ANGPTL3 Downregulation Increases Intracellular Lipids by Reducing Energy Utilization.

BACKGROUND: ANGPTL3 (angiopoietin-like protein 3) is a circulating protein with a key role in maintaining lipoprotein homeostasis. A monoclonal antibody against ANGPTL3 is an approved and well-tolerated treatment to reduce lipoproteins in familial hypercholesterolemia homozygotes. However, the reduction of hepatic ANGPTL3 synthesis using an antisense oligonucleotide unexpectedly resulted in a dose-dependent increase in liver lipid content and circulating transaminases, resulting in the termination of the clinical trial. Meanwhile, the use of silencing RNAs remains an area of active investigation. Our study sought to investigate whether intracellular downregulation of ANGPTL3 may lead to a primary increase in neutral lipids within the hepatocyte. METHODS: We downregulated ANGPTL3 by silencing RNA in primary human hepatocytes 3-dimensional spheroids, HepG2/LX-2 3-dimensional spheroids, and in HepG2, Hep3B2, and Huh7 cultured in 2 dimensions. RESULTS: ANGPTL3 downregulation increased neutral lipids in all models investigated. Interestingly, ANGPTL3 induced lower intracellular deiodinase type 1 protein levels resulting in a reduction in beta-oxidation and causing an increase in triglycerides stored in lipid droplets. CONCLUSIONS: In conclusion, intracellular ANGPTL3 downregulation by silencing RNA led to an increase in triglycerides content due to a reduction in energy substrate utilization resembling a primary intracellular hepatocyte hypothyroidism.

IL32 downregulation lowers triglycerides and type I collagen in di-lineage human primary liver organoids.

Steatotic liver disease (SLD) prevails as the most common chronic liver disease yet lack approved treatments due to incomplete understanding of pathogenesis. Recently, elevated hepatic and circulating interleukin 32 (IL-32) levels were found in individuals with severe SLD. However, the mechanistic link between IL-32 and intracellular triglyceride metabolism remains to be elucidated. We demonstrate in vitro that incubation with IL-32ß protein leads to an increase in intracellular triglyceride synthesis, while downregulation of IL32 by small interfering RNA leads to lower triglyceride synthesis and secretion in organoids from human primary hepatocytes. This reduction requires the upregulation of Phospholipase A2 group IIA (PLA2G2A). Furthermore, downregulation of IL32 results in lower intracellular type I collagen levels in di-lineage human primary hepatic organoids. Finally, we identify a genetic variant of IL32 (rs76580947) associated with lower circulating IL-32 and protection against SLD measured by non-invasive tests. These data suggest that IL32 downregulation may be beneficial against SLD.

Bergamot Polyphenol Extract Reduces Hepatocyte Neutral Fat by Increasing Beta-Oxidation.

BACKGROUND: Bergamot polyphenolic fraction (PF) extract exerts a beneficial against liver steatosis. However, the fundamental processes underlying this beneficial effect of bergamot PF remain elusive. In this work, we examined the effect of bergamot PF extract on 2D and 3D hepatocyte cultures. MATERIAL AND METHODS: We evaluated the effect of bergamot PF in 2D and 3D cultures from rat, human hepatoma cells, and human primary hepatocytes. RESULTS: In 2D cell culture, we demonstrated that incubation with bergamot PF decreases intracellular lipid content and is associated with an increase in expression levels of ß-oxidation genes (Acox1, Pparα, and Ucp2) and lipophagy (Atg7). Moreover, we confirm this effect on 3D spheroids and organoids. CONCLUSION: Incubation with bergamot PF reduces intracellular lipid neutral fat potentially by increasing intracellular pathways related to beta-oxidation.

Mediterranean Diet a Potential Strategy against SARS-CoV-2 Infection: A Narrative Review.

Mediterranean Diet represents the traditional eating habits of populations living around the Mediterranean Sea, and it is associated with a lower risk of overall mortality and cancer incidence and cardiovascular diseases. Severe acute respiratory syndrome coronavirus 2 is a new pandemic, and represents a significant and critical threat to global human health. In this study, we aimed to review the possible effects of Mediterranean Diet against the risk of the coronavirus disease 2019. Several vitamins, minerals, fatty acids, and phytochemicals with their potential anti-COVID-19 activity are presented. Different risk factors may increase or reduce the probability of contracting the disease. Mediterranean Diet has also a positive action on inflammation and immune system and could have a protective effect against severe acute respiratory syndrome coronavirus 2. Further studies are needed to corroborate the benefits of the Mediterranean Diet protective role on infection with SARS-CoV-2.

Effect of a novel functional tomato sauce (OsteoCol) from vine-ripened tomatoes on serum lipids in individuals with common hypercholesterolemia: tomato sauce and hypercholesterolemia.

BACKGROUND: Most studies focused on the benefits of lycopene on serum lipids but no studies have been specifically designed to assess the role of a tomato sauce from vine-ripened tomatoes on patients affected by polygenic hypercholesterolemia. The aim of this study was to compare the lipid-lowering effect of a novel functional tomato sauce with a well-known functional food with a lipid-lowering effect, i.e. a sterol-enriched yogurt. METHODS: In this cross-over study, we evaluated a population of 108 ambulatory patients affected by polygenic hypercholesterolemia of both gender, who were allocated to a tomato sauce (namely OsteoCol) 150 ml/day or a sterol-enriched yogurt (containing sterols 1.6 g/die) treatment, for 6 weeks. Carotenoids content was 3.5 mg per gram of product. We measured serum lipids and creatinine and transaminases at basal and follow-up visit. RESULTS: A total of 91 subjects completed the protocol. A significant difference in LDL-cholesterol change was found between participants taking yogurt, tomato sauce (high adherence) and tomato sauce (low adherence) (- 16; - 12; + 8 mg/dl respectively; p < 0.001). We found a greater LDL-cholesterol reduction in the participants with a basal LDL-cholesterol more than 152 mg/dl (15% for sterol-enriched yogurt and 12% for tomato sauce at high adherence). CONCLUSION: A novel functional tomato sauce from vine-ripened tomatoes compares favourably with a commercialised sterol-enriched yogurt in term of absolute LDL-cholesterol change. Intake of a tomato sauce with a high carotenoid content may support treatment of patients affected by common hypercholesterolemia. The present study has various limitations. The presence of other dietary components, which may have influenced the results, cannot be ruled out. Of course, these results cannot be extrapolated to other populations. Furthermore, there was a low adherence rate in the tomato sauce group. Moreover, we did not report serum carotenoids data. TRIAL REGISTRATION: ID: 13244115 on the ISRCTN registry, retrospectively registered in 2019-5-14. URL: http://www.isrctn.com/ISRCTN13244115.