Effects of a Phosphodiesterase inhibitor on the Browning of Adipose Tissue in Mice

Formononetin suppresses colitis-associated colon cancer by targeting lipid synthesis and mTORC2/Akt signaling

BACKGROUND

Colitis-associated colon cancer (CAC) is a serious gastrointestinal malignancy, with a significantly increased incidence among patients with inflammatory bowel disease, posing major challenges to patients' quality of life and prognosis. Modern research highlights Formononetin (FN) for its significant anti-inflammatory and extensively studied anti-cancer properties; however, its precise mechanisms, particularly in CAC, remain unclear and warrant further investigation.

OBJECTIVE

To investigate the anti-inflammatory and anti-tumor activity of FN and its effect on CAC, using biological fluid metabolomics to identify potential diagnostic markers for CAC.

METHODS

The MTT assay determined the survival rate of FN on murine RAW264.7 cells and the half maximal inhibitory concentration (IC50) of FN on murine CT-26 and human HCT116 cells IL-6, IL-1β, and TNF-α levels were detected by ELISA. Western blotting was used to analyze autophagic and apoptotic pathways. Utilizing an in vivo mouse model of colitis, the anti-inflammatory activity of FN was assessed by monitoring relevant indicators such as body weight, DAI score, and colon index. And an in vitro mouse colon cancer model was used to observe FN's anti-tumor activity by measuring tumor volume, size, and inhibition rate. Metabolomics analyzed differential serum metabolites and lipid metabolic pathways. Intestinal flora in mice was also analyzed.

RESULTS

FN can inhibit the activation of the NF-κB/MAPK signaling pathways in LPS-induced RAW264.7 cells, thereby exerting its anti-inflammatory effects. Moreover, FN significantly enhanced the colon length and DAI score in mice, notably suppressed the production of inflammatory cytokines, and inhibited the NF-κB/MAPK signaling pathway, leading to an improvement in DSS-induced colitis. FN significantly inhibited CT-26 and HCT116 cell growth, reduced tumor growth rate, improved pathological damage in CAC mice, and inhibited inflammatory factor production, enhancing intestinal mucosa protection. FN promoted apoptosis of colon cancer cells by increasing autophagy proteins (LC3, Beclin-1) and apoptosis proteins (CL-Caspase3, Bax), while reducing Bcl-2 expression. Metabolomics identified 34 differential metabolites, including glycerophospholipids and fatty acids, showing anti-tumor effects by regulating lipid metabolism. FN reduced IGF-1, ACLY, A-CoA, FAS, HSL, ATGL, and FFA levels, and increased GSK-3 levels (p < 0.01). FN also inhibited the expression of P-mTOR, Rictor, P-Akt, ACLY, PDE3B, P-PKA, and P-HSL (p < 0.01).

CONCLUSIONS

FN significantly inhibits colon cancer cell growth and exerts anti-CAC effects by activating autophagy and apoptosis pathways and regulating lipid metabolism. This study is the first to comprehensively integrate metabolomics, intestinal flora analysis, and molecular mechanisms to unveil FN's multifaceted role in CAC treatment, offering novel insights into its therapeutic application.

Perioperative treatment with cilostazol reverses steatosis and improves liver regeneration after major hepatectomy in a steatotic rat model

Cilostazol has previously been shown to reduce liver steatosis and enhance hepatic perfusion. We investigated the effects of cilostazol after major hepatectomy in a steatotic rat model. Six weeks prior to surgery, Sprague-Dawley rats were fed with a high-fructose diet. The treatment group received daily 5 mg/kg cilostazol. Seven days following the cilostazol treatment, all animals underwent 70% liver resection (PHX). Analysis of hepatic blood flow and microcirculation and immunohistochemical examinations were conducted 30 min after PHX (postoperative day [POD] 0) as well as on POD 1, POD 3 and POD 7. The weight of cilostazol-treated animals was significantly reduced compared to untreated controls after completion of the 6-week high-FRC diet. Furthermore, 41% macrovesicular steatosis was found in the control group compared to 8% in the cilostazol group. Hepatic arterial and portal venous perfusion were increased in the cilostazol group on POD 7. Lower liver enzyme release was found postoperatively in cilostazol-treated animals. Moreover, apoptosis and neutrophil infiltration were reduced after cilostazol treatment. Proliferation of hepatocytes and liver regeneration after PHX were significantly increased in the cilostazol group. Consequently, cilostazol should be evaluated as a novel strategy to reduce the rate of liver failure after PHX in steatotic liver.

Adipose tissue retains an epigenetic memory of obesity after weight loss

Reducing body weight to improve metabolic health and related comorbidities is a primary goal in treating obesity1,2. However, maintaining weight loss is a considerable challenge, especially as the body seems to retain an obesogenic memory that defends against body weight changes3,4. Overcoming this barrier for long-term treatment success is difficult because the molecular mechanisms underpinning this phenomenon remain largely unknown. Here, by using single-nucleus RNA sequencing, we show that both human and mouse adipose tissues retain cellular transcriptional changes after appreciable weight loss. Furthermore, we find persistent obesity-induced alterations in the epigenome of mouse adipocytes that negatively affect their function and response to metabolic stimuli. Mice carrying this obesogenic memory show accelerated rebound weight gain, and the epigenetic memory can explain future transcriptional deregulation in adipocytes in response to further high-fat diet feeding. In summary, our findings indicate the existence of an obesogenic memory, largely on the basis of stable epigenetic changes, in mouse adipocytes and probably other cell types. These changes seem to prime cells for pathological responses in an obesogenic environment, contributing to the problematic 'yo-yo' effect often seen with dieting. Targeting these changes in the future could improve long-term weight management and health outcomes.

The Role of Cilostazol, a Phosphodiesterase-3 Inhibitor, in the Development of Atherosclerosis and Vascular Biology: A Review with Meta-Analysis

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading global cause of mortality. Addressing this vital and pervasive condition requires a multifaceted approach, in which antiplatelet intervention plays a pivotal role, together with antihypertensive, antidiabetic, and lipid-lowering therapies. Among the antiplatelet agents available currently, cilostazol, a phosphodiesterase-3 inhibitor, offers a spectrum of pharmacological effects. These encompass vasodilation, the impediment of platelet activation and aggregation, thrombosis inhibition, limb blood flow augmentation, lipid profile enhancement through triglyceride reduction and high-density lipoprotein cholesterol elevation, and the suppression of vascular smooth muscle cell proliferation. However, the role of cilostazol has not been clearly documented in many guidelines for ASCVD. We comprehensively reviewed the cardiovascular effects of cilostazol within randomized clinical trials that compared it to control or active agents and involved individuals with previous coronary artery disease or stroke, as well as those with no previous history of such conditions. Our approach demonstrated that the administration of cilostazol effectively reduced adverse cardiovascular events, although there was less evidence regarding its impact on myocardial infarction. Most studies have consistently reported its favorable effects in reducing intermittent claudication and enhancing ambulatory capacity in patients with peripheral arterial disease. Furthermore, cilostazol has shown promise in mitigating restenosis following coronary stent implantation in patients with acute coronary syndrome. While research from more diverse regions is still needed, our findings shed light on the broader implications of cilostazol in the context of atherosclerosis and vascular biology, particularly for individuals at high risk of ASCVD.

Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling

OBJECTIVE

Obesity is a global health concern with management strategies encompassing bariatric surgery and anti-obesity drugs; however, concerns regarding complexities and side effects persist, driving research for more effective, low-risk strategies. The promotion of white adipose tissue (WAT) browning has emerged as a promising approach. Moreover, alisol B 23-acetate (AB23A) has demonstrated efficacy in addressing metabolic disorders, suggesting its potential as a therapeutic agent in obesity management. Therefore, in this study, we aimed to investigate the therapeutic potential of AB23A for mitigating obesity by regulating metabolic phenotypes and lipid distribution in mice fed a high-fat diet (HFD).

METHODS

An obesity mouse model was established by administration of an HFD. Glucose and insulin metabolism were assessed via glucose and insulin tolerance tests. Adipocyte size was determined using hematoxylin and eosin staining. The expression of browning markers in WAT was evaluated using Western blotting and quantitative real-time polymerase chain reaction. Metabolic cage monitoring involved the assessment of various parameters, including food and water intake, energy metabolism, respiratory exchange rates, and physical activity. Moreover, oil red O staining was used to evaluate intracellular lipid accumulation. A bioinformatic analysis tool for identifying the molecular mechanisms of traditional Chinese medicine was used to examine AB23A targets and associated signaling pathways.

RESULTS

AB23A administration significantly reduced the weight of obese mice, decreased the mass of inguinal WAT, epididymal WAT, and perirenal adipose tissue, improved glucose and insulin metabolism, and reduced adipocyte size. Moreover, treatment with AB23A promoted the expression of browning markers in WAT, enhanced overall energy metabolism in mice, and had no discernible effect on food intake, water consumption, or physical activity. In 3T3-L1 cells, AB23A inhibited lipid accumulation, and both AB23A and rapamycin inhibited the mammalian target of rapamycin-sterol regulatory element-binding protein-1 (mTOR-SREBP1) signaling pathway. Furthermore, 3-isobutyl-1-methylxanthine, dexamethasone and insulin, at concentrations of 0.25 mmol/L, 0.25 μmol/L and 1 μg/mL, respectively, induced activation of the mTOR-SREBP1 signaling pathway, which was further strengthened by an mTOR activator MHY1485. Notably, MHY1485 reversed the beneficial effects of AB23A in 3T3-L1 cells.

CONCLUSION

AB23A promoted WAT browning by inhibiting the mTOR-SREBP1 signaling pathway, offering a potential strategy to prevent obesity. Please cite this article as: Han LL, Zhang X, Zhang H, Li T, Zhao YC, Tian MH, Sun FL, Feng B. Alisol B 23-acetate promotes white adipose tissue browning to mitigate high-fat diet-induced obesity by regulating mTOR-SREBP1 signaling. J Integr Med. 2024; 22(1): 83-92.

Gut microbiota turn up the heat after bariatric surgery

Bariatric surgeries like vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) cause well-established shifts in the gut microbiota, but how this contributes to their unique metabolic benefits is poorly understood. Jin et al and Yadav et al now provide two complementary lines of evidence suggesting that gut microbiota-derived metabolites after VSG and RYGB activate thermogenesis in fat through distinct mechanisms, to in turn promote weight loss and/or improvements in glycemic control.

Effects of allicin on human Simpson-Golabi-Behmel syndrome cells in mediating browning phenotype

INTRODUCTION

Obesity is a major health problem because it is associated with increased risk of cardiovascular disease, diabetes, hypertension, and some cancers. Strategies to prevent or reduce obesity focus mainly on the possible effects of natural compounds that can induce a phenotype of browning adipocytes capable of releasing energy in the form of heat. Allicin, a bioactive component of garlic with numerous pharmacological functions, is known to stimulate energy metabolism.

METHODS

In the present study, the effects of allicin on human Simpson-Golabi-Behmel Syndrome (SGBS) cells were investigated by quantifying the dynamics of lipid droplets (LDs) and mitochondria, as well as transcriptomic changes after six days of differentiation.

RESULTS

Allicin significantly promoted the reduction in the surface area and size of LDs, leading to the formation of multilocular adipocytes, which was confirmed by the upregulation of genes related to lipolysis. The increase in the number and decrease in the mean aspect ratio of mitochondria in allicin-treated cells indicate a shift in mitochondrial dynamics toward fission. The structural results are confirmed by transcriptomic analysis showing a significant arrangement of gene expression associated with beige adipocytes, in particular increased expression of T-box transcription factor 1 (TBX1), uncoupling protein 1 (UCP1), PPARG coactivator 1 alpha (PPARGC1A), peroxisome proliferator-activated receptor alpha (PPARA), and OXPHOS-related genes. The most promising targets are nuclear genes such as retinoid X receptor alpha (RXRA), retinoid X receptor gamma (RXRG), nuclear receptor subfamily 1 group H member 3 (NR1H3), nuclear receptor subfamily 1 group H member 4 (NR1H4), PPARA, and oestrogen receptor 1 (ESR1).

DISCUSSION

Transcriptomic data and the network pharmacology-based approach revealed that genes and potential targets of allicin are involved in ligand-activated transcription factor activity, intracellular receptor signalling, regulation of cold-induced thermogenesis, and positive regulation of lipid metabolism. The present study highlights the potential role of allicin in triggering browning in human SGBS cells by affecting the LD dynamics, mitochondrial morphology, and expression of brown marker genes. Understanding the potential targets through which allicin promotes this effect may reveal the underlying signalling pathways and support these findings.