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BackgroundUnlike mammals, goose fatty liver shows a strong tolerance to fatty acids without obvious injury. Stearyl-coenzyme A desaturase 1 (SCD1) serves crucial role in desaturation of saturated fatty acids (SAFs), but its role in the SAFs tolerance of goose hepatocytes has not been reported. This study was conducted to explore the role of SCD1 in regulating palmitic acid tolerance of goose primary hepatocytes.MethodsTo evaluate the palmitic acid tolerance of cultured hepatocytes, MTT was examined to reflect the effect of palmitic acid on cell viability, and quantitative PCR was used to detect the mRNA expression levels of several genes related to ER stress, inflammation, and apoptosis, and the role of SCD1 in palmitic acid tolerance of goose hepatocytes was explored using RNA interfere.ResultsOur results indicated that goose hepatocytes exhibited a higher tolerant capacity to palmitic acid than human hepatic cell line (LO2 cells). Furthermore, the mRNA levels of fatty acid desaturation-related genes (SCD1 and FADS2) and fatty acid elongate enzyme-related gene (ELOVL6) were significantly upregulated in goose primary hepatocytes treated with 0.6 mM palmitic acid. However, in cultured LO2 cells, expression of ER stress-related genes (XBP, BIP and ATF6), inflammatory response-related genes (IL-6, IL-1β and IFN-γ) and apoptosis-related genes (Bax, Bcl-2, Caspase-3 and Caspase-9) was significantly enhanced by the addition of 0.6 mM palmitic acid. Additionally, siRNA-mediated downregulation of SCD1 significantly reduced the palmitic acid tolerance of goose primary hepatocytes under the treatment of 0.6 mM palmitic acid; meanwhile, the mRNA expression of inflammatory-related genes (IL-6 and IL-1β) and several key genes involved in the PI3K/AKT, FoxO1, mTOR and AMPK pathways (AKT1, AKT2, FOXO1 and SIRT1), as well as the protein expression of cytochrome C and the apoptosis rate were also upregulated.ConclusionIn conclusion, our data suggested that SCD1 is involved in enhancing the palmitic acid tolerance of goose primary hepatocytes by regulating inflammation- and apoptosis-related genes expression.

To determine the prevalence and evaluate the risk factors of canine echinococcosis based on a field survey of dog infections with Echinococcus granulosus and E. multilocularis in Chalong, Kalong, Dade and Chazha Townships in a district of Ganzi County, Sichuan Province, China.Questionnaire associated with the acquisition of canine echinococcosis was administered to dog owners. Stray dogs were examined post-mortem and rectal faeces at necropsy were collected to validate a copro-antigen ELISA. Owned dogs were screened for Echinococcus spp. infection in faeces using the genus specific copro-ELISA and the effectiveness of dog treatment was assessed. Chi-square and one-way ANOVA were used for statistical analysis.The prevalence of Echinococcus spp. infection at necropsy in stray dogs was 60.9% (14/23) in 2000; E. multilocularis infection accounted for 34.8% (8/23) and E. granulosus for 26.1% (6/23). The specificity of the copro-ELISA was 80.0% and the sensitivity was 92.3%, compared with the results at necropsy. Fifty percent of owned dogs (290/580) tested was copro-antigen positive at the beginning of the project in 2000, which decreased to 17% (99/580) in the same cohort of owned dogs after praziquantel treatment (5 mg/ kg) at 6-monthly period from 2003 to 2005. Analysis for risk factors associated with copro-antigen positive dogs showed that the never tethered dogs had a higher rate (40.4%, 65/161) than dogs tethered during the day (32.3%, 109/337), or tethered at night [29.2% (21/72)], or those always tethered [20%(2/10)](P0.01). Dogs that their owners lacked hydatid transmission knowledge [38.1% (121/318)] and did not have de-worming practice [47.7% (92/193)] had significantly higher copro-antigen positive rate than those dogs that their owners knew relevant knowledge [28.6% (75/262)] and were dewormed regularly [20.4% (79/387)](P0.05 and P0.01). There was no correlation between the prevalence and dog sex or age or the varieties of livestock that the owner raised.Local dogs show high prevalence with both E. granulosus and E. multilocularis. The copro-ELISA can be used to detect infection of Echinococcus in dogs. Allowing dogs to roam, lack of the basic knowledge of hydatid disease transmission and no de-worming practice for dogs are significant factors for the transmission of canine echinococcosis.

In the eastern Qinghai-Tibet Plateau region, a variety of domestic and wild mammals are involved in the transmission cycles of Echinococcus species. E. granulosus and E. multilocularis are known being sympatrically distributed in the plateau region. Recently, an unknown Echinococcus species was isolated from infected plateau pika (Ochotona curzoniae) and Tibetan fox (Vulpes ferrilata). The species shows quite distinct characteristics on morphology, genetics, host specificity and geographical distribution from others. It was therefore identified as a new Echinococcus species, Echinococcus shiquicus. This paper discussed the biological genetics and epidemiological features of the species, and proposed hypotheses and considerations for further exploration.