapa bispinosa shell (FR) when compared to leaves (LF), root (RT), and stem (ST). The FR vs. LF group had the highest number of specific genes involved in phenylpropanoid, flavonoid, flavone, and flavonol biosynthesis pathways compared to all other comparison groups. In addition, RNA sequencing revealed 18,709 SSRs spanning 14,820 unigenes and 4,387 unigenes encoding transcription factors. Metabolome analysis identified 793 metabolites, including 136 flavonoids and 31 phenylpropane compounds. In the FR group compared to the LF group, there were 202 differentially accumulated metabolites (DAMs). The combined transcriptome and metabolome analyses indicated a significant correlation between 1,050 differentially expressed genes (DEGs) and 62 DAMs. This view proposes a schematic of flavonoid biosynthesis in the FR vs. LF group, providing evidence for the differences in genes and metabolites between FR and LF. Conclusion: In this study, through de novo transcriptome assembly and metabolome analysis, several DEGs and DAMs were identified, which were subsequently used to build flavonoid biosynthesis pathways and a correlation network. The findings pave the way for future research into the molecular mechanisms and functional characterization of Trapa bispinosa candidate genes for phenolics biosynthesis.

Urolithin A protects human dermal fibroblasts from UVA-induced photoaging through NRF2 activation and mitophagy.

Photoaging, caused by exposure to sunlight and especially UVA, has been identified as one of the culprits for age-related skin deterioration. Here, we initially demonstrated that urolithin A (UroA), a metabolite derived from intestine microflora, possessed sufficient photoprotective capacity and attenuated UVA-induced senescent phenotypes in human fibroblasts, such as growth inhibition, senescence-associated ß-galactosidase activity, breakdown of extracellular matrix, synthesis of senescence-associated secretory phenotypes and cell cycle arrest. Furthermore, UroA lessened the accumulation of intracellular reactive oxygen species, which promoted the phosphorylation and afterwards nuclear translocation of NRF2, subsequently driving the activation of downstream antioxidative enzymes. In parallel, we proved that UroA restored mitochondrial function by induction of mitophagy, which was regulated by the SIRT3-FOXO3-PINK1-PARKIN network. Taken together, our results showed that UroA protected dermal fibroblast from UVA damage through NRF2/ARE activation and mitophagy process, thus supporting UroA as a potential therapeutic agent for photoaging.

DVPred: a disease-specific prediction tool for variant pathogenicity classification for hearing loss.

Numerous computational prediction tools have been introduced to estimate the functional impact of variants in the human genome based on evolutionary constraints and biochemical metrics. However, their implementation in diagnostic settings to classify variants faced challenges with accuracy and validity. Most existing tools are pan-genome and pan-diseases, which neglected gene- and disease-specific properties and limited the accessibility of curated data. As a proof-of-concept, we developed a disease-specific prediction tool named Deafness Variant deleteriousness Prediction tool (DVPred) that focused on the 157 genes reportedly causing genetic hearing loss (HL). DVPred applied the gradient boosting decision tree (GBDT) algorithm to the dataset consisting of expert-curated pathogenic and benign variants from a large in-house HL patient cohort and public databases. With the incorporation of variant-level and gene-level features, DVPred outperformed the existing universal tools. It boasts an area under the curve (AUC) of 0.98, and showed consistent performance (AUC = 0.985) in an independent assessment dataset. We further demonstrated that multiple gene-level metrics, including low complexity genomic regions and substitution intolerance scores, were the top features of the model. A comprehensive analysis of missense variants showed a gene-specific ratio of predicted deleterious and neutral variants, implying varied tolerance or intolerance to variation in different genes. DVPred explored the utility of disease-specific strategy in improving the deafness variant prediction tool. It can improve the prioritization of pathogenic variants among massive variants identified by high-throughput sequencing on HL genes. It also shed light on the development of variant prediction tools for other genetic disorders.

MiR-361-3p alleviates cerebral ischemia-reperfusion injury by targeting NACC1 through the PINK1/Parkin pathway.

Ischemic stroke is a nervous system disease with high rates of disability and mortality. MicroRNAs have been reported to modulate cerebral ischemia. The current study aimed to study the role of miR-361-3p in cerebral ischemia-reperfusion (I/R) injury. Experimental results revealed that miR-361-3p level was downregulated in a middle cerebral artery occlusion-induced ischemic stroke mouse model and in oxygen-glucose deprivation/reoxygenation-stimulated SH-SY5Y cells. After overexpressing miR-361-3p, the percentage of brain infarct volume and neurobehavioral scores in mice were significantly reduced, and the neuronal apoptosis was inhibited. Moreover, miR-361-3p overexpression could limit the production of reactive oxygen species (ROS). Furthermore, we investigated the underlying molecular mechanisms of miR-361-3p and identified that miR-361-3p combined with NACC1 3'UTR to negatively modulate its expression. In addition, NACC1 interacts with the PINK1/Parkin pathway in neurons. NACC1 overexpression could rescue the impacts of miR-361-3p mimics on cell apoptosis, ROS production and the PINK1/Parkin pathway. In conclusion, miR-361-3p could improve ischemia brain injury by targeting NACC1 through the PINK1/Parkin pathway. Therefore, miR-361-3p may serve as a potential therapeutic target for the brain injury after I/R.

Case report: Scleromyxedema associated with a monoclonal gammapathy: Successful treatment with intravenous immunoglobulins.

Scleromyxedema is a rare idiopathic fibromucinous disorder characterized by a generalized papular and sclerodermoid cutaneous eruption. Patients often have praraproteinemia and extracutaneous, even lethal, manifestations. Yet the prognostic and therapeutic features of scleromyxedema are poorly documented. High-dose intravenous immunoglobulin (IVIG), used either alone or in conjunction with systemic steroids and/or thalidomide, has been suggested as a first-line treatment. We report the case of a 45-year-old woman diagnosed with scleromyxedema with paraproteinemia that initially did not respond to systemic steroids, retinoids, and thalidomide but greatly improvement in terms of systemic and cutaneous symptoms after treatment with IVIG.

The Role of TMEM16A/ERK/NK-1 Signaling in Dorsal Root Ganglia Neurons in the Development of Neuropathic Pain Induced by Spared Nerve Injury (SNI).

Increasing evidence suggests that transmembrane protein 16A (TMEM16A) in nociceptive neurons is an important molecular component contributing to peripheral pain transduction. The present study aimed to evaluate the role and mechanism of TMEM16A in chronic nociceptive responses elicited by spared nerve injury (SNI). In this study, SNI was used to induce neuropathic pain. Drugs were administered intrathecally. The expression and cellular localization of TMEM16A, the ERK pathway, and NK-1 in the dorsal root ganglion (DRG) were detected by western blot and immunofluorescence. Behavioral tests were used to evaluate the role of TMEM16A and p-ERK in SNI-induced persistent pain and hypersensitivity. The role of TMEM16A in the hyperexcitability of primary nociceptor neurons was assessed by electrophysiological recording. The results show that TMEM16A, p-ERK, and NK-1 are predominantly expressed in small neurons associated with nociceptive sensation. TMEM16A is colocalized with p-ERK/NK-1 in DRG. TMEM16A, the MEK/ERK pathway, and NK-1 are activated in DRG after SNI. ERK inhibitor or TMEM16A antagonist prevents SNI-induced allodynia. ERK and NK-1 are downstream of TMEM16A activation. Electrophysiological recording showed that CaCC current increases and intrathecal application of T16Ainh-A01, a selective TMEM16A inhibitor, reverses the hyperexcitability of DRG neurons harvested from rats after SNI. We conclude that TMEM16A activation in DRG leads to a positive interaction of the ERK pathway with activation of NK-1 production and is involved in the development of neuropathic pain after SNI. Also, the blockade of TMEM16A or inhibition of the downstream ERK pathway or NK-1 upregulation may prevent the development of neuropathic pain.

Improving NKCC1 Function Increases the Excitability of DRG Neurons Exacerbating Pain Induced After TRPV1 Activation of Primary Sensory Neurons.

Background Our aim was to investigate the effects of the protein expression and the function of sodium, potassium, and chloride co-transporter (NKCC1) in the dorsal root ganglion (DRG) after activation of transient receptor potential vanilloid 1 receptor (TRPV1) in capsaicin-induced acute inflammatory pain and the possible mechanism of action. Methods Male Sprague-Dawley rats were randomly divided into control, capsaicin, and inhibitor groups. The expression and distribution of TRPV1 and NKCC1 in rat DRG were observed by immunofluorescence. Thermal radiation and acetone test were used to detect the pain threshold of heat and cold noxious stimulation in each group. The expressions of NKCC1 mRNA, NKCC1 protein, and p-NKCC1 in the DRG were detected by PCR and western blotting (WB). Patch clamp and chloride fluorescent probe were used to observe the changes of GABA activation current and intracellular chloride concentration. After intrathecal injection of protein kinase C (PKC) inhibitor (GF109203X) or MEK/extracellular signal-regulated kinase (ERK) inhibitor (U0126), the behavioral changes and the expression of NKCC1 and p-ERK protein in L4 - 6 DRG were observed. Result: TRPV1 and NKCC1 were co-expressed in the DRG. Compared with the control group, the immunofluorescence intensity of NKCC1 and p-NKCC1 in the capsaicin group was significantly higher, and the expression of NKCC1 in the nuclear membrane was significantly higher than that in the control group. The expression of NKCC1 mRNA and protein of NKCC1 and p-NKCC1 in the capsaicin group were higher than those in the control group. After capsaicin injection, GF109203X inhibited the protein expression of NKCC1 and p-ERK, while U0126 inhibited the protein expression of NKCC1. In the capsaicin group, paw withdrawal thermal latency (WTL) was decreased, while cold withdrawal latency (CWL) was prolonged. Bumetanide, GF109203X, or U0126 could reverse the effect. GABA activation current significantly increased in the DRG cells of the capsaicin group, which could be reversed by bumetanide. The concentration of chloride in the DRG cells of the capsaicin group increased, but decreased after bumetanide, GF109203X, and U0126 were administered. Conclusion Activation of TRPV1 by exogenous agonists can increase the expression and function of NKCC1 protein in DRG, which is mediated by activation of PKC/p-ERK signaling pathway. These results suggest that DRG NKCC1 may participate in the inflammatory pain induced by TRPV1.

Upregulation of Nav1.7 by endogenous hydrogen sulfide contributes to maintenance of neuropathic pain.

Nav1.7 is closely associated with neuropathic pain. Hydrogen sulfide (H2S) has recently been reported to be involved in numerous biological functions, and it has been shown that H2S can enhance the sodium current density, and inhibiting the endogenous production of H2S mediated by cystathionine ß­synthetase (CBS) using O­(carboxymethyl)hydroxylamine hemihydrochloride (AOAA) can significantly reduce the expression of Nav1.7 and thus the sodium current density in rat dorsal root ganglion (DRG) neurons. In the present study, it was shown that the fluorescence intensity of H2S was increased in a spared nerve injury (SNI) model and AOAA inhibited this increase. Nav1.7 is expressed in DRG neurons, and the expression of CBS and Nav1.7 were increased in DRG neurons 7, 14 and 21 days post­operation. AOAA inhibited the increase in the expression of CBS, phosphorylated (p)­MEK1/2, p­ERK1/2 and Nav1.7 induced by SNI, and U0126 (a MEK blocker) was able to inhibit the increase in p­MEK1/2, p­ERK1/2 and Nav1.7 expression. However, PF­04856264 did not inhibit the increase in CBS, p­MEK1/2, p­ERK1/2 or Nav1.7 expression induced by SNI surgery. The current density of Nav1.7 was significantly increased in the SNI model and administration of AOAA and U0126 both significantly decreased the density. In addition, AOAA, U0126 and PF­04856264 inhibited the decrease in rheobase, and the increase in action potential induced by SNI in DRG neurons. There was no significant difference in thermal withdrawal latency among each group. However, the time the animals spent with their paw lifted increased significantly following SNI, and the time the animals spent with their paw lifted decreased significantly following the administration of AOAA, U0126 and PF­04856264. In conclusion, these data show that Nav1.7 expression in DRG neurons is upregulated by CBS­derived endogenous H2S in an SNI model, contributing to the maintenance of neuropathic pain.

Highly Conductive Sb-SnO2 Nanocrystals Synthesized by Dual Nonthermal Plasmas.

Nonthermal plasma synthesis of transparent conducting oxide nanocrystals can offer advantages, for example, ligand-free surfaces, over traditionally used colloidal synthesis methods. When it comes to multicomponent (doped) metal oxide nanocrystal synthesis, uniform distribution of different metal elements and suppressing surface segregation of secondary resistive phases have been concerns. Specifically, surface segregation of resistive secondary phases reduces the electrical conductivity of nanocrystal assemblies. In this work, we demonstrate a nonthermal dual-plasma synthesis method capable of forming Sb-SnO2 (ATO) nanocrystals with a uniform composition distribution and apparently insignificant surface segregation of the dopant. A drastic increase in conductivity was observed in ATO thin films comprised of nanocrystals formed using a dual-plasma configuration compared to nanocrystals formed using a single-plasma configuration. The conductivity values of as-deposited porous films comprised of ATO nanocrystals, prepared using the dual-plasma approach, were on the order of 0.1 S cm-1, which to our knowledge is the highest conductivity reported to-date for that type of high surface area material. Annealing the films comprised of ATO nanocrystals at 500 °C for 2 h in air increased the conductivity and improved ambient stability, without significantly affecting the crystallite size.

Two-dimensional MnC as a potential anode material for Na/K-ion batteries: a theoretical study.

Sodium (Na)-ion batteries (NIBs) and potassium (K)-ion batteries (KIBs) have grabbed great attention because they are cheaper, more abundant in earth, and safer alternatives of lithium-ion batteries. However, the lack of anode materials for NIBs/KIBs with good performance has been the main obstacle. In this paper, we studied monolayer MnC by carrying out calculations on the basis of first principle study to see if it can be a potential anode material for NIBs and KIBs. Calculation results show that monolayer MnC processes good negative adsorption energies of - 2.83 eV for Na and - 2.16 eV for K. Moreover, MnC has comparable theoretical capacities for Na and K of 475 mAh/g and 253 mAh/g, respectively. Our calculation results manifest that the MnC can be a promising anode material for NIBs. MnC monolayer absorbed with two layers of Na atoms.