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Objective: To investigate the effects of Alpiniae oxyphyllae Fructus (AOF) on renal lipid deposition in diabetic kidney disease (DKD) and elucidate its molecular mechanisms. Methods: The mechanism of AOF in treating DKD was explored by network pharmacological enrichment analysis, molecular docking, and molecular dynamics simulation. The effects of AOF on renal function and lipid deposition were assessed in a mouse model of DKD and high glucose-stressed HK-2 cells. Cell viability and lipid accumulation were detected by CCK8 and oil red O staining. The expressions of PPARα and fatty acid oxidation-related genes (ACOX1 and CPT1A) were detected by quantitative RT-PCR, Western blot, and immunofluorescence. Furthermore, PPARα knockdown was performed to examine the molecular mechanism of AOF in treating DKD. Results: Network pharmacological enrichment analysis, molecular docking, and molecular dynamics simulation showed that the active compounds in AOF targeted PPARα and thus transcriptionally regulated ACOX1 and CPT1A. AOF lowered blood glucose, improved dyslipidemia, and attenuated renal injury in DKD mice. AOF-containing serum accentuated high glucose-induced decrease in cell viability and ameliorated lipid accumulation. Additionally, it significantly upregulated the expression of PPARα, ACOX1, and CPT1A in both in vivo and in vitro experiments, which was reversed by PPARα knockdown. Conclusions: AOF may promote fatty acid oxidation via PPARα to ameliorate renal lipid deposition in DKD. [ABSTRACT FROM AUTHOR]

Transcription factors collaborate with epigenetic regulatory factors to orchestrate cardiac differentiation for heart development, but the underlying mechanism is not fully understood. Here, we report that GATA‐6 induces cardiac differentiation but peroxisome proliferator‐activated receptor α (PPARα) reverses GATA‐6‐induced cardiac differentiation, possibly because GATA‐6/PPARα recruits the polycomb protein complex containing EZH2/Ring1b/BMI1 to the promoter of the cardiac‐specific α‐myosin heavy chain (α‐MHC) gene and suppresses α‐MHC expression, which ultimately inhibits cardiac differentiation. Furthermore, Ring1b ubiquitylates PPARα and GATA‐6. By overexpression and knockout of EZH2/BMI1, it was demonstrated that the polycomb protein complex inhibits cardiac differentiation induced by GATA‐6 and PPARα. Together, our results demonstrate that the polycomb protein complex interacts with GATA‐6/PPARα to inhibit cardiac differentiation, a finding that could facilitate the development of new therapies for congenital heart disease. [ABSTRACT FROM AUTHOR]

Background: The involvement of microRNA-668 (miR-668) in the onset and progression of renal fibrosis remains unclear. To this end, we aimed to explore the relevant mechanism of miR-668 in renal fibrosis. Methods: C57BL/6 J male mice were randomly divided into sham-operated, unilateral ureteral obstruction (UUO), and UUO-fenofibrate groups. Based on transfection and drug intervention, HK-2 cells were divided into blank control, TGF-β1, TGF-β1 + fenofibrate (PPARα agonist), mimics-NC, miR-668, mimics-NC + TGF-β1, miR-668 + TGF-β1, miR-668 + TGF-β1 + fenofibrate, miR-668 + TGF-β1 + GW6471 (PPARα inhibitor), mimics-NC + TGF-β1 + fenofibrate, and mimics-NC + TGF-β1 + GW6471 groups. The pathological changes in the renal tissues were observed by hematoxylin–eosin (HE) and Masson staining. The expression of PPARα, PGC-1α, miR-668, E-cadherin, Collagen III (Col III), and α-SMA in the renal tissues or HK-2 cells was detected by western blot, immunohistochemical analyses or real-time quantitative polymerase chain reaction. The regulatory effect of miR-668 on PPARα was verified by dual-luciferase reporter assay. Results: The expression of PPARα and PGC-1α decreased in UUO mice and TGF-β1-induced HK-2 cells, which was improved by fenofibrate. Compared to the non-transfected group, in TGF-β1-stimulated HK-2 cells, the expression of E-cadherin, PPARα and PGC-1α increased and the expression of Col III and α-SMA decreased in the miR-668-transfected group. The dual-luciferase reporter assay indicated the regulatory effect of hsa-mir-668-3p on PPARα. Conclusion: MiR-668 can target PPARα and positively regulate the PPARα/PGC-1α pathway to alleviate renal fibrosis. [ABSTRACT FROM AUTHOR]

Background: Recent data has shown a considerable advancement in understanding the role of lymphotoxin-β receptor (LTβR) in inflammation. However, the functions and underlying mechanisms of LTβR in acute kidney injury (AKI) remain largely unknown. Methods: AKI was induced in mice by renal ischemia-reperfusion (I/R). HK-2 cells and primary renal tubular epithelial cells (RTECs) were subjected to hypoxia/reoxygenation (H/R) injury. The effects of LTβR depletion were examined in mice, as well as primary RTECs. Bone marrow chimeric mice was generated to determine whether the involvement of LTβR expression by parenchymal cells or bone marrow derived cells contributes to renal injury during AKI. RNA sequencing techniques were employed to investigate the mechanism via which LTβR signaling provides protection against I/R-induced AKI Results: LTβR expression was downregulated both in vivo and in vitro models of AKI. Moreover, depletion of LTβR decreased renal damage and inflammation in I/R-induced AKI. We also found that LTβR deficient mice engrafted with wild type bone marrow had significantly less tubular damage, implying that LTβR in renal parenchymal cells may play dominant role in I/R-induced AKI. RNA sequencing indicated that the protective effect of LTβR deletion was associated with activation of PPARα signaling. Furthermore, upregulation of PPARα was observed upon depletion of LTβR. PPARα inhibitor, GW6471, aggravated the tubular damage and inflammation in LTβR−/− mice following I/R injury. Then we further demonstrated that LTβR depletion down-regulated non-canonical NF-κB and Bax/Bcl-2 apoptosis pathway through PPARα. Conclusions: Our results suggested that the LTβR/PPARα axis may be a potential therapeutic target for the treatment of AKI. [ABSTRACT FROM AUTHOR]

Background: PPARα and cyclooxygenase (COX)-2 are overexpressed in certain types of cancer. Thus, developing a dual inhibitor that targets both could be more effective as an anticancer agent than single inhibitors. We have previously shown that an analog of the bezafibrate named AA520 is a PPARα antagonist. Herein, we report the identification of AA520 as a potent COX-2 inhibitor using in silico approaches. In addition, we performed a thorough pharmacological characterization of AA520 towards COX-1 and COX-2 in different in vitro models. Methods: AA520 was characterized for inhibiting platelet COX-1 and monocyte COX-2 activity in human whole blood (HWB) and for effects on lipidomics of eicosanoids using LC-MS/MS. The kinetics of the interaction of AA520 with COX-2 was assessed in the human colon cancer cell line, HCA-7, expressing only COX-2, by testing the COX-2 activity after extensive washing of the cells. The impact of AA520 on cancer cell viability, metabolic activity, and cytotoxicity was tested using the MTT reagent. Results: In HWB, AA520 inhibited in a concentration-dependent fashion LPS-stimulated leukocyte prostaglandin (PG) E2 generation with an IC50 of 0.10 (95% CI: 0.05–0.263) μM while platelet COX-1 was not affected up to 300 μM. AA520 did not affect LPS-induced monocyte COX-2 expression, and other eicosanoids generated by enzymatic and nonenzymatic pathways. AA520 inhibited COX-2-dependent PGE2 generation in the colon cancer cell line HCA7. Comparison of the inhibition of COX-2 and its reversibility by AA520, indomethacin (a time-dependent inhibitor), acetylsalicylic acid (ASA) (an irreversible inhibitor), and ibuprofen (a reversible inhibitor) showed that the compound is acting by forming a tightly bound COX-2 interaction. This was confirmed by docking and molecular dynamics studies. Moreover, AA520 (1 μM) significantly reduced MTT in HCA7 cells. Conclusion: We have identified a highly selective COX-2 inhibitor with a unique scaffold. This inhibitor retains PPARα antagonism at the same concentration range. It has the potential to be effective in treating certain types of cancer, such as hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC), where COX-2 and PPARα are overexpressed. [ABSTRACT FROM AUTHOR]

To elucidate the unidentified roles of a selective peroxisome proliferator-activated receptor α (PPARα) agonist, pemafibrate (Pema), on the pathogenesis of retinal ischemic diseases (RID)s, the pharmacological effects of Pema on the retinal pigment epithelium (RPE), which is involved in the pathogenesis of RID, were compared with the pharmacological effects of the non-fibrate PPARα agonist GW7647 (GW). For this purpose, the human RPE cell line ARPE19 that was untreated (NT) or treated with Pema or GW was subjected to Seahorse cellular metabolic analysis and RNA sequencing analysis. Real-time cellular metabolic function analysis revealed that pharmacological effects of the PPARα agonist actions on essential metabolic functions in RPE cells were substantially different between Pema-treated cells and GW-treated cells. RNA sequencing analysis revealed the following differentially expressed genes (DEGs): (1) NT vs. Pema-treated cells, 37 substantially upregulated and 72 substantially downregulated DEGs; (2) NT vs. GW-treated cells, 32 substantially upregulated and 54 substantially downregulated DEGs; and (3) Pema vs. GW, 67 substantially upregulated and 51 markedly downregulated DEGs. Gene ontology (GO) analysis and ingenuity pathway analysis (IPA) showed several overlaps or differences in biological functions and pathways estimated by the DEGs between NT and Pema-treated cells and between NT and GW-treated cells, presumably due to common PPARα agonist actions or unspecific off-target effects to each. For further estimation, overlaps of DEGs among different pairs of comparisons (NT vs. Pema, NT vs. GW, and Pema vs. GW) were listed up. Angiopoietin-like 4 (ANGPTL4), which has been shown to cause deterioration of RID, was the only DEG identified as a common significantly upregulated DEG in all three pairs of comparisons, suggesting that ANGPTL4 was upregulated by the PPARα agonist action but that its levels were substantially lower in Pema-treated cells than in GW-treated cells. In qPCR analysis, such lower efficacy for upregulation of the mRNA expression of ANGPTL4 by Pema than by GW was confirmed, in addition to substantial upregulation of the mRNA expression of HIF1α by both agonists. However, different Pema and GW-induced effects on mRNA expression of HIF1α (Pema, no change; GW, significantly downregulated) and mRNA expression of ANGPTL4 (Pema, significantly upregulated; GW, significantly downregulated) were observed in HepG2 cells, a human hepatocyte cell line. The results of this study suggest that actions of the PPARα agonists Pema and GW are significantly organ-specific and that lower upregulation of mRNA expression of the DR-worsening factor ANGPTL4 by Pema than by GW in ARPE19 cells may minimize the risk for development of RID. [ABSTRACT FROM AUTHOR]

Atherosclerosis is the pathological cause of atherosclerotic cardiovascular disease (ASCVD), which rapidly progresses during the cellular senescence. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce major cardiovascular events in patients with ASCVD and have potential antisenescence effects. Here, we investigate the effects of the SGLT2 inhibitor dapagliflozin on cellular senescence in atherosclerotic mice. Compared with ApoE−/− control mice treated with normal saline, those in the ApoE−/− dapagliflozin group, receiving intragastric dapagliflozin (0.1 mg kg−1 d−1) for 14 weeks, exhibited the reduction in the total aortic plaque area (48.8%±6.6% vs. 74.6%±8.0%, P<0.05), the decrease in the lipid core area ((0.019±0.0037) mm2vs. (0.032±0.0062) mm2, P<0.05) and in the percentage of senescent cells within the plaques (16.4%±3.7% vs. 30.7%±2.0%, P<0.01), while the increase in the thickness of the fibrous cap ((21.6±2.1) µm vs. (14.6±1.5) µm, P<0.01). Transcriptome sequencing of the aortic arch in the mice revealed the involvement of the PPARα and the fatty acid metabolic signaling pathways in dapagliflozin's mechanism of ameliorating cellular aging and plaque progression. In vitro, dapagliflozin inhibited the expression of PPARα and its downstream signal FABP4, by which the accumulation of senescent cells in human aortic smooth muscle cells (HASMCs) was reduced under high-fat conditions. This effect was accompanied by a reduction in the intracellular lipid content and alleviation of oxidative stress. However, these beneficial effects of dapagliflozin could be reversed by the PPARα overexpression. Bioinformatics analysis and molecular docking simulations revealed that dapagliflozin might exert its effects by directly interacting with the RXRA protein, thereby influencing the expression of the PPARα signaling pathway. In conclusion, the cellular senescence of aortic smooth muscle cells is potentially altered by dapagliflozin through the suppression of the RXRA-PPARα-FABP4 signaling pathway, resulting in a deceleration of atherosclerotic progression. [ABSTRACT FROM AUTHOR]

Introduction: Arylamine N -acetyltransferase 2 (NAT2) expresses a well-defined genetic polymorphism in humans that modifies drug and xenobiotic metabolism. Recent studies and genome wide association studies have reported that genetic variants of NAT2 are associated with differential risks of developing dyslipidemia and cardiometabolic disorders, suggesting a previously unrecognized role of NAT2 in pathophysiology of metabolic disorders. In support of this notion, we recently showed that human NAT2 expression is differentially regulated by glucose and insulin. Moreover, our in silico analysis showed that NAT2 is co-expressed with nuclear receptors enriched in the liver, e.g., NR1H4 (FXR) and NR1I2 (PXR), that have been previously implicated in regulation of hepatic glucose and lipid homeostasis. Identification of transcriptional regulator(s) of human NAT2 would aid in understanding novel functions that it may play in the liver. Thus, the present study was designed to investigate if NAT2 is transcriptionally regulated by hepatic nuclear receptors. Methods: To test this, we treated cryopreserved human hepatocytes with agonists towards four different hepatic transcription factors/nuclear hormone receptors, namely FXR (NR1H4), PXR (NR1I2), LXR (NR1H3), and PPARα (PPARA), and measured their effects on the level of NAT2 mRNA. Results: While the treatment with a FXR, PXR, or LXR agonist (i.e., GW-4064, SR-12813, or GW-3965) significantly induced their respective target genes, treatment with these agonists did not significantly alter the transcript level of NAT2 in human hepatocytes. PPARα agonist, GW-7647, treatment resulted in a statistically significant decrease in the NAT2 transcript level. However, its magnitude was marginal. Conclusion: In summary, hepatic nuclear receptors we examined in the present study (FXR, PXR, LXR, and PPARα) did not significantly alter NAT2 expression in cryopreserved human hepatocytes. Additional studies are needed to identify transcriptional regulators of hepatic NAT2 expression. [ABSTRACT FROM AUTHOR]

Background and Purpose Experimental Approach Key Results Conclusion and Implications As a chronic metabolic syndrome, hyperlipidaemia is manifested as aberrantly elevated cholesterol and triglyceride (TG) levels, primarily attributed to disorders in lipid metabolism. Despite the promising outlook for hyperlipidaemia treatment, the need persists for the development of lipid‐lowering agents with heightened efficiency and minimal toxicity. This investigation aims to elucidate the lipid‐lowering effects and potential pharmacodynamic mechanisms of Anti‐b, a novel low MW compound.We employed high‐fat diet (HFD) in hamsters and mice or oleic acid (OA) in cultures of HepG2 cells and LO2 cells to induce hyperlipidaemia models. We administered Anti‐b to assess its therapeutic effects on dyslipidaemia and hepatic steatosis. We used western blotting, RNA sequencing, GO and KEGG analysis, oil red O staining, along with molecular docking and molecular dynamics simulation to elucidate the mechanisms underlying the effects of Anti‐b.Anti‐b exhibited a substantial reduction in HFD‐induced elevation of blood lipids, liver weight to body weight ratio, liver diameter and hepatic fat accumulation. Moreover, Anti‐b demonstrated therapeutic effects in alleviating total cholesterol (TC), TG levels, and lipid accumulation derived from OA in HepG2 cells and LO2 cells. Mechanistically, Anti‐b selectively bound to the mTOR kinase protein and increased mTOR thermal stability, resulting in downregulation of phosphorylation level. Notably, Anti‐b exerted anti‐hyperlipidaemia effects by modulating PPARγ and SREBP1 signalling pathways and reducing the expression level of mSREBP1 and PPARγ proteins.In conclusion, our study has provided initial data of a novel low MW compound, Anti‐b, designed and synthesised to target mTOR protein directly. Our results indicate that Anti‐b may represent a novel class of drugs for the treatment of hyperlipidemia and hepatic steatosis. [ABSTRACT FROM AUTHOR]

Background: Salidroside (SDS), a phenylpropanoid glycoside, is an antioxidant component isolated from the traditional Chinese medicine Rhodiola rosea and has multifunctional bioactivities, particularly possessing potent hepatoprotective function. Non-alcoholic steatohepatitis (NASH) is one of the most prevalent chronic liver diseases worldwide, but it still lacks efficient drugs. This study aimed to assess the preventive and therapeutic effects of SDS on NASH and its underlying mechanisms in a mouse model subjected to a methionine- and choline-deficient (MCD) diet. Methods: C57BL/6J mice were fed an MCD diet to induce NASH. During or after the formation of the MCD-induced NASH model, SDS (24 mg/kg/day) was supplied as a form of diet for 4 weeks. The histopathological changes were evaluated by H&E staining. Oil Red O staining and Sirius Red staining were used to quantitatively determine the lipid accumulation and collagen fibers in the liver. Serum lipid and liver enzyme levels were measured. The morphology of autophagic vesicles and autophagosomes was observed by transmission electron microscopy (TEM), and qRT-PCR and Western blotting were used to detect autophagy-related factor levels. Immunohistochemistry and TUNEL staining were used to evaluate the apoptosis of liver tissues. Flow cytometry was used to detect the composition of immune cells. ELISA was used to evaluate the expression of serum inflammatory factors. Transcript–proteome sequencing, molecular docking, qRT-PCR, and Western blotting were performed to explore the mechanism and target of SDS in NASH. Results: The oral administration of SDS demonstrated comprehensive efficacy in NASH. SDS showed both promising preventive and therapeutic effects on NASH in vivo. SDS could upregulate autophagy, downregulate apoptosis, rebalance immunity, and alleviate inflammation to exert anti-NASH properties. Finally, the results of transcript–proteome sequencing, molecular docking evaluation, and experimental validation showed that SDS might exert its multiple effects through targeting PPARα. Conclusion: Our findings revealed that SDS could regulate liver autophagy and apoptosis, regulating both innate immunity and adaptive immunity and alleviating inflammation in NASH prevention and therapy via the PPAR pathway, suggesting that SDS could be a potential anti-NASH drug in the future. [ABSTRACT FROM AUTHOR]

Regulation of energy metabolism is pivotal in the development of cardiovascular diseases. Dysregulation in mitochondrial fatty acid oxidation has been linked to cardiac lipid accumulation and diabetic cardiomyopathy. Sirtuin 1 (SIRT1) is a deacetylase that regulates the acetylation of various proteins involved in mitochondrial energy metabolism. SIRT1 mediates energy metabolism by directly and indirectly affecting multiple aspects of mitochondrial processes, such as mitochondrial biogenesis. SIRT1 interacts with essential mitochondrial energy regulators such as peroxisome proliferator-activated receptor-α (PPARα), PPARγ coactivator-1α, estrogen-related receptor-α, and their downstream targets. Apart from that, SIRT1 regulates additional proteins, including forkhead box protein O1 and AMP-activated protein kinase in cardiac disease. Interestingly, studies have also shown that the expression of SIRT1 plays a dual-edged role in energy metabolism. Depending on the physiological state, SIRT1 expression can be detrimental or protective. This review focuses on the molecular pathways through which SIRT1 regulates energy metabolism in cardiovascular diseases. We will review SIRT1 and discuss its role in cardiac energy metabolism and its benefits and detrimental effects in heart disease. [ABSTRACT FROM AUTHOR]

Background/objetives: Mexican people use Smilax dominguensis as a traditional medicine for diabetes control. Some reports have shown an anti-hyperglycemic effect in animal models. In the current research, a chemical bio-guided fractionation in vitro and in silico was performed to identify compounds with anti-hyperglycemic and hypolipidemic effects through PPARγ/α dual agonist activity because they regulate genes involved in energy storage and burning, such as GLUT4 and FATP. Methods: The S. dominguensis extract was evaluated in mice through oral glucose tolerance tests. The bioactive extract was fractionated by open-column chromatography, and seven final fractions (F1–F7) were obtained and evaluated. C2C12 myoblasts were treated with the fractions, and the mRNA expression levels of PPARs, GLUT-4, and FATP were quantified. The most active fractions were evaluated on GLUT-4 translocation and lipid storage in C2C12 cells and 3T3-L1 adipocytes, respectively. Results: The F3 fraction increased the expressions of PPARγ, GLUT-4, PPARα, and FATP, and it induced GLUT-4 translocation and decreased lipid storage. F3 was then analyzed by NMR, identifying three flavonoids: luteolin, apigenin, and kaempferol. These compounds were analyzed by molecular docking and on PPAR expressions. Luteolin, apigenin, and kaempferol produced a discrete increase in the mRNA expression of PPARs. Luteolin and kaempferol also decreased lipid storage. Conclusions: Our findings indicate that the compounds identified in S. dominguensis exhibit dual agonist activity on PPARγ/PPARα and have the potential for the development of new therapeutic agents helpful in diabetes, obesity, or metabolic syndrome. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to elucidate the mechanism of oleuropein (OLE) ameliorates non‐alcoholic fatty liver disease (NAFLD) and its underlying mechanisms. RESULTS: Male C57BL/6J mice were fed either a low‐fat diet (LFD), a high‐fat diet (HFD), or a HFD supplemented with 0.03% (w/w) OLE for 16 weeks. OLE supplementation decreased body weight and liver weight, improved serum lipid profiles, and ameliorated HFD‐induced hepatic dysfunction. Liver metabolomics analysis revealed that OLE increased the levels of nicotinamide, tauroursodeoxycholic acid, taurine, and docosahexaenoic acid, which were beneficial for lipid homeostasis and inflammation regulation. OLE exerted its protective effects by activating peroxisome proliferator‐activated receptor alpha (PPARα), a key transcription factor that regulates fibroblast growth factor 21 (FGF21) expression and modulates lipid oxidation, lipogenesis and inflammation pathways. Importantly, OLE supplementation did not significantly affect body weight or liver weight in PPARα knockout (PPARα KO) mice, indicating that PPARα is essential for OLE‐mediated NAFLD prevention. CONCLUSION: Our results suggest that OLE alleviates NAFLD in mice by activating PPARα and modulating liver metabolites. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Peroxisome proliferator-activated receptors (PPARs), including PPAR-α, PPAR-β/δ, and PPAR-γ, are involved in various cellular responses, including metabolism and cell proliferation. Increasing evidence suggests that PPARs are closely associated with tumorigenesis and metastasis. However, the exact role of PPARs in energy metabolism and cancer stem cell (CSC) proliferation remains unclear. This study investigated the role of PPARs in energy metabolism and tumorigenesis in ovarian CSCs. The expression of PPARs and fatty acid consumption as an energy source increased in spheroids derived from A2780 ovarian cancer cells (A2780-SP) compared with their parental cells. GW6471, a PPARα inhibitor, induced apoptosis in A2780-SP. PPARα silencing mediated by small hairpin RNA reduced A2780-SP cell proliferation. Treatment with GW6471 significantly inhibited the respiratory oxygen consumption of A2780-SP cells, with reduced dependency on fatty acids, glucose, and glutamine. In a xenograft tumor transplantation mouse model, intraperitoneal injection of GW6471 inhibited in vivo tumor growth of A2780-SP cells. These results suggest that PPARα plays a vital role in regulating the proliferation and energy metabolism of CSCs by altering mitochondrial activity and that it offers a promising therapeutic target to eradicate CSCs. [ABSTRACT FROM AUTHOR]

Rapid turnover of the intestinal epithelium is a critical strategy to balance the uptake of nutrients and defend against environmental insults, whereas inappropriate death promotes the spread of inflammation. PPAR α is highly expressed in the small intestine and regulates the absorption of dietary lipids. However, as a key mediator of inflammation, the impact of intestinal PPAR α signaling on cell death pathways is unknown. Here, we show that Pparα deficiency of intestinal epithelium up-regulates necroptosis signals, disrupts the gut vascular barrier, and promotes LPS translocation into the liver. Intestinal Pparα deficiency drives age-related hepatic steatosis and aggravates hepatic fibrosis induced by a high-fat plus high-sucrose diet (HFHS). PPAR α levels correlate with TRIM38 and MLKL in the human ileum. Inhibition of PPAR α up-regulates necroptosis signals in the intestinal organoids triggered by TNF- α and LPS stimuli via TRIM38/TRIF and CREB3L3/MLKL pathways. Butyric acid ameliorates hepatic steatosis induced by intestinal Pparα deficiency through the inhibition of necroptosis. Our data suggest that intestinal PPAR α is essential for the maintenance of microenvironmental homeostasis and the spread of inflammation via the gut–liver axis. Pparα deficiency in the ileum epithelium up-regulates necroptosis signals via TRIM38/TRIF and CREB3L3/MLKL pathways, leading to hepatic steatosis through the spread of gut-derived endotoxin. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background The involvement of microRNA-668 (miR-668) in the onset and progression of renal fibrosis remains unclear. To this end, we aimed to explore the relevant mechanism of miR-668 in renal fibrosis. Methods C57BL/6 J male mice were randomly divided into sham-operated, unilateral ureteral obstruction (UUO), and UUO-fenofibrate groups. Based on transfection and drug intervention, HK-2 cells were divided into blank control, TGF-β1, TGF-β1 + fenofibrate (PPARα agonist), mimics-NC, miR-668, mimics-NC + TGF-β1, miR-668 + TGF-β1, miR-668 + TGF-β1 + fenofibrate, miR-668 + TGF-β1 + GW6471 (PPARα inhibitor), mimics-NC + TGF-β1 + fenofibrate, and mimics-NC + TGF-β1 + GW6471 groups. The pathological changes in the renal tissues were observed by hematoxylin–eosin (HE) and Masson staining. The expression of PPARα, PGC-1α, miR-668, E-cadherin, Collagen III (Col III), and α-SMA in the renal tissues or HK-2 cells was detected by western blot, immunohistochemical analyses or real-time quantitative polymerase chain reaction. The regulatory effect of miR-668 on PPARα was verified by dual-luciferase reporter assay. Results The expression of PPARα and PGC-1α decreased in UUO mice and TGF-β1-induced HK-2 cells, which was improved by fenofibrate. Compared to the non-transfected group, in TGF-β1-stimulated HK-2 cells, the expression of E-cadherin, PPARα and PGC-1α increased and the expression of Col III and α-SMA decreased in the miR-668-transfected group. The dual-luciferase reporter assay indicated the regulatory effect of hsa-mir-668-3p on PPARα. Conclusion MiR-668 can target PPARα and positively regulate the PPARα/PGC-1α pathway to alleviate renal fibrosis.

Abstract Peritoneal inflammation and fibrosis remain major challenges to the long-term maintenance of peritoneal dialysis. Pemafibrate, a selective peroxisome proliferator-activated receptor α (PPARα) modulator, has been implicated in the management of fibrosis-related disorders. We investigated whether pemafibrate ameliorates peritoneal inflammation and fibrosis and explored the underlying mechanisms in mice with methylglyoxal (MGO)-induced peritoneal fibrosis (MGO mice). MGO mice exhibited peritoneal fibrosis with increased expression of mesenchymal markers, transforming growth factor-β1 (TGF-β1), and substantial deposition of extracellular matrix (ECM) proteins. Additionally, MGO mice exhibited peritoneal inflammation as indicated by elevated tumor necrosis factor-α expression and macrophage infiltration in peritoneal tissue. These effects were mitigated by pemafibrate treatment, which also restored peritoneal membrane function. Furthermore, pemafibrate promoted anti-inflammatory macrophage polarization in both mice and THP-1 cells. In human peritoneal mesothelial cells (HPMCs), pemafibrate effectively inhibited interferon-γ-induced production of TGF-β1 and ECM while suppressing the proinflammatory cytokines nuclear factor-κB (NF-κB) and activator protein 1. The NF-κB inhibitory effect of pemafibrate involved stabilization of the NF-κB inhibitory protein IkBα. Notably, pemafibrate hindered activation of the NLR family pyrin domain containing 3/caspase-1 axis in interferon-γ-stimulated THP-1 cells. These findings suggest that pemafibrate ameliorates peritoneal inflammation and fibrosis, making it a promising candidate for peritoneal fibrosis therapy.

Abstract Background Apical papilla stem cells (SCAPs) exhibit significant potential for tissue repair, characterized by their anti-inflammatory and pro-angiogenic properties. Exosomes derived from stem cells have emerged as safer alternatives that retain comparable physiological functions. This study explores the therapeutic potential of exosomes sourced from SCAPs in the treatment of non-alcoholic steatohepatitis (NASH). Methods A NASH mouse model was established through the administration of a high-fat diet (HFD), and SCAPs were subsequently isolated for experimental purposes. A cell model of NASH was established in vitro by treating hepatocellular carcinoma cells with oleic acid (OA) and palmitic acid (PA). Exosomes were isolated via differential centrifugation. The mice were treated with exosomes injected into the tail vein, and the hepatocytes were incubated with exosomes in vitro. After the experiment, physiological and biochemical markers were analyzed to assess the effects of exosomes derived from SCAPs on the progression of NASH in both NASH mouse models and NASH cell models. Results After exosomes treatment, the weight gain and liver damage induced by HFD were significantly reduced. Additionally, hepatic fat accumulation was markedly alleviated. Mechanistically, exosomes treatment promoted the expression of genes involved in hepatic fatty acid oxidation and transport, while simultaneously suppressing genes associated with fatty acid synthesis. Furthermore, the levels of serum inflammatory cytokines and the mRNA expression of inflammatory markers in liver tissue were significantly decreased. In vitro cell experiments produced similar results.

Abstract Background Primary human hepatocytes (PHHs) are highly valuable for drug-metabolism evaluation, liver disease modeling and hepatocyte transplantation. However, their availability is significantly restricted due to limited donor sources, alongside their constrained proliferation capabilities and reduced functionality when cultured in vitro. To address this challenge, we aimed to develop a novel method to efficiently expand PHHs in vitro without a loss of function. Methods By mimicking the in vivo liver regeneration route, we developed a two-step strategy involving the de-differentiation/expansion and subsequent maturation of PHHs to generate abundant functional hepatocytes in vitro. Initially, we applied SiPer, a prediction algorithm, to identify candidate small molecules capable of activating liver regenerative transcription factors, thereby formulating a novel hepatic expansion medium to de-differentiate PHHs into proliferative human hepatic progenitor-like cells (ProHPLCs). These ProHPLCs were then re-differentiated into functionally mature hepatocytes using a new hepatocyte maturation condition. Additionally, we investigated the underlying mechanism of PHHs expansion under our new conditions. Results The novel hepatic expansion medium containing hydrocortisone facilitated the de-differentiation of PHHs into ProHPLCs, which exhibited key hepatic progenitor characteristics and demonstrated a marked increase in proliferation capacity compared to cells cultivated in previously established expansion conditions. Remarkably, these subsequent matured hepatocytes rivaled PHHs in terms of transcriptome profiles, drug metabolizing activities and in vivo engraftment capabilities. Importantly, our findings suggest that the enhanced expansion of PHHs by hydrocortisone may be mediated through the PPARα signaling pathway and regenerative transcription factors. Conclusions This study presents a two-step strategy that initially induces PHHs into a proliferative state (ProHPLCs) to ensure sufficient cell quantity, followed by the maturation of ProHPLCs into fully functional hepatocytes to guarantee optimal cell quality. This approach offers a promising means of producing large numbers of seeding cells for hepatocyte-based applications.

Abstract Liver cancer is the fourth leading cause of cancer-related deaths with a steadily increasing rate worldwide, as a well-known hallmark of liver cancer, metabolic alterations are related to liposomal changes, a common characteristic of primary liver cancers based on recent lipidomics studies. Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor with important lipid homeostasis function, therefore we aimed to understand the molecular mechanisms and pathways that activate PPARα after using PPAR-α agonist WY-14643 and identify candidate biomarkers related to PPARα activity and evaluate their effects in liver cancer. The data from differently expressed genes (DEGs) between liver cancer tissue from obese subjects alone and liver tissue after treatment were evaluated by DESeq2 and module genes were analyzed using weighted gene co-expression network analysis (WGCNA). Final candidate genes were identified by intersecting genes among highly ranked DEGs and the brown module, which demonstrated a significant negative correlation with drug treatments. We conducted a protein–protein interaction network, and KEGG enrichment analysis, and core hub genes (CD40, CXCL9, CXCL10, TNFSF14, GBP2, GBP3, APOL3, CLDN1) were identified using the cyto-hubba plugin, among them we focused on GBP2 that plays key roles in oncogenesis and evaluate its expressional with clinical outcomes. In conclusion, the WGCNA-based co-expression network identified GBP2 as one of the hub genes with a negative relation with PPARα agonist treatments. higher expression of GBP2 was closely associated with HCC progression. Therefore, GBP2 might be a potential candidate for the study of PPARα activity in HCC.

Maternal obesity in pregnancy is strongly associated with complications such as fetal overgrowth and infants of obese mothers have an increased risk to develop obesity, diabetes, and cardiovascular disease later in life. However, the underlying mechanisms are not well established. Circulating levels of adiponectin are low in obese pregnant women and maternal circulating adiponectin is negatively associated with birth weight. We have reported that normalizing maternal adiponectin in obese pregnant mice prevents placental dysfunction, fetal overgrowth, and programming of offspring cardio‐metabolic disease. However, the mechanistic link between maternal adiponectin, placental function, and fetal growth remains to be established. We hypothesized that trophoblast‐specific overexpression of the adiponectin receptor 2 (Adipor2) in healthy pregnant mice inhibits placental mTORC1 signaling and nutrient transport, resulting in fetal growth restriction. Using lentiviral transduction of blastocysts with a mammalian gene expression lentiviral vector for up‐regulation of Adipor2 (Adipor2‐OX), we achieved a ~ 3‐fold increase in placenta Adipor2 mRNA levels and a 2‐fold increase of the ADIPOR2 protein in the trophoblast plasma membrane. Placenta‐specific Adipor2‐OX increased placental peroxisome proliferator‐activated receptor‐α phosphorylation, ceramide synthase expression and ceramide concentrations. Furthermore, Adipor2‐OX inhibited placental mTORC1 signaling and reduced in vivo placental transport of glucose and amino acids. Lastly, Adipor2‐OX reduced fetal weight by 11%. These data provide mechanistic evidence that placental Adipor2 signaling directly affects fetal growth. We propose that low circulating adiponectin in maternal obesity causes fetal overgrowth and programs the offspring for cardio‐metabolic disease mediated by a direct effect on placental function. [ABSTRACT FROM AUTHOR]

Background: Salidroside (SDS), a phenylpropanoid glycoside, is an antioxidant component isolated from the traditional Chinese medicine Rhodiola rosea and has multifunctional bioactivities, particularly possessing potent hepatoprotective function. Non-alcoholic steatohepatitis (NASH) is one of the most prevalent chronic liver diseases worldwide, but it still lacks efficient drugs. This study aimed to assess the preventive and therapeutic effects of SDS on NASH and its underlying mechanisms in a mouse model subjected to a methionine- and choline-deficient (MCD) diet. Methods: C57BL/6J mice were fed an MCD diet to induce NASH. During or after the formation of the MCD-induced NASH model, SDS (24 mg/kg/day) was supplied as a form of diet for 4 weeks. The histopathological changes were evaluated by H&E staining. Oil Red O staining and Sirius Red staining were used to quantitatively determine the lipid accumulation and collagen fibers in the liver. Serum lipid and liver enzyme levels were measured. The morphology of autophagic vesicles and autophagosomes was observed by transmission electron microscopy (TEM), and qRT-PCR and Western blotting were used to detect autophagy-related factor levels. Immunohistochemistry and TUNEL staining were used to evaluate the apoptosis of liver tissues. Flow cytometry was used to detect the composition of immune cells. ELISA was used to evaluate the expression of serum inflammatory factors. Transcript-proteome sequencing, molecular docking, qRT-PCR, and Western blotting were performed to explore the mechanism and target of SDS in NASH. Results: The oral administration of SDS demonstrated comprehensive efficacy in NASH. SDS showed both promising preventive and therapeutic effects on NASH in vivo. SDS could upregulate autophagy, downregulate apoptosis, rebalance immunity, and alleviate inflammation to exert anti-NASH properties. Finally, the results of transcript-proteome sequencing, molecular docking evaluation, and experimental validation showed that SDS might exert its multiple effects through targeting PPARα. Conclusion: Our findings revealed that SDS could regulate liver autophagy and apoptosis, regulating both innate immunity and adaptive immunity and alleviating inflammation in NASH prevention and therapy via the PPAR pathway, suggesting that SDS could be a potential anti-NASH drug in the future. [ABSTRACT FROM AUTHOR]

Background: (E)-5-hydroxy-7-methoxy-3-(2-hydroxybenzyl)-4-chromanone (HMC), a homoisoflavonoid isolated from Portulaca oleracea, has significant anti-adipogenesis potential; it regulates adipogenic transcription factors. However, whether HMC improves hepatic steatosis in hepatocytes remains vague. This study investigated whether HMC ameliorates hepatic steatosis in free fatty acid-treated human hepatocellular carcinoma (HepG2) cells, and if so, its mechanism of action was analyzed. Methods: Hepatic steatosis was induced by a free fatty acid mixture in HepG2 cells. Thereafter, different HMC concentrations (10, 30, and 50 µM) or fenofibrate (10 µM, a PPARα agonist, positive control) was treated in HepG2 cells.Results: HMC markedly decreased lipid accumulation and triglyceride content in free fatty acid-treated HepG2 cell; it (10 and 50 μM) markedly upregulated protein expressions of pAMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. HMC (10 and 50 μM) markedly inhibited the expression of sterol regulatory element-binding protein-1c, fatty acid synthase, and stearoyl-coA desaturase 1, which are the enzymes involved in lipid synthesis. Furthermore, HMC (10 and 50 μM) markedly upregulated the protein expression of peroxisome proliferator-activated receptor alpha (PPARα) and enhanced the protein expressions of carnitine palmitoyl transferase 1 and acyl-CoA oxidase 1. Conclusion: HMC inhibits lipid accumulation and promotes fatty acid oxidation by AMPK and PPARα pathways in free fatty acid-treated HepG2 cells, thereby attenuating hepatic steatosis. [ABSTRACT FROM AUTHOR]

Peritoneal inflammation and fibrosis remain major challenges to the long-term maintenance of peritoneal dialysis. Pemafibrate, a selective peroxisome proliferator-activated receptor α (PPARα) modulator, has been implicated in the management of fibrosis-related disorders. We investigated whether pemafibrate ameliorates peritoneal inflammation and fibrosis and explored the underlying mechanisms in mice with methylglyoxal (MGO)-induced peritoneal fibrosis (MGO mice). MGO mice exhibited peritoneal fibrosis with increased expression of mesenchymal markers, transforming growth factor-β1 (TGF-β1), and substantial deposition of extracellular matrix (ECM) proteins. Additionally, MGO mice exhibited peritoneal inflammation as indicated by elevated tumor necrosis factor-α expression and macrophage infiltration in peritoneal tissue. These effects were mitigated by pemafibrate treatment, which also restored peritoneal membrane function. Furthermore, pemafibrate promoted anti-inflammatory macrophage polarization in both mice and THP-1 cells. In human peritoneal mesothelial cells (HPMCs), pemafibrate effectively inhibited interferon-γ-induced production of TGF-β1 and ECM while suppressing the proinflammatory cytokines nuclear factor-κB (NF-κB) and activator protein 1. The NF-κB inhibitory effect of pemafibrate involved stabilization of the NF-κB inhibitory protein IkBα. Notably, pemafibrate hindered activation of the NLR family pyrin domain containing 3/caspase-1 axis in interferon-γ-stimulated THP-1 cells. These findings suggest that pemafibrate ameliorates peritoneal inflammation and fibrosis, making it a promising candidate for peritoneal fibrosis therapy. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress is a major cause of hepatic steatosis through increasing de novo lipogenesis. Forkhead box O6 (FoxO6) is a transcription factor mediating insulin signaling to glucose and lipid metabolism. Therefore, dysregulated FoxO6 is involved in hepatic lipogenesis. This study elucidated the role of FoxO6 in ER stress–induced hepatic steatosis in vivo and in vitro. Hepatic ER stress responses and β-oxidation were monitored in mice overexpressed with constitutively active FoxO6 allele and FoxO6-null mice. For the in vitro study, liver cells overexpressing constitutively active FoxO6 and FoxO6-siRNA were treated with high glucose, and lipid metabolism alterations were measured. ER stress–induced FoxO6 activation suppressed hepatic β-oxidation in vivo. The expression and transcriptional activity of peroxisome proliferator-activated receptor α (PPARα) were significantly decreased in the constitutively active FoxO6 allele. Otherwise, inhibiting β-oxidation genes were reduced in the FoxO6-siRNA and FoxO6-KO mice. Our data showed that the FoxO6-induced hepatic lipid accumulation was negatively regulated by insulin signaling. High glucose treatment as a hyperglycemia condition caused the expression of ER stress–inducible genes, which was deteriorated by FoxO6 activation in liver cells. However, high glucose-mediated ER stress suppressed β-oxidation gene expression through interactions between PPARα and FoxO6 corresponding to findings in the in vivo study—lipid catabolism is also regulated by FoxO6. Furthermore, insulin resistance suppressed b-oxidation through the interaction between FoxO6 and PPARα promotes hepatic steatosis, which, due to hyperglycemia-induced ER stress, impairs insulin signaling. Key messages: Our original aims were to delineate the interrelation between the regulation of PPARα and the transcription factor FoxO6 pathway in relation to lipid metabolism at molecular levels. Evidence on high glucose promoted FoxO6 activation induced lipid accumulation in liver cells. The effect of PPARα activation of the insulin signaling. FoxO6 plays a pivotal role in hepatic lipid accumulation through inactivation of PPARα in FoxO6-overexpression mice. [ABSTRACT FROM AUTHOR]

Recent studies have shown that epigallocatechin-3-gallate (EGCG), as an effective antioxidant, could attenuate the oxidative damage, inflammation and necrosis in the liver in response to oxidative stress. The present study investigated whether oral administration of EGCG could effectively alleviate the hepatic histopathological changes and oxidative damage in yellow-feathered broilers induced by tert-butyl hydroperoxide (t-BHP). Broilers were exposed to 600 μmol t-BHP/kg body weight (BW) to induce oxidative stress by intraperitoneal injection every five days, followed by oral administration of different doses of EGCG (0, 20, 40 and 60 mg/kg BW) and 20 mg vitamin E (VE)/kg BW every day during 5–21 days of age. The results showed that t-BHP injection decreased (p < 0.05) body weight and the relative weight of the spleen; the enzyme activities of total antioxidant capacity (T-AOC), catalase (CAT) and total superoxide dismutase (SOD); and gene mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), CAT, SOD1, SOD2 and acetyl-CoA carboxylase (ACACA); as well as increased (p < 0.05) necrosis formation, malondialdehyde (MDA) content, reactive oxygen species (ROS)accumulation, and peroxisome proliferator activates receptor-α (PPARα) mRNA expression in the liver of yellow-feathered female broilers at 21 days of age. Treatment with 60 mg EGCG/kg BW orally could enhance antioxidant enzyme activities and reverse the hepatic damage induced by t-BHP injection by reducing the accumulation of ROS and MDA in the liver and activating the Nrf2 and PPARα pathways related to the induction of antioxidant gene expression (p < 0.05). In conclusion, intraperitoneal injection of t-BHP impaired body growth and induced hepatic ROS accumulation, which destroyed the antioxidant system and led to oxidative damage in the liver of yellow-feathered broilers from 5 to 21 days of age. It is suggested that EGCG may play an antioxidant role through the Nrf2 and PPARα signaling pathways to effectively protect against t-BHP-induced hepatic oxidative damage in broilers, and the appropriate dose was 60 mg EGCG/kg BW by oral administration. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis, is a common metabolic liver disease worldwide. Currently, satisfactory drugs for NAFLD treatment remain lacking. Obesity and diabetes are the leading causes of NAFLD, and compounds with anti-obesity and anti-diabetic activities are considered suitable candidates for treating NAFLD. In this study, biochemical and histological assays revealed that a natural lignan schisanhenol (SAL) effectively decreased lipid accumulation and improved hepatic steatosis in free fatty acid (FFA)-treated HepG2 cells and high-fat diet (HFD)-induced NAFLD mice. Further, molecular analyses, microRNA (miRNA)-seq, and bioinformatics analyses revealed that SAL may improve NAFLD by targeting the miR-802/adenosine monophosphate-activated protein kinase (AMPK) pathway. Liver-specific overexpression of miR-802 in NAFLD mice significantly impaired SAL-mediated liver protection and decreased the protein levels of phosphorylated (p)-AMPK and PRKAB1. Dual-luciferase assay analysis further confirmed that miR-802 inhibits hepatic AMPK expression by binding to the 3' untranslated region of mouse Prkab1 or human PRKAA1. Additionally, genetic silencing of PRKAA1 blocked SAL-induced AMPK pathway activation in FFA-treated HepG2 cells. The results demonstrate that SAL is an effective drug candidate for treating NAFLD through regulating miR-802/AMPK-mediated lipid metabolism. A natural compound, schisanhenol (SAL), exerts anti-NAFLD effects by inhibiting miR-802 and activating the AMPK signaling pathway to regulate lipid homeostasis. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Primary human hepatocytes (PHHs) are highly valuable for drug-metabolism evaluation, liver disease modeling and hepatocyte transplantation. However, their availability is significantly restricted due to limited donor sources, alongside their constrained proliferation capabilities and reduced functionality when cultured in vitro. To address this challenge, we aimed to develop a novel method to efficiently expand PHHs in vitro without a loss of function. Methods: By mimicking the in vivo liver regeneration route, we developed a two-step strategy involving the de-differentiation/expansion and subsequent maturation of PHHs to generate abundant functional hepatocytes in vitro. Initially, we applied SiPer, a prediction algorithm, to identify candidate small molecules capable of activating liver regenerative transcription factors, thereby formulating a novel hepatic expansion medium to de-differentiate PHHs into proliferative human hepatic progenitor-like cells (ProHPLCs). These ProHPLCs were then re-differentiated into functionally mature hepatocytes using a new hepatocyte maturation condition. Additionally, we investigated the underlying mechanism of PHHs expansion under our new conditions. Results: The novel hepatic expansion medium containing hydrocortisone facilitated the de-differentiation of PHHs into ProHPLCs, which exhibited key hepatic progenitor characteristics and demonstrated a marked increase in proliferation capacity compared to cells cultivated in previously established expansion conditions. Remarkably, these subsequent matured hepatocytes rivaled PHHs in terms of transcriptome profiles, drug metabolizing activities and in vivo engraftment capabilities. Importantly, our findings suggest that the enhanced expansion of PHHs by hydrocortisone may be mediated through the PPARα signaling pathway and regenerative transcription factors. Conclusions: This study presents a two-step strategy that initially induces PHHs into a proliferative state (ProHPLCs) to ensure sufficient cell quantity, followed by the maturation of ProHPLCs into fully functional hepatocytes to guarantee optimal cell quality. This approach offers a promising means of producing large numbers of seeding cells for hepatocyte-based applications. [ABSTRACT FROM AUTHOR]

The Yak (Bos grunniens) is a special breed of livestock predominantly distributed in the Qinghai–Tibet Plateau of China. Intramuscular fat (IMF) content in beef cattle is a vital indicator of meat quality. In this study, RNA-Seq and Protein-Seq were respectively employed to sequence the transcriptome and proteome of the longissimus dorsi (LD) tissue from 4-year-old yaks with significant differences in IMF content under the same fattening conditions. Five overlapping genes (MYL3, ACADS, L2HGDH, IGFN1, and ENSBGRG00000000-926) were screened using combined analysis. Functional verification tests demonstrated that the key gene ACADS inhibited yak intramuscular preadipocyte (YIMA) differentiation and proliferation, promoted mitochondrial biogenesis gene expression, and increased the mitochondrial membrane potential (MMP). Furthermore, co-transfection experiments further demonstrated that interfering with ACADS reversed the effect of PPARα agonists in promoting lipid differentiation. In conclusion, ACADS potentially inhibits lipid deposition in YIAMs by regulating the PPARα signalling pathway. These findings offer insights into the molecular mechanisms underlying yak meat quality. [ABSTRACT FROM AUTHOR]

Hyperlipidemic pancreatitis (HP) is an inflammatory injury of the pancreas triggered by elevated serum triglyceride (TG) levels. The mechanistic target of rapamycin (mTOR) signaling pathway plays a crucial role in regulating lipid homeostasis and inflammation. This study aimed to investigate whether the activity of mTOR complex 2 (mTORC2) affects the progression of HP and its underlying mechanisms. In vivo, a high‐fat diet and retrograde administration of sodium taurocholate were employed to establish the HP models in rats, with pancreatic tissue pathology evaluated. The expression of Rictor and peroxisome proliferator‐activator receptor (PPAR) was examined. The serum levels of TG, fatty acid metabolites, inflammatory and lipid metabolism‐related factors were determined. In vitro, pancreatic acinar cells (PACs) were exposed to palmitic acid and cholecystokinin‐8. PAC apoptosis, pyroptosis, and ferroptosis were assessed. In the HP models, rats and PACs exhibited upregulated Rictor and downregulated PPARα, and Rictor knockdown promoted PPARα expression. In vivo, Rictor knockdown decreased the serum levels of TG, α‐amylase, total cholesterol, low‐density lipoprotein cholesterol, lactate dehydrogenase, and inflammatory factors, while increasing high‐density lipoprotein cholesterol levels. Rictor knockdown increased ACOX1 and CPT1α and decreased SREBP‐1, CD36, SCD1, ACLY, and ACACA. Rictor knockdown reduced damage to pancreatic tissue structure. In vitro, Rictor knockdown inhibited PAC apoptosis, pyroptosis, and ferroptosis. Treatment with the PPARα antagonist GW6471 abolished the beneficial effects of Rictor knockdown. Rictor/mTORC2 deficiency reduces serum TG levels, maintains lipid homeostasis, and suppresses inflammation by inhibiting PPARα expression. Weakening mTORC2 activity holds promise as a novel therapeutic strategy for HP. [ABSTRACT FROM AUTHOR]

Abstract Build‐up of free cholesterol (FC) substantially contributes to the development and severity of non‐alcoholic fatty liver disease (NAFLD). Here, we investigate the specific mechanism by which FC induces liver injury in NAFLD and propose a novel therapeutic approach using dihydrotanshinone I (DhT). Rather than cholesterol ester (CE), we observed elevated levels of total cholesterol, FC, and alanine transaminase (ALT) in NAFLD patients and high‐cholesterol diet‐induced NAFLD mice compared to those in healthy controls. The FC level demonstrated a positive correlation with the ALT level in both patients and mice. Mechanistic studies revealed that FC elevated reactive oxygen species level, impaired the function of lysosomes, and disrupted lipophagy process, consequently inducing cell apoptosis. We then found that DhT protected mice on an HCD diet, independent of gut microbiota. DhT functioned as a potent ligand for peroxisome proliferator‐activated receptor α (PPARα), stimulating its transcriptional function and enhancing catalase expression to lower reactive oxygen species (ROS) level. Notably, the protective effect of DhT was nullified in mice with hepatic PPARα knockdown. Thus, these findings are the first to report the detrimental role of FC in NAFLD, which could lead to the development of new treatment strategies for NAFLD by leveraging the therapeutic potential of DhT and PPARα pathway.

BackgroundPPARα and cyclooxygenase (COX)-2 are overexpressed in certain types of cancer. Thus, developing a dual inhibitor that targets both could be more effective as an anticancer agent than single inhibitors. We have previously shown that an analog of the bezafibrate named AA520 is a PPARα antagonist. Herein, we report the identification of AA520 as a potent COX-2 inhibitor using in silico approaches. In addition, we performed a thorough pharmacological characterization of AA520 towards COX-1 and COX-2 in different in vitro models.MethodsAA520 was characterized for inhibiting platelet COX-1 and monocyte COX-2 activity in human whole blood (HWB) and for effects on lipidomics of eicosanoids using LC-MS/MS. The kinetics of the interaction of AA520 with COX-2 was assessed in the human colon cancer cell line, HCA-7, expressing only COX-2, by testing the COX-2 activity after extensive washing of the cells. The impact of AA520 on cancer cell viability, metabolic activity, and cytotoxicity was tested using the MTT reagent.ResultsIn HWB, AA520 inhibited in a concentration-dependent fashion LPS-stimulated leukocyte prostaglandin (PG) E2 generation with an IC50 of 0.10 (95% CI: 0.05–0.263) μM while platelet COX-1 was not affected up to 300 μM. AA520 did not affect LPS-induced monocyte COX-2 expression, and other eicosanoids generated by enzymatic and nonenzymatic pathways. AA520 inhibited COX-2-dependent PGE2 generation in the colon cancer cell line HCA7. Comparison of the inhibition of COX-2 and its reversibility by AA520, indomethacin (a time-dependent inhibitor), acetylsalicylic acid (ASA) (an irreversible inhibitor), and ibuprofen (a reversible inhibitor) showed that the compound is acting by forming a tightly bound COX-2 interaction. This was confirmed by docking and molecular dynamics studies. Moreover, AA520 (1 μM) significantly reduced MTT in HCA7 cells.ConclusionWe have identified a highly selective COX-2 inhibitor with a unique scaffold. This inhibitor retains PPARα antagonism at the same concentration range. It has the potential to be effective in treating certain types of cancer, such as hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC), where COX-2 and PPARα are overexpressed.