Effect of High-fat Diet on Cholesterol Metabolism in Rats and Its Association with Na^+/K^+-ATPase/Src/pERK Signaling Pathway

Summary： Abnormal cholesterol metabolism is associated with an elevated risk of developing athero- sclerosis, hypertension, and diabetes etc. Na＋/K＋-ATPase was found to regulate cholesterol synthesis, distribution and trafficking. This study aimed to examine the effect of high-fat diet on cholesterol me- tabolism in rats and the role of Na＋/K＋-ATPase/Src/ERK signaling pathway in the process. Forty male SD rats were evenly divided into high-fat diet group and control group at random. Animals in the former group were fed on high-fat diet for 12 weeks, and those fed on basic diet served as control. Blood lipids, including total cholesterol （TC）, triglyceride （TG）, high density lipoprotein-cholesterol （HDL-C）, and low density lipoprotein-cholesteral （LDL-C） levels, were detected at 3, 6 and 12 weeks. The ratio of cholesterol content in cytoplasm to that in cell membrane was detected in liver tissues. RT-PCR and Western blotting were used to measure the expression of lipid metabolism-associated genes （HMG-CoA reductase and SREBP-2） after 12-week high-fat diet. Na＋/K＋-ATPase/Src/ERK signaling path- way-related components （Na＋/K＋-ATPase ctl, Src-PY418 and pERK1/2） were also measured by West- ern blotting. The results showed that the serum TC, TG, and LDL-C levels were significantly higher in high-fat diet group than those in control group, while the HDL-C level was significantly lower in high-fat diet group at 6 weeks （P〈0.01）. High-fat diet led to an increase in the cholesterol content in the cytoplasm and cell membrane. The ratio of cholesterol content in cytoplasm to that in cell membrane was elevated over time. The expression of HMG-CoA reductase and SREBP-2 was significantly sup- pressed at mRNA and protein levels after 12-week high-fat diet （P〈0.05）. Moreover, high-fat diet pro- moted the expression of Na＋/K＋-ATPase α1 but suppressed the phosphorylation of Src-PY418 and ERK1/2 at 12 weeks （P〈0.05）. It was concluded that high-fat diet regulates cholesterol metabolism, and Na＋/K＋-ATPase signaling pathway is involved in the process possibly by regulating the expression of lipid metabolism-associated proteins HMG-CoA reductase and SREBP-2.

Synthesis, Structure and H＋/K＋-ATPase Inhibitory Activity of Novel Triazolyl Substituted Tetrahydrobenzofuran Derivatives via One-pot Three-component Click Reaction

Eleven triazolyl substituted tetrahydrobenzofuran derivatives were synthesized in high yields as novel H＋/K＋- ATPase inhibitor via one-pot Cul-catalyzed three-component click reaction of azide, secondary amine and 3-bromopropyne under mild conditions in water. Their structures were characterized by NMR, IR, ESI-MS, ele- mental analysis and single-crystal X-ray diffraction analysis. Most of the target compounds exhibited better H＋/K＋- ATPase inhibitory activity than commercial omeprazole with IC50 values less than 15 gmol＇L-~. The initial struc- ture-activity analysis suggested that the triazole substituted by cycloalkyl, aromatic ring or O-containing side-chain seemed to be beneficial for enhancing the activity.

Synthesis, Structure Elucidation and H＋/K＋-ATPase Inhibitory Activity of Bisabolangelone Reduction Derivatives

Nine bisabolangelone reduction derivatives were synthesized and separated as potential anti-ulcer agent. Their structures were characterized by 2D NMR, IR, ESI-MS, elemental analysis and single-crystal X-ray diffraction analysis. Preliminarily H＋/K＋-ATPase activity evaluation indicated that all the target compounds had a certain inhibitory effect, and compounds Ⅱ and IV exhibited the better inhibitory activity against H＋/K＋-ATPase than bisabolangelone and the commercial omeprazole with the IC50 of 23.21 and 65.32 pmol/L, respectively. The initial structure-activity analysis suggested that the presence of carbonyl group in six-membered ring and double bond in side-chain seemed to be necessary to the activity.

Novel Cinobufagin Oxime Ether Derivatives as Potential Na＋/K＋-ATPase Inhibitors： Synthesis, Biological Screening and Molecular Docking

Some cinobufagin oxime ether derivatives as potential Na＋/K＋-ATPase inkibitors were synthesized by following the side chain of istaroxime. These compounds inhibit Na＋/K＋-ATPase in a dose-dependent manner. Compound 3c with an oxyethylamine side chain that is the same as that of istaroxime showed the most potent inhibi- tion, which was stronger than compound 3a with only hydroxyoxime moiety at C3 and compound 3b with a methy-lated hydroxyoxime moiety. Molecular docking was used to explore the binding modes of the target compounds with Na＋/K＋-ATPase, which suggested that the longer ethyl amine group at C3 oxime moiety of compound 3c could make stronger interaction with Na＋/K＋-ATPase via intermolecular charge-charge and H-bond interaction as compared with other derivatives.

Inhibition of Na^+,K^+-ATPase in Housefly (Musca domestica L.) by Terpinen-4-ol and Its Ester Derivatives

To reveal the insecticidal mechanism of terpinen-4-ol, the activity of Na＋,K＋-ATPase in insects tested were determined in vivo and in vitro. The results showed that terpinen-4-ol and its ester derivatives had strong contact activity to housefly and the contact toxicities of its derivatives except Z3 were all superior or equivalent to terpinen-4-ol. All the 7 compounds had strong inhibition towards activity of Na＋,K＋-ATPase. With poisoning symptom exacerbating, the inhibition rates were gradually increased. In vitro, the IC50 of terpinen-4-ol, Z1, Z2, Z4, Z5, and Z6 was 155.89, 197.98, 96.02, 121.36, 124.85, and 153.74 μg mL% respectively. There was well correlation between the LDs0 of terpinen-4-ol derivatives to housefly and the IC50 of terpinen-4-ol derivatives to Na＋,K＋-ATPase in housefly. In conclusion, Na＋,K＋-ATPase was likely the target of terpinen-4-ol against insects.

Synthesis, Crystal Structure and Na^+/K^+-ATPase Inhibitory Activity of △^(14,15)-anhydro-24-thiocarbonylbufalin

The title compound △14,15-anhydro-24-thiocarbonylbufalin （1） was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H3002S＇C24H3002S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845（2）, b = 6.8036（3）, c = 22.5791（15）/k, V= 4241.7（4） A3, Mr = 384.21, Z = 4, Dc= 1.204 g/cm3,μ = 1.463 mm4, F（000） = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed （I 〉 2σ（/））. The asymmetric unit contains two independent molecules （ⅠandⅡ）, which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and II are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02（3）, permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na＋/K＋-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group atC-14 play important roles for the inhibition of Na＋/K＊-ATPase.

Isolation, Crystal Structure and Na^＋/K^＋-ATPase Inhibitory Activity of 1β-Hydroxydigitoxigenin

The title compound 1β-hydroxydigitoxigenin（1） was isolated from the ethanol extract of the roots of Streptocaulon juventas. The crystal structure of 1, C23H34O5·H2O, was determined by Synchrotron X-ray diffraction analysis due to small crystal size（0.14 mm × 0.04 mm × 0.01 mm）. The crystal belongs to monoclinic, space group P21, with a = 7.6624（15）, b= 13.460（3）, c = 10.370（2） A, b = 92.40（3）°, V = 1068.6（4）A^3, Z = 2, Mr = 406.50, Dx = 1.263 g/cm^3, λ（synchrotron） = 1.2399 A, μ（synchrotron 1.23990） = 0.333 cm^-1, F（000） = 550, S = 1.059, R = 0.0625 and wR = 0.1687 for 4247 unique reflections, of which 3687 were observed（I 〉 2σ（I））. The asymmetric unit contains one independent molecule of 1 and one water molecule which are connected through hydrogen bonds. The conformation of 1 in crystalline state is in good agreement with the solution structure in methanol as indicated by ^1H-NMR analysis. The absolute configuration of 1 could be assigned by referring to the known configuration of the lactone ring at C（17b）. In the solid state, intermolecular hydrogen bonds involving carbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed significant inhibition on Na^＋/K^＋-ATPase with an IC50 of 2.46 mM, which is stronger thiocarbonylbufalin but weaker than a close analog digitoxigenin, suggesting that a lactone ring is important and the substitution of a hydroxyl group at C（1） is not favored for the inhibition of Na^＋/K^＋-ATPase.

Synthesis and Crystal Structure of (E)-2-phenyl-6,7dihydrobenzofuran-4(5H)-one O-cyanomethyl Oxime

A pair of E/Z-isomers of 2-phenyl-6,7-dihydrobenzofuran-4（5H）-one O-cyanomethyl oxime,C16H14N2O2,as potential drugs for treating peptic ulcer and other acid-related diseases have been synthesized and characterized by IR,MS and NMR spectra.Meanwhile,the crystal of IIIa was obtained and determined by X-ray single-crystal diffraction.Crystal data： monoclinic system,space group P21 /c,a = 8.423（8）,b = 19.596（16）,c = 8.770（8）,β = 107.750（12）°,V = 1379（2）3,Z = 4,F（000） = 560,Dc = 1.283 g/cm3,μ = 0.086 mm 1,R = 0.0681 and wR = 0.2029 for 14472 independent reflections（Rint = 0.0782） and 2428 observed ones（I 2σ（I））.

Renaldopaminergic system:Pathophysiological implications andclinical perspectives

Fluid homeostasis, blood pressure and redox balance in the kidney are regulated by an intricate interaction between local and systemic anti-natriuretic and natriuretic systems. Intrarenal dopamine plays a central role on this interactive network. By activating specifc receptors, dopamine promotes sodium excretion and stimulates anti-oxidant and anti-inflammatory pathways. Different pathological scenarios where renal sodium excretion is dysregulated, as in nephrotic syndrome, hypertension and renal infammation, can be associated with impaired action of renal dopamine including alteration in biosynthesis, dopamine receptor expression and signal transduction. Given its properties on the regulation of renal blood fow and sodium excretion, exogenous dopamine has been postulated as a potential therapeutic strategy to preventrenal failure in critically ill patients. The aim of this review is to update and discuss on the most recent findings about renal dopaminergic system and its role in several diseases involving the kidneys and the potential use of dopamine as a nephroprotective agent.

Acute toxicity of organochlorine insecticide endosulfan to the giant freshwater prawn Macrobrochium rosenbergii

Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity of endosulfan to freshwater prawns( Macrobrachium rosenbergii) of various lengths(1.5±0.03,4±0.08, and 7±0.06 cm). Additionally, the activities of peroxidase(POD), acid phosphatase(ACP),alkaline phosphatase, acetylcholinesterase(AChE), and Na + /K +-ATPase were analyzed to refl ect the effects of endosulfan exposure. The 96 h LC 50 of endosulfan for prawns 1.5, 4, and 7 cm long were 1.86, 4.53,and 6.09μg/L, respectively, improved tolerance to endosulfan with growth. The POD activities of test organisms exposed to low concentrations of endosulfan were inhibited, indicating the presence of oxygen damaged tissue. Moreover, a notable decrease in AChE activity was observed due to overstimulation of neurotransmission, which might result in abnormal behavior. The effect caused by endosulfan on phosphatase production in the hepatopancreas of prawns 1.5, 4, and 7 cm long was different because the ability of nonspecifi c immune regulation increased with growth. The 96 h LC 50 values obtained in this study could be used in the formulation of water-quality criteria in China. Moreover, the changes in enzymes activities of M. rosenbergii under stress of endosulfan could be applied in the establishment of early warning indicators for bio-safety.

Synthesis and Absolute Configuration of (2S,3S,3aS,6S,7aR)-2,3-Dihydroxy-2-((R)-1-hydroxy-3-methylbutyl)-3,6-dimethylhexahydrobenzofuran-4(2H)-one

To investigate the anti-ulcer effect of bisabolangelone reduction derivatives, the sesquiterpene was further proceeded with dihydroxylation reaction. The structure of the target compound was characterized by IR, ESI-MS, 2D NMR and elemental analysis, and its absolute configuration was confirmed with a Flack parameter of 0.08（16） by X-ray crystallography using a Cu radiation source. Compound（3）, C（15）H（26）O5, crystal data： monoclinic system, space group P21, a = 11.467（2）, b = 6.0303（12）, c = 11.711（2） A, β = 99.70（3）°, V = 798.3（3） A3, Z = 2, F（000） = 312, Dc = 1.191 g/cm3, μ = 0.723 mm-1） R = 0.0303 and wR = 0.0797 for 2590 independent reflections（Rint = 0.0164） and 2563 observed ones（I 〉 2σ（I））.

快发病性肌张力障碍-帕金森综合征

快发病性肌张力障碍-帕金森综合征(RDP)是一种临床特征为应激后快速发病,以肌张力障碍和帕金森综合征为主要表现的肌张力障碍类疾病,由ATP1A3基因突变致Na+,K+-ATPase酶泵的α3亚单位酶活性或稳定性异常,引起小脑与基底节间功能协调异常所致;与相同基因发生突变引起的儿童交替性偏瘫等疾病可能有连续性表型疾病谱,值得不断深入探究。

FXYD6： a novel therapeutic target toward hepatocellular carcinoma

FXYD6, FXYD domain containing ion transport regulator 6, has been reported to affect the activity of Na＋/K＋-ATP- ase and be associated with mental diseases. Here, we demonstrate that FXYD6 is up-regulated in hepatocellular carcinoma （HCC） and enhances the migration and prolif- eration of HCC cells. Up-regulation of FXYD6 not only positively correlates with the increase of Na＋IK＋-ATPase but also coordinates with the activation of its downstream Src-ERK signaling pathway. More importantly, blocking FXYD6 by its functional antibody significantly inhibits the growth potential of the xenografted HCC tumors in mice, indicating that FXYD6 represents a potential therapeutic target toward HCC. Altogether, our results establish a critical role of FXYD6 in HCC progression and suggest that the therapy targeting FXYD6 can benefit the clinical treatment toward HCC patients.

Experimental Study on Mechanical Vibration Massage for Treatment of Brachial Plexus Injury in Rats

Objective: To investigate the curative effect of the self-made mechanical vibration massage instrument for treatment of brachial plexus injury in rats and to explore its mechanism. Methods: Brachial plexus injury models were made in 144 Wistar rats and one week after natural healing of the wound, they were randomly divided into 3 groups, mechanical vibration treatment group (MV group), nerve growth factor treatment group (NGF group) and model group, 48 rats in each group. Then again, the each group was randomly divided into 4 subgroups, 7-day group, 14-day group, 21-day group and 28-day group, 12 rats in each subgroup. The MV group were treated by mechanical vibration at acupoints on three-yang and three-yin channels of the hand with the mechanical vibration massage instrument; The NGF group were treated with injection of NGF into musculus pectoralis major on the affected side; And the model group were normally fed with no treatment. After treatment for 7, 14, 21 and 28 days, the diameter of both forelimbs were measured, the electrophysiological examination on the brachial plexus in vitro and the ultrastructure observation with electron microscope on the affected side were carried out, the motor nerve conduction velocity (MNCV) and motor nerve action potential (MNAP) of the brachial plexus on the affected side, NGF content of submaxillary gland as well as muscular Na+, K+-ATPase activity were determined respectively. Results: The different rates of the forelimb diameter in the MV group and the NGV group on the 14th d, 21st d and 28th d were better than those in the model group (P<0.05 or P<0.001), and in the MV group were better than those in the NGF group on the 21st d and the 28th d (P<0.05). MNCV in the MV group and the NGV group on the 21st d and 28th d was better than that in the model group (P<0.05 or P<0.001), and in the MV group was better than that in the NGF group on the 28th d (P<0.05). MNAP in the MV group and the NGV group on the 14th d, 21st d and 28th d was better than that in the model group (P<0.05 or P<0.001), and in the MV group was better than that in the NGF group on the 21st d and 28th d (P<0.05). The NGF mean gray index of submaxillary gland in the model group was higher than that in the MV group and the NGF group on the 7th d (P<0.05); in the NGF group and the model group was higher than that in the MV group on the 14th d (P<0.05); and in the NGF group and the MV group was higher than that in the model group on the 21st d and 28th d (P<0.05). Na+, K+-ATPase activity in the model group and the MV group was higher than that in the NGF group (P<0.05) on the 14th d, and in the MV group was higher than that in the model group on the 28th d (P<0.05). Conclusion: As compared with the NGF group and the model group, mechanical vibration treatment can effectively accelerate repair of injured brachial plexus, slow down atrophy of skeletal muscle, and promote secretion of NGF in submaxillary gland.