Danggui Shaoyao San ameliorates the lipid metabolism via the PPAR signaling pathway in a Danio rerio (zebrafish) model of hyperlipidemia

Cardiotoxicity risk induced by sanitary insecticide Dimefluthrin

Dimefluthrin (DIM) is a commonly utilized sanitary insecticide, predominantly employed for indoor pest management within residential and public environments directly interacting with human habitation. However, the usage of DIM is escalating with increasing mosquito resistance, prompting concerns about its health risks. Here, using zebrafish as a research model, we systematically evaluated DIM's impact on human health. Findings revealed significant health hazards during embryonic development, including reduced hatching rates, shortened body lengths, and organ malformations, notably affecting the heart. It was explored the mechanism of DIM-induced cardiotoxicity in zebrafish, and histopathological analyses revealed that DIM resulted in ventricular linearization in zebrafish embryos. Antioxidant enzyme activities were reduced and cardiac reactive oxygen species (ROS) accumulated after DIM exposure, suggesting clear signs of oxidative stress. Additionally, acridine orange (AO) staining and caspase-3 immunofluorescence demonstrated cardiac apoptosis in Tg (kdrl: EGFP) zebrafish. qPCR analysis implied that DIM induced apoptosis via the p53/Caspase pathway by up-regulating the expression levels of p53, cytochrome C (cyto-C), caspase-9, and caspase-3. Together, our work provided a systematic perspective on the cardiotoxicity of sanitary pesticides, which could offer opportunities for future risk management.

Bergenin mitigates neuroinflammatory damage induced by high glucose: insights from Zebrafish, murine microbial cell line, and rat models

Background

The escalating global burden of diabetes and its associated cognitive impairment underscores the urgency for effective interventions. Bergenin shows promise in regulating glucose metabolism, mitigating inflammation, and improving cognitive function. Zebrafish models offer a unique platform for assessing drug efficacy and exploring pharmacological mechanisms, complemented by subsequent investigations in cell and rat models.

Methods

The experimental subjects included zebrafish larvae (CZ98:Tg (mpeg1:EGFP) ihb20Tg/+ ), adult zebrafish (immersed in 2% glucose), BV2 cell line (50 mM glucose + 10 μm Aβ1-42), and a streptozotocin (STZ) bilateral intracerebroventricular injection rat model. Bergenin's effects on the toxicity, behavior, and cognitive function of zebrafish larvae and adults were evaluated. The Morris water maze assessed cognitive function in rats. Neuronal histopathological changes were evaluated using HE and Nissl staining. qPCR and Western blot detected the expression of glycolysis enzymes, inflammatory factors, and Bergenin's regulation of PPAR/NF-κB pathway in these three models.

Results

1) In zebrafish larvae, Bergenin interventions significantly reduced glucose levels and increased survival rates while decreasing teratogenicity rates. Microglial cell fluorescence in the brain notably decreased, and altered swimming behavior tended to normalize. 2) In adult zebrafish, Bergenin administration reduced BMI and blood glucose levels, altered swimming behavior to slower speeds and more regular trajectories, enhanced recognition ability, decreased brain glucose and lactate levels, weakened glycolytic enzyme activities, improved pathological changes in the telencephalon and gills, reduced expression of pro-inflammatory cytokines, decreased ins expression and increased expression of irs1, irs2a, and irs2b, suggesting a reduction in insulin resistance. It also altered the expression of pparg and rela. 3) In BV2 cell line, Bergenin significantly reduced the protein expression of glycolytic enzymes (GLUT1, HK2, PKFKB3, and PKM2), lowered IL-1β, IL-6, and TNF-α mRNA expression, elevated PPAR-γ protein expression, and decreased P-NF-κB-p65 protein expression. 4) In the rat model, Bergenin improves learning and memory abilities in STZ-induced rats, mitigates neuronal damage in the hippocampal region, and reduces the expression of inflammatory factors IL-1β, IL-6, and TNF-α. Bergenin decreases brain glucose and lactate levels, as well as glycolytic enzyme activity. Furthermore, Bergenin increases PPARγ expression and decreases p-NF-κB p65/NF-κB p65 expression in the hippocampus.

Conclusion

Bergenin intervenes through the PPAR-γ/NF-κB pathway, redirecting glucose metabolism, alleviating inflammation, and preventing high glucose-induced neuronal damage.

Developmental effects and lipid disturbances of zebrafish embryos exposed to three newly recognized bisphenol A analogues

Bisphenol G (BPG), bisphenol M (BPM) and bisphenol TMC (BPTMC), are newly recognized analogues of bisphenol A (BPA), which have been detected in multiple environmental media. However, the understanding of their negative impacts on environmental health is limited. In this study, zebrafish embryos were exposed to BPA and the three analogues (0.1, 10, and 1000 μg/L) to identify their developmental toxic effects. According to our results, all of the three analogues induced significant developmental disorders on zebrafish embryos including inhibited yolk sac absorption, altered heart rate, and teratogenic effects. Oil Red O staining indicated lipid accumulation in the yolk sac region of zebrafish after bisphenol analogues exposure, which was consistent with the delayed yolk uptake. Untargeted lipidomic analysis indicated the abundance of triacylglycerols, ceramides and fatty acids was significantly altered by the three analogues. The combined analysis of lipidomics and transcriptomics results indicated BPG and BPM affected lipid metabolism by disrupting peroxisome proliferator-activated receptor pathway and interfering with lipid homeostasis and transport. This partly explained the morphological changes of embryos after bisphenol exposure. In conclusion, our study reveals that BPG, BPM and BPTMC possess acute and developmental toxicity toward zebrafish, and the developmental abnormalities are associated with the disturbances in lipid metabolism.

AN698/40746067 suppresses bone marrow adiposity to ameliorate hyperlipidemia-induced osteoporosis through targeted inhibition of ENTR1

Hyperlipidemia-induced osteoporosis is marked by increased bone marrow adiposity, and treatment with statins for hyperlipidemia often leads to new-onset osteoporosis. Endosome-associated trafficking regulator 1 (ENTR1) has been found to interact with different proteins in pathophysiology, but its exact role in adipogenesis is not yet understood. This research aimed to explore the role of ENTR1 in adipogenesis and to discover a new small molecule that targets ENTR1 for evaluating its effectiveness in treating hyperlipidemia-induced osteoporosis. We found that ENTR1 expression increased during the adipogenesis of bone marrow mesenchymal cells (BMSCs). ENTR1 gain- and loss-of-function assays significantly enhanced lipid droplets formation. Mechanistically, ENTR1 binds peroxisome proliferator-activated receptor γ (PPARγ) and enhances its expression, thereby elevating adipogenic markers including C/EBPα and LDLR. Therapeutically, AN698/40746067 attenuated adipogenesis by targeting ENTR1 to suppress PPARγ. In vivo, AN698/40746067 reduced bone marrow adiposity and bone loss, as well as prevented lipogenesis-related obesity, inflammation, steatohepatitis, and abnormal serum lipid levels during hyperlipidemia. Together, these findings suggest that ENTR1 facilitates adipogenesis by PPARγ involved in BMSCs' differentiation, and targeted inhibition of ENTR1 by AN698/40746067 may offer a promising therapy for addressing lipogenesis-related challenges and alleviating osteoporosis following hyperlipidemia.

Modulation of lipid profile by secretory phospholipase A2 group IIA: Verification with a transgenic mouse model

We previously demonstrated a positive relation of secretory phospholipase A2 group IIA (sPLA2-IIA) with circulating high-density lipoprotein cholesterol (HDL-C) in patients with coronary artery disease, and sPLA2-IIA increased cholesterol efflux in THP-1 cells through peroxisome proliferator-activated receptor-γ (PPAR-γ)/liver X receptor α/ATP-binding cassette transporter A1 (ABCA1) signaling pathway. The aim of the present study was to examine the role of sPLA2-IIA over-expression on lipid profile in a transgenic mouse model. Fifteen apoE-/- and C57BL/7 female mice received bone marrow transplantation from transgenic SPLA2-IIA mice, and treated with specific PPAR-γ inhibitor GW9662. High fat diet was given after one week of bone marrow transplantation, and animals were sacrificed after twelve weeks. Immunohistochemical staining showed over-expression of sPLA2-IIA protein in the lung and spleen. The circulating level of HDL-C, but not that of low-density lipoprotein cholesterol (LDL-C), total cholesterol, or total triglyceride, was increased by sPLA2-IIA over-expression, and was subsequently reversed by GW9662 treatment. Over-expression of sPLA2-IIA resulted in augmented expression of cholesterol transporter ABCA1 at mRNA level in the aortas, and at protein level in macrophages, co-localized with macrophage specific antigen CD68. GW9662 exerted potent inhibitory effects on sPLA2-IIA-induced ABCA1 expression. Conclusively, we demonstrated the effects of sPLA2-IIA on circulating HDL-C level and the expression of ABCA1, possibly through regulation of PPAR-γ signaling in transgenic mouse model, that is in concert with the conditions in patients with coronary artery disease.

4-tert-Butylphenol impairs the liver by inducing excess liver lipid accumulation via disrupting the lipid metabolism pathway in zebrafish

Endocrine disrupting chemicals (EDCs) can disrupt normal endocrine function by interfering with the synthesis and release of hormones, causing adverse reactions to development, immunity, nerves, and reproduction. 4-tert-Butylphenol (4-t-BP) is disruptive to early zebrafish development, but its effects on zebrafish liver are unknown. In this study, the adverse effects of 4-t-BP on the liver were investigated using zebrafish as a model organism. 4-t-BP inhibited liver development in zebrafish embryos and induced liver damage in adult zebrafish. Even if F1 was not directly exposed to 4-t-BP, its growth and development were inhibited. 4-t-BP can lead to an increase in lipid accumulation, total cholesterol and triglycerides contents, and the activities of alanine transaminase and aspartate aminotransferase in zebrafish embryos and adult zebrafish livers, and also cause an acceleration of glucose metabolism in zebrafish embryos. In addition, qRT-PCR showed that 4-t-BP induced the changes in the expressions of liver development-, steroid and unsaturated fatty acid biosynthesis-, and glycerolipid and arachidonic acid metabolism-related genes in zebrafish embryos and inflammatory factors-, antioxidant enzymes- and lipid metabolism-related genes in adult zebrafish livers. Transcriptome sequencing of embryos showed that 4-t-BP altered the expressions of lipid metabolism pathways such as steroid and unsaturated fatty acid biosynthesis, glycerolipid, and arachidonic acid metabolism pathways. Therefore, 4-t-BP may be external stimuli that cause oxidative stress, inflammation, and lipid accumulation in zebrafish liver, resulting in tissue damage and dysfunction in zebrafish liver.

Incorporating Lycium barbarum residue in diet boosts survival, growth, and liver health in juvenile grass carp (Ctenopharyngodon idellus)

This research elucidates the potential of Lycium barbarum residue (LBR), a by-product rich in bioactive substances, as a dietary supplement in aquaculture, especially for herbivorous fish like grass carp. In a detailed 120-day feeding trial, the impacts of varying LBR levels on juvenile grass carp were assessed, focusing on growth performance, survival rate, biochemical markers, and liver health. The study identified a 6% inclusion rate of LBR as optimal for enhancing survival and growth while mitigating hepatic lipid accumulation. Composition analysis of this diet revealed high concentrations of polysaccharides and flavonoids. Notably, the intake of LBR was found to enhance the antioxidant and immune-related enzymatic activities in the liver. Furthermore, it contributed to a reduction in hepatic fat deposition by decreasing the levels of triglycerides (TG) and total cholesterol (T-CHO) both in the liver and serum. Transcriptomic analysis of the liver highlighted LBR's substantial influence on lipid metabolism pathways, including the PPAR signaling pathway, primary bile acid biosynthesis, cholesterol metabolism, bile secretion, fat digestion and absorption, fatty acid degradation and fatty acid biosynthesis. Further, the expression level of genes pinpointed significant downregulation of fasn and dgat2, alongside upregulation of genes like pparda, cpt1b, cpt1ab and abca1b, in response to LBR supplementation. Overall, the findings present LBR as a promising enhancer of growth and survival in grass carp, with significant benefits in promoting fat metabolism and liver health, offering valuable insights for aquacultural nutrition strategies.

Ca2+ homeostasis imbalance induced by Pparg: A key factor in di (2-ethylhexyl) phthalate (DEHP)-induced cardiac dysfunction in zebrafish larvae

Widespread application of the typical phthalate plasticizers, di (2-ethylhexyl) phthalate (DEHP), poses a serious potential threat to the health of animals and even humans. Previous studies have confirmed the mechanism of DEHP-induced cardiac developmental defects in zebrafish larvae. However, the mechanism of cardiac dysfunction is still unclear. Thus, this work aimed to comprehensively investigate the mechanisms involved in DEHP-induced cardiac dysfunction through computational simulations, in vivo assays in zebrafish, and in vitro assays in cardiomyocytes. Firstly, molecular docking and western blot initially investigated the activating effect of DEHP on Pparg in zebrafish. Although GW9662 (PPARG antagonist) effectively alleviated DEHP-induced cardiac dysfunction and lipid metabolism disorders, it did not restore significant decreases in mitochondrial membrane potential and ATP levels. In vitro assays in cardiomyocytes, DEHP caused overexpression of PPARG and proteins involved in the regulation of Ca2+ homeostasis, and the above abnormalities were effectively alleviated by GW9662, suggesting that the Ca2+ homeostatic imbalance caused by activation of PPARG by DEHP seems to be the main cause of DEHP-induced cardiac dysfunction. To sum up, this work not only refines the mechanism of toxic effects of cardiotoxicity induced by DEHP, but provides an important theoretical basis for enriching the toxicological effects of DEHP.