Activation of TAS2R4 signaling attenuates podocyte injury induced by high glucose.

Bitter taste receptors (TAS2Rs) Tas2r108 gene possesses a high abundance in mouse kidney; however, the biological functions of Tas2r108 encoded receptor TAS2Rs member 4 (TAS2R4) are still unknown. In the present study, we found that mouse TAS2R4 (mTAS2R4) signaling was inactivated in chronic high glucose-stimulated mouse podocyte cell line MPC, evidenced by the decreased protein expressions of mTAS2R4 and phospholipase C ß2 (PLCß2), a key downstream molecule of mTAS2R4 signaling. Nonetheless, agonism of mTAS2R4 by quinine recovered mTAS2R4 and PLCß2 levels, and increased podocyte cell viability as well as protein expressions of ZO-1 and nephrin, biomarkers of podocyte slit diaphragm, in high glucose-cultured MPC cells. However, blockage of mTAS2R4 signaling with mTAS2R4 blockers γ-aminobutyric acid and abscisic acid, a Gßγ inhibitor Gallein, or a PLCß2 inhibitor U73122 all abolished the effects of quinine on NLRP3 inflammasome and p-NF-κB p65 as well as the functional podocyte proteins in MPC cells in a high glucose condition. Furthermore, knockdown of mTAS2R4 with lentivirus-carrying Tas2r108 shRNA also ablated the effect of quinine on the key molecules of the above inflammatory signalings and podocyte functions in high glucose-cultured MPC cells. In summary, we demonstrated that activation of TAS2R4 signaling alleviated the podocyte injury caused by chronic high glucose, and inhibition of NF-κB p65 and NLRP3 inflammasome mediated the protective effects of TAS2R4 activation on podocytes. Moreover, activation of TAS2R4 signaling could be an important strategy for prevention and treatment of diabetic kidney disease.

Enhanced granulation of activated sludge in an airlift reactor for organic carbon removal and ammonia retention from industrial fermentation wastewater: A comparative study.

Ammonia retention and recovery from high-nitrogenous wastewater are new concepts being used for nitrogen management. A microaerophilic activated sludge system was developed to convert organic nitrogen into ammonia and retain it for its recovery; however, the settleability of activated sludge remains a challenge. Therefore, this study proposed an aerobic granular sludge system as a potential solution. Two types of sequencing batch reactors-airlift and upflow reactors-were operated to investigate the feasibility of fast granule formation, the performance of organic carbon removal and ammonia retention, and the dynamics of microbial community composition. The operation fed with industrial fermentation wastewater demonstrated that the airlift reactor ensured a more rapid granule formation than the upflow reactor because of the high shear force, and it maintained a superior ammonia retention stability of approximately 85 %. Throughout the operational period, changes in hydraulic retention time (HRT), settling time, and exchange ratio altered the granular particle sizes and microbial community compositions. Rhodocyclaceae were replaced with Comamonadaceae, Methylophilaceae, Xanthomonadaceae, and Chitinophagaceae as core taxa instrumental in granulation, likely because of their extracellular polymeric substance secretion. As the granulation process progressed, a significant decrease in the relative abundances of nitrifying bacteria-Nitrospiraceae and Nitrosomonadaceae-was observed. The reduction of settling time and HRT enhanced granulation and inhibited the activity of nitrifying bacteria. The success in granulation for ammonia conversion and retention in this study accelerates the paradigm shift from ammonia removal to ammonia recovery from industrial fermentation wastewater.

Complete pathway elucidation and heterologous reconstitution of (+)-nootkatone biosynthesis from Alpinia oxyphylla.

(+)-Nootkatone is a natural sesquiterpene ketone widely used in food, cosmetics, pharmaceuticals, and agriculture. It is also regarded as one of the most valuable terpenes used commercially. However, plants contain trace amounts of (+)-nootkatone, and extraction from plants is insufficient to meet market demand. Alpinia oxyphylla is a well-known medicinal plant in China, and (+)-nootkatone is one of the main components within the fruits. By transcriptome mining and functional screening using a precursor-providing yeast chassis, the complete (+)-nootkatone biosynthetic pathway in Alpinia oxyphylla was identified. A (+)-valencene synthase (AoVS) was identified as a novel monocot-derived valencene synthase; three (+)-valencene oxidases AoCYP6 (CYP71BB2), AoCYP9 (CYP71CX8), and AoCYP18 (CYP701A170) were identified by constructing a valencene-providing yeast strain. With further characterisation of a cytochrome P450 reductase (AoCPR1) and three dehydrogenases (AoSDR1/2/3), we successfully reconstructed the (+)-nootkatone biosynthetic pathway in Saccharomyces cerevisiae, representing a basis for its biotechnological production. Identifying the biosynthetic pathway of (+)-nootkatone in A. oxyphylla unravelled the molecular mechanism underlying its formation in planta and also supported the bioengineering production of (+)-nootkatone. The highly efficient yeast chassis screening method could be used to elucidate the complete biosynthetic pathway of other valuable plant natural products in future.

Systematic Mining and Evaluation of the Sesquiterpene Skeletons as High Energy Aviation Fuel Molecules.

Sesquiterpenes have been identified as promising ingredients for aviation fuels due to their high energy density and combustion heat properties. Despite the characterization of numerous sesquiterpene structures, studies testing their performance properties and feasibility as fuels are scarce. In this study, 122 sesquiterpenoid skeleton compounds, obtained from existing literature reports, are tested using group contribution and gaussian quantum chemistry methods to assess their potential as high-energy aviation fuels. Seventeen sesquiterpene compounds exhibit good predictive performance and nine compounds are further selected for overproduction in yeast. Through fed-batch fermentation, all compounds achieve the highest reported titers to date. Subsequently, three representative products, pentalenene, presilphiperfol-1-ene, and α-farnesene, are selected, produced, purified in large quantities, and tested for use as potential fuels. The performance of pentalenene, presilphiperfol-1-ene, and their derivatives reveals favorable prospects as high-energy aviation fuels.

Swietenine inhibited oxidative stress through AKT/Nrf2/HO-1 signal pathways and the liver-protective effect in T2DM mice: In vivo and in vitro study.

Swietenia macrophylla King, belongs to the Meliaceae family, is a valuable medicinal plant and its fruits have been processed commercially to a variety of health foods. The seeds have long been known for their ethnomedicinal significance against these diseases. Swietenine (Swi) was isolated from S. macrophylla and could ameliorate inflammation and oxidative stress. In this study, HepG2 cells induced by H2 O2 were used to construct oxidative stress model in vitro. The aim of this study was to investigate the protective effect of Swi on H2 O2 induced oxidative injury in HepG2 cells and its molecular mechanism, and to explore the effect of Swi on liver injury in db/db mice and its possible mechanism. The results showed that Swi significantly inhibited HepG2 cells viability and reduced oxidative damage in a dose-dependent manner as evidenced by a range of biochemical analysis and immunoblotting study. Moreover, it induced the protein and mRNA expression of HO-1 together with its upstream mediator Nrf2 and activated the phosphorylation of AKT in HepG2 cells. LY294002, a PI3K/AKT inhibitor, significantly suppressed the Nrf2 nuclear translocation and HO-1 expression in H2 O2 induced HepG2 cells treated with Swi. In addition, RNA interference with Nrf2 significantly reduced the expression level of Nrf2 and HO-1 in the nucleus. Swi has a significant protective effect on cell damage in H2 O2 induced HepG2 cells by increasing the antioxidant capacity which is achieved through the AKT/Nrf2/HO-1 pathway. Additionally, in vivo, Swi could protect the liver of type 2 diabetic mice by improving lipid deposition in liver tissue and inhibiting oxidative stress. These findings indicated that Swi can be a promising dietary agent to improve type 2 diabetes.

Swietenine and swietenolide from Swietenia macrophylla king improve insulin secretion and attenuate apoptosis in H2 O2 induced INS-1 cells.

Oxidative stress is an important factor that causes pancreatic ß-cell dysfunction leading to the development and aggravation of diabetes. Swietenine (Stn) and swietenolide (Std) were isolated from the fruits of Swietenia macrophylla King and had the potential effects on treatment and prevention of diabetes. The aim of this study is to investigate the effects of Stn and Std on insulin secretion and apoptosis in H2 O2 induced insulinoma cell line (INS-1) cells. In the present study, INS-1 cells were treated with 300 µM H2 O2 for 4 h to establish the oxidative damage model. Cell apoptosis, insulin secretion, reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels, and Caspase-3 enzyme activity were measured via corresponding methods. Finally, pancreatic duodenal home box factor-1 (PDX-1), B cell lymphoma-2 (Bcl-2), and Bax protein expression were detected by western blot. Experimental results showed that Stn and Std could significantly improve the INS-1 cell viability, increase the secretion of insulin and reduce the ROS level in H2 O2 induced INS-1 cells. Furthermore, the SOD and GSH levels increased, and the MDA levels decreased compared with the model group after Stn and Std treatment. In addition, after treated with Stn and Std, cell apoptosis was improved, and the activity of Caspase 3 was also significantly inhibited. Meanwhile, Western blot results showed that Stn and Std could up-regulate the expression of PDX-1 protein, and affect the cell apoptosis pathway by up-regulating the expression of Bcl-2 protein and down-regulating the expression of Bax protein. In conclusion, Stn and Std can signifcantly improve the insulin secretion function, protect oxidative stress injury, and reduce apoptosis in H2 O2 induced INS-1 cells, which provides a research basis for Stn and Std to be new drug candidates for the treatment and prevention of diabetes.

Natural swietenine attenuates diabetic nephropathy by regulating the NF-κB/NLRP3/Caspase-1 signaling pathways: In vivo and in vitro study.

Swietenine (Swi), isolated from Swietenia macrophylla King ameliorates inflammation and oxidative stress, and diabetic nephropathy has a close connection with them. So the effects of Swi on diabetic nephropathy and its mechanism of action was explored. We divided human mesangial cells into five groups and determined the expression of NF-κB and NLRP3 inflammasomes in each group. The levels of inflammatory factors IL-1ß and IL-18 were also measured. To explore the relationship between NF-κB and NLRP3, we added PDTC, a specific NF-κB inhibitor, and LPS, and divided the experimental groups into seven groups. We measured the expressions of NF-κB and NLRP3, and then added MCC950, a specific inhibitor of NLRP3 and LPS, the expression of NLRP3, Caspase-1, and IL-1ß and IL-18 were measured. Animals divided into four groups and administered over 8 weeks. Protein excretion, creatinine, urea nitrogen, and uric acid were measured. Swi down regulated the expression of NF-κB, NLRP3, and Caspase-1. It reduced the levels of IL-1ß and IL-18. PDTC decreased the expression of NF-κB and NLRP3. Compared with the HG + PDTC group, the expression of NF-κB and NLRP3 in the HG + Swi + PDTC group decreased significantly. After adding lipopolysaccharide, the expression of NF-κB and NLRP3 increased, but this situation was reversed after adding Swi. After adding LPS, the expression of NLRP3 and Caspase-1 increased, and the levels of IL-1ß and IL-18 also increased, but this situation was reversed after the addition of Swi. Swi significantly improved the renal function of mice with diabetic nephropathy and inhibited the activation of NF-κB and the NLRP3 inflammasome and reduced inflammation by regulating the NF-κB/NLRP3/Caspase-1 signaling pathway, thereby improving diabetic nephropathy.

High-Intensity Focused Ultrasound Enhanced Anti-Tumor Activities of Paclitaxel in Breast Cancer in vitro and in vivo.

Background: Paclitaxel (PTX) is an important oncologic chemotherapeutic agent against breast cancer, but breast cancer patients develop significant resistance to PTX during chemotherapy. Alterations in tubulin and associated proteins have been implicated in resistance to PTX. High-intensity focused ultrasound (HIFU) induces deep tumor penetration of anti-tumor agents in solid tumors. Methods: We investigated the influence of HIFU on the anti-tumor activities of PTX in breast cancer. Both in vivo and in vitro experiments were performed in this research: mice were treated with 2 mg/Kg PTX through tail vein injection, while breast cancer cells were treated with 400 nM PTX. Cell viability was analyzed through Cell Counting Kit-8. Cell apoptosis was evaluated through Annexin-V/PI Apoptosis Analysis Kit. The activities of catalase (CAT) and superoxide dismutase (SOD) and the concentration of malondialdehyde (MDA) were evaluated by relative commercial kits. Results: HIFU enhanced PTX-inhibited breast cancer cell viability and PTX-induced cell apoptosis. Simultaneous treatment of HIFU and PTX decreased the activities of CAT and SOD and increased the concentration of MDA. In mice bearing MDA-MB-231 tumors, the treatment of HIFU and PTX significantly decreased tumor size, increased body weight and elevated animal survival. HIFU enhanced the distribution of PTX in tumor tissues. Conclusion: The performance of HIFU promoted the distribution of PTX and enhanced its anti-tumor activities in breast cancer.

Flavonoids from Hypericum patulum enhance glucose consumption and attenuate lipid accumulation in HepG2 cells.

Hypericum patulum has been used as a folk medicine for its varied therapeutic effects including antifungal, wound-healing, spasmolytic, stimulant, hypotensive activities. The water decoction is drank as tea could treat cold, infantile malnutrition. The present study aims to isolate the constituents of the plant and investigate their effects on the glucose consumption in insulin-resistant HepG2 cells, furthermore, lipid metabolism in oleic acid (OA)-treated HepG2 cells was also studied. The phytochemical investigation of the plant led to the isolation of eleven compounds, and their structures were identified by spectroscopic analysis as n-dotriacontanol (1), shikimic acid (2), 1-O-caffeoylquinic acid methyl ester (3), 5-O-caffeoylquinic acid methyl ester (4), 5-O-coumaroylquinic acid methyl ester (5), 5-O-caffeoylquinic acid butyl ester (6), quercetin-3-O-α-L-rhamnoside (7), quercetin (8), quercetin-3-O-(4×´-methoxy)-α-L-rahmnopyranosyl (9), hyperoside (10), and rutin (11). The results revealed that compounds 7, 9, and 10 could enhance glucose consumption significantly in hyperglycemia induced HepG2 cells and insulin-resistant HepG2 cells. In addition, the western blotting analysis result exhibited that compounds 7, 9, and 10 in high concentration (5 µM, H) group could dramatically upregulate the expression of PPARγ protein, and even the effect of them had no significant difference compared with that of rosiglitazone. Furthermore, compounds 9 and 10 in middle concentration (2.5 µM, M) group and H group could dramatically promote triglyceride metabolism and decrease TG content in OA-treated HepG2 cells, and even in H group, reactive oxygen species (ROS) level were significantly decreased compared with model group. PRACTICAL APPLICATIONS: Hypericum patulum is a well-known plant of the genera Hypericum for its varied preventive and therapeutic potential activities. To study the chemical constituents and their effects on glucose and lipid metabolism in vitro, we detected glucose consumption in insulin-resistant HepG2 cells, triglyceride content and reactive oxygen species level in OA-treated HepG2 cells. In addition, PPARγ protein was also detected by western blotting analysis in the study. Compounds 1, 2, 3, 5, 6, 9, 10, and 11 were isolated from the plant for the first time. Quercetin-3-O-(4"-methoxy)-α-L-rahmnopyranosyl (9) and hyperoside (10) had potential therapeutic benefit against glucose and lipid metabolic disease. Therefore, this study might have certain guiding significance for further research and development of H. patulum.

Limonoids isolated from fruits of Swietenia macrophylla king enhance glucose consumption in insulin-resistant HepG2 cells via activating PPARγ.

The fruits of Swietenia macrophylla King have been processed commercially to a variety of health foods and healthcare products and exhibited antidiabetic, anti-inflammatory, antimutagenicity, antitumor activity, and so on. This study was aimed to examine the glucose consumption in human hepatoma HepG2 cells and the expression of PPARγ of limonoids isolated from the fruits of S. macrophylla. The phytochemical investigation of the fruits led to the isolation of ten limonoids which structures were elucidated by spectroscopic analysis as swietenine (1), khayasin T (2), 6-deoxyswietenine (3), 3-O-tigloylswietenolide (4), swietenolide (5), 3,6-O,O-diacetylswietenolide (6), 7-deacetoxy-7-oxogedunin (7), fissinolide (8), proceranolide (9), 7-deacetoxy-7α-hydroxygedunin (10), and compound 10 was isolated from this plant for the first time. The glucose consumption assay revealed that compounds 1, 2, 3, 5, and 9 could promote glucose consumption significantly in normal hyperglycemia-induced HepG2 cells, furthermore, compounds 1, 5, and 9 had a better effect on promoting glucose consumption in insulin-resistant HepG2 cells. In addition, compounds 1 and 5 could dramatically enhance the expression of PPARγ protein in insulin-resistant HepG2 cells according to the western blotting analysis result. PRACTICAL APPLICATIONS: Swietenia macrophylla King belongs to the family Meliaceae and the fruits have been exhibited a wide range of biological activities, such as antidiabetic, anti-inflammatory, antimutagenicity, antitumor activity, and so on. Phytochemical investigations of S. macrophylla have revealed that limonoids and triterpenoids were effective antidiabetic agents. However, the mechanism of these limonoids to antidiabetic activity is unclear. In this study, limonoids were isolated from the fruit of S. macrophylla and their effects on the glucose consumption of insulin-resistant HepG2 cells were studied. The results showed that compounds 1 and 5 could dramatically enhance the expression of PPARγ protein in insulin-resistant HepG2 cells, which will give aid to explore the mechanism of these limonoids in the treatment of type 2 diabetes. Therefore, this research might facilitate further research and development of S. macrophylla.

Remote Capacitive Sensing in Two-Dimensional Quantum-Dot Arrays.

We investigate gate-induced quantum dots in silicon nanowire field-effect transistors fabricated using a foundry-compatible fully depleted silicon-on-insulator (FD-SOI) process. A series of split gates wrapped over the silicon nanowire naturally produces a 2 × n bilinear array of quantum dots along a single nanowire. We begin by studying the capacitive coupling of quantum dots within such a 2 × 2 array and then show how such couplings can be extended across two parallel silicon nanowires coupled together by shared, electrically isolated, "floating" electrodes. With one quantum dot operating as a single-electron-box sensor, the floating gate serves to enhance the charge sensitivity range, enabling it to detect charge state transitions in a separate silicon nanowire. By comparing measurements from multiple devices, we illustrate the impact of the floating gate by quantifying both the charge sensitivity decay as a function of dot-sensor separation and configuration within the dual-nanowire structure.

Sikokianin A from Wikstroemia indica protects PC12 cells against OGD/R-induced injury via inhibiting oxidative stress and activating Nrf2.

Ischemic cerebral stroke is a severe cause of human death and disability. Natural products play an important role in the discovery of novel therapy for cerebral ischemia. Herein, we investigate the neuroprotective effects of sikokianin A identifiedfrom Wikstroemia indica using PC12 cell exposed to OGD/R. The results revealed sikokianin A can improve the poor viability and release of intracellular LDH in PC12 cells induced by OGD/R. Further studies have demonstrated the increased ROS and MDA together with reduced SOD activity were attenuated by sikokianin A. Meanwhile, decreased mitochondrial membrane potential, activated Caspase-3, down-regulated Bcl-2 and up-regulated Bax were reversed. These results indicate the protective effects of sikokianin A are associated with inhibiting oxidative stress and apoptosis resulting from OGD/R. Additionally, sikokianin A can activate Nrf2 and downstream HO-1 in PC12 cells treated by OGD/R, which implied Nrf2/HO-1 signaling pathway was involved in the protective effects of sikokianin A.

Thevetiaflavone from Wikstroemia indica ameliorates PC12 cells injury induced by OGD/R via improving ROS­mediated mitochondrial dysfunction.

Cerebral ischemia and following reperfusion affects many people worldwide. To discover efficient therapeutic approaches, numerous natural products have been investigated. The current study investigated the protective effects of thevetiaflavone, a natural flavonoid obtained from Wikstroemia indica, and the associated mechanisms using PC12 cells induced by oxygen and glucose deprivation. As a result, thevetiaflavone improves cell viability and suppresses the leakage of lactate dehydrogenase from the cytoplasm. Further investigation of the mechanisms demonstrated that thevetiaflavone decreases overproduction of ROS and ameliorates ROS­mediated mitochondrial dysfunction, including collapse of mitochondrial membrane potential and mitochondrial permeability transition pore opening. Thevetiaflavone reduces the intracellular Ca2+ level, which is closely associated with mitochondrial function and interplays with ROS. Furthermore, thevetiaflavone inhibits apoptosis in PC12 cells through upregulating the expression of Bcl­2 and downregulating that of Bax and caspase­3 in addition to increasing the activity of caspase­3. These results further indicate the protective effects of thevetiaflavone in vivo and its application in the clinic.

Insight into the binding interaction of kaempferol-7-O-α-L-rhamnopyranoside with human serum albumin by multiple fluorescence spectroscopy and molecular modeling.

Human serum albumin (HSA) is a transporting protein that has multiple functions. The binding interaction between HSA and small molecules affects its function and efficacy of small molecules. The present study reports that kaempferol-7-O-α-L-rhamnopyranoside (KR) interacts with HSA as indicated by multiple fluorescence spectroscopy and molecular modeling. KR can quench the intrinsic fluorescence of HSA through the formation of a KR-HSA complex in a static manner. In addition, the binding site is located in subdomain IIA as confirmed by competitive experiments using site-specific warfarin and ibuprofen, and the driving forces include hydrogen bonds, van der Waals forces and electrostatic interaction derived from a thermodynamic analysis. The formation of KR-HSA is exothermic and spontaneous. Although there is no hydrophobic interaction around Tyr and Trp residues, the secondary structure of HSA changes through the formation of the KR-HSA complex. In addition, docking results visualized and further supported these results. Finally, these results can provide more information to further investigate the use of KR on the prevention of diabetic complications.

Probing the binding interaction of AKR with human serum albumin by multiple fluorescence spectroscopy and molecular modeling.

Human serum albumin (HSA) is the major transport protein affording endogenous and exogenous substances in plasma. It can affect the behavior and efficacy of chemicals in vivo through the binding interaction. AKR (3-O-α-l-arabinofuranosyl-kaempferol-7-O-α-l-rhamnopyranoside) is a flavonoid diglycoside with modulation of estrogen receptors (ERs). Herein, we investigated the binding interaction between AKR and HSA by multiple fluorescence spectroscopy and molecular modeling. As a result, AKR specifically binds in site I of HSA through hydrogen bonds, van der Waals force, and electrostatic interaction. The formation of AKR-HSA complex in binding process is spontaneously exothermic and leads to the static fluorescence quenching through affecting the microenvironment around the fluorophores. The complex also affects the backbone of HSA and makes AKR access to fluorophores. Molecular modeling gives the visualization of the interaction between AKR and HSA as well as ERs. The affinity of AKR with HSA is higher than the competitive site marker Warfarin. In addition, docking studies reveal the binding interaction of AKR with ERs through hydrogen bonds, van der Waals force, hydrophobic, and electrostatic interactions. And AKR is more favorable to ERß. These results unravel the binding interaction of AKR with HSA and mechanism as an ERs modulator.

[Analysis of Volatile Components of Polypodium hastatum by GC-MS].

OBJECTIVE: To further reveal the chemical constituents of Polypodium hastatum, volatile components from this plant were investigated. METHODS: The volatile components were extracted under reflux from the whole plant of Polypodium hastatum, and then analyzed qualitatively and quantitatively by GC-MS. RESULTS: 60 volatile components were detected and of all components detected, the structures and relative contents of 34 volatile compounds were elucidated. CONCLUSION: In the volatile components identified, most are fatty acid esters, especially methyl and ethyl esters, which compose the major volatile chemical constituents of Polypodium hastatum.

[Studies on the chemical constituents from the roots of Kalopanax septemlobus].

OBJECTIVE: To investigate the chemical constituents of Kalopanax septemlobus. METHODS: Chromatographic techniques including silica gel, gel, semi-preparative HPLC and PTLC as well as recrystallization were employed in the isolation and purification, and the structures were elucidated by spectral analysis and physical and chemical properties. RESULTS: 6 compounds were identified as liriodendrin (1), (-) -syringarenol (2), trans-coniferyl aldehyde (3), trans-caffeic acid (4), beta-daucosterol (5), beta-sitosterol (6). CONCLUSION: Compounds 2 -5 are obtained from this genus for the first time.