Cyclic adenosine 3', 5'-monophosphate (cAMP) signaling is a crucial therapeutic target for ulcerative colitis.

The pathogenesis of ulcerative colitis (UC), a chronic intestine inflammatory disease primarily affecting adolescents, remains uncertain. Contemporary studies suggest that a confluence of elements, including genetic predispositions, environmental catalysts, dysregulated immune responses, and disturbances in the gut microbiome, are instrumental in the initiation and advancement of UC. Among them, inflammatory activation and mucosal barrier damage caused by abnormal immune regulation are essential links in the development of UC. The impairment of the mucosal barrier is intricately linked to the interplay of various cellular mechanisms, including oxidative stress, autophagy, and programmed cell death. An extensive corpus of research has elucidated that level of cyclic adenosine 3',5'-monophosphate (cAMP) undergo modifications in the midst of inflammation and participate in a diverse array of cellular operations that mitigate inflammation and the impairment of the mucosal barrier. Consequently, a plethora of pharmacological agents are currently under development, with some advancing through clinical trials, and are anticipated to garner approval as novel therapeutics. In summary, cAMP exerts a crucial influence on the onset and progression of UC, with fluctuations in its activity being intimately associated with the severity of the disease's manifestation. Significantly, this review unveils the paramount role of cAMP in the advancement of UC, offering a tactical approach for the clinical management of individuals afflicted with UC.

Morroniside delays the progression of non-alcoholic steatohepatitis by promoting AMPK-mediated lipophagy.

BACKGROUND: Non-alcoholic steatohepatitis (NASH), the inflammatory subtype in the progression of non-alcoholic fatty liver disease, is becoming a serious burden threatening human health, but no approved medication is available to date. Mononoside is a natural active substance derived from Cornus officinalis and has been confirmed to have great potential in regulating lipid metabolism in our previous studies. However, its effect and mechanism to inhibit the progression of NASH remains unclear. PURPOSE: Our work aimed to explore the action of mononoside in delaying the progression of NASH and its regulatory mechanisms from the perspective of regulating lipophagy. METHODS AND RESULTS: Male C57BL/6 mice were fed with a high-fat and high-fructose diet for 16 weeks to establish a NASH mouse model. After 8 weeks of high-fat and high-fructose feeding, these mice were administrated with different doses of morroniside. H&E staining, ORO staining, Masson staining, RNA-seq, immunoblotting, and immunofluorescence were performed to determine the effects and molecular mechanisms of morroniside in delaying the progression of NASH. In this study, we found that morroniside is effective in attenuating hepatic lipid metabolism disorders and inflammatory response activation, thereby limiting the progression from simple fatty liver to NASH in high-fat and high-fructose diet-fed mice. Mechanistically, we identified AMPK signaling as the key molecular pathway for the positive efficacy of morroniside by transcriptome sequencing. Our results revealed that morroniside maintained hepatic lipid metabolism homeostasis and inhibited NLRP3 inflammasome activation by promoting AMPKα phosphorylation-mediated lipophagy and fatty acid oxidation. Consistent results were observed in palmitic acid-treated cell models. Of particular note, silencing AMPKα both in vivo and in vitro reversed morroniside-induced lipophagy flux enhancement and NLRP3 inflammasome inhibition, emphasizing the critical role of AMPKα activation in the effect of morroniside in inhibiting NASH progression. CONCLUSION: In summary, the present study provides strong evidence for the first time that morroniside inhibits NASH progression by promoting AMPK-dependent lipophagy and inhibiting NLRP3 inflammasome activation, suggesting that morroniside is expected to be a potential molecular entity for the development of therapeutic drugs for NASH.

Integration of network pharmacology, lipidomics, and transcriptomics analysis to reveal the mechanisms underlying the amelioration of AKT-induced nonalcoholic fatty liver disease by total flavonoids in vine tea.

Nonalcoholic fatty liver disease (NAFLD) is the main reason for chronic liver diseases and malignancies. Currently, there is a lack of approved drugs for the prevention or treatment of NAFLD. Vine tea (Ampelopsis grossedentata) has been used as a traditional Chinese beverage for centuries. Vine tea carries out several biological activities including the regulation of plasma lipids and blood glucose, hepato-protective function, and anti-tumor activity and contains the highest content of flavonoids. However, the underlying mechanisms of total flavonoids from vine tea (TF) in the attenuation of NAFLD remain unclear. Therefore, we investigated the interventions and mechanisms of TF in mice with NAFLD using an integrated analysis of network pharmacology, lipidomics, and transcriptomics. Staining and biochemical tests revealed a significant increase in AKT-overexpression-induced (abbreviated as AKT-induced) NAFLD in mice. Lipid accumulation in hepatic intracellular vacuoles was alleviated after TF treatment. In addition, TF reduced the hepatic and serum triglyceride levels in mice with AKT-induced NAFLD. Lipidomics results showed 32 differential lipids in the liver, mainly including triglycerides (TG), diglycerides (DG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Transcriptomic analysis revealed that 314 differentially expressed genes were commonly upregulated in the AKT group and downregulated in the TF group. The differential regulation of lipids by the genes Pparg, Scd1, Chpt1, Dgkz, and Pla2g12b was further revealed by network enrichment analysis and confirmed by RT-qPCR. Furthermore, we used immunohistochemistry (IHC) to detect changes in the protein levels of the key proteins PPARγ and SCD1. In summary, TF can improve hepatic steatosis by targeting the PPAR signaling pathway, thereby reducing de novo fatty acid synthesis and modulating the glycerophospholipid metabolism.

Vine tea total flavonoids activate the AMPK/mTOR pathway to amelioration hepatic steatosis in mice fed a high-fat diet.

Vine tea (Ampelopsis grossedentata), a traditional Chinese tea, is rich in flavonoids with various biological activities. Our study found that Vine tea total flavonoids (TFs) treatment reduced the body mass and blood lipid levels and improved the hepatic tissue morphology in mice fed the high-fat diet (HFD). In vivo, TF treatment activated the hepatic adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, initiated autophagy, and regulated the expression levels of proteins for lipid metabolism in those HFD-fed mice. In vitro, TF treatment dramatically reduced the lipid droplets and triacylglycerol content in HepG2 and L02 cells treated with oleic acid (OA). These were associated with the activation of the AMPK/mTOR pathway and autophagy initiation in OA-treated hepatocytes. This phenotype was abolished in the presence of 3-methyladenine, an autophagy inhibitor. Our results indicated that the TF activation of AMPK/mTOR leads to the stimulation of autophagy and a decrease in the buildup of intracellular lipids in hepatocytes, showing the potential of TF as a therapeutic agent for nonalcoholic fatty liver disease. PRACTICAL APPLICATION: Vine tea, a tea drink, has been consumed by Chinese folk for over a thousand years. The result of this study will provide evidence that vine tea total flavonoids have potential use as a functional material for the prevention and amelioration of nonalcoholic fatty liver disease.

Liver-derived Exosomal miRNA in NAFLD: Mechanisms of Action, Biomarkers, and Therapeutic Applications.

Nonalcoholic fatty liver disease (NAFLD) is of global concern due to its high prevalence worldwide. NAFLD, as one of the most common causes of liver function abnormalities, is associated with obesity, insulin resistance, and type 2 diabetes mellitus, and there are no medications available to treat NAFLD. Extracellular vesicles (EVs) are nanosized, membrane-bound vesicles that deliver biomolecules between cells. Exosomes are a subtype of EVs that mediate intercellular communication by delivering proteins and RNAs. MicroRNAs (miRNAs) are a highly conserved class of small tissue-specific non-coding RNAs that influence the expression of many functionally interacting genes. Hepatic-derived exosomal miRNAs are tightly associated with NAFLD occurrence and progression through multiple mechanisms. In addition, the characterization of miRNAs suggests that they may serve as multifunctional biomarkers for NAFLD, be used as clinical therapeutic targets for NAFLD, and be significant predictors of patient prognosis. Here, we review recent advances in the regulation and function of exosome-derived miRNAs in NAFLD, focusing on miRNAs specifically expressed or enriched in hepatocytes (HCs), hepatic macrophages, hepatic stellate cells (HSCs), and other immune cells in the liver. Finally, we discuss future research directions on exosomal miRNAs as biomarkers for NAFLD's diagnosis and clinical therapeutic targets.

Antiproliferative effect of urolithin A, the ellagic acid-derived colonic metabolite, on hepatocellular carcinoma HepG2. 2. 15 cells by targeting Lin28a/let-7a axis

An abnormality in the Lin28/let-7a axis is relevant to the progression of hepatitis B virus (HBV)-positive hepatocellular carcinoma (HCC), which could be a novel therapeutic target for this malignant tumor. The present study aimed to investigate the antiproliferative and anti-invasive effects of urolithin A in a stable full-length HBV gene integrated cell line HepG2.2.15 using CCK-8 and transwell assays. The RNA and protein expressions of targets were assessed by quantitative PCR and western blot, respectively. Results revealed that urolithin A induced cytotoxicity in HepG2.2.15 cells, which was accompanied by the cleavage of caspase-3 protein and down-regulation of Bcl-2/Bax ratio. Moreover, urolithin A suppressed the protein expressions of Sp-1, Lin28a, and Zcchc11, and elevated the expression of microRNA let-7a. Importantly, urolithin A also regulated the Lin28a/let-7a axis in transient HBx-transfected HCC HepG2 cells. Furthermore, urolithin A decelerated the HepG2.2.15 cell invasion, which was involved in suppressing the let-7a downstream factors HMGA2 and K-ras. These findings indicated that urolithin A exerted the antiproliferative effect by regulating the Lin28a/let-7a axis and may be a potential supplement for HBV-infected HCC therapy.

Total flavonoids from Ampelopsis megalophylla suppress proliferation of vascular smooth muscle cells in vivo and in vitro

ABSTRACT Various benefits of flavonoids for ameliorating cardiovascular diseases have been demonstrated. However, the lowering effects on blood pressure caused by antiproliferative potentials of flavonoids in vascular smooth muscle cells are rare. In this study, the antihypertensive effects of total flavonoids from Ampelopsis megalophylla were investigated. The dynamic pressure values and the rate of media thickness versus lumen diameter were measured by the tail-cuff system and H&E staining in vivo, respectively. The mRNA expressions of ACE, Ang II, eNOS, c-Myc, cyclin D1 and p27Kip1 in thoracic aorta or A7r5 cells were measured by qPCR, respectively. The protein expressions of c-Myc, Cyclin D1, p27Kip1 and ß-catenin in tissues or A7r5 cells were measured by Western blot assay. Total flavonoids of A. megalophylla (TFAM) reduced the expressions of ACE and Ang II, and elevated the content of eNOS in thoracic aorta cells of SHRs. Furthermore, TFAM decreased the mRNA and protein expressions of c-Myc and cyclin D1 by repressing the Wnt/ß-catenin-mediated TCF/LEF transcriptional activation both in vivo and in vitro, which is synergetic with the up-regulation of p27Kip1 expression. Our study provided evidence for developing flavonoids from A. megalophylla as herbal supplements to prevent against cardiovascular diseases by suppressing vascular remodeling