Complete Chloroplast Genome of Hypericum perforatum and Dynamic Evolution in Hypericum (Hypericaceae).

Hypericum perforatum (St. John's Wort) is a medicinal plant from the Hypericaceae family. Here, we sequenced the whole chloroplast genome of H. perforatum and compared the genome variation among five Hypericum species to discover dynamic changes and elucidate the mechanisms that lead to genome rearrangements in the Hypericum chloroplast genomes. The H. perforatum chloroplast genome is 139,725 bp, exhibiting a circular quadripartite structure with two copies of inverted repeats (IRs) separating a large single-copy region and a small single-copy region. The H. perforatum chloroplast genome encodes 106 unique genes, including 73 protein-coding genes, 29 tRNAs, and 4 rRNAs. Hypericum chloroplast genomes exhibit genome rearrangement and significant variations among species. The genome size variation among the five Hypericum species was remarkably associated with the expansion or contraction of IR regions and gene losses. Three genes-trnK-UUU, infA, and rps16-were lost, and three genes-rps7, rpl23, and rpl32-were pseudogenized in Hypericum. All the Hypericum chloroplast genomes lost the two introns in clpP, the intron in rps12, and the second intron in ycf3. Hypericum chloroplast genomes contain many long repeat sequences, suggesting a role in facilitating rearrangements. Most genes, according to molecular evolution assessments, are under purifying selection.

Near-Infrared Afterglow ONOO--Triggered Nanoparticles for Real-Time Monitoring and Treatment of Early Ischemic Stroke.

Early detection and drug intervention with the appropriate timing and dosage are the main clinical challenges for ischemic stroke (IS) treatment. The conventional therapeutic agents relay fluorescent signals, which require real-time external light excitation, thereby leading to inevitable autofluorescence and poor tissue penetration. Herein, we report endogenous peroxynitrite (ONOO-)-activated BDP-4/Cur-CL NPs that release NIR afterglow signals (λmax 697 nm) for real-time monitoring of the progression of ischemia reperfusion (I/R) brain injury while releasing curcumin for the safe treatment of IS. The BDP-4/Cur-CL NPs exhibited bright NIR afterglow luminescence (maximum 732-fold increase), superb sensitivity (LOD = 82.67 nM), high energy-transfer efficiency (94.6%), deep tissue penetration (20 mm), outstanding antiapoptosis, and anti-inflammatory effects. The activated NIR afterglow signal obtained in mice with middle cerebral artery occlusion (MCAO) showed three functions: (i) the BDP-4/Cur-CL NPs are rapidly activated by endogenous ONOO-, instantly illuminating the lesion area, distinguishing I/R damage from normal areas, which can be successfully used for endogenous ONOO- detection in the early stage of IS; (ii) real-time reporting of in situ generation and dynamic fluctuations of endogenous ONOO- levels in the lesion area, which is of great value in monitoring the evolutionary mechanisms of IS; and (iii) dynamic monitoring of the release of curcumin drug for safe treatment. Indeed, the released curcumin effectively decreased apoptosis, enhanced survival, alleviated neuroinflammation, reduced brain tissue loss, and improved the cognition of MCAO stroke mice. This work is the first example of afterglow luminescence for early diagnosis, real-time reporting, drug tracing, and treatment for IS.

Sanghuangporus sanghuang extract extended the lifespan and healthspan of Caenorhabditis elegans via DAF-16/SIR-2.1.

Sanghuangporus Sanghuang is a fungus species. As a traditional Chinese medicine, it is known for antitumor, antioxidant and anti-inflammatory properties. However, the antiaging effect of S. Sanghuang has not been deeply studied. In this study, the effects of S. Sanghuang extract (SSE) supernatants on the changes of nematode indicators were investigated. The results showed that different concentrations of SSE prolonged the lifespans of nematodes and substantially increased these by 26.41%. In addition, accumulations of lipofuscin were also visibly reduced. The treatment using SSE also played a role in increasing stress resistance, decreasing ROS accumulations and obesity, and enhancing the physique. RT-PCR analysis showed that the SSE treatment upregulated the transcription of daf-16, sir-2.1, daf-2, sod-3 and hsp-16.2, increased the expression of these genes in the insulin/IGF-1 signalling pathway and prolonged the lifespans of nematodes. This study reveals the new role of S. Sanghuang in promoting longevity and inhibiting stress and provides a theoretical basis for the application of S. Sanghuang in anti-ageing treatments.

The Integration of Nanomedicine with Traditional Chinese Medicine: Drug Delivery of Natural Products and Other Opportunities.

The integration of progressive technologies such as nanomedicine with the use of natural products from traditional medicine (TM) provides a unique opportunity for the longed-for harmonization between traditional and modern medicine. Although several actions have been initiated decades ago, a disparity of reasons including some misunderstandings between each other limits the possibilities of a truly complementation. Herein, we analyze some common challenges between nanomedicine and traditional Chinese medicine (TCM). These challenges, if solved in a consensual way, can give a boost to such harmonization. Nanomedicine is a recently born technology, while TCM has been used by the Chinese people for thousands of years. However, for these disciplines, the regulation and standardization of many of the protocols, especially related to the toxicity and safety, regulatory aspects, and manufacturing procedures, are under discussion. Besides, both TCM and nanomedicine still need to achieve a wider social acceptance. Herein, we first briefly discuss the strengths and weaknesses of TCM. This analysis serves to focus afterward on the aspects where TCM and nanomedicine can mutually help to bridge the existing gaps between TCM and Western modern medicine. As discussed, many of these challenges can be applied to TM in general. Finally, recent successful cases in scientific literature that merge TCM and nanomedicine are reviewed as examples of the benefits of this harmonization.

Modified Taohong Siwu decoction improves cardiac function after myocardial ischaemia and reperfusion in rats by promoting endogenous stem cell mobilization and regulating metabolites.

CONTEXT: Taohong Siwu decoction (THSWD) has been shown to promote heart repair in myocardial infarction. OBJECTIVE: To determine the effects of modified THSWD (THSWD plus four ingredients) on myocardial ischaemia and reperfusion (I/R) injury. MATERIALS AND METHODS: Sixty Sprague-Dawley rats were randomly divided into the I/R group and three different modified THSWD dose groups (gavage administration, 1.215, 2.43, and 4.86 g, respectively). 2,3,5-Triphenyltetrazolium chloride and Evans blue staining were used to detect the infarct area at 24 h after treatment. The serum biochemical indexes and cell apoptosis were examined to determine myocardial injury. The number of endogenous stem cells, expression of stromal dell derived factor-1 (SDF-1) and stem cell factor (SCF), and cardiac function were measured at 4 weeks. The serum was collected for metabolomic analysis. RESULTS: The high-dose modified THSWD group presented a reduced infarction area (decreased by 21.3%), decreased levels of lactate dehydrogenase and creatinine kinase, attenuated cell apoptosis, and enhanced superoxide dismutase activity in early stage I/R compared with other groups. The serum SCF and SDF-1 levels were higher in the high-dose group than in the I/R group. At 4 weeks, the infarct size and collagen content were the lowest, and the ejection fraction and fractional shortening values were the highest in the high-dose group. Moreover, high-dose modified THSWD affected the metabolism of phosphonate and phosphonate, taurine, and hypotaurine. CONCLUSIONS: Endogenous stem cell mobilization and metabolic regulation were related to the cardioprotection of modified THSWD. We provided a new strategy and direction for the treatment of cardiovascular diseases with traditional Chinese medicine.

SDF-1/CXCR4-Mediated Stem Cell Mobilization Involved in Cardioprotective Effects of Electroacupuncture on Mouse with Myocardial Infarction.

Stem cell-based therapeutic strategies have obtained a significant breakthrough in the treatment of cardiovascular diseases, particularly in myocardial infarction (MI). Nevertheless, limited retention and poor migration of stem cells are still problems for stem cell therapeutic development. Hence, there is an urgent need to develop new strategies that can mobilize stem cells to infarcted myocardial tissues effectively. Electroacupuncture (EA) intervention can improve cardiac function and alleviate myocardial injury after MI, but its molecular mechanism is still unclear. This study is aimed at observing the effects of EA treatment on the stem cell mobilization and revealing possible mechanisms in the MI model of mice. EA treatment at Neiguan (PC6) and Xinshu (BL15) acupoints was conducted on the second day after the ligation surgery. Then, the number of stem cells in peripheral blood after EA in MI mice and their cardiac function, infarct size, and collagen deposition was observed. We found that the number of CD34-, CD117-, Sca-1-, and CD90-positive cells increased at 6 h and declined at 24 h after EA intervention in the blood of MI mice. The expression of CXC chemokine receptor-4 (CXCR4) protein was upregulated at 6 h after EA treatment, while the ratio of LC3B II/I or p-ERK/ERK showed a reverse trend. In addition, there was obvious difference in EF and FS between wild-type mice and CXCR4+/- mice. The infarct size, collagen deposition, and apoptosis of the injured myocardium in CXCR4+/- mice increased but could be ameliorated by EA. In a word, our study demonstrates that EA alleviates myocardial injury via stem cell mobilization which may be regulated by the SDF-1/CXCR4 axis.

Nano-selenium and Macleaya cordata Extracts Improved Immune Function and Reduced Oxidative Damage of Sows and IUGR Piglets After Heat Stress of Sows in Late Gestation.

To investigate the effects of nano-selenium (nano-Se) and Macleaya cordata extracts (MCE) on immune function and oxidative damage of sows and intrauterine growth retardation (IUGR) piglets exposed to heat stress (HS) in large-scale farms, a 2 × 2 factorial design was adopted in this test, and the two factors were nano-Se (0, 0.50 mg/kg) and MCE (0, 500 mg/kg). A total of 80 sows ([Landrace × Yorkshire] × Duroc, parity 2) were used in a 25-day trial from day 90 of gestation to delivery with 20 replications per group and 1 sow per replication. The dietary treatments of sows were as follows: (1) CON group, basic diet (0.30 mg/kg added Se, sodium selenite); (2) Nano-Se group, basic diet (0.00 mg/kg added Se) + 0.50 mg/kg added nano-Se; (3) MCE group, basic diet (0.00 mg/kg added Se) + 500 mg/kg added MCE; and (4) Combined group, basic diet (0.00 mg/kg added Se) + 0.50 mg/kg added nano-Se and 500 mg/kg added MCE. The activities of serum SOD, CAT, and GSH-Px of sows and IUGR piglets were significantly increased in MCE group and combined group, and the MDA content was extremely decreased. There were extreme differences in serum IgG level of sows and IUGR piglets, colostrum, and serum IgM level of IUGR piglets in MCE group and combined group compared with CON group. Maternal combined diets increased greatly the levels of serum IL-10 and IFN-γ of sows and IUGR piglets, and decreased extremely the contents of serum IL-1ß and TNF-α. MCE alone or combination with nano-Se in sow diets decreased greatly mRNA level of Hsp70 and increased mRNA level of Hsp27 in sows and IUGR piglets. In conclusion, nano-Se and/or MCE can be added to sow diets for the amelioration of HS-induced oxidative damage through improving immune function.

Molybdenum Fertilization Improved Antioxidant Capacity of Grazing Nanjiang Brown Goat on Copper-Contaminated Pasture.

Copper (Cu) is an essential trace element, but excessive Cu intake can induce poor performance and Cu poisoning and result in various health problems. Cu and molybdenum (Mo) antagonize each other in vivo. Therefore, Mo can reduce the absorption and utilization of Cu. The aims of this study were to investigate the impacts of Mo fertilization on antioxidant capacity of grazing Nanjiang brown goat on Cu-polluted meadow and explore the control methods of Cu pollution in natural pasture. Fertilization and grazing experiments were carried out in Liangshan Yi Nationality Prefecture of the Western Sichuan Plateau, Sichuan Province, Southwest China. Cu-polluted meadows of 12 hm2 were fenced, and randomly divided into two groups (3 replications/group, 2 hm2/replication), control group and treatment group, fed with basic diets supplemented with 0 and 3 kg Mo/hm2 [ammonium molybdate tetrahydrate, (NH4)6Mo7O24·4H2O], respectively. In the current study, 36 healthy Nanjiang brown goats (1 year old, 32.8 ± 1.1 kg) were randomly divided into two groups (3 replications/group, 6 goats/replication) and assigned to the experimental pastures. The grazing experiment lasted for 60 days. The results showed that the concentration of Mo in soil in treatment group was 96.28 mg/kg, far exceeding the normal levels. At days 30 and 60, the levels of Hb, RBC, and PCV in blood in treatment group and the activities of serum SOD, GSH-Px, T-AOC, CAT, and Cp were higher than those in control group (P < 0.01). The MDA content in treatment group was lower than that in control group (P < 0.01). The contents of Cu in blood and liver in treatment goats were lower than those in control animals (P < 0.01). The contents of Zn and Mo in blood and liver in treatment goats were higher than those in control animals (P < 0.01). The Mn content in liver in treatment group was higher than that in control animals (P < 0.01). These results indicated that fertilization of (NH4)6Mo7O24 not only markedly influenced the mineral contents in blood and liver, but also extremely improved antioxidant capacity of grazing Nanjiang brown goat from fertilized pastures and relieved the damage caused by Cu pollution.

Nano-Molybdenum and Macleaya cordata Extracts Improved Antioxidant Capacity of Grazing Nanjiang Brown Goats on Copper and Cadmium-Contaminated Prairies.

To investigate the effects of nano-ammonium octamolybdate (nano-Mo) and Macleaya cordata extracts (MCE) on antioxidant capacity of grazing Nanjiang brown goats on natural prairies under Cu and Cd stress, a 2 × 2 factorial design was adopted in this test, and two factors were nano-Mo (0, 10 mg/kg) and MCE (0, 3000 mg/kg). 24 hm2 polluted grassland was used in this 30-day trial and was equally divided into twelve fenced units. A total of 36 Nanjiang brown goats (1 year old) with an average body weight (BW) of 40.9 ± 2.1 kg were used in this test. The dietary treatments were (1) CON group, basic diet; (2) Nano-Mo group, basic diet + 10 mg/kg added Mo (nano-Mo); (3) MCE group, basic diet + 3000 mg/kg added MCE; and (4) combined group, basic diet + 10 mg/kg added nano-Mo and 3000 mg/kg added MCE. Nano-Mo or combination of nano-Mo and MCE diets significantly decreased the Cu content in serum and the liver of grazing goats (P < 0.05) and increased the Fe and Mo contents in serum and the liver (P < 0.05). The supplementation of nano-Mo, MCE, and combined diets extremely increased the levels of blood Hb, RBC, and PCV (P < 0.05), as well as the activities of serum SOD, GSH-Px, CAT, and Cp (P < 0.05), and greatly decreased the blood WBC content (P < 0.05) and the serum MDA content (P < 0.05). In conclusion, the application of nano-Mo and/or MCE diets on contaminated grasslands changed the contents of mineral elements in serum and the liver of grazing goats, reduced oxidative stress, and improved antioxidant capacity. The combination of nano-Mo and MCE can alleviate the toxic damage of combined heavy metal contaminations.

Nano-Selenium and Macleaya cordata Extracts Improved Immune Functions of Intrauterine Growth Retardation Piglets under Maternal Oxidation Stress.

Intrauterine growth retardation (IUGR) is the main death cause of newborn piglets in large-scale farms. To investigate the effects of maternal nano-selenium (nano-Se) and Macleaya cordata extracts (MCE) on immune functions of IUGR piglets in large scale farms, a 2 × 2 factorial design was adopted in this test, and two factors were nano-Se (0, 0.50 mg/kg) and MCE (0, 500 mg/kg). A total of 32 ternary hybrid sows (Landrace × Yorkshire × Duroc, parity 2) were used in this 25-day trial from day 90 of pregnancy to delivery. The dietary treatments were as follows: (1) CON group, basic diet (0.0 mg/kg Se); (2) Nano-Se group, basic diet + 0.50 mg/kg added Se (nano-Se); (3) MCE group, basic diet + 500 mg/kg added MCE; (4) Combined group, basic diet + 0.50 mg/kg added nano-Se and 500 mg/kg added MCE. Maternal nano-Se or combination of nano-Se and MCE diets extremely increased the superoxide dismutase (SOD), catalase (CAT), superoxide dismutase (GSH-Px) contents in the serum and liver of IUGR offspring (P < 0.05), and MCE supplementation in sow diets remarkably increased the serum superoxide dismutase (SOD), catalase (CAT), and superoxide dismutase (GSH-Px) contents of IUGR piglets (P < 0.05). Adding nano-Se, MCE, or nano-Se and MCE to sow diets decreased the malondialdehyde (MDA) content in the serum and liver of IUGR piglets (P < 0.05). The supplementation of nano-Se and combined diets extremely increased the activities of immunoglobulin G (IgG) and immunoglobulin A (IgA) in the serum and liver of IUGR offspring (P < 0.05). Maternal nano-Se, MCE, and combined diets greatly decreased the levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin-1ß (IL-1ß) in the serum and liver of IUGR piglets (P < 0.05). Together, the application of nano-Se and/or MCE to sow diets improved antioxidant capacities and immune functions of IUGR offspring, and alleviated oxidative stress.

The Effects of Oral Administration of Molybdenum Fertilizers on Immune Function of Nanjiang Brown Goat Grazing on Natural Pastures Contaminated by Mixed Heavy Metal.

Mineral development and metal smelting seriously polluted the surrounding groundwater and soil, threatening human health through the food chain. To investigate the effects of different sources of molybdenum (Mo) fertilizers on immune function of Nanjiang brown goats grazing on natural pastures under compound pollutions, fertilizing experiment was carried out in Liangshan Yi Nationality Prefecture of the Western Sichuan Plateau, China. Eighteen square hectometers of polluted meadows were fenced and were randomly divided into three groups (3 replications/group and 2 hm2/replication). A total of 54 healthy Nanjiang brown goats with an average BW of 31.6 ± 1.5 kg (1 year old) were used to this 30-day test (18 goats per group). The goats from CON group, AM group, and PM group were orally supplemented with deionized water, 15 mg Mo/BW·d (ammonium molybdate tetrahydrate), and 15 mg Mo/BW·d (potassium molybdate), respectively. Compared to CON group, the serum Fe content of grazing animals from AM group and PM group was 10.05% and 3.45% higher (P < 0.05), and the serum Cu content of grazing animals from AM group and PM group was 69.05% and 67.86% lower, respectively (P < 0.05). Mo fertilization significantly increased the levels of blood Hb, RBC, and PCV, and the activities of serum SOD, GSH-Px, CAT, and Cp of grazing goats (P < 0.05), and also extremely decreased the MDA content of experimental goats fed Mo compared to the control goats (P < 0.05). Compared to CON group, the activities of serum IgG, IgA, IgM, IL-2, and TNF-α of grazing animals from AM group and PM group were significantly increased (P < 0.05), and the levels of serum IL-6 and IL-1ß of grazing goats from AM group and PM group were extremely decreased (P < 0.05). In summary, oral Mo fertilizers can alter the contents of serum mineral elements, reduce oxidative stress, improve immune function, and relieve the toxic damage of goats grazing on contaminated natural grasslands.

Engineering Electronic Band Structure of Binary Thermoelectric Nanocatalysts for Augmented Pyrocatalytic Tumor Nanotherapy.

Photothermal therapy (PTT) has emerged as a distinct therapeutic modality owing to its noninvasiveness and spatiotemporal selectivity. However, heat-shock proteins (HSPs) endow tumor cells with resistance to heat-induced apoptosis, severely lowering the therapeutic efficacy of PTT. Here, a high-performance pyroelectric nanocatalyst, Bi13 S18 I2 nanorods (NRs), with prominent pyroelectric conversion and photothermal conversion performance for augmented pyrocatalytic tumor nanotherapy, is developed. Canonical binary compounds are reconstructed by inserting a third biocompatible agent, thus facilitating the formation of Bi13 S18 I2 NRs with enhanced pyrocatalytic conversion efficiency. Under 808 nm laser irradiation, Bi13 S18 I2 NRs induce a conspicuous temperature elevation for photonic hyperthermia. In particular, Bi13 S18 I2 NRs harvest pyrocatalytic energy from the heating and cooling alterations to produce abundant reactive oxygen species, which results in the depletion of HSPs and hence the reduction of thermoresistance of tumor cells, thereby significantly augmenting the therapeutic efficacy of photothermal tumor hyperthermia. By synergizing the pyroelectric dynamic therapy with PTT, tumor suppression with a significant tumor inhibition rate of 97.2% is achieved after intravenous administration of Bi13 S18 I2 NRs and subsequent exposure to an 808 nm laser. This work opens an avenue for the design of high-performance pyroelectric nanocatalysts by reconstructing canonical binary compounds for therapeutic applications in biocatalytic nanomedicine.

Designer exosomes enabling tumor targeted efficient chemo/gene/photothermal therapy.

Exosomes, endogenous nanosized particles (50-150 nm) secreted and absorbed by cells, have been recently used as diagnostic and therapeutic platforms in cancer treatment. The integration of exosome-based delivery with multiple therapeutic modalities could result in better clinical outcomes and reduced-sided effects. Here, we combined the targeting and biocompatibility of designer exosomes with chemo/gene/photothermal therapy. Our platform consists of exosomes loaded with internalized doxorubicin (DOX, a model cancer drug) and coated with magnetic nanoparticles conjugated with molecular beacons capable of targeting miR-21 for responsive molecular imaging. The coated magnetic nanoparticle enables enrichment of the exosomes at the tumor site by external magnetic field guidance. After the exosomes are gathered at the tumor site, the application of near-infrared radiation (NIR) induces localized hyperthermia and triggers the release of cargoes loaded inside the exosome. The released molecular beacon can target the miR-21 for both imaging and gene silencing. Meanwhile, the released doxorubicin serves to kill the cancer cells. About 91.04 % of cancer cells are killed after treatment with Exo-DOX-Fe3O4@PDA-MB under NIR. The ability of the exosome-based method for cancer therapy has been demonstrated by animal models, in which the tumor size is reduced dramatically by 97.57 % with a magnetic field-guided tumor-targeted chemo/gene/photothermal approach. Thus, we expected this designer exosome-mediated multi-mode therapy to be a promising platform for the next-generation precision cancer nanomedicines.

Pollen-Specific Protein PSP231 Activates Callose Synthesis to Govern Male Gametogenesis and Pollen Germination.

Spatiotemporally regulated callose deposition is an essential, genetically programmed phenomenon that promotes pollen development and functionality. Severe male infertility is associated with deficient callose biosynthesis, highlighting the significance of intact callose deposition in male gametogenesis. The molecular mechanism that regulates the crucial role of callose in production of functional male gametophytes remains completely unexplored. Here, we provide evidence that the gradual upregulation of a previously uncharacterized cotton (Gossypium hirsutum) pollen-specific SKS-like protein (PSP231), specifically at the post pollen-mitosis stage, activates callose biosynthesis to promote pollen maturation. Aberrant PSP231 expression levels caused by either silencing or overexpression resulted in late pollen developmental abnormalities and male infertility phenotypes in a dose-dependent manner, highlighting the importance of fine-tuned PSP231 expression. Mechanistic analyses revealed that PSP231 plays a central role in triggering and fine-tuning the callose synthesis and deposition required for pollen development. Specifically, PSP231 protein sequesters the cellular pool of RNA-binding protein GhRBPL1 to destabilize GhWRKY15 mRNAs, turning off GhWRKY15-mediated transcriptional repression of GhCalS4/GhCalS8 and thus activating callose biosynthesis in pollen. This study showed that PSP231 is a key molecular switch that activates the molecular circuit controlling callose deposition toward pollen maturation and functionality and thereby safeguards agricultural crops against male infertility.

Effect of Leifsonia sp. on retardation of uranium in natural soil and its potential mechanisms.

Uranium mining and milling activities for many years resulted in release of uranium into the adjoining soil in varying degrees. Bioremediation approaches (i.e., immobilization via the action of bacteria) resulting in uranium bearing solid is supposed as an economic and clean in-situ approach for the treatment of uranium contaminated sites. This study purposes to determine the immobilization efficiency of uranium in soil by Leifsonia sp. The results demonstrated that cells have a good proliferation ability under the stress of uranium and play a role in retaining uranium in soil. Residual uranium in active Leifsonia-medium group (66%) was higher than that in the controls, which was 31% in the deionised water control, 46% in the Leifsonia group, and 47% in the medium group, respectively. This indicated that Leifsonia sp. facilitates the immobilization efficiency of uranium in soil by converting part of the reducible and oxidizable fraction of uranium into the residual fraction. X-ray photoelectron fitting results showed that tetravalent states uranium existed in the soil samples, which indicated that the hexavalent uranium was converted into tetravalent by cells. This is the first report of effect of Leifsonia sp. on uranium immobilization in soil. The findings implied that Leifsonia sp. could, to some extent, prevent the migration and diffusion of uranium in soil by changing the chemical states into less toxicity and less risky forms.

Chemogenetics-mediated acute inhibition of excitatory neuronal activity improves stroke outcome.

BACKGROUND AND PURPOSE: Ischemic stroke significantly perturbs neuronal homeostasis leading to a cascade of pathologic events causing brain damage. In this study, we assessed acute stroke outcome after chemogenetic inhibition of forebrain excitatory neuronal activity. METHODS: We generated hM4Di-TG transgenic mice expressing the inhibitory hM4Di, a Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-based chemogenetic receptor, in forebrain excitatory neurons. Clozapine-N-oxide (CNO) was used to activate hM4Di DREADD. Ischemic stroke was induced by transient occlusion of the middle cerebral artery. Neurologic function and infarct volumes were evaluated. Excitatory neuronal suppression in the hM4Di-TG mouse forebrain was assessed electrophysiologically in vitro and in vivo, based on evoked synaptic responses, and in vivo based on occurrence of potassium-induced cortical spreading depolarizations. RESULTS: Detailed characterization of hM4Di-TG mice confirmed that evoked synaptic responses in both in vitro hippocampal slices and in vivo motor cortex were significantly reduced after CNO-mediated activation of the inhibitory hM4Di DREADD. Further, CNO treatment had no obvious effects on physiology and motor function in either control or hM4Di-TG mice. Importantly, hM4Di-TG mice treated with CNO at either 10 min before ischemia or 30 min after reperfusion exhibited significantly improved neurologic function and smaller infarct volumes compared to CNO-treated control mice. Mechanistically, we showed that potassium-induced cortical spreading depression episodes were inhibited, including frequency and duration of DC shift, in CNO-treated hM4Di-TG mice. CONCLUSIONS: Our data demonstrate that acute inhibition of a subset of excitatory neurons after ischemic stroke can prevent brain injury and improve functional outcome. This study, together with the previous work in optogenetic neuronal modulation during the chronic phase of stroke, supports the notion that targeting neuronal activity is a promising strategy in stroke therapy.

The Adverse Effects of Se Toxicity on Inflammatory and Immune Responses in Chicken Spleens.

Selenium (Se) is an essential trace element, but excessive intake of Se could induce Se poisoning, and result in various health problems. NF-κB regulated many molecules of the immune response and the inflammatory response, and Th1/Th2 balance played a key in the regulation of immune response. The aim of this study is to investigate the role of NF-κB pathway and Th1/Th2 imbalance in the adverse influence of Se poisoning on chicken spleens. In the current study, 90 chickens were randomly divided into two groups (n = 45 per group). The chickens were maintained either on a basal diet (the control group) containing 0.2 mg/kg Se or a high supplemented diet (the Se group) containing 15 mg/kg Se for 45 days. Then, we observed the pathohistology of spleen cells and detected NO content, iNOS activity, and the expression of NF-κB, iNOS, COX-2, PTGE, IL-6, TNF-α, Foxp3, IL-4, and IFN-γ in chicken spleens. In chicken spleens of the Se group, the result showed typical characteristics of inflammation: the content of NO and the activity of iNOS were increased, and the expression of NF-κB, iNOS, COX-2, PTGE, IL-6, TNF-α, and IL-4 was enhanced and that of Foxp3 and IFN-γ was decreased. Our study showed that Se toxicity could promote inflammation via NF-κB pathway, impairing the immune function, and changing Th1/Th2 balance in the chicken spleens.

Excessive Selenium Supplementation Induced Oxidative Stress and Endoplasmic Reticulum Stress in Chicken Spleen.

Excessive selenium (Se) intake is harmful for animals and humans. The aim of the present study was to examine the effect of long-term excessive Se supplementation on oxidative stress and endoplasmic reticulum (ER) stress-related injuries in chicken spleen. A total of 180 1-day-old chickens were randomly divided into four groups with different Se dietary contents (0.2 mg/kg Se, 5 mg/kg Se, 10 mg/kg Se, or 15 mg/kg Se) for 45 days. Then, the levels of antioxidative enzymes, GPx, SOD, and MDA as well as the expression levels of GRP78, ARF6, caspase 3, caspase 12, and Bcl 2 in the spleen were determined at days 15, 30, and 45, respectively. The results showed that excessive Se treatment decreased the activities of GPx and SOD (P < 0.05) but increased the levels of MDA (P < 0.05) in a dose- and time-dependent manner. In addition, the ER stress genes GRP78 and ATF6 were highly expressed (P < 0.05), and the apoptosis genes caspase 3 and caspase 12 were increased, but Bcl 2 was decreased by Se treatment (P < 0.05). Correlation analysis showed that there was a high correlation between these biomarkers, which indicated that ER stress and ER stress-related apoptosis were correlated with oxidative stress. These results showed the important role of oxidative stress and ER stress in Se-related immune injuries in chicken.

Effect of Different Selenium Supplementation Levels on Oxidative Stress, Cytokines, and Immunotoxicity in Chicken Thymus.

This study assessed the effects of different selenium (Se) supplementation levels on oxidative stress, cytokines, and immunotoxicity in chicken thymus. A total of 180 laying hens (1 day old; Mianyang, China) were randomly divided into 4 groups (n = 45). The chickens were maintained either on a basic diet (control group) containing 0.2 mg/kg Se, a low-supplemented diet containing 5 mg/kg Se, a medium-supplemented diet containing 10 mg/kg Se, or a high-supplemented diet containing 15 mg/kg Se for 15, 30, and 45 days, respectively. Over the entire experimental period, serum and thymus samples were collected and used for the detection of the experimental index. The results indicated that the antioxidative enzyme activities and messenger RNA (mRNA) levels of antioxidative enzymes, IFN-γ and IL-2 in the thymus, and the content of IFN-γ and IL-2 in the serum of excessive-Se-treated chickens at all time points (except for the 5 mg/kg Se supplement group at 15 days) were significantly decreased (P < 0.05) compared to the corresponding control groups. Interestingly, a significantly increase (P < 0.05) in the content of IFN-γ was observed in the serum and thymus in the 5 mg/kg Se supplement group at 15 and 30 days compared to the corresponding control groups. In histopathological examination, the thymus tissue from excessive-Se-treated chickens revealed different degrees of cortex drop, incrassation of the medulla, and degeneration of the reticular cells. These results suggested that the excessive Se could result in a decrease in immunity, an increase in oxidative damage, and a series of clinical pathology changes, such as cortex drop, incrassation of the medulla, and degeneration of the reticular cells.