Targeting mTOR/YY1 signaling pathway by quercetin through CYP7A1-mediated cholesterol-to-bile acids conversion alleviated type 2 diabetes mellitus induced hepatic lipid accumulation

Genome-Wide Profiling of H3K27ac Identifies TDO2 as a Pivotal Therapeutic Target in Metabolic Associated Steatohepatitis Liver Disease

H3K27ac has been widely recognized as a representative epigenetic marker of active enhancer, while its regulatory mechanisms in pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD) remain elusive. Here, a genome-wide comparative study on H3K27ac activities and transcriptome profiling in high fat diet (HFD)-induced MASLD model is performed. A significantly enhanced H3K27ac density with abundant alterations of regulatory transcriptome is observed in MASLD rats. Based on integrative analysis of ChIP-Seq and RNA-Seq, TDO2 is identified as a critical contributor for abnormal lipid accumulation, transcriptionally activated by YY1-promoted H3K27ac. Furthermore, TDO2 depletion effectively protects against hepatic steatosis. In terms of mechanisms, TDO2 activates NF-κB pathway to promote macrophages M1 polarization, representing a crucial event in MASLD progression. A bovine serum albumin nanoparticle is fabricated to provide sustained release of Allopurinol (NPs-Allo) for TDO2 inhibition, possessing excellent biocompatibility and desired targeting capacity. Venous injection of NPs-Allo robustly alleviates HFD-induced metabolic disorders. This study reveals the pivotal role of TDO2 and its underlying mechanisms in pathogenesis of MASLD epigenetically and genetically. Targeting H3K27ac-TDO2-NF-κB axis may provide new insights into the pathogenesis of abnormal lipid accumulation and pave the way for developing novel strategies for MASLD prevention and treatment.

Quercetin represses cholesterol metabolism and mitigates resistance to cisplatin in oral squamous cell carcinoma by regulating AGR2/AKT/SREBP2 axis

Purpose

This study aimed to explore the effects of quercetin on cholesterol metabolism and cisplatin sensitivity in oral squamous cell carcinoma (OSCC) cell line (CAL27) and investigate the potential molecular mechanisms.

Methods

CAL27 cells were exposed to quercetin or cisplatin after upregulation or downregulation of AGR2. The expression of proteins and genes associated with cholesterol metabolism were assessed. The levels of cholesterol and LDL were also measured, and the cisplatin sensitivity of CAL27 cells was analyzed.

Results

RNA high-throughput sequencing revealed that after treatment with quercetin, the expression of AGR2 was significantly reduced in cisplatin-resistant CAL27 cells (CAL-27R), which was associated with lipid metabolism. AGR2 deletion ameliorated but its overexpression exacerbated cisplatin resistance and cholesterol metabolism, evidenced by changes in SQLE, HMGCS, LDLR, and n-SREBP2 expression and cholesterol and LDL levels. Moreover, AGR2 promoted cisplatin resistance by activating the AKT signaling pathway and enhancing SREBP2-mediated cholesterol metabolism. Quercetin increased cisplatin sensitivity by repressing cholesterol metabolism but suppressed the AGR2/AKT/SREBP2 signaling pathway in a concentration-dependent manner. These effects were partly reversed by AGR2 overexpression and AKT activation.

Conclusion

Our findings demonstrated that quercetin inhibits cholesterol metabolism and cisplatin resistance in CAL27 cells by modulating the AGR2/AKT/SREBP2 axis.

Jujuboside A through YY1/CYP2E1 signaling alleviated type 2 diabetes-associated fatty liver disease by ameliorating hepatic lipid accumulation, inflammation, and oxidative stress

Non-alcoholic fatty liver disease (NAFLD) was a chronic complication of type 2 diabetes mellitus (T2DM), and this comorbid disease lacked therapeutic drugs. Semen Ziziphi Spinosae (SZS) was the seed of Ziziphus jujuba var. Spinosa (Bunge) Hu ex H.F. Chow, and it could alleviate the symptoms of T2DM patients. As a triterpene saponin, Jujuboside A (Ju A) was the main active substance isolated from SZS and could improve hyperglycemia of diabetic mice. However, it was still unknown whether Ju A has protective effects on T2DM-associated NAFLD. Our study showed that Ju A attenuated T2DM-associated liver damage by alleviating hepatic lipid accumulation, inflammatory response, and oxidative stress in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-stimulated human hepatocellular carcinomas (HepG2) cells. Along with the improved hyperglycemia and liver injury, Ju A restrained Yin Yang 1 (YY1)/cytochrome P450 2E1 (CYP2E1) signaling in vivo and in vitro. YY1 overexpression intercepted the protective effects of Ju A on T2DM-induced liver injury via promoting hepatic lipid accumulation, inflammatory response, and oxidative stress. While, the blocking effect of YY1 overexpression on Ju A's hepatoprotective effect was counteracted by further treatment of CYP2E1 specific inhibitor diethyldithiocarbamate (DDC) in vitro. In-depth mechanism research showed that Ju A through YY1/CYP2E1 signaling promoted hepatic fatty acid β-oxidation, and inhibited inflammatory response and oxidative stress by activating peroxisome proliferator-activated receptor alpha (PPARα), leading to the improvement of T2DM-associated NAFLD. Ju A might be a potential agent in the treatment and health care of T2DM-associated liver disease, especially NAFLD.

Role of HSP90 in Type 2 Diabetes Mellitus and Its Association with Liver Diseases

Non-alcoholic fatty acid liver disease (NAFLD), non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) are the fatal liver diseases which encompass a spectrum of disease severity associated with increased risk of type 2 diabetes mellitus (T2DM), a metabolic disorder. Heat shock proteins serve as markers in early prognosis and diagnosis of early stages of liver diseases associated with metabolic disorder. This review aims to comprehensively investigate the significance of HSP90 isoforms in T2DM and liver diseases. Additionally, we explore the collective knowledge on plant-based drug compounds that regulate HSP90 isoform targets, highlighting their potential in treating T2DM-associated liver diseases. Furthermore, this review focuses on the computational systems' biology and next-generation sequencing technology approaches that are used to unravel the potential medicine for the treatment of pleiotropy of these 2 diseases and to further elucidate the mechanism.

Unlocking Cholesterol Metabolism in Metabolic-Associated Steatotic Liver Disease: Molecular Targets and Natural Product Interventions

Metabolic-associated steatotic liver disease (MASLD), the hepatic manifestation of metabolic syndrome, represents a growing global health concern. The intricate pathogenesis of MASLD, driven by genetic, metabolic, epigenetic, and environmental factors, leads to considerable clinical variability. Dysregulation of hepatic lipid metabolism, particularly cholesterol homeostasis, is a critical factor in the progression of MASLD and its more severe form, metabolic dysfunction-associated steatohepatitis (MASH). This review elucidates the multifaceted roles of cholesterol metabolism in MASLD, focusing on its absorption, transportation, biosynthesis, efflux, and conversion. We highlight recent advancements in understanding these processes and explore the therapeutic potential of natural products such as curcumin, berberine, and resveratrol in modulating cholesterol metabolism. By targeting key molecular pathways, these natural products offer promising strategies for MASLD management. Finally, this review also covers the clinical studies of natural products in MASLD, providing new insights for future research and clinical applications.

Emerging mechanisms of non-alcoholic steatohepatitis and novel drug therapies

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of chronic liver disease globally. It initiates with simple steatosis (NAFL) and can progress to the more severe condition of non-alcoholic steatohepatitis (NASH). NASH often advances to end-stage liver diseases such as liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Notably, the transition from NASH to end-stage liver diseases is irreversible, and the precise mechanisms driving this progression are not yet fully understood. Consequently, there is a critical need for the development of effective therapies to arrest or reverse this progression. This review provides a comprehensive overview of the pathogenesis of NASH, examines the current therapeutic targets and pharmacological treatments, and offers insights for future drug discovery and development strategies for NASH therapy.

Role of FXR in the development of NAFLD and intervention strategies of small molecules

Non-alcoholic fatty liver disease (NAFLD) remains a prevailing etiological agent behind hepatocyte diseases like chronic liver disease. The spectrum of processes involved in NAFLD stages includes hepatic steatosis, non-alcoholic fatty liver, and non-alcoholic steatohepatitis (NASH). Without intervention, the progression of NASH can further deteriorate into cirrhosis and ultimately, hepatocellular carcinoma. The cardinal features that characterize NAFLD are insulin resistance, lipogenesis, oxidative stress and inflammation, extracellular matrix deposition and fibrosis. Due to its complex pathogenesis, existing pharmaceutical agents fail to take a curative or ameliorative effect on NAFLD. Consequently, it is imperative to identify novel therapeutic targets and strategies for NAFLD, ideally to improve the aforementioned key features in patients. As an enterohepatic regulator of bile acid homeostasis, lipid metabolism, and inflammation, FarnesoidX receptor (FXR) is an important pharmacological target for the treatment of NAFLD. Manipulating FXR to regulate lipid metabolic signaling pathways is a potential mechanism to mitigate NAFLD. Therefore, elucidating the modulatory character of FXR in regulating lipid metabolism in NAFLD has the potential to yield groundbreaking perspectives for drug design. This review details recent advances in the regulation of lipid depletion in hepatocytes and investigates the pivotal function of FXR in the progress of NAFLD.

TGR5 deficiency in excitatory neurons ameliorates Alzheimer's pathology by regulating APP processing

Bile acids (BAs) metabolism has a significant impact on the pathogenesis of Alzheimer's disease (AD). We found that deoxycholic acid (DCA) increased in brains of AD mice at an early stage. The enhanced production of DCA induces the up-regulation of the bile acid receptor Takeda G protein-coupled receptor (TGR5), which is also specifically increased in neurons of AD mouse brains at an early stage. The accumulation of exogenous DCA impairs cognitive function in wild-type mice, but not in TGR5 knockout mice. This suggests that TGR5 is the primary receptor mediating these effects of DCA. Furthermore, excitatory neuron-specific knockout of TGR5 ameliorates Aβ pathology and cognition impairments in AD mice. The underlying mechanism linking TGR5 and AD pathology relies on the downstream effectors of TGR5 and the APP production, which is succinctly concluded as a "p-STAT3-APH1-γ-secretase" signaling pathway. Our studies identified the critical role of TGR5 in the pathological development of AD.

Quercetin exerts anti-tumor immune mechanism by regulating IL-6/JAK2/STAT3 signaling pathway to deplete Treg cells

Breast cancer is still the leading cause of death among women worldwide. Due to the lack of effective drug targets, triple-negative breast cancer has a worse prognosis and higher mortality compared with other types of breast cancer, and chemotherapy is still the main treatment for triple-negative breast cancer at present. Quercetin (QUE) is a flavonoid compound found in a variety of fruits and vegetables. The mechanism of QUE has been extensively studied, such as prostate cancer, colon cancer, ovarian cancer, etc. However, the anti-tumor immune mechanism of QUE in triple-negative breast cancer remains unclear. Therefore, we assessed the anti-tumor immune effects of QUE on triple-negative breast cancer using both 4T1 cells and a xenograft mouse model of 4T1 cells. In vitro, we examined the inhibitory effects of QUE on 4T1 cells and its molecular mechanisms through MTT, Transwell, ELISA, and Western blotting. In vivo, by establishing a xenograft mouse model, we utilized flow cytometry, immunohistochemistry, ELISA, and Western blotting to evaluate the anti-tumor immune effects of QUE on triple-negative breast cancer. The results indicate that QUE inhibits the proliferation, migration, and invasion of 4T1 cells, concurrently significantly suppressing the IL-6/JAK2/STAT3 signaling pathway. Furthermore, it depletes Treg cell content in 4T1 xenograft mice, thereby improving the tumor immune microenvironment and promoting the cytotoxicity of relevant tumor immune cells. These findings suggest that QUE may serve as a potential adjuvant for immune therapy in triple-negative breast cancer.

Human diet-derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

This review focuses on the potential ameliorative effects of polyphenolic compounds derived from human diet on hepatic diseases. It discusses the molecular mechanisms and recent advancements in clinical applications. Edible polyphenols have been found to play a therapeutic role, particularly in liver injury, liver fibrosis, NAFLD/NASH, and HCC. In the regulation of liver injury, polyphenols exhibit anti-inflammatory and antioxidant effects, primarily targeting the TGF-β, NF-κB/TLR4, PI3K/AKT, and Nrf2/HO-1 signaling pathways. In the regulation of liver fibrosis, polyphenolic compounds effectively reverse the fibrotic process by inhibiting the activation of hepatic stellate cells (HSC). Furthermore, polyphenolic compounds show efficacy against NAFLD/NASH by inhibiting lipid oxidation and accumulation, mediated through the AMPK, SIRT, and PPARγ pathways. Moreover, several polyphenolic compounds exhibit anti-HCC activity by suppressing tumor cell proliferation and metastasis. This inhibition primarily involves blocking Akt and Wnt signaling, as well as inhibiting the epithelial-mesenchymal transition (EMT). Additionally, clinical trials and nutritional evidence support the notion that certain polyphenols can improve liver disease and associated metabolic disorders. However, further fundamental research and clinical trials are warranted to validate the efficacy of dietary polyphenols.

Recent Insights into the Biomarkers, Molecular Targets and Mechanisms of Non-Alcoholic Steatohepatitis-Driven Hepatocarcinogenesis

Non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (NASH) are chronic hepatic conditions leading to hepatocellular carcinoma (HCC) development. According to the recent "multiple-parallel-hits hypothesis", NASH could be caused by abnormal metabolism, accumulation of lipids, mitochondrial dysfunction, and oxidative and endoplasmic reticulum stresses and is found in obese and non-obese patients. Recent translational research studies have discovered new proteins and signaling pathways that are involved not only in the development of NAFLD but also in its progression to NASH, cirrhosis, and HCC. Nevertheless, the mechanisms of HCC developing from precancerous lesions have not yet been fully elucidated. Now, it is of particular importance to start research focusing on the discovery of novel molecular pathways that mediate alterations in glucose and lipid metabolism, which leads to the development of liver steatosis. The role of mTOR signaling in NASH progression to HCC has recently attracted attention. The goals of this review are (1) to highlight recent research on novel genetic and protein contributions to NAFLD/NASH; (2) to investigate how recent scientific findings might outline the process that causes NASH-associated HCC; and (3) to explore the reliable biomarkers/targets of NAFLD/NASH-associated hepatocarcinogenesis.

Genipin Analogue (G300) Inhibits Adipogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells through the Suppression of Adipogenic Promoting Factors

While obesity is a well-known health threatening condition worldwide, effective pharmacological interventions for obesity suppression have been limited due to adverse effects. Therefore, it is important to explore alternative medical treatments for combating obesity. Inhibition of the adipogenesis process and lipid accumulation are critical targets for controlling and treating obesity. Gardenia jasminoides Ellis is a traditional herbal remedy for various ailments. A natural product from its fruit, genipin, has major pharmacological properties; it is anti-inflammatory and antidiabetic. We investigated the effects of a genipin analogue, G300, on adipogenic differentiation in human bone marrow mesenchymal stem cells (hBM-MSCs). G300 suppressed the expression of adipogenic marker genes and adipokines secreted by adipocytes at concentrations of 10 and 20 μM, which effectively reduced the adipogenic differentiation of hBM-MSCs and lipid accumulation in adipocytes. It also improved adipocyte function by lowering inflammatory cytokine secretion and increasing glucose uptake. For the first time, we show that G300 has the potential to be a novel therapeutic agent for the treatment of obesity and its related disorders.