Overexpression of Smad7 suppressed ROS/MMP9-dependent collagen synthesis through regulation of heme oxygenase-1

We previously reported that AngiotensinII receptor blocker effectively inhibited TGF-β1-mediated epithelial-to-mesenchymal transition progress through regulating Smad7. However, the underlying mechanism by which Smad7 exerted in regulating MMP9 and fibrogenic response has not been fully elucidated. In the current study, we proved that NADPH p47^phox-dependent reactive oxygen species (ROS) production contributed to MMP9 activation and collagen expression, which was suppressed by transfecting pcDNA3–Smad7 in cardiac fibroblasts. The effect of Smad7 overexpression on MMP9 activity and collagen expression was further reversed by adding H₂O₂ (10 μmol/L). In contrast, knockdown of Smad7 caused the enhanced collagen synthesis in cardiac fibroblasts, which was also reversed by treating cells with a ROS inhibitor, YCG063 (2 μmol/L). Further investigation showed that Smad7 regulated NADPH-mediated ROS production through activating Heme oxygenase-1 (HO-1). Meanwhile, the intercellular level of bilirubin (product of hemin) and nitric oxide (NO) in cell supernatant were not significantly increased in cells treated with AngII or transfected with Smad7. Knockdown of HO-1 in Smad7-overexpressed cardiac fibroblasts or cells pretreated with SnPP IX, a competitive inhibitor of HO-1 activity, resulted in increased productions of ROS and NADPH p47^phox, and abolished the inhibitory effects of Smad7 on MMP9 activity and collagen expression. Our results indicated that HO-1 might be critically involved in Smad7-mediated regulation of MMP9 activity and fibrogenic genes expression via antagonizing the enhanced myocardial oxidative stress.     

温度和紫外照射对紫苏FAD7基因表达的影响

植物ω-3脂肪酸脱氢酶(ω-3FAD)基因是催化亚油酸转化为α-亚麻酸(ALA)的关键酶基因,通过调节该基因的表达,可以提高植物ALA的含量。为了研究温度和紫外照射对紫苏PfFAD7的影响,通过RTPCR方法分析了紫苏地上组织的特异性表达和温度、紫外胁迫下紫苏叶片和茎中PfFAD7基因的积累情况。分析表明,PfFAD7基因在紫苏全植株中均有表达,但在叶片中表达量最高,温度和紫外照射均影响PfFAD7基因的表达,低温可诱导PfFAD7基因的表达,而高温则抑制PfFAD7基因的表达;UV-B照射下,PfFAD7基因在叶片和茎中表达量均表现为先升高再降低。本试验对于紫苏ω-3脂肪酸脱氢酶的研究有利于高水平ALA的积累,更有利于紫苏资源的开发和利用,同时对于进一步了解不饱和脂肪酸的积累和代谢过程以及关键基因PfFAD7在此过程中的功能提供了依据。     

Regulation by Hsp27/P53 in testis development and sperm apoptosis of male cattle (cattle-yak and yak)

Heat shock protein 27 (Hsp27)/protein 53 (P53) plays an important role in testis development and spermatozoa regulation, but the relationship between Hsp27/P53 and infertility in cattle is unclear. Here, we focus on male cattle-yak and yak to investigate the expression and localization of Hsp27/P53 in testis tissues and to explore the influence of Hsp27/P53 on infertility. In our study, a total of 54 cattle (24 cattle-yak and 30 yak) were examined. The Hsp27 and P53 messenger RNA (mRNA) of cattle-yak were cloned, and amino acid variations in Hsp27 and P53 were found; the variations led to differences in the protein spatial structure compared with yak. We used real-time quantitative polymerase chain reaction and western blot to investigate whether the expression of Hsp27/P53 mRNA and protein was different in cattle-yak and yak. We found that the expression levels of Hsp27/P53 mRNA and protein were different in the testis developmental stages and the highest expression was observed in testicles during adulthood. Moreover, the Hsp27 expression was significantly higher in yak, whereas P53 expression was higher in cattle-yak (p < 0.01). On this basis, we detected the location of Hsp27/P53 in the testis by immunohistochemistry and immunofluorescence. The results demonstrated that Hsp27 was located in spermatogenic cells at different developmental stages and mesenchymal cells of the yak testicles. However, P53 was located in the primary spermatocyte and interstitial cells of the cattle-yak testicles. In summary, our study proved that the expression of Hsp27/P53 differed across the testis developmental stages and the expression of P53 was higher in the testis of cattle-yak, which suggested that the infertility of cattle-yak may be caused by the upregulation of P53.     

Gene expression associated with indicated faster growth of crossbreeding in Sinocyclocheilus grahami

In this study, pure‐breeding and crossbreeding of Sinocyclocheilus grahami were established to test heterosis and expression of growth‐related genes which were examined in the first‐generation (F1). Genetic distances results showed that Muyang river (M) and Sanbaimu reservoir (S) populations had smaller interspecific distances (genetic distance: 0.000) while larger distances were shown to other two populations (0.024 of Jiuzhai vauclusian spring [J] and 0.044 of Chenglong vauclusian spring [C]). Full‐sib families were created by using the Muyang river population as females: MM, MS, MJ and MC. Growth performance had significant differences between each group of F1 hybrids; the fastest growth group was shown in MJ while the slowest was in MS. For growth‐related genes, the fast growth group of MJ hybrids showed significantly higher levels of ghrelin expression in strong expression tissues of the intestine and liver. Among the four combinations, mRNA levels of insulin‐like growth factor I (IGF‐I) were the highest expression in MJ hybrids than others in all tested tissues. Myostatin b and somatostatin1 (SST1) were strongly expressed in the brain and MJ hybrids showed relatively lower expression level. In the muscle, slow growth group of MS hybrids showed extremely higher expression levels of these two genes, especially SST1 gene. In conclusion, associating growth with growth‐related genes expression indicated faster growth of crossbreeding in S. grahami and can make a contribution to commercial fish production in the future.     

AMPKα1 regulates Idh2 transcription through H2B O-GIcNAcylation during brown adipogenesis

AMP-activated protein kinase (AMPK) is indispensable for the development and maintenance of brown adipose tissue (BAT),and its activity is inhibited due to obes...     

Foraging habitats and utilization distributions of Black-necked Cranes wintering at the Napahai Wetland, China

ABSTRACT.   One of the most endangered populations of Black-necked Cranes ( Grus nigricollis ), the central population, is declining due to habitat loss and degradation, but little is known about their space use patterns and habitat preferences. We examined the space use and habitat preferences of Black-necked Cranes during the winter of 2007–2008 at the Napahai wetland in northwest Yunnan, China, where approximately 300 Black-necked Cranes (>90% of the total central population) spent the winter. Euclidean distance analysis was employed to determine the habitat preferences of Black-necked Cranes, and a local nearest-neighbor, convex-hull construction method was used to examine space use. Our results indicate that Black-necked Cranes preferred shallow marsh and wet meadow habitats and avoided farmland and dry grassland. Core-use areas (50% isopleths) and total-use areas (100% isopleths) accounted for only 1.2% and 28.2% of the study area, respectively. We recommend that habitat protection efforts focus on shallow marsh and wet meadow habitats to maintain preferred foraging sites. Core-use areas, such as the primary foraging areas of Black-necked Cranes, should be designated as part of the core zone of the nature reserve. Monthly shifts in the core-use areas of the cranes also indicate that the reserve should be large enough to permit changes in space use. In addition to preserving habitat, government officials should also take measures to decrease human activity in areas used by foraging Black-necked Cranes.     

Molecular phylogeography and population structure of a mid-elevation montane frog Leptobrachium ailaonicum in a fragmented habitat of southwest China

Leptobrachium ailaonicum is a vulnerable anuran restricted to a patchy distribution associated with small mountain streams surrounded by forested slopes at mid-elevations (approximately 2000–2600 m) in the subtropical Mount Wuliang and Mount Ailao ranges in southwest China (Yunnan Province) and northern Vietnam. Given high habitat specificity and lack of suitable habitat in lower elevations between these ranges, we hypothesized limited gene flow between populations throughout its range. We used two mitochondrial genes to construct a phylogeographic pattern within this species in order to test our hypothesis. We also examined whether this phylogeographic pattern is a response to past geological events and/or climatic oscillations. A total of 1989 base pairs were obtained from 81 individuals of nine populations yielding 51 unique haplotypes. Both Bayesian and maximum parsimony phylogenetic analyses revealed four deeply divergent and reciprocally monophyletic mtDNA lineages that approximately correspond to four geographical regions separated by deep river valleys. These results suggest a long history of allopatric separation by vicariance. The distinct geographic distributions of four major clades and the estimated divergence time suggest spatial and temporal separations that coincide with climatic and paleogeographic changes following the orogeny and uplift of Mount Ailao during the late Miocene to mid Pliocene in southwest China. At the southern distribution, the presence of two sympatric yet differentiated clades in two areas are interpreted as a result of secondary contact between previously allopatric populations during cooler Pleistocene glacial cycles. Analysis of molecular variance indicates that most of the observed genetic variation occurs among the four regions implying long-term interruption of maternal gene flow, suggesting that L. ailaonicum may represent more than one distinct species and should at least be separated into four management units corresponding to these four geographic lineages for conservation.     

Monophyly and phylogenetic relationships of the catfish genus Glyptothorax (Teleostei: Sisoridae) inferred from nuclear and mitochondrial gene sequences

GlyptothoraxBlyth (1860) is the most species-diverse and widely-distributed genus in the Sisoridae, but few studies have examined monophyly of the genus and phylogenetic relations within it. We used the nuclear RAG2 gene and mitochondrial COI and Cyt b genes from 50 of the approximately 70 species to examine monophyly of Glyptothorax and phylogenetic relationships within the genus. Molecular phylogenetic trees were constructed using maximum parsimony, maximum likelihood and Bayesian inference methods. All methods strongly supported monophyly of Glyptothorax, with Bagarius as its sister group. Both analyses of two- and three-gene datasets recovered nine major subclades of Glyptothorax, but some internal nodes remained poorly resolved. The phylogenetic relationships within the genus and existing taxonomic problems are discussed.