Effects of hypoxia and reoxygenation on oxidative stress, histological structure, and apoptosis in a new hypoxia-tolerant variety of blunt snout bream (Megalobrama amblycephala).

A new hypoxia-tolerant variety of blunt snout bream was obtained by successive breeding of the wild population, which markedly improved hypoxia tolerance. In this study, the hypoxia-tolerant variety was exposed to hypoxia (2.0 mg O2·L-1) for 4, 7 days. The contents of blood biochemical indicators including the number of red blood cells (RBC), total cholesterol (T-CHO), total protein (TP), triglyceride (TG), glucose (GLU), and lactic acid (LD) increased significantly (P < 0.05) under hypoxia. The glycogen content in the liver and muscle decreased significantly (P < 0.05) and the LD content in the brain, muscle and liver increased significantly (P < 0.05) under hypoxia. The levels of oxidative stress-related indicators i.e., superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT), and total antioxidant capacity (T-AOC) also changed significantly (P < 0.05) in the heart, liver, and intestine of the new variety under hypoxia. Additionally, hypoxia has caused injuries to the heart, liver, and intestine, but it shows amazing repair ability during reoxygenation. The apoptotic cells and apoptosis rate in the heart, liver, and intestine increased under hypoxia. Under hypoxia, the expression of the B-cell lymphomas 2 (Bcl-2) gene in the heart, liver, and intestine was significantly (P < 0.05) down-regulated, while the expression of the BCL2-associated agonist of cell death (Bad) gene was significantly (P < 0.05) up-regulated. These results are of great significance for enriching the basic data of blunt snout bream new variety in response to hypoxia and promoting the healthy development of its culture industry.

Gill remodeling increases the respiratory surface area of grass carp (Ctenopharyngodon idella) under hypoxic stress.

Seasonal changes, diurnal variations, and eutrophication result in periodic hypoxia in fish habitats, thus affecting the success of commercial aquaculture. In this study, the grass carp (Ctenopharyngodon idella) presented moderate hypoxia tolerance; they showed a medium critical oxygen tension during the loss of equilibrium. In response to 7 d of hypoxic exposure, the erythrocyte count and hemoglobin (Hb) concentration significantly increased (p < 0.01). To cope with the hypoxic environment, the grass carp underwent gill remodeling marked by reduction in the interlamellar cell mass (ILCM) and an increase in respiratory surface area. The gill remodeling under hypoxia was enabled by apoptosis induction. Although apoptotic signals were not found on ILCM cells, transferase dUTP nick end labeling (TUNEL) assay results indicated that after 1 d of hypoxic exposure, the number of TUNEL-positive cells per lamella increased until 4 d and then began to decrease. Consistent with the results of the TUNEL assay, the mRNA expression of apoptosis-related genes, caspase-3, Bax, and Bcl-2, increased at 1, 4, and 7 d of the hypoxia treatment. In addition, gill remodeling significantly (p < 0.01) decreased the concentration of sodium and chloride ions in the fish serum. These findings provide evidence that grass carps increase their respiratory surface area through gill remodeling by apoptosis in the gill filaments to acclimate to a hypoxic environment. This study expands our understanding of the morphological and physiological changes in grass carp in response to a hypoxic environment; therefore, it could be useful for maintaining grass carp production.

Uranium induces kidney cells apoptosis via reactive oxygen species generation, endoplasmic reticulum stress and inhibition of PI3K/AKT/mTOR signaling in culture.

Uranium (U) induces generation of excessive intracellular reactive oxygen species (ROS), which is generally considered as a possible mediator of U-triggered kidney tubular cells injury and nephrotoxicity. Our goal is designed to elucidate that the precise molecular mechanism in ROS downstream is association with U-induced NRK-52E cells apoptosis. The results show that U intoxication in NRK-52E cells reduced cell activity and triggered apoptosis, as demonstrated by flow cytometry and apoptotic marker cleaved Caspase-3 expression. U exposure triggered endoplasmic reticulum (ER) stress, which is involvement of apoptosis determined by marker molecules including GRP78, PERK, IRE1, ATF6, CHOP, cleaved Caspase-12, and Caspase-3. Administration of antioxidant N-acetylcysteine (NAC) effectively blocked U-triggered ROS generation, ER stress, and apoptosis. U contamination evidently decreased the expression of phosphorylation PI3K, AKT, and mTOR and ratios of their respective phosphorylation to the corresponding total proteins. Application of a PI3K activator IGF-1 significantly abolished these adverse effects of U intoxication on PI3K/AKT/mTOR signaling and subsequently abrogated U-triggered apoptosis. NAC also effectively reversed down-regulation of phosphorylated PI3K induced by U exposure. Taken together, these data strongly suggest that U treatment induces NRK-52E cells apoptosis through ROS production, ER stress, and down-regulation of PI3K/AKT/mTOR signaling. Targeting ROS formation-, ER stress-, and PI3K/AKT/mTOR pathway-mediated apoptosis could be a novel approach for attenuating U-triggered nephrotoxicity.

Role of the BDNF/TrkB/CREB signaling pathway in the cytotoxicity of bisphenol S in SK-N-SH cells.

Bisphenol S (BPS) is associated with neurotoxicity, but its molecular mechanisms are unclear. Our aim was to investigate the role of the brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB)/cAMP-response element-binding protein (CREB) signaling pathway in BPS-induced cytotoxicity in SK-N-SH cells. The cells were treated with various concentrations of BPS, and cell viability, apoptosis rate, mitochondrial membrane potential (MMP), and the BDNF, cleaved-caspase-3, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), TrkB, CREB, and phospho-CREB (p-CREB) levels were determined. The effects of pretreatment with the TrkB activator 7,8-dihydroxyflavone (7,8-DHF) were also explored. BPS decreased SK-N-SH cell viability and altered their morphology. Their apoptosis rate was increased, as were the levels of the proapoptotic proteins Bax and cleaved-caspase-3, but MMP was decreased. Thus, BPS may induce mitochondria-dependent apoptosis pathways. BPS also reduced the BDNF, TrkB, and p-CREB levels, and pretreatment with 7,8-DHF alleviated its cytotoxic effects. Thus, BPS-induced cytotoxicity might be mediated by the BDNF/TrkB/CREB signaling pathway.

Genome mining of Streptomyces xinghaiensis NRRL B-24674T for the discovery of the gene cluster involved in anticomplement activities and detection of novel xiamycin analogs.

Marine actinobacterium Streptomyces xinghaiensis NRRL B-24674T has been characterized as a novel species, but thus far, its biosynthetic potential remains unexplored. In this study, the high-quality genome sequence of S. xinghaiensis NRRL B-24674T was obtained, and the production of anticomplement agents, xiamycin analogs, and siderophores was investigated by genome mining. Anticomplement compounds are valuable for combating numerous diseases caused by the abnormal activation of the human complement system. The biosynthetic gene cluster (BGC) nrps1 resembles that of complestatins, which are potent microbial-derived anticomplement agents. The identification of the nrps1 BGC revealed a core peptide that differed from that in complestatin; thus, we studied the anticomplement activity of this strain. The culture broth of S. xinghaiensis NRRL B-24674T displayed good anticomplement activity. Subsequently, the disruption of the genes in the nrps1 BGC resulted in the loss of anticomplement activity, confirming the involvement of this BGC in the biosynthesis of anticomplement agents. In addition, the mining of the BGC tep5, which resembles that of the antiviral pentacyclic indolosesquiterpene xiamycin, resulted in the discovery of nine xiamycin analogs, including three novel compounds. In addition to the BGCs responsible for desferrioxamine B, neomycin, ectoine, and carotenoid, 18 BGCs present in the genome are predicted to be novel. The results of this study unveil the potential of S. xinghaiensis as a producer of novel anticomplement agents and provide a basis for further exploration of the biosynthetic potential of S. xinghaiensis NRRL B-24674T for the discovery of novel bioactive compounds by genome mining.

[Label-Free Resonance Light Scattering Detection of Hg²âº Based on Specific Structure Thymine-Hg²âº-Thymine].

A new label-free resonance light scattering method for the highly selective and sensitive detection of mercury ion was designed. This strategy makes use of the target-induced DNA conformational change to enhance the resonance light scattering intensity leading to an amplified optical signal. The Hg²âº ion, which possesses a unique property to bind specifically to two DNA thymine (T) bases, in the presence of Hg²âº, the specific oligonucleotide probes form a conformational reorganization of the oligonucleotide probes from single-chain structure to duplex-like complexes, which can greatly enhance the resonance light scattering intensity. Under the optimum experimental conditions, the enhanced resonance light scattering intensity at 566 nm was in proportion of mercury ion concentration in the range 7.2 x 10⁻9 x 10⁻8 mol · L⁻¹ with the linear regression equation was ΔI = 5.12c+3.55 (r = 0.999 5). This method was successfully applied to detection of Hg²âº in enviro nmental water samples, the RSD were less than 1.9% and recoveries were 99.4%-104.3%. This label-free strategy uses the mercury specific oligonucleotide probes as recognition elements and control the strength of resonance light scattering by changing the concentration of Hg²âº. It translating the small molecule detection into the DNA hybridization behavior leading to an amplified resonance light scattering signal can well enhance the sensitive detection of Hg²âº. With amplification by DNA hybridization behavior, the sensitivity for the detection of Hg²âº can achieve 2.16 x 10⁻9 mol · L(⁻¹). In this study, the stacked T-Hg²âº-Tfunctioned not only as amplification property but also as an selective recognition. The highly specific detection of Hg²âº is attributed to the formation of a stable T-Hg²âº-T complex.

Folding-induced folding: the assembly of aromatic amide and 1,2,3-triazole hybrid helices.

Folding-induced folding for the construction of artificial hybrid helices from two different kinds of aromatic sequences is described. Linear compounds 1 a, 1 b, and 2, containing one aromatic amide trimer or pentamer and one or two aromatic 1,2,3-triazole tetramers, have been designed and synthesized. The trimeric and pentameric amide segments are driven by intramolecluar N-H⋅⋅⋅F hydrogen bonding to adopt a folded or helical conformation, whereas the triazole segment is intrinsically disordered. In organic solvents of low polarity, the amide foldamer segment induces the attached triazole segment(s) to fold through intramolecular stacking, leading to the formation of hybrid helices. The helical conformation of these hybrid sequences has been confirmed by (1)H and (19)F NMR spectroscopy, UV/Vis spectroscopy, circular dichroism (CD) experiments, and theoretical calculations. It was found that the amide pentamer exhibits a stronger ability to induce the folding of the attached triazole segment(s) compared with that of the shorter trimer. Enantiomers (R)-3 and (S)-3, which contain an R- or S-(1-naphthyl)ethylamino group at the end of a tetraamide segment, have also been synthesized. CD experiments showed that introduction of a chiral group caused the whole framework to produce a strong helicity bias. Density-functional-theory calculations on (S)-3 suggested that this compound exists as a right-handed (P) helix.

Vasodilatory effect of a novel Rho-kinase inhibitor, DL0805-2, on the rat mesenteric artery and its potential mechanisms.

PURPOSE: In the present study, we investigated the vasodilatory effect of a novel scaffold Rho-kinase inhibitor, DL0805-2, on isolated rat arterial rings including mesenteric, ventral tail, and renal arteries. We also examined the potential mechanisms of its vasodilatory action using mesenteric artery rings. METHODS: A DMT multiwire myograph system was used to test the tension of isolated small arteries. Several drugs were employed to verify the underlying mechanisms. RESULTS: DL0805-2 (10(-7)-10(-4) M) inhibited KCl (60 mM)-induced vasoconstriction in three types of small artery rings (pEC50: 5.84 ± 0.03, 5.39 ± 0.03, and 5.67 ± 0.02 for mesenteric, renal, and ventral tail artery rings, respectively). Pre-incubation with DL0805-2 (1, 3, or 10 µM) attenuated KCl (10-60 mM) and angiotensin II (AngII; 10(-6) M)-induced vasoconstriction in mesenteric artery rings. The relaxant effect on the rat mesenteric artery was partially endothelium-dependent (pEC50: 6.02 ± 0.05 for endothelium-intact and 5.72 ± 0.06 for endothelium-denuded). The influx and release of Ca(2+) were inhibited by DL0805-2. In addition, the increased phosphorylation levels of myosin light chain (MLC) and myosin-binding subunit of myosin phosphatase (MYPT1) induced by AngII were blocked by DL0805-2. However, DL0805-2 had little effect on K(+) channels. CONCLUSIONS: The present results demonstrate that DL0805-2 has a vasorelaxant effect on isolated rat small arteries and may exert its action through the endothelium, Ca(2+) channels, and the Rho/ROCK pathway.

[Effect and mechanism of total flavonoids of bugloss on rats with myocardial ischemia and reperfusion injury].

This study is to investigate the effect of total flavonoids of Uygur medicine bugloss (BTF) on rats with myocardial ischemia/reperfusion injury, and to explore the mechanisms by which it acts. Left anterior descending (LAD) coronary artery in rats was occluded for 30 min followed by 4 h reperfusion. Meanwhile, BTF dissolved in saline was administered intraperitoneally at dosage of 10, 30 and 50 mg x kg(-1). Electrocardiograph, infarction index, serum myocardial enzymes and heart function were determined to evaluate the effect of BTF. Some other observations were carried out to explore whether inhibiting inflammation and apoptosis is involved in the mechanisms underlying BTF. Our results showed that in ischemia/reperfusion injured rats BTF could dose-dependently reduce myocardial infarction index and myocardial enzyme leakage, and enhance heart function, indicating that it possesses significant cardio protection. ELISA analysis showed that BTF could decrease the content of myocardial inflammatory cytokines such as IL-1beta, IL-6 and TNF-alpha. Western-blotting confirmed that BTF could increase the expression of anti-apoptotic protein Bcl-2 and reduce the expression of proapoptosis protein Bax. Further more, the phosphorylation level of PI3K and Akt was upregulated by BTF treatment. BTF can protect rat against myocardial ischemia/reperfusion injury. Anti-inflammation and inhibition of apoptosis through upregulating PI3K/Akt signal pathway may contribute to the protective effect of BTF.

4-Octyl itaconate inhibits inflammation via the NLRP3 pathway in neuromyelitis optica spectrum disorders.

OBJECTIVE: Neuromyelitis optica spectrum disorders (NMOSD) are rare inflammatory astrocytic diseases of the central nervous system (CNS). The roles of immune response gene-1 (IRG1) and the IRG1-itaconic acid-NLRP3 inflammatory pathway in the pathogenesis of NMOSD and the effects of 4-octyl itaconate (4-OI) on the NLRP3 inflammatory pathway in NMOSD are unclear. This study aimed to determine the role of IRG1 and the activation status of the NLRP3 inflammatory pathway in acute-onset NMOSD and to investigate the inhibitory effects of 4-OI on NLRP3 inflammasome activation via the IRG1-itaconic acid-NLRP3 pathway in monocytes and macrophages by using in vitro models. METHODS: Peripheral blood mononuclear cells (PBMCs) and serum were collected from patients with acute NMOSDs and healthy controls (HC), followed by monocyte typing and detection of the expression of NLRP3-related inflammatory factors. Subsequently, the effects of 4-OI on the IRG1-itaconic acid-NLRP3 pathway were investigated in peripheral monocytes from patients with NMOSD and in macrophages induced by human myeloid leukemia mononuclear cells (THP-1 cells) via in vitro experiments. RESULTS: Patients with acute NMOSD exhibited upregulated IRG1 expression. In particular, the upregulation of the expression of the NLRP3 inflammasome and proinflammatory factors was notable in monocytes in acute NMOSD patients. 4-OI inhibited the activation of the IRG1-itaconic acid-NLRP3 inflammatory pathway in the PBMCs of patients with NMOSD. INTERPRETATION: 4-OI could effectively inhibit NLRP3 signaling, leading to the inhibition of proinflammatory cytokine production in patients with NMOSD-derived PBMCs and in a human macrophage model. Thus, 4-OI and itaconate could have important therapeutic value for the treatment of NMOSD in the future.

Targeting critical pathways in ferroptosis and enhancing antitumor therapy of Platinum drugs for colorectal cancer.

Colorectal cancer (CRC) can be resistant to platinum drugs, possibly through ferroptosis suppression, albeit the need for further work to completely understand this mechanism. This work aimed to sum up current findings pertaining to oxaliplatin resistance (OR) or resistance to ascertain the potential of ferroptosis to regulate oxaliplatin effects. In this review, tumor development relating to iron homeostasis, which includes levels of iron that ascertain cells' sensitivity to ferroptosis, oxidative stress, or lipid peroxidation in colorectal tumor cells that are connected with ferroptosis initiation, especially the role of c-Myc/NRF2 signaling in regulating iron homeostasis, coupled with NRF2/GPX4-mediated ferroptosis are discussed. Importantly, ferroptosis plays a key role in OR and ferroptotic induction may substantially reverse OR in CRC cells, which in turn could inhibit the imbalance of intracellular redox induced by oxaliplatin and ferroptosis, as well as cause chemotherapeutic resistance in CRC. Furthermore, fundamental research of small molecules, ferroptosis inducers, GPX4 inhibitors, or natural products for OR coupled with their clinical applications in CRC have also been summarized. Also, potential molecular targets and mechanisms of small molecules or drugs are discussed as well. Suggestively, OR of CRC cells could significantly be reversed by ferroptosis induction, wherein this result is discussed in the current review. Prospectively, the existing literature discussed in this review will provide a solid foundation for scientists to research the potential use of combined anticancer drugs which can overcome OR via targeting various mechanisms of ferroptosis. Especially, promising therapeutic strategies, challenges ,and opportunities for CRC therapy will be discussed.

Targeting cellular energy metabolism- mediated ferroptosis by small molecule compounds for colorectal cancer therapy.

Alterations in cellular energy metabolism, including glycolysis, glutamine and lipid metabolism that affects ferroptosis in the tumour microenvironment (TME), play a critical role in the development and progression of colorectal cancer (CRC) and offer evolutionary advantages to tumour cells and even enhance their aggressive phenotype. This review summarises the findings on the dysregulated energy metabolism pathways, including lipid and fatty acid metabolism especially for regulating the ferroptosis in TME. Moreover, the cellular energy metabolism and tumour ferroptosis to be regulated by small molecule compounds, which targeting the different aspects of metabolic pathways of energy production as well as metabolic enzymes that connect with the tumour cell growth and ferroptosis in CRC are also discussed. In this review, we will provide a comprehensive summary on small molecule compounds regulatory function of different energy metabolic routes on ferroptosis in tumour cells and discuss those metabolic vulnerabilities for the development of potential ferroptosis-based tumour therapies for colorectal cancer.

Aesculin suppresses the NLRP3 inflammasome-mediated pyroptosis via the Akt/GSK3ß/NF-κB pathway to mitigate myocardial ischemia/reperfusion injury.

BACKGROUND: Aesculin (AES), an effective component of Cortex fraxini, is a hydroxycoumarin glucoside that has diverse biological properties. The nucleotide-binding domain leucine-rich repeat-containing receptor, pyrin domain-containing 3 (NLRP3) inflammasome has been heavily interwoven with the development of myocardial ischemia/reperfusion injury (MIRI). Nevertheless, it remains unclear whether AES makes a difference to the changes of the NLRP3 inflammasome in MIRI. PURPOSE: We used rats that were subjected to MIRI and neonatal rat cardiomyocytes (NRCMs) that underwent oxygen-glucose deprivation/restoration (OGD/R) process to investigate what impacts AES exerts on MIRI and the NLRP3 inflammasome activation. METHODS: The establishment of MIRI model in rats was conducted using the left anterior descending coronary artery ligation for 0.5 h ischemia and then untying the knot for 4 h of reperfusion. After reperfusion, AES were administered intraperitoneally using 10 and 30 mg/kg doses. We evaluated the development of reperfusion ventricular arrhythmias, hemodynamic changes, infarct size, and the biomarkers in myocardial injury. The inflammatory mediators and pyroptosis were also assessed. AES at the concentrations of 1, 3, and 10 µM were imposed on the NRCMs immediately before the restoration process. We also determined the cell viability and cell death in the NRCMs exposed to OGD/R insult. Furthermore, we also analyzed the levels of proteins that affect the NLRP3 inflammasome activation, pyroptosis, and the AKT serine/threonine kinase (Akt)/glycogen synthase kinase 3 beta (GSK3ß)/nuclear factor-kappa B (NF-κB) signaling pathway via western blotting. RESULTS: We found that AES notably attenuated reperfusion arrhythmias and myocardia damage, improved the hemodynamic function, and ameliorated the inflammatory response and pyroptosis of cardiomyocytes in rats and NRCMs. Additionally, AES reduced the NLRP3 inflammasome activation in rats and NRCMs. AES also enhanced the phosphorylation of Akt and GSK3ß, while suppressing the phosphorylation of NF-κB. Moreover, the allosteric Akt inhibitor, MK-2206, abolished the AES-mediated cardioprotection and the NLRP3 inflammasome suppression. CONCLUSIONS: These findings indicate that AES effectively protected cardiomyocytes against MIRI by suppressing the NLRP3 inflammasome-mediated pyroptosis, which may relate to the upregulated Akt activation and disruption of the GSK3ß/NF-κB pathway.

[Effects of farnesyltransferase silencing on the migration and invasion of tongue squamous cell carcinoma].

OBJECTIVE: This study aimed to explore the effects of silencing farnesyltransferase (FTase) on the migration and invasion of tongue squamous cell carcinoma (TSCC) through RNA interference. METHODS: TSCC cells (CAL27 and SCC-4) were cultured in vitro and then transfected with siRNA to silence FTase expression. The tested cells were categorized as follows: experimental group (three RNA interference groups), negative control group, and blank control group. mRNA expression of FTase and HRAS in each group was analyzed by quantitative real-time polymerase chain reaction. On the basis of FTase mRNA expression, the optimum interference group (highest silencing efficiency) was selected as the experimental group for further study. The protein expression of FTase, HRAS, p65, p-p65(S536), matrix metalloprotein-9 (MMP-9), hypoxia inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) was analyzed by Western blot. The invasion and migration abilities of TSCC cells were determined by Transwell invasion assay and cell wound healing assay. RESULTS: The mRNA and protein expression of FTase in the experimental group decreased compared with that in the negative control and blank control groups (P<0.05). The mRNA and protein expression of HRAS was not significantly different among the groups (P>0.05). In the experimental group, the protein expression of p-p65(S536), MMP-9, HIF-1α, and VEGF decreased (P<0.05), whereas that of p65 had no significant change (P>0.05). The migration and invasion abilities of the experimental group were inhibited significantly (P<0.05). CONCLUSIONS: Silencing FTase in vitro could effectively downregulate its expression in TSCC cell lines and reduce the migration and invasion abilities to a certain extent. FTase could be a new gene therapy target of TSCC, and this research provided a new idea for the clinical treatment of TSCC.

[Effect of human bone marrow mesenchymal stem cells on invasion of tongue squamous cell carcinoma cell line Cal-27].

PURPOSE: To investigate the effect of human bone marrow mesenchymal stem cells (hBM-MSCs) on invasion of tongue squamous cell carcinoma cell line Cal-27 and its mechanism. METHODS: hBM-MSCs and Cal-27 were cultured respectively, and the morphology of the cells was observed under an inverted microscope. The co-cultured Cal-27 cells were obtained by co-culture of hBM-MSCs and Cal-27. The migration area of Cal-27 was observed by scratch test;transwell migration and invasion experiments were performed to observe migration and invasion of Cal-27, and a bar graph was then drawn. Fluorescence quantitative PCR was used to observe the effect of hBM-MSCs on gene expression of the tumor markers E-cadherin, twist, slug, snail, MMP-2 and MMP-9. Western blot was used to observe the effect of hBM-MSCs on protein expression of MMP-2 and MMP-9, related to the invasion of Cal-27. SPSS 19.0 software package was used for statistical analysis of the data. RESULTS: Under the influence of hBM-MSCs, the invasion of Cal-27 was promoted, accompanied by down-regulation of E-cadherin, up-regulation of twist, slug, snail, MMP-2, MMP-9 and up-regulation of MMP-2 and MMP-9 expression. CONCLUSIONS: hBM-MSCs can promote invasion of Cal-27 cells, which may be related to up-regulation of the expression of tumor markers related to invasion of Cal-27 cells.

Selective brain hypothermia-induced neuroprotection against focal cerebral ischemia/reperfusion injury is associated with Fis1 inhibition.

Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke, and avoids the complications of general hypothermia. However, the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown. In this study, we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein, a key factor in the mitochondrial fission system, during focal cerebral ischemia/reperfusion injury. Sprague-Dawley rats were divided into four groups. In the sham group, the carotid arteries were exposed only. In the other three groups, middle cerebral artery occlusion was performed using the intraluminal filament technique. After 2 hours of occlusion, the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group. Saline, at 4°C and 37°C, were perfused through the carotid artery in the hypothermia and normothermia groups, respectively, followed by restoration of blood flow. Neurological function was assessed with the Zea Longa 5-point scoring method. Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining, and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. Fis1 and cytosolic cytochrome c levels were assessed by western blot assay. Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction. Mitochondrial ultrastructure was evaluated by transmission electron microscopy. Compared with the sham group, apoptosis, Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups. These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group. These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis, thereby ameliorating focal cerebral ischemia/reperfusion injury in rats. Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No. 2019008).

Hydrogen-bonding-mediated dynamic covalent synthesis of macrocycles and capsules: new receptors for aliphatic ammonium ions and the formation of pseudo[3]rotaxanes.

This paper describes a novel, highly efficient approach to the self-assembly of monomacrocycles and two-layered capsules by using dynamic covalent chemistry. Intramolecular hydrogen-bonding was used to preorganize aromatic amide-based monomers that contain aldehyde and tert-butoxycarbonylamino units. As a result, in the presence of an excess of trifluoroacetic acid (TFA), four monomers could self-couple to produce macrocycles selectively through the formation of three imine or hydrazone bonds. Three dipodal precursors were also prepared by connecting two hydrogen-bonded segments with a flexible linker. In the presence of TFA, these precursors could also self-couple, leading to the exclusive formation of two-layered capsules. As a result of intramolecular hydrogen-bonding, all the macrocycles and capsules were stable in solution and could be purified by simple recrystallization. The new capsules were able to form complexes with linear propylenediammonium derivatives to give unique two-layered pseudo[3]rotaxanes.

Comparison of the volatile constituents of different parts of Cortex magnolia officinalis by GC-MS combined with chemometric resolution method.

Volatile compositions of different parts (stem, branch and root barks) of cortex Magnolia officinalis, cultivated in China, were investigated for the first time by GC-MS with the help of heuristic evolving latent projection (HELP). Identification of components was conducted by similarity matching to NIST mass library but also assisted by comparison of temperature-programmed retention indices (PTRIs) with the data web available. A total of 90, 82 and 76 volatile compounds in the essential oils of the three samples taken from the same batch aforementioned were qualitatively and quantitatively determined, representing 84.03, 83.68 and 83.10% of the total content, respectively. Among the constituents determined, there were 50 components coexisting. Eudesmol and its isomers were shown to be the principal compounds in the studied samples, accounting for 47.66, 36.74 and 36.31%, respectively. The three kinds of isomers (alpha-, beta- and gamma-eudesmol) in houpo volatile oils have been tentatively qualified and quantified simultaneously for the first time. By comparative analysis, significant qualitative and semi-quantitative differences and similarities were observed among the three samples. The results achieved provide a scientific evidence for further exploitation of Magnolia bark and clinical medication.

Association between gallstone and cardio-cerebrovascular disease: Systematic review and meta-analysis.

Increasing evidence connects gallstone disease (GD) to cardio-cerebrovascular disease (CVD). The aim of the present systematic review and meta-analysis was to determine whether and to what extent an association between GD and CVD existed. PubMed, EMBASE and the Cochrane Library were systemically searched up to March 3rd, 2018. A total of 10 studies (1,272,177 participants; 13,833 records; 5 prospective cohorts and 5 retrospective cohorts) were included. It was demonstrated that GD was associated with an increased risk of incidence [hazard ratio=1.24, 95% (CI) confidence interval: 1.17-1.31] and prevalence (unadjusted odds ratio=1.23, 95% CI: 1.21-1.25) of CVD. In conclusion, the presence of GD was associated with an increased risk of CVD incidence and prevalence. The association may be influenced by age and sex. These findings suggest that individuals identified with cardio-cerebrovascular disease should be evaluated for GD.

Hydrogen bonding-directed multicomponent dynamic covalent assembly of mono- and bimacrocycles. Self-sorting and macrocycle exchange.

This paper describes the multicomponent dynamic covalent assembly of macrocyclic structures by utilizing hydrogen bonding-driven zigzag anthranilamides as "leading" components. Two or three amino groups have been introduced to one side of hydrogen bonded anthranilamide oligomers. The preorganization of the frameworks enabled the amino groups to condense with structurally matched aldehydes to form mono- and bimacrocycles in good to quantitative yields. Reactions from up to five components have been investigated, which involved one-step formation of up to six imine bonds. The preorganization of the templates highly enhanced the stability of the macrocyclic structures. As a result, all the macrocycles could be purified by simply recrystallizing the crude products from suitable solvents. Coexisting experiments of three series of three to five components were also performed, which all revealed that the preorganized precursors possessed high self-sorting capacity. On the basis of the same approach, a hydrazone-based macrocycle was also prepared quantitatively, while an intermacrocycle hydrazone-imine exchange was revealed to facilitate the formation of the hydrazone-based macrocycle from an imine-based macrocycle.