Raloxifene is a selective estrogen receptor modulator; which plays beneficial roles in the treatment of cardiovascular diseases in women. However, its underlying mechanism remains unclear. In the present study, we investigated whether mitochondria-derived reactive oxygen species (ROS) are involved in raloxifene-induced vasodilation. Results showed that endothelium removal attenuated the vasodilatory effect of raloxifene in rat aortic rings, whereas treatment with the cyclooxygenase inhibitor indomethacin or the estrogen receptor antagonist ICI-182,780 had no significant effect, indicating that neither COX2 nor estrogen receptors are involved. The NADPH oxidase inhibitor apocynin also did not affect raloxifene-induced vasodilation. In contrast, the mitochondrial oxidase inhibitor rotenone and the mitochondrial antioxidant mito-tempo significantly attenuated raloxifene-induced vascular relaxation. In cultured vascular smooth muscle cells (VSMCs), phenylephrine (PE) markedly increased both total intracellular and mitochondrial ROS production, which was significantly inhibited by raloxifene. Accordingly, raloxifene effectively prevented the PE-induced increase in mitochondrial membrane potential, a key component of the mitochondrial electrochemical gradient. Finally, PE induced an acute decrease in uncoupling protein-2 (UCP2) expression, which was significantly prevented by raloxifene. In conclusion, this study demonstrates that raloxifene relaxes the rat aorta, at least in part, by inhibiting mitochondria-derived ROS.

Background: Choriocarcinoma (CC), a highly aggressive and malignant subtype of gestational trophoblastic disease (GTD), arises from the dysregulated proliferation of trophoblastic cells, which normally mediate placental development during pregnancy. This study aimed to characterize the expression and functional significance of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a nuclear-enriched long non-coding RNA, in CC pathogenesis. Methods: We analyzed MALAT1 expression levels in 30 normal placental villi, 46 hydatidiform moles (repressive subtype), and 52 CC specimens. To identify MALAT1-interacting proteins, we performed RNA antisense purification followed by immunoblotting, with subsequent validation via co-immunoprecipitation (Co-IP) and immunofluorescence (IF) assays. Results: MALAT1 was significantly upregulated in CC tissues compared to controls. In vivo xenograft experiments further revealed that MALAT1 overexpression enhanced tumor growth. Mechanistically, we identified RNA-binding motif protein 10 (RBM10), a key spliceosomal regulator, as a novel MALAT1-binding partner. Strikingly, MALAT1 promoted p53 protein degradation without affecting its transcriptional levels, and this oncogenic effect was mediated through an RBM10-dependent mechanism. Conclusions: In conclusion, our findings establish MALAT1 as a critical oncogenic driver in CC, functioning through its interaction with RBM10 to destabilize p53 and accelerate tumor progression. These insights highlight the potential of the MALAT1-RBM10-p53 axis as a therapeutic target in CC.

Gangliosides play vital biological regulatory roles and are associated with neurological system diseases, malignancies, and immune deficiencies. They have received extensive attention in developing targeted drugs and diagnostic markers. However, it is difficult to obtain enough structurally defined gangliosides and analogs especially at an industrial-relevant scale, which prevent exploring structure-activity relationships and identifying drug ingredients. Here, we report a highly modular chemoenzymatic cascade assembly (MOCECA) strategy for customized and large-scale synthesis of ganglioside analogs with various glycan and ceramide epitopes. We typically accessed five gangliosides with therapeutic promising and systematically prepared ten GM1 analogs with diverse ceramides. Through further process amplification, we achieved industrial production of ganglioside GM1 in the form of modular assembly at hectogram scale. Using MOCECA-synthesized GM1 analogs, we found unique ceramide modifications on GM1 could enhance the ability to promote neurite outgrowth. By comparing the structures with synthetic analogs, we further resolved the problem of contradicting descriptions for GM1 components in different pharmaceutical documents by reinterpreting the exact two-component structures of commercialized GM1 drugs. Because of its applicability and stability, the MOCECA strategy can be extended to prepare other glycosphingolipid structures, which may pave the way for developing new glycolipid drugs.

Abstract Gangliosides play vital biological regulatory roles and are associated with neurological system diseases, malignancies, and immune deficiencies. They have received extensive attention in developing targeted drugs and diagnostic markers. However, it is difficult to obtain enough structurally defined gangliosides and derivatives especially at an industrial-relevant scale, which prevent exploring structure-activity relationships and identifying drug ingredients. Here, we report a highly modular chemo-enzymatic cascade assembly (MOCECA) strategy for customized and large-scale synthesis of ganglioside derivatives with various glycan and ceramide epitopes. We represently access several gangliosides with therapeutic promising and systematically prepared primary GM1 derivatives with diverse ceramides found in human brain. Through further process amplification, we achieved industrial production of ganglioside GM1 in the form of modular assembly at hectogram scale. Using MOCECA-synthesized GM1 derivatives, we found unique ceramide modifications on GM1 could enhance the ability to promote neurite outgrowth and cell viability. By comparing the structures with synthetic derivatives, we further resolved the contradicting descriptions of GM1 components in different pharmaceutical documents by reinterpreting the exact two-component structures of commercialized GM1 drugs. Because of its applicability and stability, the MOCECA strategy can be extended to prepare other glycosphingolipid structures, which may pave the way for developing new glycolipid drugs.

Ganglioside GM1 is a glycosphingolipid found on mammalian cell membranes, and it is involved in ischemic encephalopathy, spinal cord injury and neurodegenerative diseases. Fatty acids, as a structure module of GM1, have been reported to affect its physiological function and neurite growth activity. Due to the limitation of preparation methods, the function of GM1 derivatives containing different fatty acids in nerve cells has not been systematically studied. To discover novel GM1 derivatives as nerve growth-promoting agents, we developed an efficient SA_SCDase enzymatic synthetic system of GM1 derivatives, yielding twenty GM1 derivatives with unsaturated fatty acid chains in high total yields (16-67%). Subsequently, the neurite outgrowth activities of GM1 derivatives were assessed on Neuro2a Cells. Among all the GM1 derivatives, GM1 (d18:1/C16:1) induced demonstrably neurite outgrowth activity. The subsequent RNA-sequencing (RNA-seq) and Western blot analysis was then performed and indicated that the mechanism of nerve cells growth involved cholesterol biosynthesis regulation by up-regulating SREBP2 expression or ERBB4 phosphorylation to activate the PI3K-mTOR pathway.

鞘糖脂(glycosphingolipids,GSLs)是真核生物细胞膜的重要组成部分,广泛参与细胞信号传导、免疫、增殖及凋亡等各项生理活动.鞘糖脂类具有作为药物、治疗靶标及潜在诊断标记的潜力,并且与多种疾病的发病机制及相关药物开发密切相关.目前,鞘糖脂类药物的大量制备主要依赖从动物脑组织中提取,存在成本较高、来源有限且有受疯牛病等人畜共患病污染的潜在危险.因此,对鞘糖脂的人工生物合成研究成为学术界的热点.本文中,笔者主要阐述鞘糖脂的化学酶法合成和人工细胞工厂构建方面的研究进展.

Ginsenoside Rh2 is a potential anticancer drug isolated from medicinal plant ginseng. Fermentative production of ginsenoside Rh2 in yeast has recently been investigated as an alternative strategy compared to extraction from plants. However, the titer was quite low due to low catalytic capability of the key ginseng glycosyltransferase in microorganisms. Herein, we have demonstrated high-level production of ginsenoside Rh2 in Saccharomyces cerevisiae via repurposing an inherently promiscuous glycosyltransferase, UGT51. The semi-rationally designed UGT51 presented an ~1800-fold enhanced catalytic efficiency (kcat/Km) for converting protopanaxadiol to ginsenoside Rh2 in vitro. Introducing the mutant glycosyltransferase gene into yeast increased Rh2 production from 0.0032 to 0.39 mg/g dry cell weight (DCW). Further metabolic engineering, including preventing Rh2 degradation and increasing UDP-glucose precursor supply, increased Rh2 production to 2.90 mg/g DCW, which was more than 900-fold higher than the starting strain. Finally, fed-batch fermentation in a 5-L bioreactor led to production of ~300 mg/L Rh2, which was the highest titer reported.