N-glycosylation of CREBH improves lipid metabolism and attenuates lipotoxicity in NAFLD by modulating PPARα and SCD-1

Insights on post-translational modifications in fatty liver and fibrosis progression

Metabolic dysfunction-associated steatotic liver disease [MASLD] is a pervasive multifactorial health burden. Post-translational modifications [PTMs] of amino acid residues in protein domains demonstrate pivotal roles for imparting dynamic alterations in the cellular micro milieu. The crux of identifying novel druggable targets relies on comprehensively studying the etiology of metabolic disorders. This review article presents how different chemical moieties of various PTMs like phosphorylation, methylation, ubiquitination, glutathionylation, neddylation, acetylation, SUMOylation, lactylation, crotonylation, hydroxylation, glycosylation, citrullination, S-sulfhydration and succinylation presents the cause-effect contribution towards the MASLD spectra. Additionally, the therapeutic prospects in the management of liver steatosis and hepatic fibrosis via targeting PTMs and regulatory enzymes are also encapsulated. This review seeks to understand the function of protein modifications in progression and promote the markers discovery of diagnostic, prognostic and drug targets towards MASLD management which could also halt the progression of a catalogue of related diseases.

Current Therapeutic Landscape for Metabolic Dysfunction-Associated Steatohepatitis

In recent years, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been proposed to better connect liver disease to metabolic dysfunction, which is the most common chronic liver disease worldwide. MASLD affects more than 30% of individuals globally, and it is diagnosed by the combination of hepatic steatosis and obesity, type 2 diabetes, or two metabolic risk factors. MASLD begins with the buildup of extra fat, often greater than 5%, within the liver, causing liver hepatocytes to become stressed. This can proceed to a more severe form, metabolic dysfunction-associated steatohepatitis (MASH), in 20-30% of people, where inflammation in the liver causes tissue fibrosis, which limits blood flow over time. As fibrosis worsens, MASH may lead to cirrhosis, liver failure, or even liver cancer. While the pathophysiology of MASLD is not fully known, the current "multiple-hits" concept proposes that dietary and lifestyle factors, metabolic factors, and genetic or epigenetic factors contribute to elevated oxidative stress and inflammation, causing liver fibrosis. This review article provides an overview of the pathogenesis of MASLD and evaluates existing therapies as well as pharmacological drugs that are currently being studied in clinical trials for MASLD or MASH.

Therapeutic Targets and Approaches to Manage Inflammation of NAFLD

Non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), are the leading causes of chronic liver disease globally. They are driven by complex mechanisms where inflammation plays a pivotal role in disease progression. Current therapies, including lifestyle changes and pharmacological agents, are limited in efficacy, particularly in addressing the advanced stages of the disease. Emerging approaches targeting inflammation, metabolic dysfunction, and fibrosis offer promising new directions, though challenges such as treatment complexity and heterogeneity persist. This review concludes the main therapeutic targets and approaches to manage inflammation currently and emphasizes the critical need for future drug development and combination therapy for NAFLD/NASH management.

Site-specific analysis and functional characterization of N-linked glycosylation for β-Klotho protein

β-Klotho (KLB), a type I transmembrane protein, serves as an obligate co-receptor determining the tissue-specific actions of endocrine fibroblast growth factors (FGFs). Despite accumulative evidence suggesting the occurrence of N-glycosylation in the KLB protein, the precise N-glycosites, glycoforms, and the impacts of N-glycosylation on the expression and function of the KLB protein remain unexplored. Employing a mass spectrometry-based approach, a total of 12 N-glycosites displaying heterogeneous site occupancy and glycoforms were identified within the extracellular region of the recombinant human KLB protein. Molecular simulation revealed negligible impact of these N-glycans on the overall structure of the KLB protein. However, both pharmacological inhibition of N-glycosylation and mutagenesis targeting N-glycosites reduced mature KLB protein content without impacting KLB mRNA synthesis in cells, underscoring the critical role of N-glycosylation in maintaining the stability of the KLB protein. Further studies revealed that the underglycosylated KLB mutant underwent rapid degradation via both lysosomal and proteasomal pathways and was unable to be efficiently trafficked to the plasma membrane, leading to impaired FGF21 signaling transduction. Collectively, multisite N-glycosylation is essential for the stability and cell surface localization of the KLB protein, representing a novel modulatory mechanism of endocrine FGF signaling.

CREB3 protein family: the promising therapeutic targets for cardiovascular and metabolic diseases

Significant advancements in cardiovascular and metabolic disease research have been made with the CREB3 protein family. Studies have revealed that members of this family are crucial in the development of these diseases, contributing to the regulation of lipid metabolism, inflammation, and vascular function. These studies provide useful information for future therapeutic strategies in cardiovascular and metabolic diseases.

Protein posttranslational modifications in metabolic diseases: basic concepts and targeted therapies

Metabolism-related diseases, including diabetes mellitus, obesity, hyperlipidemia, and nonalcoholic fatty liver disease, are becoming increasingly prevalent, thereby posing significant threats to human health and longevity. Proteins, as the primary mediators of biological activities, undergo various posttranslational modifications (PTMs), including phosphorylation, ubiquitination, acetylation, methylation, and SUMOylation, among others, which substantially diversify their functions. These modifications are crucial in the physiological and pathological processes associated with metabolic disorders. Despite advancements in the field, there remains a deficiency in contemporary summaries addressing how these modifications influence processes of metabolic disease. This review aims to systematically elucidate the mechanisms through which PTM of proteins impact the progression of metabolic diseases, including diabetes, obesity, hyperlipidemia, and nonalcoholic fatty liver disease. Additionally, the limitations of the current body of research are critically assessed. Leveraging PTMs of proteins provides novel insights and therapeutic targets for the prevention and treatment of metabolic disorders. Numerous drugs designed to target these modifications are currently in preclinical or clinical trials. This review also provides a comprehensive summary. By elucidating the intricate interplay between PTMs and metabolic pathways, this study advances understanding of the molecular mechanisms underlying metabolic dysfunction, thereby facilitating the development of more precise and effective disease management strategies.

An insight into advances and challenges in the development of potential stearoyl Co-A desaturase 1 inhibitors

Stearoyl-CoA desaturase 1 (SCD1) is one of the key enzymes involved in lipid metabolism, plays a vital role in the synthesis of monounsaturated fatty acids (MUFAs) from saturated fatty acids (SFAs). Due to its promising therapeutic potential in treating metabolic disorders, cancers, and skin diseases there is an increasing interest in the development of novel inhibitors against SCD1. This review comprehensively explores the evolution of potential SCD1 inhibitors, focusing on systemic and liver-targeted inhibitors and discusses their structure-activity relationship (SAR) pattern. Among the various small molecules reported, natural products like sterculic acid have emerged as significant SCD1 inhibitors, highlighting the potential of naturally derived compounds in therapeutic development. This review also addresses the challenges in optimizing pharmacokinetic properties and reducing adverse effects, providing insights into the future directions for the development of potential novel SCD1 inhibitors with maximum therapeutic effect and minimum side effects.

Exploration of the Key Genes Involved in Non-alcoholic Fatty Liver Disease and Possible MicroRNA Therapeutic Targets

Background

MicroRNAs (miRNAs) are promising therapeutic agents for non-alcoholic fatty liver disease (NAFLD). This study aimed to identify key genes/proteins involved in NAFLD pathogenesis and progression and to evaluate miRNAs influencing their expression.

Methods

Gene expression profiles from datasets GSE151158, GSE163211, GSE135251, GSE167523, GSE46300, and online databases were analyzed to identify significant NAFLD-related genes. Then, protein-protein interaction networks and module analysis identified hub genes/proteins, which were validated using real-time PCR in oleic acid-treated HepG2 cells. Functional enrichment analysis evaluated signaling pathways and biological processes. Gene-miRNA interaction networks identified miRNAs targeting critical NAFLD genes.

Results

The most critical overexpressed hub genes/proteins included: TNF, VEGFA, TLR4, CYP2E1, ACE, SCD, FASN, SREBF2, and TGFB1 based on PPI network analysis, of which TNF, TLR4, SCD, FASN, SREBF2, and TGFB1 were up-regulated in oleic acid-treated HepG2 cells. Functional enrichment analysis for biological processes highlighted programmed necrotic cell death, lipid metabolic process response to reactive oxygen species, and inflammation. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the highest adjusted P-value signaling pathways encompassed AGE-RAGE in diabetic complications, TNF, and HIF-1 signaling pathways. In gene-miRNA network analysis, miR-16 and miR-124 were highlighted as the miRNAs exerting the most influence on important NAFLD-related genes.

Conclusion

In silico analyses identified NAFLD therapeutic targets and miRNA candidates to guide further experimental investigation.

Crosstalk between metabolism and cell death in tumorigenesis

It is generally recognized that tumor cells proliferate more rapidly than normal cells. Due to such an abnormally rapid proliferation rate, cancer cells constantly encounter the limits of insufficient oxygen and nutrient supplies. To satisfy their growth needs and resist adverse environmental events, tumor cells modify the metabolic pathways to produce both extra energies and substances required for rapid growth. Realizing the metabolic characters special for tumor cells will be helpful for eliminating them during therapy. Cell death is a hot topic of long-term study and targeting cell death is one of the most effective ways to repress tumor growth. Many studies have successfully demonstrated that metabolism is inextricably linked to cell death of cancer cells. Here we summarize the recently identified metabolic characters that specifically impact on different types of cell deaths and discuss their roles in tumorigenesis.

NAFLD and NASH: etiology, targets and emerging therapies

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) pose a significant threat to human health and cause a tremendous socioeconomic burden. Currently, the molecular mechanisms of NAFLD and NASH remain incompletely understood, and no effective pharmacotherapies have been approved. In the past five years, significant advances have been achieved in our understanding of the pathomechanisms and potential pharmacotherapies of NAFLD and NASH. Research advances include the investigation of the effects of the fibroblast growth factor 21 (FGF21) analog pegozafermin and the thyroid hormone receptor-β (THRβ) agonist resmetriom on hepatic fat content, NASH resolution and/or fibrosis regression. Future directions of NAFLD and NASH research (including combination therapy, organoids and humanized mouse models) are also discussed in this state-of-the-art review.

Medium- and long-chain triglyceride propofol activates PI3K/AKT pathway and inhibits non-alcoholic fatty liver disease by inhibiting lipid accumulation

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease. The mechanism by which medium- and long-chain triglyceride (MCT/LCT) propofol plays a role in promoting NAFLD remains unclear. In this study, we investigated the effect of MCT/LCT propofol on NAFLD progression and its mechanism of action. In Huh-7 and HepG3 cells induced by free fatty acids (FFA), propofol downregulated the expression levels of TG and lipid metabolism-related proteins by promoting the activation of the PI3K/AKT pathway and suppressing FFA-induced lipid metabolic disorders. In a high-fat diet (HFD) -induced NAFLD mouse model, we demonstrated that propofol significantly inhibited liver steatosis, inflammatory cell infiltration, and fibrosis. In conclusion, our results suggest that MCT/LCT propofol reduces liver lipid accumulation by activating the PI3K/AKT pathway and further suppressing the NAFLD process.

CREBH promotes autophagy to ameliorate NASH by regulating Coro1a

Dysfunctional autophagy aggravates oxidative stress and inflammation in hepatocytes and accelerates the progression of nonalcoholic steatohepatitis (NASH). Here, we demonstrated that cAMP-responsive element-binding protein H (CREBH) is a transcriptional regulator of hepatic autophagy in response to diet-induced NASH. The results showed that the upregulation of CREBH in lipid-overloaded hepatocytes improves cell damage, dysfunction of autophagic flux and associated abnormal accumulation of the autophagosome marker LC3-II and autophagic substrate p62. CREBH deficiency aggravated the dysfunctional autophagy and liver injury and even caused NASH-associated liver fibrosis. In addition, the changing trend of autolysosomes and lysosome membrane-associated protein (LAMP1) was consistent with the expression level of CREBH. This result indicated that CREBH might promote autophagic degradation by restoring the formation of autolysosomes, thereby improving the blocked autophagic flux. Moreover, we observed that CREBH inhibited the expression of Coronin 1a (Coro1a), an autophagosome-lysosome fusion-related gene, through transcriptional regulation. The overexpression of Coro1a in LO2 liver cells inhibited autophagic flux and elevated inflammatory cytokine levels upon palmitic acid (PA) stimulation. Overall, our findings provide new insights into the regulatory role of CREBH in the progression of NASH and reveal that Coro1a is a novel target gene of CREBH based on the autophagy pathway.

SCD1 is the critical signaling hub to mediate metabolic diseases: Mechanism and the development of its inhibitors

Metabolic diseases, featured with dysregulated energy homeostasis, have become major global health challenges. Patients with metabolic diseases have high probability to manifest multiple complications in lipid metabolism, e.g. obesity, insulin resistance and fatty liver. Therefore, targeting the hub genes in lipid metabolism may systemically ameliorate the metabolic diseases, along with the complications. Stearoyl-CoA desaturase 1(SCD1) is a key enzyme that desaturates the saturated fatty acids (SFAs) derived from de novo lipogenesis or diet to generate monounsaturated fatty acids (MUFAs). SCD1 maintains the metabolic and tissue homeostasis by responding to, and integrating the multiple layers of endogenous stimuli, which is mediated by the synthesized MUFAs. It critically regulates a myriad of physiological processes, including energy homeostasis, development, autophagy, tumorigenesis and inflammation. Aberrant transcriptional and epigenetic activation of SCD1 regulates AMPK/ACC, SIRT1/PGC1α, NcDase/Wnt, etc, and causes aberrant lipid accumulation, thereby promoting the progression of obesity, non-alcoholic fatty liver, diabetes and cancer. This review critically assesses the integrative mechanisms of the (patho)physiological functions of SCD1 in metabolic homeostasis, inflammation and autophagy. For translational perspective, potent SCD1 inhibitors have been developed to treat various types of cancer. We thus discuss the multidisciplinary advances that greatly accelerate the development of SCD1 new inhibitors. In conclusion, besides cancer treatment, SCD1 may serve as the promising target to combat multiple metabolic complications simultaneously.

Nuclear Receptor PPARα as a Therapeutic Target in Diseases Associated with Lipid Metabolism Disorders

Lipid metabolic diseases have substantial morbidity and mortality rates, posing a significant threat to human health. PPARα, a member of the peroxisome proliferator-activated receptors (PPARs), plays a crucial role in lipid metabolism and immune regulation. Recent studies have increasingly recognized the pivotal involvement of PPARα in diverse pathological conditions. This comprehensive review aims to elucidate the multifaceted role of PPARα in metabolic diseases including liver diseases, diabetes-related diseases, age-related diseases, and cancers, shedding light on the underlying molecular mechanisms and some regulatory effects of natural/synthetic ligands of PPARα. By summarizing the latest research findings on PPARα, we aim to provide a foundation for the possible therapeutic exploitation of PPARα in lipid metabolic diseases.

Exploring the underlying mechanisms of Ashitaba in the management of non-alcoholic fatty liver disease by integrating the analysis of transcriptomics and metabolomics

Ashitaba seems to improve glucose intolerance and decrease triglyceride (TG) and total cholesterol (TC), which contribute to the development of non-alcoholic fatty liver disease (NAFLD). However, it remains to be explored the mechanism of Ashitaba in managing NAFLD. We determined the impact of Ashitaba on NAFLD, particularly its underlying mechanisms at the bioinformatic level. The established NAFLD mouse model was treated with or without Ashitaba, and the underlying mechanism was explored using transcriptomics paired with metabolomics. Ashitaba reduced obesity and liver steatosis in NAFLD mice. It identified 429 differentially expressed genes (DEGs) and verified 45 differential metabolites, especially those that alleviate NAFLD via the FXR signaling pathway. Our data may provide insight into the therapeutic impact of Ashitaba in the management of NAFLD and may be useful in clinical interventions for NAFLD.

Targeting PPARs for therapy of atherosclerosis: A review

Atherosclerosis, a chief pathogenic factor of cardiovascular disease, is associated with many factors including inflammation, dyslipidemia, and oxidative stress. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors and are widely expressed with tissue- and cell-specificity. They control multiple genes that are involved in lipid metabolism, inflammatory response, and redox homeostasis. Given the diverse biological functions of PPARs, they have been extensively studied since their discovery in 1990s. Although controversies exist, accumulating evidence have demonstrated that PPAR activation attenuates atherosclerosis. Recent advances are valuable for understanding the mechanisms of action of PPAR activation. This article reviews the recent findings, mainly from the year of 2018 to present, including endogenous molecules in regulation of PPARs, roles of PPARs in atherosclerosis by focusing on lipid metabolism, inflammation, and oxidative stress, and synthesized PPAR modulators. This article provides information valuable for researchers in the field of basic cardiovascular research, for pharmacologists that are interested in developing novel PPAR agonists and antagonists with lower side effects as well as for clinicians.

O-GlycNacylation Remission Retards the Progression of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease spectrum associated with insulin resistance (IR), from non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma (HCC). O-GlcNAcylation is a posttranslational modification, regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Abnormal O-GlcNAcylation plays a key role in IR, fat deposition, inflammatory injury, fibrosis, and tumorigenesis. However, the specific mechanisms and clinical treatments of O-GlcNAcylation and NAFLD are yet to be elucidated. The modification contributes to understanding the pathogenesis and development of NAFLD, thus clarifying the protective effect of O-GlcNAcylation inhibition on liver injury. In this review, the crucial role of O-GlcNAcylation in NAFLD (from NAFL to HCC) is discussed, and the effect of therapeutics on O-GlcNAcylation and its potential mechanisms on NAFLD have been highlighted. These inferences present novel insights into the pathogenesis and treatments of NAFLD.

CREBH alleviates mitochondrial oxidative stress through SIRT3 mediating deacetylation of MnSOD and suppression of Nlrp3 inflammasome in NASH

Lipotoxicity and unresolved oxidative stress are key drivers of metabolic inflammation in nonalcoholic steatohepatitis (NASH). cAMP-response element binding protein H(CREBH) is a liver-specific transcription factor and regulates the glucose and lipid metabolism of NASH. However, its role in mitochondrial oxidative stress and its association with sirtuin 3 (SIRT3), a master regulator of deacetylation for mitochondrial proteins, remains elusive. In this study, AML-12 cells were treated with palmitic acid to imitate the pathological changes of NASH in vitro and 8-week-old male C57BL/6J mice were fed with a high-fat (HF) diet or a methionine-choline-deficient (MCD) diet to build the widely accepted in vivo model of NASH. We found that lipid overload induced mitochondrial oxidative stress and stimulated the expression of CREBH and SIRT3. CREBH overexpression alleviated the mitochondrial oxidative stress. Moreover, CREBH promoted SIRT3 expression, which regulated the deacetylation of manganese superoxide dismutase (MnSOD) and inhibited NOD-Like Receptor Pyrin Domain Containing 3 (Nlrp3) inflammasome activation whereas suppression of SIRT3 damaged the protecting ability of CREBH in mitochondrial oxidative stress. CREBH knockout mice were highly susceptible to HF and MCD diet-induced NASH with more severe oxidative stress. Collectively, our results firstly provided the support that CREBH could serve as a protective factor in the progression of NASH by regulating the acetylation of MnSOD and the activation of Nlrp3 inflammasome through SIRT3. These results suggest that CREBH might be a valuable therapeutic candidate for NASH.

The Role and Mechanism of CREBH Regulating SIRT3 in Metabolic Associated Fatty Liver Disease

AIMS

To investigate the effect of cAMP response element-binding protein H (CREBH) on metabolic associated fatty liver disease by regulating sirtuin 3 (SIRT3).

MAIN METHODS

Two mouse models of fatty liver induced by a methionine-choline deficient (MCD) diet and a high-fat (HF) diet and an in vitro model of palmitic acid (PA) induced lipid-overloaded hepatocytes were constructed to detect the expression of CREBH, SIRT3, total acetylation, and downstream protein interactions and lipid metabolism phenotype, which were further validated in CREBH^-/- mice and lentivirus-overexpressing CREBH hepatocytes.

KEY FINDINGS

In fatty liver and lipid overload models, the expressions of CREBH and SIRT3 were down-regulated and their expression was positively correlated, accompanied by an increase in the level of total protein acetylation. Overexpression of CREBH alleviated excess lipid accumulation, impaired viability, and the ability to metabolize energy through the fatty acid oxidation pathway in hepatocytes in vitro. Furthermore, overexpression of CREBH restored the interaction of the deacetylase SIRT3 with the molecules carnitine palmitoyl-transferase 2 (CPT2) and long-chain acyl CoA dehydrogenase (ACADL) involved in the fatty acid oxidation pathway and their deacetylation status. However, CREBH^-/- aggravated the damage of lipid metabolism in the liver tissue of mice.

SIGNIFICANCE

CREBH increased the enzymatic activity of downstream factors by positively regulating the expression of SIRT3, which promoted the oxidative decomposition of fatty acids in hepatocytes and played an important role in fatty acid oxidation in MAFLD.

Synergistic effects of ISL1 and KDM6B on non-alcoholic fatty liver disease through the regulation of SNAI1

Background

The increasing incidence of non-alcoholic fatty liver disease (NAFLD) has been reported worldwide, which urges understanding of its pathogenesis and development of more effective therapeutical methods for this chronic disease. In this study, we aimed to investigate the effects of a LIM homeodomain transcription factor, islet1 (ISL1) on NAFLD.

Methods

Male C57BL/6J mice were fed with a diet high in fat content to produce NAFLD models. These models were then treated with overexpressed ISL1 (oe-ISL1), oe-Lysine-specific demethylase 6B (KDM6B), oe-SNAI1, or short hairpin RNA against SNAI1. We assessed triglyceride and cholesterol contents in the plasma and liver tissues and determined the expressions of ISL1, KDM6B and SNAI1 in liver tissues. Moreover, the in vitro model of lipid accumulation was constructed using fatty acids to explore the in vitro effect of ISL1/KDM6B/SNAI1 in NAFLD.

Results

The results showed that the expressions of ISL1, KDM6B, and SNAI1 where decreased, but contents of triglyceride and cholesterol increased in mice exposed to high-fat diet. ISL1 inhibited lipogenesis and promoted lipolysis and exhibited a synergizing effect with KDM6B to upregulate the expression of SNAI1. Moreover, both KDM6B and SNAI1 could inhibit lipogenesis and induce lipolysis. Importantly, the therapeutic effects of ISL1 on in vitro model of lipid accumulations was also confirmed through the modulation of KDM6B and SNAI1.

Conclusions

Taken together, these findings highlighted that ISL1 effectively ameliorated NAFLD by inducing the expressions of KDM6B and SNAI1, which might be a promising drug for the treatment of NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00428-7.

Stearoyl-CoA desaturase 1: A potential target for non-alcoholic fatty liver disease?-perspective on emerging experimental evidence

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease and one of the leading causes of death. An unnamed disease has become a global epidemic disease of public health concern. This spectrum of diseases manifests itself with initial accumulation of excessive triglycerides (due to de novo lipogenesis) in the hepatocytes, leading to simple steatosis. Although its aetiology is multi-factorial, lifestyle changes (diet and physical activity) are considered to be the key thriving factors. In this context, high fructose consumption is associated with an increased risk for developing NAFLD in humans, while high-fructose feeding to experimental animals results in hepatic steatosis and non-alcoholic steatohepatitis, by increasing hepatic lipogenesis. Among several lipogenic genes, the endoplasmic reticulum-bound stearoyl-CoA desaturase 1 (SCD1) is the key determinant of triglycerides biosynthesis pathway, by providing monounsaturated fatty acids, through the incorporation of a double bond at the delta-9 position of saturated fatty acids, specifically, palmitic (C16:0) and stearic (C18:0) acids, yielding palmitoleic (C16:1) and oleic (C18:1) acids, respectively. Various experimental studies involving SCD1 gene knockout and diet-induced rodent models have demonstrated that SCD1 plays a key role in the development of NAFLD, by modulating hepatic lipogenesis and thus triglyceride accumulation in the liver. Several pharmacological and dietary intervention studies have shown the benefits of inhibiting hepatic SCD1 in the pathogenesis of NAFLD. In this review, we give an overview of SCD1 in NAFLD, based on the current experimental evidence and the translational applicability of SCD1 inhibition in human NAFLD conditions, besides discussing the limitations and way-forward.

Mitochondrial Lipid Homeostasis at the Crossroads of Liver and Heart Diseases

The prevalence of NAFLD (non-alcoholic fatty liver disease) is a rapidly increasing problem, affecting a huge population around the globe. However, CVDs (cardiovascular diseases) are the most common cause of mortality in NAFLD patients. Atherogenic dyslipidemia, characterized by plasma hypertriglyceridemia, increased small dense LDL (low-density lipoprotein) particles, and decreased HDL-C (high-density lipoprotein cholesterol) levels, is often observed in NAFLD patients. In this review, we summarize recent genetic evidence, proving the diverse nature of metabolic pathways involved in NAFLD pathogenesis. Analysis of available genetic data suggests that the altered operation of fatty-acid β-oxidation in liver mitochondria is the key process, connecting NAFLD-mediated dyslipidemia and elevated CVD risk. In addition, we discuss several NAFLD-associated genes with documented anti-atherosclerotic or cardioprotective effects, and current pharmaceutical strategies focused on both NAFLD treatment and reduction of CVD risk.