A Novel Sensor for Undrained Shear Strength Measurement in Very Soft to Soft Marine Sediments Based on Optical Frequency Domain Reflectometry Technology.

Due to the short supply of conventional fill materials, such as sand, land reclamation using dredged marine deposits has recently been proposed, in which marine deposits with high water content are blow-filled into reclaiming areas. The strength development of the filled marine soils is of great importance during the sedimentation and consolidation to guide the filling process and construction of reclamation. In this study, a novel sensor based on optical frequency domain reflectometry (OFDR) technology with a simple design was developed for undrained shear strength measurement. The novel sensor consists of an optical fiber and a series of polyoxymethylene coins. Owing to the merits of OFDR technology on high resolution, fully distributed sensing, and immunity to electromagnetic interference, the novel sensor can be used to determine undrained shear strength profiles of very soft to soft marine sediments/soils with good accuracy. The sensor was calibrated in remolded marine deposits with different water contents. The good feasibility and performance of the novel sensor for undrained shear strength measurement were well validated in two physical model tests on marine deposits treated by horizontal drains with vacuum preloading.

Losartan Potassium and Verapamil Hydrochloride Compound Transdermal Drug Delivery System: Formulation and Characterization.

In this study, we developed a sustained-release transdermal delivery system containing losartan potassium (LP) and verapamil hydrochloride (VPH). LP and VPH have low bioavailability and long half-life. Therefore, the development of an optimum administration mode is necessary to overcome these drawbacks and enhance the antihypertensive effect. A transdermal diffusion meter was used to determine the optimal formulation of LP-VPH transdermal drug delivery systems (TDDS). Based on in vitro results, a sustained-release patch was prepared. Physical characteristics, including quality, stickiness, and appearance, were evaluated in vitro, while pharmacokinetics and skin irritation were evaluated in vivo. The results showed that 8.3% polyvinyl alcohol, 74.7% polyvinylpyrrolidone K30, 12% oleic acid-azone, and 5% polyacrylic acid resin II provided an optimized TDDS product for effective administration of LP and VPH. Furthermore, in vitro and in vivo release tests showed that the system continuously released LP and VPH for 24 h. The pharmacokinetic results indicated that although the maximum concentration was lower, both the area under the curve from 0-time and the mean residence time of the prepared patch were significantly higher than those of the oral preparations. Furthermore, the prepared LP-VPH transdermal patch showed good stability and no skin irritation. The developed LP-VPH TDDS showed a sustained-release effect and good characteristics and pharmacokinetics; therefore, it is an ideal formulation.

Curcumin inhibits alloxan-induced pancreatic islet cell damage via antioxidation and antiapoptosis.

The present study elucidates the possible protective effects of curcumin on ß-cells damaged by oxidative stress and its significance in controlling diabetes mellitus in in vitro experiments. Pancreatic islet (RIN-m5F) cells were treated with 25 mmol/L alloxan (AXN) to induce cell damage and the protective effects of curcumin were observed. The results showed that curcumin significantly promoted the cellular activity of AXN-treated RIN-m5F cells, decreased the ratio of apoptosis, downregulated the level of malondialdehyde, upregulated the levels of superoxide dismutase and reactive oxygen species, increased the expression of Bcl-2, cleaved caspase-3, and cleaved PARP1, and decreased the expression of Bax in AXN-treated cells. These results suggest that curcumin inhibits AXN-induced damage in RIN-m5F cells via antioxidative and antiapoptotic mechanisms.

The Underlying Mechanisms of Curcumin Inhibition of Hyperglycemia and Hyperlipidemia in Rats Fed a High-Fat Diet Combined With STZ Treatment.

Curcumin is the main secondary metabolite of Curcuma longa and other Curcuma spp, and has been reported to have some potential in preventing and treating some physiological disorders. This study investigated the effect of curcumin in inhibiting high-fat diet and streptozotocin (STZ)-induced hyperglycemia and hyperlipidemia in rats. Twenty-six male Sprague-Dawley (SD) rats (170-190 g) were randomly divided into a standard food pellet diet group (Control group), a high-fat diet and streptozotocin group (HF + STZ group), and a high-fat diet combined with curcumin and STZ group (HF + Cur + STZ group). Compared with the HF + STZ group, the HF + Cur + STZ group exhibited significantly reduced fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (AST), and aspartate transaminase (ALT) levels, as well as liver coefficients. In the livers of these rats, the expression of malondialdehyde (MDA) and Bax was downregulated, whereas that of superoxide dismutase (SOD) and Bcl-2 was upregulated. Moreover, the liver histology of these rats was improved and resembled that of the control rats. These results suggest that curcumin prevents high-fat diet and STZ-induced hyperglycemia and hyperlipidemia, mainly via anti-oxidant and anti-apoptotic mechanisms in the liver.

Antioxidant and Anti-inflammatory Capacity of Ferulic Acid Released from Wheat Bran by Solid-state Fermentation of Aspergillus niger.

OBJECTIVE: A strain of Aspergillus niger (A. niger), capable of releasing bound phenolic acids from wheat bran, was isolated. This strain was identified by gene sequence identification. The antioxidant and anti-inflammatory capacity of ferulic acid released from wheat bran by this A. niger strain (FA-WB) were evaluated. METHODS: Molecular identification techniques based on PCR analysis of specific genomic sequences were conducted; antioxidant ability was examined using oxygen radical absorbance capacity (ORAC), cellular antioxidant activity (CAA) assays, and erythrocyte hemolysis assays. RAW264.7 cells were used as a model to detect anti-inflammatory activity. RESULTS: The filamentous fungal isolate was identified to be A. niger. ORAC and CAA assay showed that FA-WB had better antioxidant activity than that of the ferulic acid standard. The erythrocyte hemolysis assay results suggested that FA-WB could attenuate AAPH-induced oxidative stress through inhibition of reactive oxy gen species (ROS) generation. FA-WB could significantly restore the AAPH-induced increase in intracellular antioxidant enzyme activities to normal levels as well as inhibit the intracellular malondialdehyde formation. TNF-a, IL-6, and NO levels indicated that FA-WB can inhibit the inflammation induced by lipopolysaccharide (LPS). CONCLUSION: Ferulic acid released from wheat bran by a new strain of A. niger had good anti-inflammatory activity and better antioxidant ability than standard ferulic acid.

Transgenic cotton co-expressing chimeric Vip3AcAa and Cry1Ac confers effective protection against Cry1Ac-resistant cotton bollworm.

Wide planting of transgenic Bt cotton in China since 1997 to control cotton bollworm (Helicoverpa armigera) has increased yields and decreased insecticide use, but the evolution of resistance to Bt cotton by H. armigera remains a challenge. Toward developing a new generation of insect-resistant transgenic crops, a chimeric protein of Vip3Aa1 and Vip3Ac1, named Vip3AcAa, having a broader insecticidal spectrum, was specifically created previously in our laboratory. In this study, we investigated cross resistance and interactions between Vip3AcAa and Cry1Ac with three H. armigera strains, one that is susceptible and two that are Cry1Ac-resistant, to determine if Vip3AcAa is a good candidate for development the pyramid cotton with Cry1Ac toxin. Our results showed that evolution of insect resistance to Cry1Ac toxin did not influence the sensitivity of Cry1Ac-resistant strains to Vip3AcAa. For the strains examined, observed mortality was equivalent to the expected mortality for all the combinations of Vip3AcAa and Cry1Ac tested, reflecting independent activity between these two toxins. When this chimeric vip3AcAa gene and the cry1Ac gene were introduced into cotton, mortality rates of Cry1Ac resistant H. armigera larvae strains that fed on this new cotton increased significantly compared with larvae fed on non-Bt cotton and cotton producing only Cry1Ac. These results suggest that the Vip3AcAa protein is an excellent option for a "pyramid" strategy for pest resistance management in China.

Transgenic cotton coexpressing Vip3A and Cry1Ac has a broad insecticidal spectrum against lepidopteran pests.

Although farmers in China have grown transgenic Bt-Cry1Ac cotton to resist the major pest Helicoverpa armigera since 1997 with great success, many secondary lepidopteran pests that are tolerant to Cry1Ac are now reported to cause considerable economic damage. Vip3AcAa, a chimeric protein with the N-terminal part of Vip3Ac and the C-terminal part of Vip3Aa, has a broad insecticidal spectrum against lepidopteran pests and has no cross resistance to Cry1Ac. In the present study, we tested insecticidal activities of Vip3AcAa against Spodoptera litura, Spodoptera exigua, and Agrotis ipsilon, which are relatively tolerant to Cry1Ac proteins. The bioassay results showed that insecticidal activities of Vip3AcAa against these three pests are superior to Cry1Ac, and after an activation pretreatment, Vip3AcAa retained insecticidal activity against S. litura, S. exigua and A. ipsilon that was similar to the unprocessed protein. The putative receptor for this chimeric protein in the brush border membrane vesicle (BBMV) in the three pests was also identified using biotinylated Vip3AcAa toxin. To broaden Bt cotton activity against a wider spectrum of pests, we introduced the vip3AcAa and cry1Ac genes into cotton. Larval mortality rates for S. litura, A. ipsilon and S. exigua that had fed on this new cotton increased significantly compared with larvae fed on non-Bt cotton and Bt-Cry1Ac cotton in a laboratory experiment. These results suggested that the Vip3AcAa protein is an excellent option for a "pyramid" strategy for integrated pest management in China.

Detecting Electron Transport of Amino Acids by Using Conductance Measurement.

The single molecular conductance of amino acids was measured by a scanning tunneling microscope (STM) break junction. Conductance measurement of alanine gives out two conductance values at 10-1.85 G0 (1095 nS) and 10-3.7 G0 (15.5 nS), while similar conductance values are also observed for aspartic acid and glutamic acid, which have one more carboxylic acid group compared with alanine. This may show that the backbone of NH2-C-COOH is the primary means of electron transport in the molecular junction of aspartic acid and glutamic acid. However, NH2-C-COOH is not the primary means of electron transport in the methionine junction, which may be caused by the strong interaction of the Au-SMe (methyl sulfide) bond for the methionine junction. The current work reveals the important role of the anchoring group in the electron transport in different amino acids junctions.

Electron-Poor, Fluoro-Containing Arylboronic Acids as Efficient Coupling Partners for Bis(1,5-cyclooctadiene)nickel(0)/Tricyclohexylphosphine-Catalyzed Cross-Coupling Reactions of Aryl Arenesulfonates.

The use of electron-poor, fluoro-containing arylboronic acids as general coupling partners for nickel(0) /tricyclohexylphosphine-catalyzed cross-coupling of aryl arenesulfonates is described. Electron-poor fluoro-containing arylboronic acids were found to react, faster than electron-rich/neutral arylboronic acids, with (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylphosphine)nickel. Bis(1,5-cyclooctadiene)nickel(0)/tricyclohexylphosphine, (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylpho sphine)nickel and bis(tricyclohexylphosphine)nickel (II) bromide were all found to be efficient catalysts/catalyst precursors.

Using intravoxel incoherent motion MR imaging to study the renal pathophysiological process of contrast-induced acute kidney injury in rats: Comparison with conventional DWI and arterial spin labelling.

OBJECTIVES: To investigate the potential of intravoxel incoherent motion (IVIM) to assess the renal pathophysiological process in contrast-induced acute kidney injury (CIAKI). METHODS: Twenty-seven rats were induced with CIAKI model, six rats were imaged longitudinally at 24 h prior to and 30 min, 12, 24, 48, 72 and 96 h after administration; three rats were randomly chosen from the rest for serum creatinine and histological studies. D, f, D* and ADC were calculated from IVIM, and renal blood flow (RBF) was obtained from arterial spin labelling (ASL). RESULTS: A progressive reduction in D and ADC was observed in cortex (CO) by 3.07 and 8.62 % at 30 min, and by 25.77 and 28.16 % at 48 h, respectively. A similar change in outer medulla (OM) and inner medulla (IM) was observed at a later time point (12-72 h). D values were strongly correlated with ADC (r = 0.885). As perfusion measurement, a significant decrease was shown for f in 12-48 h and an increase in 72-96 h. A slightly different trend was found for D*, which was decreased by 26.02, 21.78 and 10.19 % in CO, OM and IM, respectively, at 30 min. f and D* were strongly correlated with RBF in the cortex (r = 0.768, r = 0.67), but not in the medulla. CONCLUSIONS: IVIM is an effective imaging tool for monitoring progress in renal pathophysiology undergoing CIAKI. KEY POINTS: • IVIM analysis permits separate quantification of diffusion and perfusion. • IVIM can provide useful biomarkers ifor changes in renal pathophysiology. • IVIM can be useful for monitoring progress in renal pathophysiology undergoing CIAKI.

Celecoxib enhances radiosensitivity via induction of G2-M phase arrest and apoptosis in nasopharyngeal carcinoma.

BACKGROUND: Previous work has proposed that celecoxib may be able to enhance the effects of radiotherapy. However, the underlying mechanism of this activity has not yet been determined. METHODS: The cell colony formation assay after the combination of celecoxib and radiation treatment was done on C666-1, CNE-1 and CNE-2 nasopharyngeal carcinoma cells, which expressed different COX-2 levels. Moreover, COX-2 knocked down or overexpressed cells were developed, and apoptosis and cell cycle analysis were performed. RESULTS: Celecoxib enhances radiation cytotoxicity in C666-1 and CNE-1 nasopharyngeal carcinoma cells that expressed high COX-2 but not in CNE-2 cells that expressed low COX-2. The radiosensitization of celecoxib in C666-1 cells disappeared after the COX-2 knocked down, while the CNE-2 cells were radiosensitized by celecoxib after the transfection of COX-2. Moreover, celecoxib enhanced radiation-induced G2-M phase arrest was observed in some of the tested cells. Furthermore, we found that the radiosensitivity of celecoxib in nasopharyngeal carcinoma was correlated with the apoptosis induction. Additionally, the combination of celecoxib (25 mg/kg) and radiation (6 Gy) treatment significantly reduced tumor volume in C666-1 and CNE-2 nasopharyngeal carcinoma xenograft models. CONCLUSION: These results indicate that the combination of celecoxib and radiation treatment has potential application in radiotherapy, and these effects may be attributable to the G2-M cell phase arrest and enhancement of cell apoptosis.

Intravoxel incoherent motion MRI: emerging applications for nasopharyngeal carcinoma at the primary site.

OBJECTIVES: We compared pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) based on intravoxel incoherent motion (IVIM) theory in patients with nasopharyngeal carcinoma (NPC). METHODS: Sixty-five consecutive patients (48 men) with suspected NPC were examined using a 3.0-T MR system. Diffusion-weighted imaging (DWI) was performed with 13 b values (range, 0-800 s/mm(2)). We regarded the result of endoscopy and biopsy as the gold standard for detection. D, D* and f were compared between patients with primary NPC and enlarged adenoids. RESULTS: IVIM DWI was successful in 37 of 40 NPC and 23 of 25 enlarged adenoids cases. D (P = 0.001) and f (P < 0.0001) were significantly lower in patients with NPC than in patients with enlarged adenoids, whereas D* was significantly higher (P < 0.0001). However, the ADC was not significantly different between the two groups (P > 0.05). The area under the ROC curve (AUC) for D was 0.849 and was significantly larger than that for ADC (P < 0.05). CONCLUSIONS: IVIM DWI is a feasible technique for investigating primary NPC. D was significantly decreased in primary NPC, and increased D* reflected increased blood vessel generation and parenchymal perfusion in primary NPC. KEY POINTS: • Intravoxel incoherent motion (IVIM) analysis permits separate quantification of diffusion and perfusion. • IVIM DWI is a feasible technique for investigating primary NPC. • IVIM suggests that primary NPC tissue voxels exhibit both perfusion and diffusion.

Initial experience of correlating parameters of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging at 3.0 T in nasopharyngeal carcinoma.

PURPOSE: To determine the correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters. METHODS: Thirty-eight newly diagnosed NPC patients were prospectively enrolled. Diffusion-weighted images (DWI) at 13 b-values were acquired using a 3.0-T MRI system. IVIM parameters including the pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f), DCE-MRI parameters including maximum slope of increase (MSI), enhancement amplitude (EA) and enhancement ratio (ER) were calculated by two investigators independently. Intra- and interobserver agreement were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Relationships between IVIM and DCE-MRI parameters were evaluated by calculation of Spearman's correlation coefficient. RESULTS: Intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.887-0.997; narrow width of 95 % limits of agreement). The highest correlation was observed between f and EA (r = 0.633, P < 0.001), with a strong correlation between f and MSI (r = 0.598, P = 0.001). No correlation was observed between f and ER (r = -0.162; P = 0.421) or D* and DCE parameters (r = 0.125-0.307; P > 0.119). CONCLUSION: This study suggests IVIM perfusion imaging using 3.0-T MRI is feasible in NPC, and f correlates significantly with EA and MSI. KEY POINTS: Assessment of tumour perfusion is important in nasopharyngeal carcinoma. DCE-MRI provided perfusion information with the use of intravenous contrast media. Perfusion information could be provided by non-invasive IVIM MRI. IVIM parameter f correlated with DCE-MRI parameters.

Enhancement of extracellular pullulanase production from recombinant Escherichia coli by combined strategy involving auto-induction and temperature control.

Pullulanase was extracellularly produced with an engineered Escherichia coli with a combined strategy. When auto-induction instead of isopropyl ß-D-1-thiogalactopyranoside (IPTG) induction method was implemented, we observed increased extracellular activity (4.2 U ml(-1)) and cell biomass (7.95 g DCW l(-1)). Subsequent investigation of temperature effect on fermentation showed cultivation performed at 25 °C presented the highest extracellular titer and cell biomass. In order to reduce the extended production period, we developed a two-stage temperature control strategy. Its application not only reduced the production period from 72 to 36 h, but also further enhanced the yield of extracellular pullulanase. Finally, with a view to releasing more intracellular pullulanase, we altered cell membrane permeability with various medium additives. As a result, extracellular titer was elevated to 68.23 U ml(-1), nearly 35-fold higher than that with IPTG induction method. The combined strategy developed here may be useful for the production of other extracellular proteins by recombinant E. coli.

Applications of single-cell RNA sequencing in spermatogenesis and molecular evolution.

Spermatogenic cell heterogeneity is determined by the complex process of spermatogenesis differentiation. However, effectively revealing the regulatory mechanisms underlying mammalian spermatogenic cell development and differentiation via traditional methods is difficult. Advances in technology have led to the emergence of many single-cell transcriptome sequencing protocols, which have partially addressed these challenges. In this review, we detail the principles of 10x Genomics technology and summarize the methods for downstream analysis of single-cell transcriptome sequencing data. Furthermore, we explore the role of single-cell transcriptome sequencing in revealing the heterogeneity of testicular ecological niche cells, delineating the establishment and disruption of testicular immune homeostasis during human spermatogenesis, investigating abnormal spermatogenesis in humans, and, ultimately, elucidating the molecular evolution of mammalian spermatogenesis.

ANXA1sp attenuates sepsis-induced myocardial injury by promoting mitochondrial biosynthesis and inhibiting oxidative stress and autophagy via SIRT3 upregulation.

Sepsis-induced myocardial injury is one of the most difficult complications of sepsis in intensive care units. Annexin A1 (ANXA1) short peptide (ANXA1sp) protects organs during the perioperative period. However, the protective effect of ANXA1sp against sepsis-induced myocardial injury remains unclear. We aimed to explore the protective effects and mechanisms of ANXA1sp against sepsis-induced myocardial injury both in vitro and in vivo. Cellular and animal models of myocardial injury in sepsis were established with lipopolysaccharide. The cardiac function of mice was assessed by high-frequency echocardiography. Elisa assay detected changes in inflammatory mediators and markers of myocardial injury. Western blotting detected autophagy and mitochondrial biosynthesis-related proteins. Autophagic flux changes were observed by confocal microscopy, and autophagosomes were evaluated by TEM. ATP, SOD, ROS, and MDA levels were also detected.ANXA1sp pretreatment enhanced the 7-day survival rate, improved cardiac function, and reduced TNF-α, IL-6, IL-1ß, CK-MB, cTnI, and LDH levels. ANXA1sp significantly increased the expression of sirtuin-3 (SIRT3), mitochondrial biosynthesis-related proteins peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), and mitochondrial transcription factor A (TFAM). ANXA1sp increased mitochondrial membrane potential (△Ψm), ATP, and SOD, and decreased ROS, autophagy flux, the production of autophagosomes per unit area, and MDA levels. The protective effect of ANXA1sp decreased significantly after SIRT3 silencing in vitro and in vivo, indicating that the key factor in ANXA1sp's protective role is the upregulation of SIRT3. In summary, ANXA1sp attenuated sepsis-induced myocardial injury by upregulating SIRT3 to promote mitochondrial biosynthesis and inhibit oxidative stress and autophagy.

Silencing of GATA6 suppresses SW1990 pancreatic cancer cell growth in vitro and up-regulates reactive oxygen species.

BACKGROUND/AIMS: Pancreatic cancer has the worst prognosis of any gastrointestinal cancer with a mortality rate approaching its incidence. Previous studies have indicated that GATA6 plays a key role in organ development and function, and that abnormal expression of GATA6 may induce tumorigenesis. Meanwhile, it has been reported that generation of reactive oxygen species contributes to carcinogenesis. In this study, we set out to study the role of GATA6 expression on proliferation and apoptosis of pancreatic cancer cells and the role of reactive oxygen species. METHODS: Four target miRNA sequences against GATA6 mRNA were synthesized and used to transfect SW1990 cells. Then, GATA6 expression in SW1990 cells was examined by western blot and quantative real-time polymerase chain reaction. Cell proliferation was examined by WST-8 and colony formation assay. Cell cycle progression and apoptosis were measured by flow cytometry. We also measured the generation of reactive oxygen species by immunofluorescence and flow cytometry. RESULTS: RNA interference against GATA6 successfully inhibited mRNA and protein expression of GATA6 in the SW1990 pancreatic cancer cell line. Silencing of GATA6 by RNA interference inhibited cell proliferation and increased apoptosis of SW1990, and enhanced the expression of reactive oxygen species. CONCLUSIONS: These results suggest that the RNA interference approach against GATA6 may be an effective therapeutic approach for treatment of pancreatic cancer.

Anti-obesity effects exerted by Dioscorea opposita Thunb. polysaccharides in diet-induced obese mice.

Obesity is characterized by chronic inflammation, insulin resistance, and gut microbiota dysbiosis. Dioscorea opposita Thunb. is a traditional food and medicine homolog from China. In the present study, polysaccharides isolated from a water extract of Dioscorea opposita Thunb. (DOTPs) were prepared. We showed that DOTPs reduced body weight, accumulation of fat tissues, insulin resistance, and inflammation in high-fat diet (HFD)-fed mice. Further experiments showed that DOTPs could regulate the composition of the gut microbiota in HFD mice. DOTPs supplementation in HFD-fed mice resulted in the reduction of the Firmicutes-to-Bacteroidetes ratio. We further demonstrated that DOTPs supplementation enhanced bacterial levels of Akkermansia and reduced levels of Ruminiclostridium_9. A significant reduction of glycolysis metabolism related to obesity and gut microbiota dysbiosis was also observed upon administration of DOTPs. Our results suggest that DOTPs can produce significant anti-obesity effects, by inhibiting systematic inflammation and ameliorating gut microbiota dysbiosis in diet-induced obese mice.

Depletion of stearoyl-CoA desaturase (scd) leads to fatty liver disease and defective mating behavior in zebrafish.

Stearyl coenzyme A desaturase (SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids. In mammals, depletion or inhibition of SCD activity generally leads to a decrease in triglycerides and cholesteryl esters. However, the endogenous role of scd in teleost fish remains unknown. Here, we generated a zebrafish scd mutant (scd-/-) to elucidate the role of scd in lipid metabolism and sexual development. Gas chromatography-mass spectrometry (GC-MS) showed that the scd-/- mutants had increased levels of saturated fatty acids C16:0 and C18:0, and decreased levels of monounsaturated fatty acids C16:1 and C18:1. The mutant fish displayed a short stature and an enlarged abdomen during development. Unlike Scd-/- mammals, the scd-/- zebrafish showed significantly increased fat accumulation in the whole body, especially in the liver, leading to hepatic mitochondrial dysfunction and severe cell apoptosis. Mechanistically, srebf1, a gene encoding a transcriptional activator related to adipogenesis, acc1 and acaca, genes involved in fatty acid synthesis, and dgat2, a key gene involved in triglyceride synthesis, were significantly upregulated in mutant livers to activate fatty acid biosynthesis and adipogenesis. The scd-/- males exhibited defective natural mating behavior due to defective genital papillae but possessed functional mature sperm. All defects in the scd-/- mutants could be rescued by ubiquitous transgenic overexpression of scd. In conclusion, our study demonstrates that scd is indispensable for maintaining lipid homeostasis and development of secondary sexual characteristics in zebrafish.

Role of TPEN in Amyloid-ß25-35-Induced Neuronal Damage Correlating with Recovery of Intracellular Zn2+ and Intracellular Ca2+ Overloading.

The overproduction of neurotoxic amyloid-ß (Aß) peptides in the brain is a hallmark of Alzheimer's disease (AD). To determine the role of intracellular zinc ion (iZn2+) dysregulation in mediating Aß-related neurotoxicity, this study aimed to investigate whether N, N, N', N'­tetrakis (2­pyridylmethyl) ethylenediamine (TPEN), a Zn2+­specific chelator, could attenuate Aß25-35­induced neurotoxicity and the underlying mechanism. We used the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay to measure the viability of primary hippocampal neurons. We also determined intracellular Zn2+ and Ca2+ concentrations, mitochondrial and lysosomal functions, and intracellular reactive oxygen species (ROS) content in hippocampal neurons using live-cell confocal imaging. We detected L-type voltage-gated calcium channel currents (L-ICa) in hippocampal neurons using the whole­cell patch­clamp technique. Furthermore, we measured the mRNA expression levels of proteins related to the iZn2+ buffer system (ZnT-3, MT-3) and voltage-gated calcium channels (Cav1.2, Cav1.3) in hippocampal neurons using RT-PCR. The results showed that TPEN attenuated Aß25-35­induced neuronal death, relieved the Aß25-35­induced increase in intracellular Zn2+ and Ca2+ concentrations; reversed the Aß25-35­induced increase in ROS content, the Aß25-35­induced increase in the L-ICa peak amplitude at different membrane potentials, the Aß25-35­induced the dysfunction of the mitochondria and lysosomes, and the Aß25-35­induced decrease in ZnT-3 and MT-3 mRNA expressions; and increased the Cav1.2 mRNA expression in the hippocampal neurons. These results suggest that TPEN, the Zn2+-specific chelator, attenuated Aß25-35­induced neuronal damage, correlating with the recovery of intracellular Zn2+ and modulation of abnormal Ca2+-related signaling pathways.