Changes of physiological rhythms of N-methyl-d-aspartate receptors in the chum salmon Oncorhynchus keta: effect of seawater acclimation during the parr-smolt transformation

We examined changes on N-methyl-d-aspartate receptors (NRs) in different growth stages (early parr, parr, and early smolt) of chum salmon, Oncorhynchus keta, during parr-smolt transformation from freshwater to seawater. Expression levels of NR genes mRNA and concentration of cortisol, T₃, T₄, dopamine and Na⁺/K⁺-ATPase activity significantly increased at salinity change condition. Moreover, in cultured brain cells, NRs were significantly lower in all groups treated with MK-801 (an antagonist of NRs) than in the early parr stage group in the FW treatment. We confirmed that the reduction in mRNA expression levels of NRs increased from the early parr to the early smolt stage. The information reported here should be taken into account in future studies on the relationship between memory factors of natal streams and homing mechanisms in Salmonidae.     

Differential daily rhythms of melatonin in the pineal gland and gut of goldfish Carassius auratus in response to light

The objectives of this study were to test the effects of light on melatonin rhythms in the pineal gland and gut of goldfish Carassius auratus and to investigate whether melatonin function differed in these two tissues, which are photosensitive and non-photosensitive respectively. Rhythms were evaluated by measuring arylalkylamine N-acetyltransferase (AANAT2) and melatonin receptor 1 (MT-R1) mRNA expression and melatonin concentration in the pineal gland, gut (in vivo), and cell cultures of the two tissues (in vitro). Compared to control, pineal gland melatonin secretion was higher at night, whereas the 24-h dark and ophthalmectomy groups maintained higher AANAT2 and MT-R1 mRNA expression during the day. Melatonin levels and AANAT2 and MT-R1 mRNA expression in the gut were also the highest at night, but the 24-h light, dark, and ophthalmectomy groups did not significantly differ from control. Furthermore, we measured AANAT2 and MT-R1 mRNA expression in high temperature water (30 °C) to investigate differences in the antioxidant capacity of pineal gland vs. gut melatonin. Melatonin and H₂O₂ levels, as well as AANAT2 and MT-R1 mRNA expression, were all higher in the two tissues under thermal stress, compared with their levels at 22 °C. Taken together, our results suggest that light has no effect on melatonin patterns in the gut, which appears to exhibit its own circadian rhythm, but both gut and pineal gland melatonin exhibit similar antioxidant function.     

灵芝子实体中三萜类物质抗肿瘤活性的谱效关系

通过HPLC指纹图谱结合多元线性回归分析对不同产地灵芝子实体的功效性特征进行评价,为寻找灵芝中活性三萜提供理论依据。利用高效液相分析方法,结合样品对肿瘤细胞L1210的增殖抑制率,运用“中药色谱指纹图谱相似度评价系统2004A版”软件和多元线性回归分析11批不同品种灵芝子实体中的三萜活性成分。样品与标准指纹图谱的相似度均在0.9以上,共标定了12个共有物质峰,其中与抗L1210肿瘤细胞活性关系密切的三萜物质有灵芝酸C₂、灵芝酸G、灵芝烯酸B、灵芝烯酸A、灵芝酸K、灵芝酸A、灵芝酸F和灵芝醛A。     

BAG3‐positive pancreatic stellate cells promote migration and invasion of pancreatic ductal adenocarcinoma

BAG3 is constitutively expressed in multiple types of cancer cells and its high expression is associated with tumour progression and poor prognosis of PDAC . However, little is known about the role of BAG3 in the regulation of stromal microenvironment of PDAC. The current study demonstrated that beside PDAC tumour cells, BAG3 was also expressed in some activated stroma cells in PDAC tissue, as well as in activated PSCs. In addition, the current study demonstrated that BAG3 expression in PSCs was involved in maintenance of PSCs activation and promotion of PDACs invasion via releasing multiple cytokines. The current study demonstrated that BAG3‐positive PSCs promoted invasion of PDACs via IL‐8, MCP1, TGF‐β2 and IGFBP2 in a paracrine manner. Furthermore, BAG3 sustained PSCs activation through IL‐6, TGF‐β2 and IGFBP2 in an autocrine manner. Thereby, the current study provides a new insight into the involvement of BAG3 in remodelling of stromal microenvironment favourable for malignant progression of PDAC, indicating that BAG3 might serve as a potential target for anti‐fibrosis of PDAC.