Deep learning-based characterization and redesign of major potato tuber storage protein.

Potato is one of the most important crops worldwide, to feed a fast-growing population. In addition to providing energy, fiber, vitamins, and minerals, potato storage proteins are considered as one of the most valuable sources of non-animal proteins due to their high essential amino acid (EAA) index. However, low tuber protein content and limited knowledge about potato storage proteins restrict their widespread utilization in the food industry. Here, we report a proof-of-concept study, using deep learning-based protein design tools, to characterize the biological and chemical characteristics of patatins, the major potato storage proteins. This knowledge was then employed to design multiple cysteines on the patatin surface to build polymers linked by disulfide bonds, which significantly improved viscidity and nutrient of potato flour dough. Our study shows that deep learning-based protein design strategies are efficient to characterize and to create novel proteins for future food sources.

Purification and structural characterization of two polysaccharides with anti-inflammatory activities from Plumbago zeylanica L.

Plumbago zeylanica L., a traditional Chinese medicine, has anti-bacterial and anti-inflammatory effects, and it is critical important to explore the chemical compounds and evaluate their biological actions from the medicinal plant. However, the chemical structure and biological activities of polysaccharides from P. zeylanica. were still poorly understood. In this study, two water-soluble polysaccharides named WPZP-2-1 and WPZP-2-2 were purified from P. zeylanica L. Chemical and spectroscopic tests showed that the main chain of WPZP-2-1 was →4)-α-D-GalpA-(1 â†’ 2)-α-L-Rhap-(1→, and the branch chain was galactose or arabinose. The main chain of WPZP-2-2 was composed of →4)-α-D-GalpA-(1 â†’ 2)-α-L-Rhap-(1→, and the O-2 and O-3 of →4)-α-D-GalpA had a small amount of acetylation. In addition, in vitro test showed that WPZP-2-1 and WPZP-2-2 significantly improved the inflammatory damage of LPS + IFN-γ-induced THP-1 cells via reducing the protein levels of CD14, TLR4 and MyD88, thereby promoting IL-10 expression and inhibiting the mRNA levels of TNF-α and IL-1ß. Those findings indicated that WPZP-2-1 and WPZP-2-2 from the plant should be served as the potential anti-inflammatory agents.

Risk factors for the comorbidity of osteoporosis/osteopenia and kidney stones: a cross-sectional study.

Low femoral neck bone mineral density (BMD) was associated with the increased risk of kidney stones. Low dietary magnesium intake and increased serum alkaline phosphatase were associated with the increased risk of low femoral neck BMD in kidney stone formers. PURPOSE: To evaluate whether low femoral neck bone mineral density (BMD) was associated with a higher risk of kidney stones, and identify risk factors for the comorbidity of osteoporosis/osteopenia and kidney stones. METHODS: We analyzed individuals aged ≥ 20 years from National Health and Nutrition Examination Survey 2007-2020 data. Osteoporosis/osteopenia is defined as any T-score < -1.0 of femoral neck, total femoral, and mean lumbar spine (L1-L4) BMD. Dietary intakes (sodium, potassium, magnesium, calcium, phosphorus, calcium/phosphorus, vitamin D (25OHD2+25OHD3)) and serum parameters (sodium, potassium, calcium, phosphorus, bicarbonate, vitamin D, alkaline phosphatase (ALP)) were screened for identifying risk factors for the comorbidity. RESULTS: The prevalence of comorbidity of osteoporosis/osteopenia and kidney stones was 4.82%. Femoral neck BMD T-score was negatively associated with the prevalence of kidney stones (n=11,864). Dietary magnesium intake, serum phosphorus, and bicarbonate were negatively associated with the comorbidity prevalence, and serum ALP was positively associated with the comorbidity prevalence (n=6978). Additionally, there remain significant associations of dietary magnesium intake, serum ALP, and bicarbonate with not only femoral neck BMD T-score (n=11331), but also the prevalence of kidney stones (n=23,111) in general population. Furthermore, dietary magnesium intake was positively correlated to femoral neck BMD T-score in stone formers (SFs), while serum ALP was negatively correlated to femoral neck BMD T-score in SFs (n=1163). CONCLUSION: Low femoral neck BMD was closely associated with an increased risk of kidney stones. Low magnesium intake and increased serum ALP were associated with the increased risk of the comorbidity, as well as indicative of low femoral neck BMD T-score in SFs, which offered a clue to further clarify the mechanism leading to paradoxical calcification of bone resorption and kidney stones, and had the potential to perform personalized diagnostic workup for low BMD in SFs.

Blocked conversion of Lactobacillus johnsonii derived acetate to butyrate mediates copper-induced epithelial barrier damage in a pig model.

BACKGROUND: High-copper diets have been widely used to promote growth performance of pigs, but excess copper supplementation can also produce negative effects on ecosystem stability and organism health. High-copper supplementation can damage the intestinal barrier and disturb the gut microbiome community. However, the specific relationship between high-copper-induced intestinal damage and gut microbiota or its metabolites is unclear. OBJECTIVE: Using fecal microbiota transplantation and metagenomic sequencing, responses of colonic microbiota to a high-copper diet was profiled. In addition, via comparison of specific bacteria and its metabolites rescue, we investigated a network of bacteria-metabolite interactions involving conversion of specific metabolites as a key mechanism linked to copper-induced damage of the colon. RESULTS: High copper induced colonic damage, Lactobacillus extinction, and reduction of SCFA (acetate and butyrate) concentrations in pigs. LefSe analysis and q-PCR results confirmed the extinction of L. johnsonii. In addition, transplanting copper-rich fecal microbiota to ABX mice reproduced the gut characteristics of the pig donors. Then, L. johnsonii rescue could restore decreased SCFAs (mainly acetate and butyrate) and colonic barrier damage including thinner mucus layer, reduced colon length, and tight junction protein dysfunction. Given that acetate and butyrate concentrations exhibited a positive correlation with L. johnsonii abundance, we investigated how L. johnsonii exerted its effects by supplementing acetate and butyrate. L. johnsonii and butyrate administration but not acetate could correct the damaged colonic barrier. Acetate administration had no effects on butyrate concentration, indicating blocked conversion from acetate to butyrate. Furthermore, L. johnsonii rescue enriched a series of genera with butyrate-producing ability, mainly Lachnospiraceae NK4A136 group. CONCLUSIONS: For the first time, we reveal the microbiota-mediated mechanism of high-copper-induced colonic damage in piglets. A high-copper diet can induce extinction of L. johnsonii which leads to colonic barrier damage and loss of SCFA production. Re-establishment of L. johnsonii normalizes the SCFA-producing pathway and restores colonic barrier function. Mechanistically, Lachnospiraceae NK4A136 group mediated conversion of acetate produced by L. johnsonii to butyrate is indispensable in the protection of colonic barrier function. Collectively, these findings provide a feasible mitigation strategy for gut damage caused by high-copper diets. Video Abstract.

Algorithms Research and Precision Comparison of Different Frequency Combinations of BDS-3\GPS\Galileo for Precise Point Positioning in Asia-Pacific Region.

With the continuous construction and development of the BeiDou navigation satellite system (BDS), its positioning performance is constantly being improved. In this study, the positioning performance of different frequency combinations of BDS-3/GPS/Galileo in the Asia-Pacific region was investigated. The precision products of Wuhan University and the observation data of nine MGEX stations were selected to compare and analyze the B1I\B1C\B2a\B3I and L1\E1 pseudo-range Standard Point Positioning (SPP) and B1IB2a\B1IB3I\B1CB2a\B1CB3I\B2aB3I\L1L2\E1E5a precise point positioning (PPP) performance, while B1I\B3I\L1 SPP and B1IB3I PPP were investigated using BDS-2 with QZSS supplemented with BDS-3 and GPS. The experimental results showed that the positioning precision of BDS-3/GPS/Galileo SPP was in the order of B1C > E1 > L1 > B1I > B3I > B2a, and it was not significantly improved after BDS-2 and QZSS were added. Moreover, for the PPP of different frequency combinations, the convergence speed was in the order of L1L2 > B1IB3I > E1E5a > B1CB3I > B1CB2a > B1IB2a > B2aB3I. After adding BDS-2, B1IB3I improved by about 11% in static mode and 27% in kinematic mode, which was similar to the L1L2 frequency combination. The positioning precision of different frequency combinations of BDS-3/GPS/Galileo was B1IB3I > B1CB3I > L1L2 > E1E5a > B1B2a > B1CB2a > B2aB3I. In static mode, after adding BDS-2, B1IB3I did not show significant improvement in the plane direction, and showed ~61% improvement in the elevation direction, and ~67% in the three-dimensional (3D) direction. In kinematic mode, after adding BDS-2, B1IB3I was improved by about 16% in the E direction, the N direction did not show significant change, it improved by ~38% in the U direction and by ~70% in the 3D direction. In general, the positioning performance of BDS-3 was slightly better than those of GPS and Galileo in the Asia-Pacific region, and it is believed that with the continuous development of BDS, its positioning performance will surely be improved further.

IL5RA as an immunogenic cell death-related predictor in progression and therapeutic response of multiple myeloma.

Previous studies have shown the potential of immunogenic cell death-related modalities in myeloma. The significance of IL5RA in myeloma and immunogenic cell death remains unknown. We analyzed IL5RA expression, the gene expression profile, and secretory protein genes related to IL5RA level using GEO data. Immunogenic cell death subgroup classification was performed using the ConsensusClusterPlus and pheatmap R package. Enrichment analyses were based on GO/KEGG analysis. After IL5RA-shRNA transfection in myeloma cells, cell proliferation, apoptosis, and drug sensitivity were detected. P < 0.05 was considered statistically significant. IL5RA was upregulated in myeloma and progressed smoldering myeloma. We observed enrichment in pathways such as the PI3K-Akt signaling pathway, and Natural killer cell mediated cytotoxicity in the high-IL5RA group. IL5RA was also closely associated with secretory protein genes such as CST6. We observed the enrichment of cellular apoptosis and hippo signaling pathway on differential genes in the immunogenic cell death cluster. Furthermore, IL5RA was associated with immune infiltration, immunogenic cell death-related genes, immune-checkpoint-related genes, and m6A in myeloma. In vitro and in vivo experiments showed the involvement of IL5RA in apoptosis, proliferation, and drug resistance of myeloma cells. IL5RA shows the potential to be an immunogenic cell death-related predictor for myeloma.

Design, Synthesis, and Anti-Inflammatory Activities of 12-Dehydropyxinol Derivatives.

Pyxinol skeleton is a promising framework of anti-inflammatory agents formed in the human liver from 20S-protopanaxadiol, the main active aglycone of ginsenosides. In the present study, a new series of amino acid-containing derivatives were produced from 12-dehydropyxinol, a pyxinol oxidation metabolite, and its anti-inflammatory activity was assessed using an NO inhibition assay. Interestingly, the dehydrogenation at C-12 of pyxinol derivatives improved their potency greatly. Furthermore, half of the derivatives exhibited better NO inhibitory activity than hydrocortisone sodium succinate, a glucocorticoid drug. The structure-activity relationship analysis indicated that the kinds of amino acid residues and their hydrophilicity influenced the activity to a great extent, as did R/S stereochemistry at C-24. Of the various derivatives, 5c with an N-Boc-protected phenylalanine residue showed the highest NO inhibitory activity and relatively low cytotoxicity. Moreover, derivative 5c could dose-dependently suppress iNOS, IL-1ß, and TNF-α via the MAPK and NF-κB pathways, but not the GR pathway. Overall, pyxinol derivatives hold potential for application as anti-inflammatory agents.

L-selenomethionine affects liver development and glucolipid metabolism by inhibiting autophagy in zebrafish embryos.

Selenium plays a vital role in cancer prevention, antioxidation, and the growth of humans and other vertebrates. Excessive selenium can cause liver injury and metabolic disorders, which can lead to hepatic disease, but few studies have shown the effects of excessive selenium on liver development and its mechanism in zebrafish embryos. In this study, liver development and glucolipid metabolism were investigated in selenium-stressed zebrafish embryos. Under selenium treatment, transgenic fabp10a-eGFP zebrafish embryos showed reduced liver size, and wild-type zebrafish embryos exhibited steatosis and altered lipid metabolism-related indexes and glucose metabolism-related enzyme activities. In addition, selenium-stressed embryos exhibited damaged mitochondria and inhibited autophagy in the liver. An autophagy inducer (rapamycin) alleviated selenium-induced liver injury and restored the expression of some genes related to liver development and glucolipid metabolism. In summary, our research evaluated liver developmental toxicity and metabolic disorders under selenium stress, and confirmed that autophagy and oxidative stress might involve in the selenium-induced hepatic defects.

(-)-Epigallocatechin-3-gallate, a Polyphenol from Green Tea, Regulates the Liquid-Liquid Phase Separation of Alzheimer's-Related Protein Tau.

The microtubule-associated protein tau is involved in Alzheimer's disease and other tauopathies. Recently, tau has been shown to undergo liquid-liquid phase separation (LLPS), which is implicated in the physiological function and pathological aggregation of tau. In this report, we demonstrate that the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) promotes the formation of liquid tau droplets at neutral pH by creating a network of hydrophobic interactions and hydrogen bonds, mainly with the proline-rich domain of tau. We further show that EGCG oxidation, tau phosphorylation, and the chemical structure of the polyphenol influence the efficacy of EGCG in facilitating tau LLPS. Complementary to the inhibitory activity of EGCG in tau fibrillization, our findings provide novel insights into the biological activity of EGCG and offer new clues for future studies on the molecular mechanism by which EGCG alleviates neurodegenerative diseases.

Loop pathways are responsible for tuning the accumulation of C19- and C22-sterol intermediates in the mycobacterial phytosterol degradation pathway.

4-Androstene-3,17-dione (4-AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (BA) are the most important and representative C19- and C22-steroidal materials. The optimalization of sterol production with mycobacterial phytosterol conversion has been investigated for decades. One of the major challenges is that current industrial mycobacterial strains accumulate unignorable impurities analogous to desired sterol intermediates, significantly hampering product extractions and refinements. Previously, we identified Mycobacterium neoaurum HGMS2 as an efficient 4-AD-producing strain (Wang et al. in Microb Cell Fact. 19:187, 2020). Recently, we have genetically modified the HGMS2 strain to remove its major impurities including ADD and 9OH-AD (Li et al. in Microb Cell Fact. 20:158, 2021). Unexpectedly, the modified mutants started to significantly accumulate BA compared with the HGMS2 strain. In this work, while we attempted to block BA occurrence during 4-AD accumulation in HGMS2 mutants, we identified a few loop pathways that regulated metabolic flux switching between 4-AD and BA accumulations and found that both the 4-AD and BA pathways shared a 9,10-secosteroidial route. One of the key enzymes in the loop pathways was Hsd4A1, which played an important role in determining 4-AD accumulation. The inactivation of the hsd4A1 gene significantly blocked the 4-AD metabolic pathway so that the phytosterol degradation pathway flowed to the BA metabolic pathway, suggesting that the BA metabolic pathway is a complementary pathway to the 4-AD pathway. Thus, knocking out the hsd4A1 gene essentially made the HGMS2 mutant (HGMS2Δhsd4A1) start to efficiently accumulate BA. After further knocking out the endogenous kstd and ksh genes, an HGMS2Δhsd4A1 mutant, HGMS2Δhsd4A1/Δkstd1, enhanced the phytosterol conversion rate to BA in 1.2-fold compared with the HGMS2Δhsd4A1 mutant in pilot-scale fermentation. The final BA yield increased to 38.3 g/L starting with 80 g/L of phytosterols. Furthermore, we knocked in exogenous active kstd or ksh genes to HGMS2Δhsd4A1/Δ kstd1 to construct DBA- and 9OH-BA-producing strains. The resultant DBA- and 9OH-BA-producing strains, HGMS2Δhsd4A1/kstd2 and HGMS2Δkstd1/Δhsd4A1/kshA1B1, efficiently converted phytosterols to DBA- and 9OH-BA with the rates of 42.5% and 40.3%, respectively, and their final yields reached 34.2 and 37.3 g/L, respectively, starting with 80 g/L phytosterols. Overall, our study not only provides efficient strains for the industrial production of BA, DBA and 9OH-BA but also provides insights into the metabolic engineering of the HGMS2 strain to produce other important steroidal compounds.

Doped Graphene To Mimic the Bacterial NADH Oxidase for One-Step NAD+ Supplementation in Mammals.

Nicotinamide adenine dinucleotide (NAD) is a critical regulator of metabolic networks, and declining levels of its oxidized form, NAD+, are closely associated with numerous diseases. While supplementing cells with precursors needed for NAD+ synthesis has shown poor efficacy in combatting NAD+ decline, an alternative strategy is the development of synthetic materials that catalyze the oxidation of NADH into NAD+, thereby taking over the natural role of the NADH oxidase (NOX) present in bacteria. Herein, we discovered that metal-nitrogen-doped graphene (MNGR) materials can catalyze the oxidation of NADH into NAD+. Among MNGR materials with different transition metals, Fe-, Co-, and Cu-NGR displayed strong catalytic activity combined with >80% conversion of NADH into NAD+, similar specificity to NOX for abstracting hydrogen from the pyridine ring of nicotinamide, and higher selectivity than 51 other nanomaterials. The NOX-like activity of FeNGR functioned well in diverse cell lines. As a proof of concept of the in vivo application, we showed that FeNGR could specifically target the liver and remedy the metabolic flux anomaly in obesity mice with NAD+-deficient cells. Overall, our study provides a distinct insight for exploration of drug candidates by design of synthetic materials to mimic the functions of unique enzymes (e.g., NOX) in bacteria.

Effects of Citrus aurantium L. on Gastrointestinal Motility and Gastric Cancer Cell Proliferation.

Background: To research the impact of a Chinese traditional medicine (Citrus aurantium L.) on gastric cancer proliferation and mice gastrointestinal motility. Materials and Methods: The intestinal transit rates (ITRs) and gastric emptying (GE) values in mice with experimentally induced gastrointestinal motility dysfunction (GMD) and in normal mice were calculated to research the in vivo influences of C. aurantium L. on gastrointestinal motility. CCK-8 was used to examined the effect of C. aurantium L. on gastric cancer proliferation. Results: The GE and ITR values were dose-dependently and notably added by C. aurantium L. in normal ICR mice (with 1 g/kg C. aurantium L., ITR values: 53.3% ± 0.8% versus 64.3% ± 0.9% and 53.3% ± 0.8% versus 79.8% ± 2.0%, p < 0.01; GE values: 59.3% ± 0.8% versus 70.1% ± 1.9% and 59.9% ± 0.8% versus 69.9% ± 2.1%, p < 0.01). Compared with the normal mice, the GMD mice's ITRs were notably declined; however, C. aurantium L. could dose-dependently and significantly reverse it. In addition, in the model of delayed GE induced by loperamide and cisplatin, C. aurantium L. administration reversed the GE deficit. Furthermore, C. aurantium L. significantly reduced gastric cancer proliferation. Conclusion: The results indicate that C. aurantium L. could become a new drug for gastrointestinal prokinetic and gastric cancer therapy.

Ti3C2(OH)x-assisted LDI-TOF-MS for the rapid analysis of natural small molecules.

The inhomogeneous distribution of co-crystallized analytes and the traditional organic matrices as well as the intensive background interference in the low molecular weight range hinder the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in the analysis of small-molecular compounds. New two-dimensional material MXene (e.g., Ti3C2) exerts better hydrophilicity, homogeneity and repeatability, and higher laser desorption efficiency, as well as less background interference than traditional organic matrices and other nanomaterial matrices such as titanium oxide, graphene, and gold nanostructures. This study was aimed to design Ti3C2 matrix with abundant hydroxyls on its surface, enhance the stability of this hydroxyl-rich Ti3C2 (Ti3C2(OH)x), and evaluate the analytical performances of Ti3C2(OH)x-assisted laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF-MS) for small-molecular natural compounds in complex samples. The developed Ti3C2(OH)x showed the distinct advantages such as minimum background interference, high peak intensity (~105), high salt (0.6 M) and protein (0.5 mg/mL) tolerance, good repeatability (relative standard deviation<20%), and good stability after eight months of storage. Ti3C2(OH)x-assisted LDI-TOF-MS analysis could be used to rapidly identify Artemisia annua (a world-famous traditional Chinese medicine) and quantify the contents of the main chemical ingredients (oxymatrine (OXY) and matrine) of Compound Kushen Injection (CKI). Interestingly, the content of OXY in CKI could be accurately quantified by Ti3C2(OH)x-assisted LDI-TOF-MS, and there was a good linear relationship (R2 -0.9929), a low limit of detection (400 pg), and a low limit of quantification (600 pg) of OXY. Taken together, the rapid and accurate analysis of small-molecular natural compounds in complicated samples could be achieved by the Ti3C2(OH)x-assisted LDI-TOF-MS analysis.

CaCO3 Crystals with Unique Morphologies Controlled by the Hydrogen-Bonded Supramolecular Assemblies of Ureido-Pyrimidinone-Amino Acid Derivatives.

Biomineral materials such as nacre of shells exhibit high mechanical strength and toughness on account of their unique "brick-mortar" multilayer structure. 2-Ureido-4[1H]-pyrimidinone (UPy) derivatives with different types of end groups, due to the self-complementary quadruple hydrogen bonds and abundant Ca2+ binding sites, can easily self-assemble into supramolecular aggregates and act as templates and skeleton in the process of inducing mineral crystallization. In this work, UPy derivatives were used as templates to induce the mineralization and growth of CaCO3 through a CO2 diffusion method. The morphology of CaCO3 crystals was modulated and analyzed by adjusting the synthesizing parameters including Ca2+ concentration, pH, and end groups. The results showed that, by the regulatory role of the mineralization template, it was easier to realize the multilayer crystal structure at a lower concentration of Ca2+ (less than 0.01 mol L-1). Under alkaline regulation, the quadruple hydrogen bonds would be destroyed, and the template's regulation effect on the morphology of CaCO3 crystals would be weakened. Moreover, by comparing different types of end groups, it was proven that the UPy derivatives with carboxylic acid groups (-COOH) played a crucial role in the process of CaCO3 crystallization with unique morphologies.

Design, Synthesis, and Biological Evaluation of Pyrrole-2-carboxamide Derivatives as Mycobacterial Membrane Protein Large 3 Inhibitors for Treating Drug-Resistant Tuberculosis.

In this work, pyrrole-2-carboxamides were designed with a structure-guided strategy based on the crystal structure of MmpL3 and a pharmacophore model. The structure-activity relationship studies revealed that attaching phenyl and pyridyl groups with electron-withdrawing substituents to the pyrrole ring and attaching bulky substituents to the carboxamide greatly improved anti-TB activity. Most compounds showed potent anti-TB activity (MIC < 0.016 µg/mL) and low cytotoxicity (IC50 > 64 µg/mL). Compound 32 displayed excellent activity against drug-resistant tuberculosis, good microsomal stability, almost no inhibition of the hERG K+ channel, and good in vivo efficacy. Furthermore, the target of the pyrrole-2-carboxamides was identified by measuring their potency against M. smegmatis expressing wild-type and mutated variants of the mmpL3 gene from M. tuberculosis (mmpL3tb) and determining their effect on mycolic acid biosynthesis using a [14C] acetate metabolic labeling assay. The present study provides new MmpL3 inhibitors that are promising anti-TB agents.

Dioscin alleviates myocardial infarction injury via regulating BMP4/NOX1-mediated oxidative stress and inflammation.

BACKGROUND: Dioscin, a steroidal saponin natural product, has various pharmacological activities, such as anti-inflammatory, antioxidant, lipid-lowering. However, little is known about its effects on myocardial infarction (MI) injury. Thus, the study aimed to investigate the protective effects and possible mechanisms of dioscin. METHODS: We evaluated protective effects of Dioscin on HL-1 cells after hypoxia based on MTT and ROS in vitro. In vivo, we ligated left anterior descending (LAD) of C57BL/6 mice to establish MI model and assess serum levels of LDH, CK-MB, cTnI, SOD, MDA and CAT treated by dioscin. In addition, myocardial damages were reflected by H&E, masson and ultrastructural examination and Electrocardiograph (ECG) was detected in MI mice. And the BMP4/NOX1 pathway was measured by western blotting, immunofluorescence assay and Real-time PCR. Furthermore, to investigate cardio-protective effects of dioscin via targeting BMP4, we transfected siBMP4 into HL-1 cells in vitro and injected BMP4 siRNA though tail veins in vivo. RESULTS: In vitro, dioscin significantly increased the viability of HL-1 cells and inhibited ROS level under hypoxia. In vivo, dioscin markedly reduced the elevation of ST segment and alleviated myocardial infarct area in mice. In terms of serology, dioscin evidently decreased LDH, CK-MB, cTnI, MDA levels, and increased SOD level. In addition, dioscin improved the pathological status of myocardial tissue and restrained the production of collagen fibers. Mechanism study proved that dioscin notablely regulated the levels of Nrf2, Keap1, HO-1, p-NF-κB, nNF-κB, TNF-α, IL-1ß and IL-6 by down-regulating the protein levels of BMP4 and NOX1 against oxidative stress and inflammation. Further investigation showed that siBMP4 transfection diminished hypoxia and MI-induced oxidative and inflammation injury. The transfection decreased LDH, CK-MB and cTnI levels, improved ischemia T-wave inversion and reduced striated muscle necrosis, nucleus dissolution, collagen fibrosis and mitochondrial swelling in mice. In addition, siBMP4 decreased ROS and MDA levels, increased SOD and CAT levels and down-regulated mRNA levels of TNF-α, IL-1ß and IL-6. Moreover, BMP4, NOX1 and nNF-κB protein levels were decreased and Nrf2 levels were increased by siBMP4. CONCLUSION: Our study confirmed that dioscin showed an outstanding anti-myocardial infarction effect via regulating BMP4/NOX1-mediated oxidative stress and inflammation, which has a promising application value and development prospect against MI injury in the future.

Ferroptosis and Apoptosis Are Involved in the Formation of L-Selenomethionine-Induced Ocular Defects in Zebrafish Embryos.

Selenium is an essential trace element for humans and other vertebrates, playing an important role in antioxidant defense, neurobiology and reproduction. However, the toxicity of excessive selenium has not been thoroughly evaluated, especially for the visual system of vertebrates. In this study, fertilized zebrafish embryos were treated with 0.5 µM L-selenomethionine to investigate how excessive selenium alters zebrafish eye development. Selenium-stressed zebrafish embryos showed microphthalmia and altered expression of genes required for retinal neurogenesis. Moreover, ectopic proliferation, disrupted mitochondrial morphology, elevated ROS-induced oxidative stress, apoptosis and ferroptosis were observed in selenium-stressed embryos. Two antioxidants-reduced glutathione (GSH) and N-acetylcysteine (NAC)-and the ferroptosis inhibitor ferrostatin (Fer-1) were unable to rescue selenium-induced eye defects, but the ferroptosis and apoptosis activator cisplatin (CDDP) was able to improve microphthalmia and the expression of retina-specific genes in selenium-stressed embryos. In summary, our results reveal that ferroptosis and apoptosis might play a key role in selenium-induced defects of embryonic eye development. The findings not only provide new insights into selenium-induced cellular damage and death, but also important implications for studying the association between excessive selenium and ocular diseases in the future.

Excessive selenium affects neural development and locomotor behavior of zebrafish embryos.

Selenium is an essential micronutrient derived from daily diet to maintain the normal growth and development of vertebrates. Excessive selenium intake will induce cardiovascular toxicity, reproductive toxicity and neurotoxicity. However, there have been few studies of the toxic effects of selenium on neural development and locomotor behavior. In this study, newly fertilized zebrafish embryos were treated with selenium. As a result, selenium treatment at the concentration of 0.5 µM decreased the moving speed and distance and blunted the touch response of zebrafish embryos. TUNEL assay and immunofluorescence analysis revealed that selenium induced nervous system impairment including promoted cell apoptosis, proliferation and neuroinflammation, and decreased neurons in zebrafish embryos. RNA-seq and RT-PCR results indicated that selenium treatment significantly decreased the expression of the dopaminergic neuron, motor neuron, GABAergic neuron and neurotransmitter transport marker genes in zebrafish embryos. The expression of PPAR signaling pathway marker genes was significantly down-regulated in selenium-treated embryos. Two PPAR agonists (rosiglitazone and bezafibrate) and an anti-cancer drug (cisplatin) were tested for their effects to alleviate selenium-induced locomotor defects. Rosiglitazone and bezafibrate could restore the expression of some neural marker genes but could not fully rescue the selenium-induced locomotor behavior defects. The supplementation of cisplatin could restore the dysfunctional locomotor behavior and the abnormal expression of the PPAR and neural marker genes to almost the normal levels. In conclusion, the results of this study reveal that selenium-induced neural development and locomotor behavior defects are caused by multiple complex factors including PPAR signaling, and all the factors might be recovered by cisplatin through unknown mechanisms.

Cyclocarya paliurus triterpenoids suppress hepatic gluconeogenesis via AMPK-mediated cAMP/PKA/CREB pathway.

BACKGROUND: Abnormal enhancement of hepatic gluconeogenesis is a vital mechanism of the pathogenesis of Type 2 diabetes mellitus (T2DM); thus, its suppression may present an efficient therapeutic strategy for T2DM. Cyclocarya paliurus (CP), a plant species native to China, has been reported to have anti-hyperglycemia activity. Our previous studies have revealed that Cyclocarya paliurus triterpenic acids (CPT) exert the favorable glucose-lowering activity, but the regulatory effect of CPT on hepatic gluconeogenesis is still unclarified. PURPOSE: This study aimed to investigate the potential role and mechanism of CPT in gluconeogenesis. STUDY DESIGN: In this study, the ameliorative effect and underlying mechanism of CPT on gluconeogenesis were investigated: high-fat diet and streptozotocin-induced T2DM mice and glucagon-challenged mouse primary hepatocytes. METHODS: T2DM model mice with or without oral administration of CPT for 4 weeks were monitored for body weight, glucose and lipid metabolism. Hematoxylin and eosin staining was used to observe liver lipid deposition. Real-time PCR assays were performed to examine the mRNA expression of glucose-6-phosphate (G6Pase), and phosphoenolpyruvate carboxykinase (PEPCK), two key enzymes involved in liver gluconeogenesis. Western blotting was used to determine AMP-dependent protein kinase (AMPK) expression and induction of the glucagon signaling pathway. The possible mechanism of CPT on liver gluconeogenesis was further explored in glucagon-induced mouse primary hepatocytes. RESULTS: In vivo and in vitro experiments revealed that CPT treatment significantly reduced fasting blood glucose, total cholesterol and triglyceride levels, and improved insulin resistance. Furthermore, CPT could obviously decreased the mRNA and protein expression of G6Pase and PEPCK, the cyclic AMP content, the phosphorylation level of protein kinase A and cyclic AMP response element-binding protein. But CPT promoted the phosphorylation of AMP-dependent protein kinase (AMPK) and activation of phosphodiesterase 4B. Mechanistically, intervention with Compound C (an AMPK inhibitor) partially blocked the suppressive effect of CPT on hepatic gluconeogenesis. CONCLUSION: These findings suggested that CPT may inhibit hepatic gluconeogenesis against T2DM by activating AMPK.

Salidroside protects against osteoporosis in ovariectomized rats by inhibiting oxidative stress and promoting osteogenesis via Nrf2 activation.

BACKGROUND: Osteoporosis (OP) is characterized as low bone mass, bone microarchitecture breakdown and bone fragility. The increase of oxidative stress could lead to breakdown in the balance of bone formation and resorption which gives rise to OP. Nrf2 is a transcription factor which takes part in oxidative stress and recently was reported that it can regulate the occurrence of OP. Salidroside (SAL) with the efficacies of anti-oxidation, anti-aging and bone-protection is one of the active ingredients in Ligustri Lucidi Fructus, a traditional Chinese medicinal herb. Nevertheless, few studies have explored the potential mechanism of SAL preventing OP development from the perspective of oxidative stress intervention. PURPOSE: This study aimed to investigate the pharmacological effect and molecular mechanisms of SAL on OP. STUDY DESIGNS AND METHODS: A tert-butyl hydroperoxide (t-BHP)-induced oxidative stress model was applied for investigating the effects of SAL in vitro, and an ovariectomized (OVX) model was used for in vivo study on the effect of SAL for OP. Related pharmacodynamic actions and molecular mechanisms of SAL were explored in both rat osteoblasts (ROBs) and OVX rats. Network biology and cell metabolomics were performed for further investigating the correlation and association among potential biomarkers, targets and pathways. RESULTS: SAL reduced levels of ROS and lipid peroxidation (LPO), increased activities of antioxidant enzymes like GPx and SOD, and enhanced osteogenic differentiation in t-BHP-induced ROBs and OVX rats. Mechanistic studies showed SAL prevented OP development and reduced oxidative damage in ROBs and OVX rats through up-regulating Nrf2 expression and facilitating its nuclear translocation. The joint analysis of network biology and cell metabolomics revealed that galactose metabolism and fatty acid metabolism could be the major influenced pathways following treatment with SAL. CONCLUSION: SAL could protect against OP by inhibiting oxidative stress, promoting osteogenesis through the up-regulation of Nrf2 and intervening galactose metabolism and fatty acid metabolism. Our study implied that SAL may be a potential drug to treat OP.