Pterostilbene upregulates MICA/B via the PI3K/AKT signaling pathway to enhance the capability of natural killer cells to kill cervical cancer cells.

Natural killer (NK) cells are triggered by the innate immune response in the tumor microenvironment. The extensive set of stimulating and inhibiting receptors mediates the target recognition of NK cells, and controls the strength of the effector reaction countering specific targeted cells. Yet, lacking major MHC (histocompatibility complex) MICA/B class I chain-related proteins on the membrane of tumor cells results in the failure of NK cell recognition and ability to resist NK cell destruction. Searching databases and molecular docking suggested that in cervical cancer, pterostilbene (3,5-dimethoxy-40-hydroxystilbene; PTS) in Vaccinium corymbosum extract could constrain PI3K/AKT signaling and improving the MICA/B expression. In flow cytometry, MTT assay, viability/cytotoxicity assay, and colony development assays, PTS reduced the development of cervical cancer cells and increased apoptosis. The quantitative real-time PCR (qRT-PCR) and a Western blot indicate that PTS controlled the cytolytic action of NK cells in tumor cells via increasing the MICA/B expression, thus modifying the anti-tumor immune response in cervical cancer.

The hysteresis damage of cold exposure on tissue and transcript levels in mice.

OBJECTIVES: Although cold stress-induced damage to the heart and thyroid has been reported, specific organ associations between the heart and thyroid with delayed injury mechanisms have not been investigated. In this study, we determined the damage time and transcript levels of a large number of genes in the heart and thyroid after cold exposure. Meanwhile, we analysed the relationship between heart and thyroid injury in human medical records to determine the association of delayed injury from cold exposure. METHODS: Mice were exposed to cold stress and hysteresis injury. Gene changes at the transcriptional level were detected using high throughput sequencing technology. The most variable genes were verified at the protein level using Western Blotting and medical records were collected and analysed. RESULTS: The damage was the most severe when the animals were allowed to recover to room temperature for 4 h after exposure to cold stress. During this process, STAT1 and ATF3 genes were acutely up-regulated. Analysis of human medical records showed the highest correlation between AST and T4 under cold stress (p = 0.0011). CONCLUSIONS: Exposure to cold increases blood level of free thyroid hormone and biomarkers of myocardial injury, as well as related mRNA levels. These changes were more pronounced after return to room temperature.

New "Destruction Seek to Survive" Strategy Based on a Serum Albumin Assembly with a Squaraine Molecule for the Detection of Peroxynitrite.

Peroxynitrite (ONOO-), a kind of active nitrogen species, plays an important role in biological systems. Overproduction of ONOO- is closely related to the pathogenesis of many diseases. Therefore, it is necessary to quantify intracellular ONOO- for differentiating health and disease states. Fluorescent probes with near-infrared (NIR) fluorescence can detect ONOO- with high sensitivity and selectivity. However, there is an inevitable problem that many NIR fluorophores are easily oxidized by ONOO- to give a false-negative result. To avoid this problem, herein, we ingeniously propose a "destruction to seek to survive" strategy to detect ONOO-. Two NIR squaraine (SQ) dyes were connected together to form a fluorescent probe (SQDC). This method utilizes the destructive effect of peroxynitrite on one of the SQ moieties of SQDC to eliminate the steric hindrance, enabling the other "survived" SQ segment to enter the hydrophobic cavity of bovine serum albumin (BSA) via the well-known host-guest interactions. The encapsulation of albumin protects the "survived" SQ from further attack of ONOO-. As a result, a NIR fluorescence turn-on response coming from the host-guest interaction between BSA and the "survived" SQ escaped from SQDC was found, which can be used for the detection of ONOO-. The assembly of SQDC mixed with BSA can be located in mitochondria to detect endogenous and exogenous ONOO- sensitively in living cells. As a proof-of-concept method, it is envisioned that this novel detection strategy with a simple assembly would become a powerful means for the detection of ONOO- when employing NIR fluorophores.

Advances in Natural Polymer-Based Transdermal Drug Delivery Systems for Tumor Therapy.

As an alternative to traditional oral and intravenous injections with limited efficacy, transdermal drug delivery (TDD) has shown great promise in tumor treatment. Over the past decade, natural polymers have been designed into various nanocarriers due to their excellent biocompatibility, biodegradability, and easy availability, providing more options for TDD. In addition, surface functionalization modification of the rich functional groups of natural polymers, which in turn are developed into targeted and stimulus-responsive functional materials, allows precise delivery of drugs to tumor sites and release of drugs in response to specific stimuli. It not only improves the treatment efficiency of tumor but also reduces the toxic and side effects to normal tissues. Therefore, the development of natural polymer-based TDD (NPTDD) systems has great potential in tumor therapy. In this review, the mechanism of NPTDD systems such as penetration enhancers, nanoparticles, microneedles, hydrogels and nanofibers prepared from hyaluronic acid, chitosan, sodium alginate, cellulose, heparin and protein, and their applications in tumor therapy are overviewed. This review also outlines the future prospects and current challenges of NPTDD systems for local treatment tumors.

Construction of SLC16A1/3 Targeted Gallic Acid-Iron-Embelin Nanoparticles for Regulating Glycolysis and Redox Pathways in Cervical Cancer.

SLC16A1 and SLC16A3 (SLC16A1/3) are highly expressed in cervical cancers and associated with the malignant biological behavior of cancer. SLC16A1/3 is the critical hub for regulating the internal and external environment, glycolysis, and redox homeostasis in cervical cancer cells. Inhibiting SLC16A1/3 provides a new thought to eliminate cervical cancer effectively. There are few reports on effective treatment strategies to eliminate cervical cancer by simultaneously targeting SLC16A1/3. GEO database analysis and quantitative reverse transcription polymerase chain reaction experiment were used to confirm the high expression of SLC16A1/3. The potential inhibitor of SLC16A1/3 was screened from Siwu Decoction by using network pharmacology and molecular docking technology. The mRNA levels and protein levels of SLC16A1/3 in SiHa and HeLa cells treated by Embelin (EMB) were clarified, respectively. Furthermore, the Gallic acid-iron (GA-Fe) drug delivery system was used to improve its anti-cancer performance. Compared with normal cervical cells, SLC16A1/3 mRNA was over-expressed in SiHa and HeLa cells. Through the analysis of Siwu Decoction, a simultaneously targeted SLC16A1/3 inhibitor EMB was discovered. It was found for the first time that EMB promoted lactic acid accumulation and further induced redox dyshomeostasis and glycolysis disorder by simultaneously inhibiting SLC16A1/3. The gallic acid-iron-Embelin (GA-Fe@EMB) drug delivery system delivered EMB, which had a synergistic anti-cervical cancer effect. Under the irradiation of a near-infrared laser, the GA-Fe@EMB could elevate the temperature of the tumor area effectively. Subsequently, EMB was released and mediated the lactic acid accumulation and the GA-Fe nanoparticle synergistic Fenton reaction to promote ROS accumulation, thereby increasing the lethality of the nanoparticles on cervical cancer cells. GA-Fe@EMB can target cervical cancer marker SLC16A1/3 to regulate glycolysis and redox pathways, synergistically with photothermal therapy, which provides a new avenue for the synergistic treatment of malignant cervical cancer.

Structural Characterization, Simulated Digestion and Anti-Aging Activities of an Acidic Polysaccharide from Salvia Miltiorrhiza.

An acidic polysaccharide (SMP) with a molecular weight (Mw) of 1.28 × 106 Da was isolated from Salvia miltiorrhiza. The monosaccharide composition in molar percentages was rhamnose (Rha): galacturonic acid (GalA): galactose (Gal): arabinose (Ara) = 6.15: 55.98: 21.27: 16.69. The results of simulated digestion in vitro showed that SMP was not degraded in saliva, gastric juice or intestinal juice. The Y maze test and new object recognition test showed that SMP could improve the working memory impairment of aging mice. SMP could also increase the activity of superoxide dismutase (SOD) and catalase (CAT) in serum and brain tissue, decrease the content of malondialdehyde (MDA), decrease the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in brain tissue, and increase the content of short-chain fatty acids (SCFA) in the intestine. In addition, SMP could also regulate the intestinal flora structure, including increasing the relative abundance of Firmicutes and Bacteroidetes and decreasing the relative abundance of Proteobacteria. This work lays a foundation for the development of functional foods related to Salvia miltiorrhiza.

In-vitro and in-vivo monitoring of gold(III) ions from intermediate metabolite of sodium aurothiomalate through water-soluble ruthenium (II) complex-based luminescent probe.

Real-time monitoring of drug metabolism in vivo is of great significance to drug development and toxicology research. The purpose of this study is to establish a rapid and visual in vivo detection method for the detection of an intermediate metabolite of the gold (I) drug. Gold (I) drugs such as sodium aurothiomalate (AuTM) have anti-inflammatory effects in the treatment of rheumatoid arthritis. Gold(III) ions (Au3+) are the intermediate metabolite of gold medicine, and they are also the leading factor of side effects in the treatment of patients. However, the rapid reduction of Au3+ to Au+ by thiol proteins in organisms limits the in-depth study of metabolism of gold drugs in vivo. Here we describe a luminescence Au3+ probe (RA) based on ruthenium (II) complex for detecting Au3+ in vitro and in vivo. RA with large Stokes shift, good water solubility and biocompatibility was successfully applied to detect Au3+ in living cells and vivo by luminescence imaging, and to trap the fluctuation of Au3+ level produced by gold (I) medicine. More importantly, the luminescent probe was used to the detection of the intermediate metabolites of gold (I) drugs for the first time. Overall, this work offers a new detection tool/method for a deeper study of gold (I) drugs metabolite.

A novel fluorescent probe based on naphthalimide for imaging nitroreductase (NTR) in bacteria and cells.

A nitroreductase (NTR) responsive fluorescent probe, Na-NO2, comprising p-nitrobenzyl as the unique recognition group and 1,8-naphthalimide as fluorophore, was synthesized. Na-NO2 showed remarkable fluorescence "turn-on" signal in the presence of NTR under DMSO/H2O (1:19, v/v) buffered with PBS (pH = 7) solution in the presence of NADH (300 µM). Furthermore, the probe has a low detection limit down to 3.4 ng/mL and it is very sensitive towards the NTR in Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), normal and tumor cells such as HL-7702, HepG-2 and MCF-7.

GSH-responsive anti-mitotic cell penetrating peptide-linked podophyllotoxin conjugate for improving water solubility and targeted synergistic drug delivery.

Podophyllotoxin (PPT) is a chemotherapeutic agent which has shown significant anti-cancer effects through inhibiting microtubule assembly. However, because of the poor water solubility and obvious side effects, PPT cannot be used in clinical cancer therapy. In order to solve these problems, a novel glutathione-responsive PPT conjugate has been synthesized in which PPT was linked to an anti-mitotic cell penetrating peptide (PRA) via a disulfide linkage. In particular, the as-prepared PPT-PRA conjugate can self-assemble into vesicle in water, furthermore, another anti-cancer drug (doxorubicin was chosen as an example) can be loaded in the vesicle for synergistic drug delivery. For better cancer cells targeting, the vesicle was then modified with folic acid (FA). The results indicated that the as-prepared FA modified drug-loaded vesicle not only could overcome the poor water solubility and side effects of PPT but also exhibited targeted toxicity and synergistic therapeutic effect.

In Situ Formation of Homogeneous Tellurium Nanodots in Paclitaxel-Loaded MgAl Layered Double Hydroxide Gated Mesoporous Silica Nanoparticles for Synergistic Chemo/PDT/PTT Trimode Combinatorial Therapy.

A folic acid (FA) functional drug delivery system (MT@L-PTX@FA) based on in situ formation of tellurium nanodots (Te NDs) in paclitaxel (PTX)-loaded MgAl layered double hydroxide (LDHs) gated mesoporous silica nanoparticles (MSNs) has been designed and fabricated for targeted chemo/PDT/PTT trimode combinatorial therapy. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption-desorption, Fourier transform infrared (FT-IR) spectra, and UV-vis spectra were used to demonstrate the successful fabrication of MT@L-PTX@FA. In particular, the in situ generated Te NDs showed a homogeneous ultrasmall size. Reactive oxygen species (ROS) generation, photothermal effects, and photostability evaluations indicated that the in situ generated homogeneous Te NDs could serve as the phototherapeutic agent, converting the photon energy to ROS and heat under near-infrared (NIR) irradiation efficiently. The drug-release test revealed that MT@L-PTX@FA showed an apparent sustained release character in a pH-sensitive manner. In addition, cell imaging experiments demonstrated that MT@L-PTX@FA could selectively enter into cancer cells owing to the function of FA and release of PTX efficiently for chemotherapy for the reason that the low intracellular pH would dissolve MgAl LDHs to Mg2+ and Al3+. Cytotoxicity tests also indicated that MT@L-PTX@FA exhibited enhanced therapeutic effect in cancer cells under NIR irradiation, benefiting from the synergy based on targeted chemo/PDT/PTT trimode combinatorial therapy. The preliminary results reported here will shed new light on the future design and applications of nanosystems for synergistic combinatorial therapy.

A Rhodamine B-based fluorescent probe for imaging Cu2+ in maize roots.

A new Rhodamine B-based fluorescent probe (RBO) is successfully designed and synthesized, which is a higher selective and sensitive chemosensor for Cu2+ than other ions. Under physiological conditions (pH = 7.0), the non emission RBO displays a rapid fluorescence increase together with a color change after addition of Cu2+ and the detection limit is down to 28nM, which can clearly illustrate the distribution of Cu2+ with the help of laser scanning confocal microscope in plant tissues. Eventually, it confirmed that the Cu2+ accumulates mostly in the vascular cylinder and very less in the epidermal cells of maize roots, which is important to understand how the plants take up, transport and store in the Cu2+.

A water-soluble near-infrared fluorescent probe for specific Pd2+ detection.

Palladium (Pd) is widely used in chemistry, biology, environmental science etc., and Pd2+ is the most plenitudinous oxidation state of the Pd that can exist under physiological conditions or in living cells, which could have adverse effects on both our health and environment. Thus, it is of great significance to monitor the changes of Pd2+. Hence, a novel near-infrared fluorescent probe M-PD has been developed for selective detection of Pd2+ based on naphthofluorescein in this work. The result demonstrated that M-PD exhibited favorable properties for sensing Pd2+ such as excellent water solubility, high selectivity and sensitivity. And the limit of detection was estimated as 10.8 nM, much lower than the threshold in drugs (5-10 ppm) specified by European Directorate for the Quality Control of Medicines. More importantly, detection and recovery experiments of Pd2+ in aspirin aqoeous solution and soil are satisfactory. In addition, M-PD has also been successfully used for near-infrared fluorescence imaging of Pd2+ in living cells, indicating that the probe has better feasibility and application potential in the determination of Pd2+.

Electrochemiluminescent aptasensor for thrombin using nitrogen-doped graphene quantum dots.

An electrochemiluminescent (ECL) aptamer based method is described for the determination of thrombin. Three-dimensional nitrogen-doped graphene oxide (3D-NGO) was placed on a glassy carbon electrode (GCE) to provide an electrode surface that displays excellent electrical conductivity and acts as a strong emitter of ECL. The modified electrode was further coated with chitosan via electrodeposition. Finally, the amino-modified aptamer was immobilized on the modified GCE. The interaction between thrombin and aptamer results in a decrease in ECL. The assay has a linear response in the 1 fM to 1 nM thrombin concentration range and a 0.25 fM lower detection limit (at an S/N ratio of 3). The method was applied to the determination of thrombin in spiked human plasma samples, and recoveries ranged between 94 and 105% (with RSDs of <3.6%). The calibration plot was recorded at potential and wavelength of fluorescence emission (wavelength: 445 nm; potential: 0 to -2 V). Graphical abstract A bare glassy carbon electrode (GCE) does not display electrochemiluminescence (ECL). If, however, nitrogen-doped graphene quantum dots, chitosan, and three-dimensional nitrogen-doped graphene oxide (NGQD-chitosan/3D-NGO) are electrodeposited on the GCE, strong ECL can be observed. The ECL intensity decreased after aptamer and bovine serum albumin (BSA) were dropped onto the electrode (curve a). However, the ECL further decreases after addition of thrombin (TB; curve b).

Diverse gatekeepers for mesoporous silica nanoparticle based drug delivery systems.

Conventional cancer chemotherapy is often associated with toxicity issues. Thus, new drug delivery systems (DDSs) are developed as alternatives owing to their potential to selectively target affected cells while sparing normal tissues. Among them, noninvasive and biocompatible mesoporous silica nanoparticle (MSN)-based targeted DDSs have developed rapidly. In particular, controlled gatekeepers capping the pore entrances of MSNs play prominent and crucial roles in achieving specific drug release and avoiding premature leakage in the delivery process before the target is reached, and perfect gatekeepers can only be removed under specific internal or external stimuli, such as pH, redox potential, temperature, biomolecules, light, magnetic field and ultrasound, or a combination of these stimuli, which is significant for precise therapeutic treatments and potential applications in human bodies. Thus, the main focus of this review is to highlight the most recent progress on the design of various controlled MSN gatekeepers to achieve 'zero premature release' drug delivery. The diverse gatekeepers are categorised into the following kinds according to their types and characteristics: (1) polymers; (2) inorganic nanomaterials; (3) host-guest assemblies; and (4) biomacromolecules. This review will offer a broad palette of opportunities for researchers with interests including nanomaterial fabrication and modification, targeted drug delivery and stimuli-responsive drug release.

Nectar properties and the role of sunbirds as pollinators of the golden-flowered tea (Camellia petelotii).

PREMISE OF THE STUDY: Properties of floral nectar have been used to predict if a plant species is pollinated by birds. To see whether winter-flowering plants evolve nectar properties corresponding to bird pollinators, nectar properties of several Camellia species (including the golden-flowered tea), as well as the role of floral visitors as effective pollinators, were examined. METHODS: Potential pollinators of Camellia petelotii were identified at different times of day and under various weather conditions. A bird exclusion experiment was used to compare the pollination effectiveness of birds and insects. Nectar sugar components (fructose, glucose, and sucrose) from C. petelotii growing wild and another seven Camellia species and 22 additional cultivars (all in cultivation) were examined by high-performance liquid chromatography (HPLC). KEY RESULTS: The sunbird Aethopyga siparaja and honeybees were the most frequent floral visitors to C. petelotii. Honeybee visits were significantly reduced in cloudy/rainy weather. The fruit and seed set of flowers with birds excluded were reduced by 64%, indicating that bird pollination is significant. For the wild populations of C. petelotii, a bagged flower could secrete 157 µL nectar; this nectar has a low sugar concentration (19%) and is sucrose-dominant (87%). The eight Camellia species and 22 cultivars had an average sugar concentration of around 30% and a sucrose concentration of 80%, demonstrating sucrose-dominant nectar in Camellia species. CONCLUSIONS: The nectar sugar composition of Camellia species was characterized by sucrose dominance. In addition, the large reduction in seed set when birds are excluded in the golden-flowered tea also supports the suggestion that these winter-flowering plants may have evolved with birds as significant pollinators.

Geographic consistency and variation in conflicting selection generated by pollinators and seed predators.

BACKGROUNDS AND AIMS: Floral traits that attract pollinators may also attract seed predators, which, in turn, may generate conflicting natural selection on such traits. Although such selection trade-offs are expected to vary geographically, few studies have investigated selection mediated by pollinators and seed predators across a geographic mosaic of environments and floral variation. METHODS: Floral traits were investigated in 14 populations of the bumble-bee-pollinated herb, Pedicularis rex, in which tubular flowers are subtended by cupular bracts holding rain water. To study potentially conflicting selection on floral traits generated by pollinators and florivores, stigmatic pollen loads, initial seed set, pre-dispersal seed predation and final viable seed production were measured in 12-14 populations in the field. KEY RESULTS: Generalized Linear Model (GLM) analyses indicated that the pollen load on stigmas was positively related to the exsertion of the corolla beyond the cupular bracts and size of the lower corolla lip, but so too was the rate of seed predation, creating conflicting selection on both floral traits. A geographic mosaic of selection mediated by seed predators, but not pollinators, was indicated by significant variation in levels of seed predation and the inclusion of two-, three- and four-way interaction terms between population and seed predation in the best model [lowest corrected Akaike Information Criterion (AICc)] explaining final seed production. CONCLUSIONS: These results indicate opposing selection in operation: pollinators generated selection for greater floral exsertion beyond the bracts, but seed predators generated selection for reduced exsertion above the protective pools of water, although the strength of the latter varied across populations.

A novel platform self-assembled from squaraine-embedded Zn(ii) complexes for selective monitoring of ATP and its level fluctuation in mitotic cells.

Using multiple interactions, a simple self-assembly based on a Zn(ii) coordination compound and squaraine () demonstrated a selective turn-on fluorescence response to ATP in the near infrared (NIR) region. More importantly, the self-assembly has been successfully applied to ATP imaging in the mitochondria of the gastric cancer cell line SGC-7901 and monitoring of level fluctuation of ATP during the mitotic period.

Are long corolla tubes in Pedicularis driven by pollinator selection?

The evolution of long corolla tubes has been hypothesized to be driven by long-tongued pollinators. Corolla tubes in Pedicularis species can be longer than 10 cm which may function as flower stalks to increase visual attractiveness to pollinators because these species provide no nectar and are pollinated by bumblebees. The corolla tube length was manipulated (shorter or longer) in two Pedicularis species in field to examine whether longer tubes are more attractive to pollinators and produce more seeds than short tubes. Our results did not support the pollinator attraction hypothesis, leaving the evolution of long tubes in Pedicularis remains mysterious.

Pollen size strongly correlates with stigma depth among Pedicularis species.

Darwin proposed that pollen size should be positively correlated with stigma depth rather than style length among species given that pollen tubes first enter the stigma autotrophically, then grow through the style heterotrophically. However, studies often show a positive relationship between pollen size and style length. Five floral traits were observed to be correlated among 42 bumblebee-pollinated Pedicularis species (Orobanchaceae) in which stigmas are distinct from styles. The phylogenetic independent contrast analysis revealed that pollen grain volume was more strongly correlated with stigma depth than with style length, consistent with Darwin's functional hypothesis between pollen size and stigma depth.

Reversible and selective luminescent determination of ClO(-)/H2S redox cycle in vitro and in vivo based on a ruthenium trisbipyridyl probe.

A rapid and highly selective luminescent probe has been developed to determine the in vitro and in vivo ClO(-)/H2S redox cycle using a ruthenium tris-bipyridyl complex covalently linked with phenothiazine. The luminescence intensity was considerably enhanced upon the addition of ClO(-) due to the oxidation of the probe to its sulfoxide derivative, which quickly returned to the original level by the reaction with H2S due to the reconstitution of the probe. The redox cycle can be repeated at least 12 times. Under optimal conditions, the luminescence intensities are linear over the concentration range of 1 × 10(-9) to 1 × 10(-4) mol L(-1) for ClO(-) and 1 × 10(-9) to 1 × 10(-4) mol L(-1) for H2S, and the detection limits are 1.8 × 10(-11) mol L(-1) for ClO(-) and 1.2 × 10(-11) mol L(-1) for H2S, which are much lower than those obtained with other detection methods. The proposed method is simple in design and fast in operation, and is suitable for the reversible determination of ClO(-) and H2S in vitro and in vivo with high selectivity.