Transcellular progression of infection threads in Medicago truncatula roots is associated with locally confined cell wall modifications.

The root nodule symbiosis with its global impact on nitrogen fertilization of soils is characterized by an intracellular colonization of legume roots by rhizobia. Although the symbionts are initially taken up by morphologically adapted root hairs, rhizobia persistently progress within a membrane-confined infection thread through several root cortical and later nodular cell layers. Throughout this transcellular passaging, rhizobia have to repeatedly pass host plasma membranes and cell walls. Here, we investigated this essential process and describe the concerted action of one of the symbiosis-specific pectin methyl esterases (SyPME1) and the nodulation pectate lyase (NPL) at the infection thread and transcellular passage sites. Their coordinated function mediates spatially confined pectin alterations in the cell-cell interface that result in the establishment of an apoplastic compartment where bacteria are temporarily released into and taken up from the subjacent cell. This process allows successful intracellular progression of infection threads through the entire root cortical tissue.

Tetramethylpyrazine Inhibits the Proliferation and Invasion of Glioma Cells by Regulating the UBL7-AS1/miR-144-3p Pathway.

This work aims to investigate the effects of tetramethylpyrazine (TMP) on the proliferation, migration, and invasion of glioma cells and to analyze the regulation mechanism of TMP on the long noncoding RNA UBL7-AS1/miR-144-3p pathway. Glioma cell line and normal astrocytes were collected. The expression of UBL7-AS1 was detected by real-time PCR. The glioma cells were overexpressed with UBL7-AS1. CCK-8 and Transwell assays were used to detect cell proliferation and cell invasion ability, respectively. Bioinformatics was adopted to predict the possible regulatory mechanisms of UBL7-AS1. The dual luciferase reporter gene was applied to verify the regulatory effect of RNA UBL7-AS1 with miR-144-3p. TMP inhibited the proliferation and invasion of glioma cells. UBL7-AS1 was highly expressed in glioma tissues and cells. The overexpression of UBL7-AS1 promotes the cell proliferation and invasion of glioma. UBL7-AS1 can act as a sponge for miR-144-3p in glioma cells. The overexpression of UBL7-AS1 can reverse the inhibition of TMP on proliferation, migration, and invasion of glioma cells. TMP inhibits the proliferation, migration, and invasion of glioma cells by regulating the UBL7-AS1/miR-144-3p pathway.

Acidity/Reducibility Dual-Responsive Hollow Mesoporous Organosilica Nanoplatforms for Tumor-Specific Self-Assembly and Synergistic Therapy.

Featured with a large surface area, uniform interpenetrating mesopores, diverse organic framework hybridization, and well-defined surface properties, the hollow mesoporous organosilica nanoparticle (HMON) represents a promising paradigm in drug delivery systems with excellent biocompatibility. However, effective tumor accumulation and precise cancer theranostics of the HMON still remain a challenge. In this study, an "ammonia-assisted hot water etching" method is applied for the successful construction of sub-50 nm thioether/phenylene dual-hybridized HMON with low hemolytic effect. Particularly, the surface modification with Mo(VI)-based polyoxometalate (POM) clusters drives the self-assembly of HMON in the mild acidic tumor microenvironment (TME) to achieve enhanced tumor retention and accumulation. More importantly, the reducibility-activated Mo(VI)-to-Mo(V) conversion within POM not only endows the POM-anchored HMON with outstanding TME-responsive photoacoustic (PA) imaging contrast and photothermal therapy (PTT) performance but also plays an indispensable role in controllably triggering the decomposition of the Mn2(CO)10 payload for CO release, which gives rise to remarkable synergistic PTT-enhanced CO gas therapy for complete tumor eradication. By harnessing the unique acidic and redox properties of TME, the judiciously designed smart POM-anchored HMON nanoplatform is expected to act as a "magic bomb" to selectively destroy cancer without damaging normal tissues. This nanoplatform holds significant potential in realizing TME-responsive self-assembly for enhanced tumor accumulation and precise tumor-specific synergistic therapy, which is very promising for clinical translation.

Biodegradable Hollow Mesoporous Organosilica Nanotheranostics for Mild Hyperthermia-Induced Bubble-Enhanced Oxygen-Sensitized Radiotherapy.

Alleviation of tumor hypoxia has been the premise for improving the effectiveness of radiotherapy, which hinges upon the advanced delivery and rapid release of oxygen within the tumor region. Herein, we propose a "bubble-enhanced oxygen diffusion" strategy to achieve whole tumor oxygenation for significant radiation enhancement based on the "bystander effect". Toward this end, sub-50 nm CuS-modified and 64Cu-labeled hollow mesoporous organosilica nanoparticles were constructed for tumor-specific delivery of O2-saturated perfluoropentane (PFP). Through the aid of PFP gasification arising from NIR laser-triggered mild hyperthermia, simultaneous PET/PA/US multimodality imaging and rapid oxygen diffusion across the tumor can be achieved for remarkable hypoxic radiosensitization. Furthermore, the multifunctional oxygen-carrying nanotheranostics also allow for other oxygen-dependent treatments, thus greatly advancing the development of bubble-enhanced synergistic therapy platforms.

Tri-stimuli-responsive biodegradable theranostics for mild hyperthermia enhanced chemotherapy.

The combination of hyperthermia and chemotherapy is able to greatly enhance the treatment efficacy mainly due to the synergistic interactions between these two treatments. In this study, we propose a new concept of mild hyperthermia enhanced chemotherapy to explore and validate the synergistic mechanism in vitro and in vivo. To do this, a novel kind of biodegradable nanotheranostics based on copper sulfide doped periodic mesoporous organosilica nanoparticles (CuS@PMOs) was constructed via an in situ growth method for light-triggered mild hyperthermia and drug delivery. The as-prepared CuS@PMOs exhibit a high doxorubicin (DOX) loading capacity of 470 mg/g. The DOX release from CuS@PMOs can be precisely controlled by three stimuli, including intracellular glutathione (GSH), acidic environment in tumor cells, and external laser irradiation. Most intriguingly, mild hyperthermia induced by laser-irradiated CuS nanoparticles can dramatically improve the cell uptake of nanotheranostics both in vitro and in vivo, thus significantly enhancing the chemotherapeutic efficacy for complete tumor growth suppression without recurrence. Meanwhile, the fluorescence recovery following the DOX release can be used as an indicator to monitor the chemotherapeutic progress.

Multimodal-Imaging-Guided Cancer Phototherapy by Versatile Biomimetic Theranostics with UV and γ-Irradiation Protection.

A versatile biomimetic theranostic agent based on magnetic melanin nanoparticles is developed for positron-emission tomography/magnetic resonance/photoacoustic/photothermal multimodal-imaging-guided cancer photothermal therapy and UV and γ-irradiation protection.

Tumor-Specific Formation of Enzyme-Instructed Supramolecular Self-Assemblies as Cancer Theranostics.

Despite the effort of developing various nanodelivery systems, most of them suffer from undesired high uptakes by the reticuloendothelial system, such as liver and spleen. Herein we develop an endogenous phosphatase-triggered coassembly strategy to form tumor-specific indocyanine green (ICG)-doped nanofibers (5) for cancer theranostics. Based on coordinated intermolecular interactions, 5 significantly altered near-infrared absorbance of ICG, which improves the critical photoacoustic and photothermal properties. The phosphatase-instructed coassembly process, as well as its theranostic capability, was successfully conducted at different levels ranging from in vitro, living cell, tissue mimic, to in vivo. Specifically, the tumor uptake of ICG was markedly increased to 15.05 ± 3.78%ID/g, which was 25-fold higher than that of free ICG (0.59 ± 0.24%ID/g) at 4 h after intravenous injection. The resulting ultrahigh T/N ratios (>15) clearly differentiated tumors from the surrounding normal tissue. Complete tumor elimination with high therapeutic accuracy has been successfully achieved upon laser irradiation (0.8 W/cm(2), 5 min) within 24-48 h postinjection. As the first example, in vivo formation of tumor-specific ICG-doped nanofiber for PTT theranostics owns the immense potential for clinical translation of personalized nanomedicine with targeted drug delivery as well as for cancer theranostics.

Adjuvant therapy for hepatocellular carcinoma: current situation and prospect.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, accounting for 90% of primary liver cancers, and its incidence is still increasing. While the curative treatment for HCC is surgical resection and liver transplantation, most patients are in advanced stage, and lose the chance of surgery. Other palliative treatments include radiofrequency ablation, transarterial embolization, chemotherapy, and radiotherapy. Although there are so many treatments, the prognosis of HCC is still very poor. A major obstacle for the treatment for HCC is the high frequency of tumor recurrence even after curative resection and liver transplantation. Since HCC is frequently resistant to conventional chemotherapy and radiotherapy, clinical development of novel therapeutic agents against HCC has begun in earnest. Thus far, a series of adjuvant therapies for HCC have emerged, including small molecular target agents, monocolonal antibodies, microRNA, and Chinese herbal medicine. Some agents such as sorafenib have shown an advantage in prolonging the overall survival time, and has been approved by FDA for the treatment of advanced HCC. In this article we review the current situation and prospects of adjuvant therapies for HCC.

Nicotinamide forestalls pathology and cognitive decline in Alzheimer mice: evidence for improved neuronal bioenergetics and autophagy procession.

Impaired brain energy metabolism and oxidative stress are implicated in cognitive decline and the pathologic accumulations of amyloid ß-peptide (Aß) and hyperphosphorylated tau in Alzheimer's disease (AD). To determine whether improving brain energy metabolism will forestall disease progress in AD, the impact of the ß-nicotinamide adenine dinucleotide precursor nicotinamide on brain cell mitochondrial function and macroautophagy, bioenergetics-related signaling, and cognitive performance were studied in cultured neurons and in a mouse model of AD. Oxidative stress resulted in decreased mitochondrial mass, mitochondrial degeneration, and autophagosome accumulation in neurons. Nicotinamide preserved mitochondrial integrity and autophagy function, and reduced neuronal vulnerability to oxidative/metabolic insults and Aß toxicity. ß-Nicotinamide adenine dinucleotide biosynthesis, autophagy, and phosphatidylinositol-3-kinase signaling were required for the neuroprotective action of nicotinamide. Treatment of 3xTgAD mice with nicotinamide for 8 months resulted in improved cognitive performance, and reduced Aß and hyperphosphorylated tau pathologies in hippocampus and cerebral cortex. Nicotinamide treatment preserved mitochondrial integrity, and improved autophagy-lysosome procession by enhancing lysosome/autolysosome acidification to reduce autophagosome accumulation. Treatment of 3xTgAD mice with nicotinamide resulted in elevated levels of activated neuroplasticity-related kinases (protein kinase B [Akt] and extracellular signal-regulated kinases) and the transcription factor cyclic adenosine monophosphate (AMP) response element-binding protein in the hippocampus and cerebral cortex. Thus, nicotinamide suppresses AD pathology and cognitive decline in a mouse model of AD by a mechanism involving improved brain bioenergetics with preserved functionality of mitochondria and the autophagy system.

In vitro and in vivo evaluation of ribavirin and pleconaril antiviral activity against enterovirus 71 infection.

Enterovirus 71(EV71) causes recurring outbreaks of hand, foot and mouth disease and encephalitis leading to complications or death in young children. More effective antiviral drugs are needed to prevent or reduce EV71-related disease and complications. However, there are no standard models currently in use to evaluate activity against EV71 infection both in vitro and in vivo. In this study, the activity of ribavirin and pleconaril against EV71 infection was evaluated in two models. An in vitro EV71 infection model was developed in RD cells, and an in vivo EV71 infection model was applied. Ribavirin and pleconaril effectively increased the viability of infected cells. Pleconaril reduced the morbidity and mortality of one-day-old infected mice, but ribavirin did not protect the infected mice. In all, the results demonstrated that infected cells and infected mice can be used to evaluate antiviral activity of ribavirin and pleconaril against EV71 infection in vitro and in vivo.

Simultaneous determination of vitexin-4''-O-glucoside, vitexin-2''-O-rhamnoside, rutin and vitexin from hawthorn leaves flavonoids in rat plasma by UPLC-ESI-MS/MS.

A sensitive and accurate ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for the simultaneous determination of vitexin-4''-O-glucoside (VGL), vitexin-2''-O-rhamnoside (VRH), rutin (RUT) and vitexin (VIT) in rat plasma after intravenous administration of hawthorn leaves flavonoids (HLF). Following protein precipitation by methanol, the analytes were separated on an ACQUITY UPLC BEH C(18) column packed with 1.7 microm particles by gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.20 mL/min. The analytes and diphenhydramine (internal standard, IS) were detected in the multiple reaction monitoring (MRM) mode by means of an electrospray ionization (ESI) interface (m/z 292.96 for vitexin-4''-O-glucoside, m/z 293.10 for vitexin-2''-O-rhamnoside, m/z 299.92 for rutin, m/z 310.94 for vitexin and m/z 166.96 for IS). The calibration curve was linear over the range 10-40,000 ng/mL for vitexin-4''-O-glucoside, 10-50,000 ng/mL for vitexin-2''-O-rhamnoside, 8-1000 ng/mL for rutin and 16-2000 ng/mL for vitexin. The intra- and inter-run precisions (relative standard deviation, RSD) of these analytes were all within 15% and the accuracy (the relative error, RE) ranged from -10% to 10%. The stability experiment indicated that the four analytes in rat plasma samples and plasma extracts under anticipated conditions were stable. The developed method was applied for the first time to pharmacokinetic studies of the four bioactive compounds of hawthorn leaves flavonoids following a single intravenous administration of 20 mg/kg in rats.

The pentacovalent phosphorus intermediate of a phosphoryl transfer reaction.

Enzymes provide enormous rate enhancements, unmatched by any other type of catalyst. The stabilization of high-energy states along the reaction coordinate is the crux of the catalytic power of enzymes. We report the atomic-resolution structure of a high-energy reaction intermediate stabilized in the active site of an enzyme. Crystallization of phosphorylated beta-phosphoglucomutase in the presence of the Mg(II) cofactor and either of the substrates glucose 1-phosphate or glucose 6-phosphate produced crystals of the enzyme-Mg(II)-glucose 1,6-(bis)phosphate complex, which diffracted x-rays to 1.2 and 1.4 angstroms, respectively. The structure reveals a stabilized pentacovalent phosphorane formed in the phosphoryl transfer from the C(1)O of glucose 1,6-(bis)phosphate to the nucleophilic Asp8 carboxylate.