ATP-citrate lyase regulates stemness and metastasis in hepatocellular carcinoma via the Wnt/β-catenin signaling pathway

Background: Hepatocellular carcinoma(HCC) is one of the most highly malignant tumors. Liver tumor-initiating cells(LTICs) have been considered to contribute to HCC progression and metastasis. ATP-citrate lyase(ACLY), as a key enzyme for de novo lipogenesis, has been reported to be upregulated in various tumors. However, its expression and role in HCC and LTICs remain unknown. Methods: The expressions of ACLY in HCC tissues were detected by quantitative real-time PCR(q RT-PCR), Western blotting and immunohistochemistry. Kaplan-Meier curves and Chi-square test were used to determine the clinical significance of ACLY expression in HCC patients. A series of assays were performed to determine the function of ACLY on stemness, migration and invasion of HCC cells. Luciferase reporter assay, Western blotting and immunoprecipitation were used to study the regulation of the Wnt/β-catenin signaling by ACLY. Rescue experiments were performed to investigate whether β-catenin was the mediator of ACLY-regulated stemness and migration in HCC cells. Results: ACLY was highly expressed in HCC tissues and LTICs. Overexpression of ACLY was significantly correlated with poor prognosis, progression and metastasis of HCC patients. Knockdown of ACLY remarkably suppressed stemness properties, migration and invasion in HCC cells. Mechanistically, ACLY could regulate the canonical Wnt pathway by affecting the stability of β-catenin, and Lys49 acetylation of β-catenin might mediate ACLY-regulated β-catenin level in HCC cells. Conclusions: ACLY is a potent regulator of Wnt/β-catenin signaling in modulating LTICs stemness and metastasis in HCC. ACLY may serve as a new target for the diagnosis and treatment of HCC.

Development of the novel ACLY inhibitor 326E as a promising treatment for hypercholesterolemia

Hepatic cholesterol accumulation is an important contributor to hypercholesterolemia,which results in atherosclerosis and cardiovascular disease(CVD).ATP-citrate lyase(ACLY)is a key lipogenic enzyme that converts cytosolic citrate derived from tricarboxylic acid cycle(TCA cycle)to acetyl-CoA in the cytoplasm.Therefore,ACLY represents a link between mitochondria oxidative phosphorylation and cytosolic de novo lipogenesis.In this study,we developed the small molecule 326E with an enedioic acid structural moiety as a novel ACLY inhibitor,and its CoA-conjugated form 326E-CoA inhibited ACLY activity with an IC_(50)=5.31±1.2μmol/L in vitro.326E treatment reduced de novo lipogenesis,and increased cholesterol efflux in vitro and in vivo.326E was rapidly absorbed after oral administration,exhibited a higher blood exposure than that of the approved ACLY inhibitor bempedoic acid(BA)used for hypercholesterolemia.Chronic 326E treatment in hamsters and rhesus monkeys resulted in remarkable improvement of hyperlipidemia.Once daily oral administration of 326E for 24 weeks prevented the occurrence of atherosclerosis in ApoE^(-/-)mice to a greater extent than that of BA treatment.Taken together,our data suggest that inhibition of ACLY by 326E represents a promising strategy for the treatment of hypercholesterolemia.

cis-Clerodane Diterpenoids with Structural Diversity and Anti-inflammatory Activity from Tinospora crispa

Twelve new cis-clerodane diterpenoids, designated as crispinoids A—L (1—12), together with three known analogues (13—15), were isolated from Tinospora crispa. Their structures were fully assigned by comprehensive spectroscopic techniques, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) analyses. The isolated clerodanes displayed diverse heterocyclic frameworks including 6/6/6-, 6/5/6/6-, 6/6/5-, 6/6-, and 6/5/6-fused ring systems. Some of the isolates showed ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB) pathway inhibition. The NF-κB inhibitors further suppressed the lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 cells.