Oridonin restores hepatic lipid homeostasis in an LXRα-ATGL/EPT1 axis-dependent manner

Insights from selenoprotein I mouse models for understanding biological roles of this enzyme

Selenoprotein I (selenoi) is a metabolic enzyme expressed in a wide variety of tissues that catalyzes the transfer of the ethanolamine phosphate group from CDP-ethanolamine to lipid acceptors to generate ethanolamine phospholipids. It is a member of the selenoprotein family, a class of proteins that mostly play fundamental roles in redox homeostasis and are defined by the co-translational incorporation of selenium in the form of selenocysteine. Loss-of-function mutations in the human SELENOI gene have been found in rare cases leading to a complex form of hereditary spastic paraplegia. Understanding the roles of this selenoprotein and its phospholipid products in different cell types has benefited from the development of mouse models. In particular, global and conditional knockout (KO) of the Selenoi gene in mice has enabled a more complete picture to emerge of how this important selenoprotein is integrated into metabolic pathways. These data have revealed how Selenoi loss-of-function affects embryogenesis, neurodevelopment, the immune system and liver physiology. This review summarizes the insights gained through mouse model experiments and the current understanding the different physiological roles played by this selenoprotein.

Metabolomics based analysis reveals the therapeutic effects of Incarvillea arguta (Royle) Royle aqueous extract against alcohol-induced liver injury

BACKGROUND

Alcohol-induced liver injury (ALI) poses a significant threat to global human health. The Chinese Yi medicine Liangtoumao (LTM), which originated from the whole plant of Incarvillea arguta Royle (Royle), has been widely used by the Yi ethnic group to prevent and treat ALI and other liver diseases. However, its effectiveness and mechanisms are still under-researched.

PURPOSE

The objective of our research is to investigate the chemical composition of LTM aqueous extract, evaluate its potential therapeutic intervention effect on ALI, and explore its mechanisms in rat models.

METHODS

The chemical components and constituents of LTM aqueous extract migrating to the blood were analyzed by UPLC-Q-TOF/MS. Sprague-Dawley rats subjected to chronic binge alcohol exposure were utilized to establish chronic ALI models and evaluate the therapeutic effects of LTM aqueous extract. Serum and spatial metabolomics analyses were used to investigate potential mechanisms.

RESULTS

A total of 60 chemical components in LTM aqueous extract were identified, with 67 absorbed into the blood, including 29 original compounds and 38 metabolites. Treatment with LTM aqueous extract remarkably alleviated hepatic lesions in livers of ALI rats, improved liver function, reduced oxidative stress and inflammation. Serum metabolomics and hepatic spatial metabolomics identified 30 and 215 differential metabolites, respectively. Metabolic pathways of glyoxylate and dicarboxylate, glycerophospholipid, linoleic acid, taurine and hypotaurine, and cysteine and methionine were closely related to the hepaprotective effects of LTM.

CONCLUSION

Our research confirmed significant effects of LTM on ALI prevention and treatment for the first time. Metabolomic findings revealed that LTM significantly influences various aspects of lipid metabolism. This study supports expanded mechanism investigations of LTM and explores its possibility as a potential ALI therapy.

Protective effects of Notoginsenoside R2 on reducing lipid accumulation and mitochondrial dysfunction in diabetic nephropathy through regulation of c-Src

BACKGROUND

The treatment options to delay the progression of diabetic nephropathy (DN), a key contributor to chronic kidney disease (CKD), are urgently needed. Previous studies reported that traditional Chinese medicine Panax notoginseng (PNG) exerted beneficial effects on DN. However, the renoprotective effects of Notoginsenoside R2 (NR2), an active component of PNG, on DN have not been investigated. This study aimed to assess the therapeutic potential of NR2 in DN and explore its underlying mechanisms.

METHODS

In vivo models were developed using db/db mice, while in vitro models utilized HK-2 cells exposed to high glucose and palmitic acid (HGPA). Online databases and Cytoscape software were employed to predict the potential targets of NR2. The expression of associated proteins was measured using immunohistochemistry and western blot. Lipid accumulation, oxidative stress levels, mitochondrial function and cell apoptosis were also assessed. Small interfering RNA was used in in vitro experiments to examine the effect of c-Src.

RESULTS

NR2 ameliorated albuminuria, renal function and renal pathology in db/db mice. The activation of c-Src was suppressed in db/db mice and in HK-2 cells exposed to HGPA. NR2 inhibited JNK/STAT1 phosphorylation and CD36 overexpression. NR2 also ameliorated lipid accumulation, oxidative stress, mitochondrial dysfunction and cell apoptosis in vivo and in vitro. By inhibiting c-Src, HK-2 cells exposed to HGPA experienced less lipid deposition and mitochondrial damage, indicating the renoprotective effects of NR2 were correlated with the inhibition of c-Src.

CONCLUSION

NR2 ameliorated mitochondrial dysfunction and delayed the progression of DN partly through suppression of c-Src. The protective effects of NR2 might be related to a reduction in lipid accumulation.

Holistic Comparison of the Lipidomes Simultaneously From 12 Panax Herbal Medicines By Ultra-High-Performance Supercritical Fluid Chromatography Coupled With Ion Mobility-Quadrupole Time-of-Flight Mass Spectrometry

Researches regarding quality control of ginseng focusing on the lipids are rare. Herein, ultra-high-performance supercritical fluid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (UHPSFC/IM-QTOF-MS) combined with untargeted metabolomic analysis was utilized to holistically characterize and compare the lipidomic difference among 12 Panax-derived herbal medicines. The established UHPSFC/IM-QTOF-MS method, using a Torus 1-AA column with CO2/CH3OH (modifier) as the mobile phase, well resolved the ginseng lipidome within 30 min. The lipid isomers and those easily co-eluted by conventional reversed-phase chromatography got separated, and integrated analyses of the positive-/negative-mode MS data and IM-derived collision cross section (CCS) greatly enhanced lipids identification. By the pattern recognition chemometric analysis of 90 batches of ginseng samples, the root ginseng samples showed significant differences in lipidome composition from those stem/leaf and flower samples. In contrast, red ginseng also contained lipids significantly different from the other root ginseng. Totally 82 potential differential lipids were discovered and identified based on the positive-mode data and 90 ones in the negative mode. Some of these lipid markers might be diagnostic for their authentication. Conclusively, we first report the lipidomic difference among 12 ginseng varieties, and the information obtained can lay foundation for the accurate identification of ginseng from the lipidome level.

Parkin deficiency promotes liver cancer metastasis by TMEFF1 transcription activation via TGF-β/Smad2/3 pathway

Parkin (PARK2) deficiency is frequently observed in various cancers and potentially promotes tumor progression. Here, we showed that Parkin expression is downregulated in liver cancer tissues, which correlates with poor patient survival. Parkin deficiency in liver cancer cells promotes migration and metastasis as well as changes in EMT and metastasis markers. A negative correlation exists between TMEFF1 and Parkin expression in liver cancer cells and tumor tissues. Parkin deficiency leads to upregulation of TMEFF1 which promotes migration and metastasis. TMEFF1 transcription is activated by Parkin-induced endogenous TGF-β production and subsequent phosphorylation of Smad2/3 and its binding to TMEFF1 promotor. TGF-β inhibitor and TMEFF1 knockdown can reverse shParkin-induced cell migration and changes of EMT markers. Parkin interacts with and promotes the ubiquitin-dependent degradation of HIF-1α/HIF-1β and p53, which accounts for the suppression of TGF-β production. Our data have revealed that Parkin deficiency in cancer leads to the activation of the TGF-β/Smad2/3 pathway, resulting in the expression of TMEFF1 which promotes cell migration, EMT, and metastasis in liver cancer cells.