Fenofibrate and Dyslipidemia: Still a Place in Therapy?

Fenofibrate inhibits MOXD1 and PDZK1IP1 expression and improves lipid deposition and inflammation in mice with alcoholic fatty liver

AIMS

Alcoholic liver disease (ALD) can develop into cirrhosis and hepatocellular carcinoma but no specific drugs are available. Fenofibrate is therapeutically effective in ALD, however, the exact mechanism remains unknown. We explored the hub genes of ALD and the role of fenofibrate in ALD.

MAIN METHODS

The hub genes of ALD were screened by bioinformatics method, and their functional enrichment, signalling pathways, target genes and their correlation with immune microenvironment and pathogenic genes were analysed. We also analysed the binding affinity of fenofibrate to proteins of hub genes using molecular docking techniques, and the effects on hub gene expression, lipid deposition, oxidative stress and inflammation in the liver of National Institute on Alcohol Abuse and Alcoholism (NIAAA) model mice. The regulatory effects of fenofibrate on MOXD1 and PDZK1P1 were investigated after gene silencing of peroxisome proliferator-activated receptor-α (Ppar-α).

KEY FINDINGS

Hub genes identified, including monooxygenase DBH-like 1 (MOXD1), PDZK1-interacting protein 1 (PDZK1IP1) and solute carrier 51 β (SLC51B), are highly predictive for ALD. Hepatic MOXD1 and PDZK1IP1 expression was elevated in patients with ALD and NIAAA model mice, with no significant difference in SLC51B expression between the groups. Fenofibrate binds tightly to MOXD1 and PDZK1IP1, inhibits their hepatic expression independently of PPAR-α signalling, and ameliorates lipid deposition, oxidative stress and inflammatory responses in NIAAA model mice.

SIGNIFICANCE

MOXD1 and PDZK1IP1 are key genes in ALD progression; fenofibrate improves liver damage in NIAAA model mice by downregulating their expression. Our findings provide insight for improving diagnostic and therapeutic strategies for ALD.

Dissecting the multifaced function of transcription factor EB (TFEB) in human diseases: From molecular mechanism to pharmacological modulation

The transcription factor EB (TFEB) is a transcription factor of the MiT/TFE family that translocations from the cytoplasm to the nucleus in response to various stimuli, including lysosomal stress and nutrient starvation. By activating genes involved in lysosomal function, autophagy, and lipid metabolism, TFEB plays a crucial role in maintaining cellular homeostasis. Dysregulation of TFEB has been implicated in various diseases, including cancer, neurodegenerative diseases, metabolic diseases, cardiovascular diseases, infectious diseases, and inflammatory diseases. Therefore, modulating TFEB activity with agonists or inhibitors may have therapeutic potential. In this review, we reviewed the recently discovered regulatory mechanisms of TFEB and their impact on human diseases. Additionally, we also summarize the existing TFEB inhibitors and agonists (targeted and non-targeted) and discuss unresolved issues and future research directions in the field. In summary, this review sheds light on the crucial role of TFEB, which may pave the way for its translation from basic research to practical applications, bringing us closer to realizing the full potential of TFEB in various fields.

Pharmacotherapeutics for dyslipidemia management

ABSTRACT

Effective management of dyslipidemia is of paramount importance to prevent cardiovascular (CV) complications. Using current clinical practice guidelines is recommended to correct lipid levels and prevent further pathologic processes. This article presents an overview of treatment options for patients with dyslipidemia and CV disease, with a special focus on the following drug classes: HMG-CoA reductase inhibitors (also called statins), cholesterol absorption inhibitors (ezetimibe), bile acid sequestrants, fibrates, icosapent ethyl, and PCSK9 inhibitors.

Inflammatory Links Between Hypertriglyceridemia and Atherogenesis

PURPOSE OF REVIEW

Recent studies indicate an association between hypertriglyceridemia (HTG) and atherosclerotic cardiovascular disease (ASCVD). The purpose of this review is to discuss the potential mechanism connecting HTG and ASCVD risk and the potential efficacy of HTG-targeting therapies in ASCVD prevention.

RECENT FINDINGS

HTG, with elevations in triglyceride-rich lipoproteins (TGRL) and their remnants, are causal ASCVD risk factors. The mechanisms whereby HTG increases ASCVD risk are not well understood but may include multiple factors. Inflammation plays a crucial role in atherosclerosis. TGRL compared to low-density lipoproteins (LDL) correlate better with inflammation. TGRL remnants can penetrate endothelium and interact with macrophages leading to foam cell formation and inflammation in arterial walls, thereby contributing to atherogenesis. In addition, circulating monocytes can take up TGRL and become lipid-laden foamy monocytes, which infiltrate the arterial wall and may also contribute to atherogenesis. Novel therapies targeting HTG or inflammation are in development and have potential of reducing residual ASCVD risk associated with HTG. Clinical and preclinical studies show a causal role of HTG in promoting ASCVD, in which inflammation plays a vital role. Novel therapies targeting HTG or inflammation have potential of reducing residual ASCVD risk.

CES2 sustains HNF4α expression to promote pancreatic adenocarcinoma progression through an epoxide hydrolase-dependent regulatory loop

OBJECTIVE

Intra-tumoral expression of the serine hydrolase carboxylesterase 2 (CES2) contributes to the activation of the pro-drug irinotecan in pancreatic ductal adenocarcinoma (PDAC). Given other potential roles of CES2, we assessed its regulation, downstream effects, and contribution to tumor development in PDAC.

METHODS

Association between the mRNA expression of CES2 in pancreatic tumors and overall survival was assessed using The Cancer Genome Atlas. Cell viability, clonogenic, and anchorage-independent growth assays as well as an orthotopic mouse model of PDAC were used to evaluate the biological relevance of CES2 in pancreatic cancer. CES2-driven metabolic changes were determined by untargeted and targeted metabolomic analyses.

RESULTS

Elevated tumoral CES2 mRNA expression was a statistically significant predictor of poor overall survival in PDAC patients. Knockdown of CES2 in PDAC cells reduced cell viability, clonogenic capacity, and anchorage-independent growth in vitro and attenuated tumor growth in an orthotopic mouse model of PDAC. Mechanistically, CES2 was found to promote the catabolism of phospholipids resulting in HNF4α activation through a soluble epoxide hydrolase (sEH)-dependent pathway. Targeting of CES2 via siRNA or small molecule inhibitors attenuated HNF4α protein expression and reduced gene expression of classical/progenitor markers and increased basal-like markers. Targeting of the CES2-sEH-HNF4α axis using small molecule inhibitors of CES2 or sEH reduced cell viability.

CONCLUSIONS

We establish a novel regulatory loop between CES2 and HNF4α to sustain the progenitor subtype and promote PDAC progression and highlight the potential utility of CES2 or sEH inhibitors for the treatment of PDAC as part of non-irinotecan-containing regimens.

Four Citrus Flavanones Exert Atherosclerosis Alleviation Effects in ApoE-/- Mice via Different Metabolic and Signaling Pathways

Citrus flavanones have the potential to alleviate atherosclerosis. The metabolism and anti-atherosclerosis signaling pathways of four citrus flavanones (naringin, naringenin, hesperidin, and hesperetin) were compared in ApoE^-/- mice. Naringin had the most potent anti-atherogenic effect, followed by hesperidin, naringenin, and hesperetin with reductions of 55.92, 34.98, 42.87, and 24.70% in the atherosclerotic plaque rate compared with the control, respectively. Oral naringin mainly existed in the intestine due to the high water solubility of 7-O-nohesperidoside and alleviated atherosclerosis mainly by enhancing bile acid synthesis in the gut microbiota-FXR/FGF15-CYP7A1 pathway. The other three flavanones mainly alleviated atherosclerosis in the liver after absorption from the intestine. Hesperidin upregulates ABCA1 by 1.8-fold to enhance cholesterol reverse transport, while the aglycones naringenin and hesperetin inhibited cholesterol synthesis via downregulating HMGCR by 2.4- and 2.3-fold, respectively. Hesperetin was more resistant to absorption than naringenin due to the existence of a 4'-methoxyl group and had relatively weak effects on atherosclerosis. The alleviation of atherosclerosis by the four citrus flavanones was tightly related to differences in their in vivo metabolism and signaling pathways. This provides new insights into the anti-atherosclerotic mechanisms of food functional flavanones and guidance for the design of novel, efficient strategies for preventing atherosclerosis based on citrus flavanones.

Effect of polyphenol, flavonoid, and saponin fractions from Thymus atlanticus on acute and chronic hyperlipidemia in mice

Background

Thymus atlanticus is an endemic plant of the Mediterranean region, which has been used in the Moroccan mountain area to treat several diseases. This study aimed to investigate the effect of polyphenol, flavonoid, and saponin fractions derived from this plant on acute and chronic hyperlipidemia in male albino mice.

Results

The results indicated that the injection of Triton WR-1339 (20 mg/100 g body weight (B.wt.)) and 6-week administration of a high-fat diet (which is an 81.8% standard diet supplemented with 2% cholesterol, 16% lard, and 0.2% cholic acid) significantly increased plasma total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C), but did not affect high-density lipoprotein cholesterol (HDL-C) levels in mice. Administration of a single dose (2 mg/kg B.wt.) of polyphenol, flavonoid, or saponin fractions significantly suppressed the effect of Triton injection on plasma total cholesterol, triglycerides, and LDL-C. In addition, the supplementation of the high-fat diet with polyphenol fraction (2 mg/kg B.wt./day) prevented the increase of total cholesterol, triglycerides, and LDL-C, and effectively increased HDL-C level when compared to mice feeding only the high-fat diet.

Conclusion

In conclusion, phenolic compounds from Thymus atlanticus possess a significant hypocholesterolemic and hypotriglyceridemic effects and, therefore, could have an important role in the management of dyslipidemia.

Successful fenofibrate therapy for severe and persistent hypertriglyceridemia in a boy with cirrhosis and glycerol-3-phosphate dehydrogenase 1 deficiency

Glycerol-3-phosphate dehydrogenase 1 deficiency is a rare autosomal recessive disorder caused by mutations in the GPD1 gene (GPD1; OMIM*138420). Very few cases are reported in literature. It usually manifests in early infancy with transient hypertriglyceridemia, hepatomegaly, steatosis, and fibrosis. We report the case of a 16-year-old boy followed since the age of 1 year for hepatomegaly, elevated liver enzymes, and persistent hypertriglyceridemia. Abdominal ultrasound showed diffuse liver echogenicity and liver biopsy disclosed cirrhosis with micro and macrovesicular steatosis. Next-generation sequencing for metabolic and genetic liver diseases was conducted with the identification of the homozygous mutation c.895G>A in GPD1 gene resulting in the aminocidic substitution p.G299R. Considering the persistent and progressive increase of plasma triglycerides, fenofibrate treatment was started at 15 years of age allowing triglyceride level reduction in the following 1-year follow-up.

Lipid-lowering and antioxidative effects ofApium graveolensL. root flavonoid extracts

Apium graveolensL. root flavone extract can improve hyperlipidemia induced by high-fat emulsion diet in rats.