Fatty Acid Synthase Inhibitor Platensimycin Intervenes the Development of Nonalcoholic Fatty Liver Disease in a Mouse Model

Therapeutic Nanomaterials in NAFLD: Current Advances and Potential Applications in Patients with Concurrent HBV Infection

Due to the high prevalence of non-alcoholic fatty liver disease (NAFLD) and chronic hepatitis B virus (HBV) infection, a significant proportion of patients suffer from both conditions simultaneously. The management of NAFLD in patients with concurrent HBV infection presents unique challenges, primarily due to the complex interplay between these two diseases. Nanomaterials have gained widespread attention due to their ability to overcome the limitations of conventional therapies. This review provides an overview of the current advances in therapeutic nanomaterials for NAFLD and explores their potential applications for personalized and effective management in patients with concurrent HBV infection. Furthermore, we discuss the challenges and future directions in the development of nanomaterials for the treatment of coexisting liver diseases.

Targeting fatty acid synthase reduces aortic atherosclerosis and inflammation

Fatty acid synthase (FAS) is predominantly expressed in the liver and adipose tissue. It plays vital roles in de novo synthesis of saturated fatty acids and regulates insulin sensitivity. We previously demonstrated that serum circulating FAS (cFAS) is a clinical biomarker for advanced atherosclerosis, and that it is conjugated to low-density lipoproteins (LDL). However, it remains unknown whether cFAS can directly impact atheroprogression. To investigate this, we evaluate whether cFAS impacts macrophage foam cell formation - an important cellular process leading to atheroprogression. Macrophages exposed to human serum containing high levels of cFAS show increased foam cell formation as compared to cells exposed to serum containing low levels of cFAS. This difference is not observed using serum containing either high or low LDL. Pharmacological inhibition of cFAS using Platensimycin (PTM) decreases foam cell formation in vitro. In Apoe-/- mice with normal FAS expression, administration of PTM over 16 weeks along with a high fat diet decreases cFAS activity and aortic atherosclerosis without affecting circulating total cholesterol. This effect is also observed in Apoe-/- mice with liver-specific knockout of hepatic Fasn. Reductions in aortic root plaque are associated with decreased macrophage infiltration. These findings demonstrate that cFAS plays an important role in arterial atheroprogression.

Lipid nanosystems for fatty liver therapy and targeted medication delivery: a comprehensive review

Fatty liver is considered to be the most common chronic liver disease with a high global incidence, which can lead to cirrhosis and liver cancer in severe cases, and there is no specific drug for the treatment of fatty liver in the clinic. The use of lipid nanosystems has the potential to be an effective means of fatty liver treatment. The pathogenesis and intervening factors associated with the development of fatty liver are reviewed, and the advantages and the disadvantages of different lipid nanosystems for the treatment of fatty liver are comprehensively discussed, including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, microemulsions, and phospholipid complexes. The composition and characterisation of these lipid nanosystems are highlighted and summarised with a view to improving the efficiency of lipid nanosystems for the treatment of fatty liver. In addition, active targeting and passive targeting strategies used for fatty liver therapy are discussed in detail.

Nano-drug delivery systems (NDDS) in metabolic dysfunction-associated steatotic liver disease (MASLD): current status, prospects and challenges

About one-third of the global population suffers from metabolic dysfunction-associated steatotic liver disease (MASLD), but specific treatments for MASLD have long been lacking, primarily due to the unclear etiology of the disease. In addition to lifestyle modifications and weight loss surgery, pharmacotherapy is the most common treatment among MASLD patients, and these drugs typically target the pathogenic factors of MASLD. However, bioavailability, efficacy, and side effects all limit the maximum therapeutic potential of the drugs. With the development of nanomedicine, recent years have seen attempts to combine MASLD pharmacotherapy with nanomaterials, such as liposomes, polymer nanoparticles, micelles, and cocrystals, which effectively improves the water solubility and targeting of the drugs, thereby enhancing therapeutic efficacy and reducing toxic side effects, offering new perspectives and futures for the treatment of MASLD.

PF-05231023 reduces lipid deposition in apolipoprotein E-deficient mice by inhibiting the expression of lipid synthesis genes

Fibroblast growth factor 21 (FGF21) is a peptide hormone that is primarily expressed and secreted by the liver. The hormone is crucial for regulation of glucose homeostasis, lipid metabolism, and energy balance. Compared with natural FGF21, FGF21 analogs have become drug candidates for the treatment of cardiovascular and metabolic diseases owing to their long half-life and greater stability in vitro. Apolipoprotein E (Apoe)-knockout (Apoe -/-) mice exhibit progressive disruptions in lipid metabolism in vivo and develop further atherosclerosis pathological features owing to Apoe deletion. Therefore, this study used an Apoe -/- mouse model to investigate the effects of a long-acting FGF21 analog (PF-05231023) on lipid metabolism and related parameters. Eighteen Apoe -/- female mice were fed a Western diet equivalent for 12 weeks, and then randomly assigned to intraperitoneally receive either physiological saline (the control group) or 10 mg/kg PF-05231023 (the treatment group) three times a week for seven consecutive weeks. Body composition, glucose tolerance, blood and liver cholesterol, triglyceride levels, liver vacuolization levels, peri-ovarian white adipocyte hypertrophy, aortic atherosclerotic plaque formation, and the expression of genes related to lipid metabolism in adipose tissue were subsequently assessed before and after treatment. The aortic atherosclerotic plaque area was reduced in mice in the PF-05231023 treatment group compared with that in the saline group. Although the effect of PF-05231023 on the plasma biochemical indexes of mice was small, it significantly reduced lipid levels and lipid droplet accumulation in the liver, and reduced adipocyte hypertrophy in white adipose tissue. Transcriptome analysis of adipose tissue showed that PF-05231023 treatment downregulated the expression of lipid synthesis-related genes and inhibited the sterol regulatory element binding transcription factor 1 gene, thereby improving lipid deposition. PF-05231023 effectively improved the lipid metabolism of Apoe -/- mice, demonstrating an anti-atherosclerotic effect and providing a scientific basis and experimental foundation for the clinical treatment of cardiovascular diseases by using long-acting FGF21 analogs.

Inhibitory Effects of the Polyphenols from the Root of Rhizophora apiculata Blume on Fatty Acid Synthase Activity and Human Colon Cancer Cells

Marine mangrove vegetation has been traditionally employed in folk medicine to address various ailments. Notably, Rhizophora apiculata Blume has exhibited noteworthy properties, demonstrating efficacy against cancer, viruses, and bacteria. The enzyme fatty acid synthase (FAS) plays a pivotal role in de novo fatty acid synthesis, making it a promising target for combating colon cancer. Our study focused on evaluating the FAS inhibitory effects of both the crude extract and three isolated compounds from R. apiculata. The n-butanol fraction of R. apiculata extract (BFR) demonstrated a significant inhibition of FAS, with an IC50 value of 93.0 µg/mL. For inhibition via lyoniresinol-3α-O-β-rhamnopyranoside (LR), the corresponding IC50 value was 20.1 µg/mL (35.5 µM). LR competitively inhibited the FAS reaction with acetyl-CoA, noncompetitively with malonyl-CoA, and in a mixed manner with NADPH. Our results also suggest that both BFR and LR reversibly bind to the KR domain of FAS, hindering the reduction of saturated acyl groups in fatty acid synthesis. Furthermore, BFR and LR displayed time-dependent inhibition for FAS, with kobs values of 0.0045 min-1 and 0.026 min-1, respectively. LR also exhibited time-dependent inhibition on the KR domain, with a kobs value of 0.019 min-1. In human colon cancer cells, LR demonstrated the ability to reduce viability and inhibit intracellular FAS activity. Notably, the effects of LR on human colon cancer cells could be reversed with the end product of FAS-catalyzed chemical reactions, affirming the specificity of LR on FAS. These findings underscore the potential of BFR and LR as potent FAS inhibitors, presenting novel avenues for the treatment of human colon cancer.

Intervention effect of Cigu Xiaozhi prescription on ceramide lipoapoptosis in non-alcoholic fatty liver disease

OBJECTIVE

To explore the mechanism of the Chinese medicine Cigu Xiaozhi prescription (, CGXZ) in the treatment of the non-alcoholic fatty liver disease (NAFLD) by detoxification and phlegm-reducing, the effect of CGXZ prescription on ceramide-mediated lipid apoptosis in Hep G2 cells with NAFLD.

METHODS

The experiment was randomly divided into 6 groups: normal control group, model group, CGXZ prescription medicated serum high, medium, and low dose groups, and pioglitazone positive control group. Using 500 μmol/L free fatty acid (FFA) mixture to induce Hep G2 cells to establish NAFLD cell model, respectively, with 2%, 4%, and 6% concentration of CGXZ prescription medicated serum intervention for 24 h. The changes in organelles and lipid droplet accumulation were observed under the electron microscope. Furthermore, TdT-mediated dUTP Nick-End Labeling method was used to assay hepatocyte apoptosis; Biochemical determination of glutamic-pyruvic transaminase, glutamic oxalacetic transaminase, triglycerides, and FFA levels in Hep G2 cells; the content of ceramide was determined by high-performance thin-layer chromatography. Finally, Western Blot and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the protein and gene expression levels, such as inducible nitric oxide synthase (iNOS), nuclear factor κB (NF-κB), B cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax).

RESULTS

Under the electron microscope, the cells in the model group showed moderate-to-severe steatosis, and apoptotic bodies could be seen. The model group had greater improvements in the apoptosis rate (P < 0.01), and the levels of ceramide C2 and FFA in the cytoplasm (P < 0.01) than the normal control group. The protein expressions of NF-κB, iNOS, and Bax were significantly up-regulated (P < 0.05), while the Bcl-2 had no significant change (P > 0.05). Compared with the model group, the levels of ceramide C2 and FFA (P < 0.01), the protein expressions of NF-κB, iNOS, and Bax (P < 0.05) in the CGXZ prescription treatment group and pioglitazone positive control group were significantly decreased; Only the Bcl-2 protein was significantly up-regulated in the high-dose Chinese medicine group (P < 0.05). The down-regulation of Bax mRNA expression in each Chinese medicine treatment group was significantly better than in the pioglitazone positive control group (P < 0.01).

CONCLUSIONS

The CGXZ prescription, formulated with the method of detoxification and phlegm, can inhibit lipoapoptosis in the NAFLD cell model by down-regulating the levels of ceramide C2 and FFA, which may be achieved by regulating ceramide/iNOS/NF-κB signaling pathway.

TRIM56 protects against nonalcoholic fatty liver disease by promoting the degradation of fatty acid synthase

Nonalcoholic fatty liver disease (NAFLD) encompasses a disease continuum from simple steatosis to nonalcoholic steatohepatitis (NASH). However, there are currently no approved pharmacotherapies for NAFLD, although several drugs are in advanced stages of clinical development. Because of the complex pathophysiology and heterogeneity of NAFLD, the identification of potential therapeutic targets is clinically important. Here, we demonstrated that tripartite motif 56 (TRIM56) protein abundance was markedly downregulated in the livers of individuals with NAFLD and of mice fed a high-fat diet. Hepatocyte-specific ablation of TRIM56 exacerbated the progression of NAFLD, while hepatic TRIM56 overexpression suppressed it. Integrative analyses of interactome and transcriptome profiling revealed a pivotal role of TRIM56 in lipid metabolism and identified the lipogenesis factor fatty acid synthase (FASN) as a direct binding partner of TRIM56. TRIM56 directly interacted with FASN and triggered its K48-linked ubiquitination-dependent degradation. Finally, using artificial intelligence-based virtual screening, we discovered an orally bioavailable small-molecule inhibitor of FASN (named FASstatin) that potentiates TRIM56-mediated FASN ubiquitination. Therapeutic administration of FASstatin improved NAFLD and NASH pathologies in mice with an optimal safety, tolerability, and pharmacokinetics profile. Our findings provide proof of concept that targeting the TRIM56/FASN axis in hepatocytes may offer potential therapeutic avenues to treat NAFLD.

Si-Ni-San inhibits hepatic Fasn expression and lipid accumulation in MAFLD mice through AMPK/p300/SREBP-1c axis

BACKGROUND

Soothing the liver and regulating qi is one of the core ideas of traditional Chinese medicine (TCM) in the treatment of fatty liver. Si-Ni-San (SNS) is a well-known herbal formula in TCM for liver soothing and qi regulation in fatty liver treatment. However, its efficacy lacks modern scientific evidence.

PURPOSE

This study was aimed to investigate the impact of SNS on metabolic associated fatty liver disease (MAFLD) in mice and explore the underlying molecular mechanisms, particularly its effects on lipid metabolism in hepatocytes.

METHODS

The therapeutic effect of SNS was evaluated using in vivo and in vitro models of high-fat/high-cholesterol (HFHC) diet-induced mice and palmitic acid (PA)-induced hepatocytes, respectively. Molecular biological techniques such as RNA-sequencing (RNA-seq), co-immunoprecipitation (co-IP), and western blotting were employed to elucidate the molecular mechanism of SNS in regulating lipid metabolism in hepatocytes.

RESULTS

Our findings revealed that SNS effectively reduced lipid accumulation in the livers of HFHC diet-induced mice and PA-induced hepatocytes. RNA-seq analysis demonstrated that SNS significantly down-regulated the expression of fatty acid synthase (Fasn) in the livers of HFHC-fed mice. Mechanistically, SNS inhibited Fasn expression and lipid accumulation by activating adenosine monophosphate (AMP)-activated protein kinase (AMPK). Activation of AMPK suppressed the activity of the transcriptional coactivator p300 and modulated the protein stability of sterol regulatory element-binding protein-1c (SREBP-1c). Importantly, p300 was required for the inhibition of Fasn expression and lipid accumulation by SNS. Furthermore, SNS activated AMPK by decreasing adenosine triphosphate (ATP) production in hepatocytes.

CONCLUSION

This study provided novel evidence on the regulatory mechanisms underlying the effects of SNS on Fasn expression. Our findings demonstrate, for the first time, that SNS exerts suppressive effects on Fasn expression through modulation of the AMPK/p300/SREBP-1c axis. Consequently, this regulatory pathway mitigates excessive lipid accumulation and ameliorates MAFLD in mice.

Liposome-Based Silibinin for Mitigating Nonalcoholic Fatty Liver Disease: Dual Effects via Parenteral and Intestinal Routes

Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological entity that is typically characterized by intrahepatic ectopic steatosis. Nowadays, NAFLD has surpassed viral hepatitis and become the most common chronic liver disease worldwide, which poses a great threat to human health. Silibinin (Sil), a well-known natural product, has been widely used in clinical treatment for liver disorders and exhibited therapeutic potential for NAFLD. However, the suitability of Sil for NAFLD treatment still requires further investigation due to its limited absorption and low bioavailability. This study aimed to construct a Sil-loaded liposome (Sil-Lip) to overcome the limitations of Sil, thereby enhancing its beneficial effects on NAFLD and then investigate the underlying mechanisms of action of Sil-Lip. Herein, Sil-Lip was fabricated by a well-established thin-film dispersion method and carefully characterized, followed by evaluating their therapeutic efficacy using high-fat diet-induced NAFLD mice and free fatty acid -stimulated HepG2 cells. Then, liver transcriptome analysis and 16S ribosomal RNA (16S rRNA) sequencing were utilized to elucidate the potential mechanisms of action of Sil-Lip. Our data indicated that Sil-Lip harbored good gastrointestinal tract stability, mucus layer permeation, and excellent oral absorption and bioavailability. In vivo and in vitro NAFLD models demonstrated that Sil-Lip had better effects in alleviating lipid metabolism disorders, insulin resistance, and inflammation than did Sil alone. Further investigations revealed that the beneficial effects of Sil-Lip were mediated by modulating intrahepatic insulin resistance-related and nuclear factor-kappa B (NF-κB) signaling pathways and extrahepatic gut microbiota. Our study confirmed that Sil-Lip can effectively improve the absorption and bioavailability of Sil, resultantly potentiating its ameliorative effects on NAFLD through modulating intrahepatic insulin resistance-related and NF-κB signaling pathways and extrahepatic gut microbiota.

Recent updates on targeting the molecular mediators of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common disease worldwide in an era of rapid economic growth. NAFLD is a multifactorial disease, involving multiple genetic, metabolic, and environmental factors, and is closely associated with metabolic syndrome, obesity, and cardiovascular disease. NAFLD can be classified into nonalcoholic fatty liver disease (NAFL) and nonalcoholic steatohepatitis (NASH), which can both progress to cirrhosis and even hepatocellular carcinoma (HCC). Due to the enormous burden of NAFLD and its complications, no FDA-approved drugs for the treatment of NAFLD are on the market, and therapeutic targets and drug therapies are being actively investigated. In view of the various pathological mechanisms of NAFLD, numbers of preclinical studies and clinical trials have made rapid progress. This review mainly summarizes the most recently characterized mechanisms and therapeutic targets in each mechanism of NAFLD, focusing on the mechanism and application potential.

Therapeutic Effect of Polymeric Nanomicelles Formulation of LY2157299-Galunisertib on CCl4-Induced Liver Fibrosis in Rats

Hepatic fibrosis (HF) is a major cause of liver-related disorders and together with cancer-associated fibroblasts can favor liver cancer development by modulating the tumor microenvironment. Advanced HF, characterized by an excess of extracellular matrix (ECM), is mediated by TGF- β1, that activates hepatic stellate cells (HSCs) and fibroblasts. A TGF-β1 receptor inhibitor, LY2157299 or Galunisertib (GLY), has shown promising results against chronic liver progression in animal models, and we show that it can be further improved by enhancing GLYs bioavailability through encapsulation in polymeric polygalacturonic-polyacrylic acid nanomicelles (GLY-NMs). GLY-NMs reduced HF in an in vivo rat model of liver fibrosis induced by intraperitoneal injection of CCl₄ as shown by the morphological, biochemical, and molecular biology parameters of normal and fibrotic livers. Moreover, GLY-NM was able to induce recovery from HF better than free GLY. Indeed, the encapsulated drug reduces collagen deposition, hepatic stellate cells (HSCs) activation, prevents fatty degeneration and restores the correct lobular architecture of the liver as well as normalizes the serum parameters and expression of the genes involved in the onset of HF. In summary, GLY-NM improved the pharmacological activity of the free TGF- β1 inhibitor in the in vivo HF treatment and thus is a candidate as a novel therapeutic strategy.