The lipid substrate preference of CETP controls the biochemical properties of HDL in fat/cholesterol-fed hamsters

Identification of predictive biomarkers for endometrial cancer diagnosis and treatment response monitoring using plasma metabolome profiling

BACKGROUND

Endometrial cancer (EMC) is the most common female genital tract malignancy with an increasing prevalence in many countries including Japan, a fact that renders early detection and treatment necessary to protect health and fertility. Although early detection and treatment are necessary to further improve the prognosis of women with endometrial cancer, biomarkers that accurately reflect the pathophysiology of EMC patients are still unclear. Therefore, it is clinically critical to identify biomarkers to assess diagnosis and treatment efficacy to facilitate appropriate treatment and development of new therapies for EMC.

METHODS

In this study, wide-targeted plasma metabolome analysis was performed to identify biomarkers for EMC diagnosis and the prediction of treatment responses. The absolute quantification of 628 metabolites in plasma samples from 142 patients with EMC was performed using ultra-high-performance liquid chromatography with tandem mass spectrometry.

RESULTS

The concentrations of 111 metabolites increased significantly, while the concentrations of 148 metabolites decreased significantly in patients with EMC compared to healthy controls. Specifically, LysoPC and TGs, including unsaturated fatty acids, were reduced in patients with stage IA EMC compared to healthy controls, indicating that these metabolic profiles could be used as early diagnostic markers of EMC. In contrast, blood levels of amino acids such as histidine and tryptophan decreased as the risk of recurrence increased and the stages of EMC advanced. Furthermore, a marked increase in total TG and a decrease in specific TGs and free fatty acids including polyunsaturated fatty acids levels were observed in patients with EMC. These results suggest that the polyunsaturated fatty acids in patients with EMC are crucial for disease progression.

CONCLUSIONS

Our data identified specific metabolite profiles that reflect the pathogenesis of EMC and showed that these metabolites correlate with the risk of recurrence and disease stage. Analysis of changes in plasma metabolite profiles could be applied for the early diagnosis and monitoring of the course of treatment of EMC patients.

Brazilian green propolis extracts modulate cholesterol homeostasis in a preclinical guinea pig model: an in vitro and in vivo study

Green propolis produced by Apis melífera bees, having Baccharis dracunculifolia D.C. (Asteraceae) as the primary botanical source, has been used in traditional medicine to treat numerous disorders. However, studies evaluating propolis' potential in treating cardiovascular diseases via its effects on cholesterol metabolism are lacking. Therefore, this study investigated the effects of green propolis extracts on lipid metabolism in hypercholesterolemic guinea pigs. Chemical characterization of ethanolic extracts of green propolis samples was undertaken using HPLC. The in vitro characterization included an evaluation of the antioxidant capacity of the hydroalcoholic extract of green propolis (DPPH and FRAP assays) and its ability to act as an inhibitor of the HMG-CoA reductase enzyme. In vivo, we investigated the effect of the hydroalcoholic extract of green propolis on lipid metabolism in hypercholesterolemic guinea pigs. Results obtained validated previous reports of significant antioxidant activity. HPLC analysis confirmed that coumaric acid, artepillin C, and baccharin were the most common and abundant compounds in green propolis samples among the studied compounds. Furthermore, the compounds in these extracts acted as effective HMG-CoA reductase inhibitors in vitro. In vivo assays demonstrated that a hypercholesterolemic diet significantly reduced serum levels of the HDL cholesterol fraction. Simvastatin and propolis hydroalcoholic extracts promoted a significant increase in HDL cholesterol, suggesting that these extracts can improve the serum lipid profile of hypercholesterolemic guinea pigs. Results obtained in this study provide a perspective on the possible hypocholesterolemic effect of green propolis, suggesting that it can improve the serum lipid profile in hypercholesterolemic guinea pigs.

Endocytosis of LXRs: Signaling in liver and disease

Nuclear receptors are among one of the major transcriptional factors that induces gene regulation in the nucleus. Liver X receptor (LXR) is a transcription factor which regulates essential lipid homeostasis in the body including fatty acid, cholesterol and phospholipid synthesis. Liver X receptor-retinoid X receptor (LXR-RXR) heterodimer is activated by either of the ligand binding on LXR or RXR. The promoter region of the gene which is targeted by LXR is bound to the response element of LXR. The activators bind to the heterodimer once the corepressor is dissociated. The cellular process such as endocytosis aids in intracellular trafficking and endosomal formation in transportation of molecules for essential signaling within the cell. LXR isotypes play a crucial role in maintaining lipid homeostasis by regulating the level of cholesterol. In the liver, the deficiency of LXRα can alter the normal physiological conditions depicting the symptoms of various cardiovascular and liver diseases. LXR can degrade low density lipoprotein receptors (LDLR) by the signaling of LXR-IDOL through endocytic trafficking in lipoprotein uptake. Various gene expressions associated with cholesterol level and lipid synthesis are regulated by LXR transcription factor. With its known diversified ligand binding, LXR is capable of regulating expression of various specific genes responsible for the progression of autoimmune diseases. The agonists and antagonists of LXR stand to be an important factor in transcription of the ABC family, essential for high density lipoprotein (HDL) formation. Endocytosis and signaling mechanism of the LXR family is broad and complex despite their involvement in cellular growth and proliferation. Here in this chapter, we aimed to emphasize the master regulation of LXR activation, regulators, and their implications in various metabolic activities especially in lipid homeostasis. Furthermore, we also briefed the significant role of LXR endocytosis in T cell immune regulation and a variety of human diseases including cardiovascular and neuroadaptive.

C1QL1/CTRP14 Is Largely Dispensable for Atherosclerosis Formation in Apolipoprotein-E-Deficient Mice

The purpose of this study was to investigate the influence of C1QL1 on atherosclerosis as well as the transcriptomic alteration of the aorta. While complement C1ql-like 1 (C1QL1) is one of the C1q/tumor-necrosis-factor-related protein (CTRP) family members, also known as CTRP14, and is synthesized and secreted mainly by the brain and adipose tissues, the functional properties of the C1QL1/CTRP14 protein outside the brain and adipocytes remain, however, unknown. In this regard, apolipoprotein E (ApoE) knockout (KO) mice were fed a Western diet and injected with adenovirus (Ad) green fluorescent protein or Ad-C1QL1 through the tail vein for 12 weeks. In contrast with the control cohort, the area of atherosclerotic plaque in ApoE KO mice overexpressing C1QL1 showed no significant difference, and the RNA sequence revealed that there were only 111 differentially expressed genes (DEGs) enriched in 26 signaling pathways of the mRNA profile in the aortic atherosclerosis lesions. This analysis also revealed the expression of several genes related to metabolism, organismal system, and human diseases such as type II diabetes, which are not associated with the formation of atherosclerosis in the aorta. These findings illustrate that C1QL1 is largely dispensable for atherosclerosis formation in ApoE-deficient mice and does not improve atherosclerotic plaque formation in the aorta.

Characterization of serum protein expression profiles in the early sarcopenia older adults with low grip strength: a cross-sectional study

Background

Sarcopenia refers to the progressive loss of skeletal muscle mass and muscle function, which seriously threatens the quality of life of the older adults. Therefore, early diagnosis is urgently needed. This study aimed to explore the changes of serum protein profiles in sarcopenia patients through a cross-sectional study, and to provide the reference for clinical diagnosis.

Methods

This study was a cross-sectional study carried out in the Tianjin institute of physical education teaching experiment training center from December 2019 to December 2020. Ten older adults were recruited, including 5 sarcopenia and 5 healthy older adults. After a detailed diagnostic evaluation, blood samples were collected to prepare serum for proteomic analysis using the HPLC System Easy nLC method. The differentially expressed proteins (DEPs) were screened by the limma package of R software (version 4.1.0).

Results

A total of 114 DEPs were identified between the patients and healthy older adults, including 48 up-regulated proteins and 66 down-regulated proteins. The functional enrichment analysis showed that the 114 DEPs were significantly enriched in 153 GO terms, which mainly involved in low-density lipoprotein particle remodeling, and negative regulation of immune response,etc. The PPI network further suggested that the cholesteryl ester transfer protein and Apolipoprotein A2 could serve as biomarkers to facilitate diagnosis of sarcopenia.

Conclusions

This study provided a serum proteomic profile of sarcopenia patients, and identified two proteins with diagnostic value, which might help to improve the diagnostic accuracy of sarcopenia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05844-2.

“Big Data” Approaches for Prevention of the Metabolic Syndrome

Metabolic syndrome (MetS) is characterized by the concurrence of multiple metabolic disorders resulting in the increased risk of a variety of diseases related to disrupted metabolism homeostasis. The prevalence of MetS has reached a pandemic level worldwide. In recent years, extensive amount of data have been generated throughout the research targeted or related to the condition with techniques including high-throughput screening and artificial intelligence, and with these “big data”, the prevention of MetS could be pushed to an earlier stage with different data source, data mining tools and analytic tools at different levels. In this review we briefly summarize the recent advances in the study of “big data” applications in the three-level disease prevention for MetS, and illustrate how these technologies could contribute tobetter preventive strategies.

Both full length-cholesteryl ester transfer protein and exon 9-deleted cholesteryl ester transfer protein promote triacylglycerol storage in cultured hepatocytes

We previously reported that overexpression of full-length cholesteryl ester transfer protein (FL-CETP), but not its exon 9-deleted variant (∆E9-CETP), in an adipose cell line reduces their triacylglycerol (TAG) content. This provided mechanistic insight into several in vivo studies where FL-CETP levels are inversely correlated with adiposity. However, increased FL-CETP is also associated with elevated hepatic lipids, suggesting that the effect of CETP on cellular lipid metabolism may be tissue-specific. Here, we directly investigated the role of FL-CETP and ∆E9-CETP in hepatic lipid metabolism. FL- or ∆E9-CETP was overexpressed in HepG2-C3A by adenovirus transduction. Overexpression of either FL or ∆E9-CETP in hepatocytes increased cellular TAG mass by 25% but reduced TAG secretion. This cellular TAG was contained in larger and more numerous lipid droplets. Analysis of TAG synthetic and catabolic pathways showed that this elevated TAG content was due to increased incorporation of fatty acid into TAG (24%), and higher de novo synthesis of fatty acid (50%) and TAG from acetate (40%). siRNA knockdown of CETP had the opposite effect on TAG synthesis and lipogenesis, and decreased cellular TAG. This novel increase in cellular TAG by FL-CETP overexpression was reproduced in Caco-2 intestinal epithelial cells. We conclude that, unlike that seen in adipocyte cells, overexpression of either CETP isoform in lipoprotein-secreting cells promotes the accumulation of TAG. These data suggest that the in vivo correlation between CETP levels and hepatic steatosis can be explained, in part, by a direct effect of CETP on hepatocyte cellular metabolism.

Wide-Targeted Metabolome Analysis Identifies Potential Biomarkers for Prognosis Prediction of Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is a fatal gynecologic cancer, and its poor prognosis is mainly due to delayed diagnosis. Therefore, biomarker identification and prognosis prediction are crucial in EOC. Altered cell metabolism is a characteristic feature of cancers, and metabolomics reflects an individual’s current phenotype. In particular, plasma metabolome analyses can be useful for biomarker identification. In this study, we analyzed 624 metabolites, including uremic toxins (UTx) in plasma derived from 80 patients with EOC using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Compared with the healthy control, we detected 77 significantly increased metabolites and 114 significantly decreased metabolites in EOC patients. Especially, decreased concentrations of lysophosphatidylcholines and phosphatidylcholines and increased concentrations of triglycerides were observed, indicating a metabolic profile characteristic of EOC patients. After calculating the parameters of each metabolic index, we found that higher ratios of kynurenine to tryptophan correlates with worse prognosis in EOC patients. Kynurenine, one of the UTx, can affect the prognosis of EOC. Our results demonstrated that plasma metabolome analysis is useful not only for the diagnosis of EOC, but also for predicting prognosis with the variation of UTx and evaluating response to chemotherapy.