The reaction medium was optimized to accomplish epoxide hydrolase-catalyzed, batch enantioselective hydrolysis of racemic styrene oxide at high initial substrate concentrations. The recombinant Pichia pastoris containing the epoxide hydrolase gene of Rhodotorula glutinis was used as the biocatalyst. Enantiopure (S)-styrene oxide with 98% ee was obtained with 41% yield (maximum yield = 50%) from 1.8 M racemic styrene oxide at pH 8.0, 4 degrees C in the presence of 40% (v/v) Tween 20 and 5% (v/v) glycerol.
Chitinase-3-like protein 1 (CHI3L1), which is secreted by immune and inflammatory cells, is associated with several inflammatory diseases. However, the basic cellular pathophysiological functions of CHI3L1 are not well characterized. To investigate the novel pathophysiological function of CHI3L1, we performed LC-MS/MS analysis of cells transfected with Myc-vector and Myc-CHI3L1. We analyzed the changes in the protein distribution in Myc-CHI3L1 transfected-cells, and identified 451 differentially expressed proteins (DEPs) compared with Myc-vector-transfected-cells. The biological function of the 451 DEPs was analyzed and it was found that the proteins with endoplasmic reticulum (ER)-associated function were much more highly expressed in CHI3L1-overexpressing cells. We then compared and analyzed the effect of CHI3L1 on the ER chaperon levels in normal lung cells and cancer cells. We identified that CHI3L1 is localized in the ER. In normal cells, the depletion of CHI3L1 did not induce ER stress. However, the depletion of CHI3L1 induces ER stress and eventually activates the unfolded protein response, especially the activation of Protein kinase R-like endoplasmic reticulum kinase (PERK), which regulates protein synthesis in cancer cells. CHI3L1 may not affect ER stress owing to the lack of misfolded proteins in normal cells, but instead activate ER stress as a defense mechanism only in cancer cells. Under ER stress conditions induced by the application of thapsigargin, the depletion of CHI3L1 induces ER stress through the upregulation of PERK and PERK downstream factors (eIF2α and ATF4) in both normal and cancer cells. However, these signaling activations occur more often in cancer cells than in normal cells. The expression of Grp78 and PERK in the tissues of patients with lung cancer was higher compared with healthy tissues. It is well known that ER stress-mediated PERK-eIF2α-ATF4 signaling activation causes apoptotic cell death. ER stress-mediated apoptosis induced by the depletion of CHI3L1 occurs in cancer cells, but rarely occurs in normal cells. Consistent with results from the in vitro model, ER stress-mediated apoptosis was greatly increased during tumor growth and in the lung metastatic tissue of CHI3L1-knockout (KO) mice. The analysis of "big data" identified superoxide dismutase-1 (SOD1) as a novel target of CHI3L1 and interacted with CHI3L1. The depletion of CHI3L1 increased SOD1 expression, resulting in ER stress. Furthermore, the depletion of SOD1 reduced the expression of ER chaperones and ER-mediated apoptotic marker proteins, as well as apoptotic cell death induced by the depletion of CHI3L1 in in vivo and in vitro models. These results suggest that the depletion of CHI3L1 increases ER stress-mediated apoptotic cell death through SOD1 expression, and subsequently inhibits lung metastasis.
IntroductionAlzheimer's disease (AD) is the most common form of dementia. Depression is one of the most critical psychiatric complications of AD, and 20%–30% of patients with AD experience symptoms of depression. Phospho‐glycogen synthase kinase‐3 beta (GSK3β) is known to be associated with AD and depression. Furthermore, the role of disheveled (DVL) is known to regulate GSK3β. Moreover, presenilin‐2 (PS2) and DVL have cross‐talk with each other. Also, it is widely hypothesized that stress leads to hypersecretion of cortisol and is thus associated with depression. Dickkopf WNT signaling pathway inhibitor‐1 (DKK‐1) is a crucial factor regulating depression and both amyloid beta (Aβ) and phosphorylation of tau are widely known as a biomarker of AD.MethodsTo investigate the relationship between AD and depression, and possible pathways connecting the two diseases, we examined memory function and depression‐related behavior test results in PS2 knock‐in AD mice (PS2 MT). Next, we confirmed that there are relationships between DVL, depression, and cognitive disease through the comparative toxicogenomics database (https://ctdbase.org) and STRING (https://string‐db.org) database.ResultsPS2 knock‐in mice showed much more severe memory impairment and depression than PS2 wild‐type mice (PS2 WT). In AD‐related behavioral experiments, PS2 MT mice showed more memory dysfunction compared with PS2 WT group mice. Moreover, Aβ and phosphorylation of tau showed higher expression in PS2 MT mice than in PS2 WT mice. Depression‐related behavioral tests showed that PS2 MT mice exhibited more depressive behaviors than PS2 WT mice. Furthermore, both higher cortisol levels and higher expression of DKK‐1 were found in PS2 MT mice relative to PS2 WT mice. The results indicated that there is a relationship between DVL and the release of AD‐related mediators and expression of the depression‐related glucocorticoid receptor and DKK‐1. In the PS2 knock‐in group, DVL was significantly decreased compared with the PS2 WT group.ConclusionDepression increases the risk of developing AD and other forms of dementia. Recent evidence indicates that depression symptoms could trigger changes in memory and thinking over time. However, it is recognized that there are no drugs to facilitate a full recovery for both AD and depression. However, our results suggest that AD and depression could be associated, and DVL could be a significant target for the association between AD and depression.
Background Alzheimer's disease (AD) is characterized by to neuronal cell death and neuroinflammation. Neurofibrillary tangle (NFTs) is one of the neuropathological hallmarker of AD. Also our previous study indicated that bee venom leads to neuroprotective effects in a lipopolysaccharide (LPS)-induced AD mouse model. Thus, in this study we investigated whether that phospholipase A2 (PLA2) reduces tau phosphorylation and neuroinflammation, and thus ameliorates AD development. Results To validate pathological activities in in vivo, we examined of the inhibitory effect of bvPLA2 on memory loss and tau phosphorylation as well as neuroinflammation by subcutaneous injection of bvPLA2 (0.5 mg/kg) to Tg2576 mice. For in vitro study, we examined the effect of bvPLA2 on cell death, tau pathology and neuroinflammation by treatment of bvPLA2 in LPS-activated PC12 cells. Our study showed that bvPLA2 mitigated memory impairment and spatial memory in Tg2576 mice, Agreed with the memory improvement, tau level and phosphorylation of tau were decreased by bvPLA2 treatment. Expression level of pro-inflammatory cytokines and inflammation-related proteins were also decreased in the brain of bvPLA2-treated Tg2576 mice. Conclusions Consideration of reduced tau level and phosphorylation of tau, GSK3β phosphorylation was studied. Phosphorylated GSK3β on Ser9 was significantly increased by treatment of bvPLA2, but a phosphorylated GSK3β on Tyr216 was significantly decreased in the Tg2576 mice brains. These data thus indicate that bvPLA2 prevents memory impairment through reduction of tau phosphorylation.
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