Fenofibrate attenuates renal lipotoxicity in uninephrectomized mice with high-fat diet-induced obesity.

INTRODUCTION: The objective of this study was to investigate the role of fenofibrate, a peroxisome proliferator-activated receptor-α agonist, in obesity-induced kidney damage (lipotoxicity) in mice with uninephrectomy. METHODS: C57BL/6 mice underwent uninephrectomy and sham surgeries and were fed normocaloric or high-fat diets. After 10 weeks, obese mice were administered 0.02% fenofibrate for 10 weeks. Kidney function and morphology were evaluated, as well as levels of inflammatory and fibrotic mediators and lipid metabolism markers. RESULTS: High-fat diet-fed mice developed characteristic obesity and hyperlipidemia, with subsequent renal lipid accumulation and damage, including mesangial expansion, interstitial fibrosis, inflammation, and proteinuria. These changes were greater in obese uninephrectomy mice than in obese sham mice. Fenofibrate treatment prevented hyperlipidemia and glomerular lesions, lowered lipid accumulation, ameliorated renal dysfunction, and attenuated inflammation and renal fibrosis. Furthermore, fenofibrate treatment downregulated renal tissue expression of plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, and local expression of fibroblast growth factor-21. CONCLUSION: Peroxisome proliferator-activated receptor-α activation by fenofibrate, with subsequent lipolysis, attenuated glomerular and tubulointerstitial lesions induced by renal lipotoxicity, thus protecting the kidneys of uninephrectomy mice from obesity-induced lesions. The study findings suggest a pathway in the pharmacological action of fenofibrate, providing insight into the mechanisms involved in kidney damage caused by obesity in kidney donors.

PPAR-α Insufficiency Enhances Doxorubicin-Induced Nephropathy in PPAR-α Knockout Mice and a Murine Podocyte Cell Line.

Peroxisome proliferator-activated receptor-alpha (PPAR-α) and its exogenous activators (fibrates) promote autophagy. However, whether the deleterious effects of PPAR-α deficiency on doxorubicin (DOX)-induced podocytopathy are associated with reduced autophagy remains to be clarified. We investigated the mechanisms of PPAR-α in DOX-induced podocytopathy and tubular injury in PPAR-α knockout (PAKO) mice and in a murine podocyte cell line. DOX-treated PAKO mice showed higher serum levels of triglycerides and non-esterified fatty acids and more severe podocytopathy than DOX-treated wild-type mice, as evidenced by higher urinary levels of proteins and podocalyxin at 3 days to 2 weeks and higher blood urea nitrogen and serum creatinine levels at 4 weeks. Additionally, there was an increased accumulation of p62, a negative autophagy marker, in the glomerular and tubular regions in DOX-treated PAKO mice at Day 9. Moreover, DOX-treated PAKO mice showed more severe glomerulosclerosis and tubular damage and lower podocalyxin expression in the kidneys than DOX-treated control mice at 4 weeks. Furthermore, DOX treatment increased p-p53, an apoptosis marker, and cleaved the caspase-3 levels and induced apoptosis, which was ameliorated by fenofibrate, a PPAR-α activator. Fenofibrate further enhanced AMPK activation and autophagy under fed and fasting conditions. Conclusively, PPAR-α deficiency enhances DOX-induced podocytopathy, glomerulosclerosis, and tubular injury, possibly by reducing autophagic activity in mouse kidneys.

Cardiometabolic benefits of fenofibrate in heart failure related to obesity and diabetes.

BACKGROUND: Heart failure (HF) is a serious and common condition affecting millions of people worldwide, with obesity being a major cause of metabolic disorders such as diabetes and cardiovascular disease. This study aimed to investigate the effects of fenofibrate, a peroxisome proliferator-activated receptor alpha (PPARα) agonist, on the obese- and diabetes-related cardiomyopathy. METHODS AND RESULTS: We used db/db mice and high fat diet-streptozotocin induced diabetic mice to investigate the underlying mechanisms of fenofibrate's beneficial effects on heart function. Fenofibrate reduced fibrosis, and lipid accumulation, and suppressed inflammatory and immunological responses in the heart via TNF signaling. In addition, we investigated the beneficial effects of fenofibrate on HF hospitalization. The Korean National Health Insurance database was used to identify 427,154 fenofibrate users and 427,154 non-users for comparison. During the 4.22-year follow-up, fenofibrate use significantly reduced the risk of HF hospitalization (hazard ratio, 0.907; 95% CI 0.824-0.998). CONCLUSIONS: The findings suggest that fenofibrate may be a useful therapeutic agent for obesity- and diabetes-related cardiomyopathy.

Function and mechanism of the human SOD2 gene in mice cerebral ischemia/ reperfusion injury.

PURPOSE: To investigate the neuroprotective effects of the SOD2 gene in cerebral ischemia reperfusion injury function and the underlying mechanisms in a mice model of middle cerebral artery ischemia reperfusion. METHODS: SOD2 transgenic mice were engineered using transcription activator-like effector nucleases, and the genotype was identified using PCR after every three generations. Transgenic and C57BL/6J wild type mice were simultaneously subjected to the middle cerebral artery occlusion model. RESULTS: SOD2 expression in the brain, heart, kidney, and skeletal muscle of transgenic mice was significantly higher than that in the wild type. Following ischemia reperfusion, the infarct volume of wild type mice decreased after treatment with fenofibrate compared to the CMC group. Infarction volume in SOD2 transgenic mice after CMC and fenofibrate treatment was significantly reduced. The recovery of cerebral blood flow in wild type mice treated with fenofibrate was significantly enhanced compared with that in the CMC group. CONCLUSIONS: The expression of SOD2 in transgenic mice was significantly higher than that in wild type mice, the neuroprotective role of fenofibrate depends on an increase in SOD2 expression.

A chitosan-based hydrogel loaded with fenofibrate for diabetic wound healing.

Diabetic wounds represent a common chronic condition, posing significant challenges in the treatment process due to bacterial infections, increased generation of reactive oxygen species (ROS) and exacerbated inflammation. Fenofibrate (FEN) is a clinical medication used for lipid regulation. In this study, it was utilized for the first time as an effective component of wound dressings for treating diabetic ulcers, exploring its novel applications further. Therefore, we prepared a polyvinyl alcohol/chitosan/FEN (PCF) hydrogel using a freeze-thaw method and conducted physicochemical characterization of the PCF hydrogel to further elucidate its biological functions. In vitro studies demonstrated that the PCF hydrogel exhibits excellent biocompatibility along with significant antimicrobial, pro-angiogenic, ROS-scavenging, and anti-inflammatory properties. Subsequent animal experiments indicated that the PCF hydrogel has the ability to promote blood vessel formation and collagen deposition. Additionally, the PCF hydrogel showed a significant inhibitory effect on the inflammatory response, as evidenced by the reductions in the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). These compelling findings accentuate the promising application of the PCF hydrogel in the treatment of diabetic wounds.

Effect of Fenofibrate on Progression of Diabetic Retinopathy.

BACKGROUND: Findings from cardiovascular outcome trials suggest that fenofibrate therapy may reduce the progression of diabetic retinopathy. METHODS: We recruited and followed adults with nonreferable diabetic retinopathy or maculopathy using the national Diabetic Eye Screening (DES) program in Scotland. We randomly assigned participants to receive 145-mg fenofibrate tablets or placebo (taken daily or, in those with impaired renal function, on alternate days). The primary outcome was a composite of developing referable diabetic retinopathy or maculopathy (based on Scotland's DES grading scheme) or treatment (intravitreal injection, retinal laser, vitrectomy) for retinopathy or maculopathy. RESULTS: A total of 1151 participants were randomly assigned to treatment. During a median of 4.0 years, progression to referable diabetic retinopathy or maculopathy, or treatment thereof, occurred in 131 (22.7%) of 576 participants in the fenofibrate group and 168 (29.2%) of 575 in the placebo group (hazard ratio, 0.73; 95% confidence interval [CI], 0.58 to 0.91; P=0.006). In the fenofibrate group compared with the placebo group, the frequencies for any progression of retinopathy or maculopathy were 185 (32.1%) vs. 231 (40.2%); hazard ratio, 0.74; 95% CI, 0.61 to 0.90 and for the development of macular edema were 22 (3.8%) vs. 43 (7.5%); hazard ratio, 0.50; 95% CI, 0.30 to 0.84. Seventeen (3.0%) participants assigned fenofibrate and 28 (4.9%) assigned placebo were given treatment for retinopathy (hazard ratio, 0.58; 95% CI, 0.31 to 1.06). There was no effect on visual function, quality of life, or visual acuity. Trial-averaged estimated glomerular filtration rate was 7.9 (95% CI, 6.8 to 9.1) ml/min/1.73 m2 lower in participants in the fenofibrate group compared with the placebo group. Serious adverse events occurred in 208 (36.1%) participants allocated fenofibrate and 204 (35.5%) participants allocated placebo. CONCLUSIONS: Fenofibrate reduced progression of diabetic retinopathy compared with placebo among participants with early retinal changes. (Funded by the National Institute for Health and Care Research; ClinicalTrials.gov number, NCT03439345; ISRCTN number, ISRCTN15073006.).

Promotion of maturation of human pluripotent stem cell-derived cardiomyocytes via treatment with the peroxisome proliferator-activated receptor alpha agonist Fenofibrate.

As research on in vitro cardiotoxicity assessment and cardiac disease modeling becomes more important, the demand for human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is increasing. However, it has been reported that differentiated hPSC-CMs are in a physiologically immature state compared to in vivo adult CMs. Since immaturity of hPSC-CMs can lead to poor drug response and loss of acquired heart disease modeling, various approaches have been attempted to promote maturation of CMs. Here, we confirm that peroxisome proliferator-activated receptor alpha (PPARα), one of the representative mechanisms of CM metabolism and cardioprotective effect also affects maturation of CMs. To upregulate PPARα expression, we treated hPSC-CMs with fenofibrate (Feno), a PPARα agonist used in clinical hyperlipidemia treatment, and demonstrated that the structure, mitochondria-mediated metabolism, and electrophysiology-based functions of hPSC-CMs were all mature. Furthermore, as a result of multi electrode array (MEA)-based cardiotoxicity evaluation between control and Feno groups according to treatment with arrhythmia-inducing drugs, drug response was similar in a dose-dependent manner. However, main parameters such as field potential duration, beat period, and spike amplitude were different between the 2 groups. Overall, these results emphasize that applying matured hPSC-CMs to the field of preclinical cardiotoxicity evaluation, which has become an essential procedure for new drug development, is necessary.

Evaluation of the Influence of Hypolipidemic Medication on Albino Wistar Rats' Bone Tissue by NMR Diffusiometry.

Introduction: The ongoing concern of the medical profession regarding chronic medication is related to increasing patient adherence and compliance to treatment and reducing medication side effects. In this respect, drugs represented by fixed-dose combinations of active substances within the same tablet have emerged. Such a principle can be extrapolated by following the potential beneficial effects that a chronic medication can have on chronic pathologies affecting different systems. Materials and Methods: The study included 48 female Albino Wistar rats, aged 16-18 months, which were divided into two groups: ovariectomized and non-ovariectomized rats. One batch of 12 non-ovariectomized rats received no treatment, becoming a control batch (NOVX-M). The ovariectomized (OVX) group was divided into 3 batches of 12 rats each: no treatment, control (OVX-M), fenofibrate-treated (OVX-F) and statin-treated (OVX-S) rats. At 12 weeks after ovariectomy, a femoral fracture occurred in the right hind limb of all animals included in the experiment To reveal the changes, at intervals of 2, 4, 6 and 8 weeks post-fracture, the proximal part of the femur was evaluated by NMR diffusiometry, which allows random motion of proton molecules expressed by self-diffusion coefficients, D, thus allowing analysis of the size and complexity of microscopic order cavities within biological structures, such as pores inside bones. Results: The effects of hypolipidemic medication in the absence of estrogen were evidenced, proving the beneficial effect that fenofibrate can have in preserving healthy tissue exposed to osteoporotic risk during the menopausal period. The effects of lipid-lowering medication are also influenced by the duration of administration. Conclusions: Osteoporosis and heart disease are two chronic pathologies that affect mainly female population in the second half of life, and proving the dual therapeutic potential of lipid-lowering medication may also have positive effects by increasing adherence and compliance to treatment.

Topical and oral peroxisome proliferator-activated receptor-α agonist ameliorates diabetic corneal neuropathy.

Diabetic corneal neuropathy (DCN) is a common diabetic ocular complication with limited treatment options. In this study, we investigated the effects of topical and oral fenofibrate, a peroxisome proliferator-activated receptor-α agonist, on the amelioration of DCN using diabetic mice (n = 120). Ocular surface assessments, corneal nerve and cell imaging analysis, tear proteomics and its associated biological pathways, immuno-histochemistry and western blot on PPARα expression, were studied before and 12 weeks after treatment. At 12 weeks, PPARα expression markedly restored after topical and oral fenofibrate. Topical fenofibrate significantly improved corneal nerve fibre density (CNFD) and tortuosity coefficient. Likewise, oral fenofibrate significantly improved CNFD. Both topical and oral forms significantly improved corneal sensitivity. Additionally, topical and oral fenofibrate significantly alleviated diabetic keratopathy, with fenofibrate eye drops demonstrating earlier therapeutic effects. Both topical and oral fenofibrate significantly increased corneal ß-III tubulin expression. Topical fenofibrate reduced neuroinflammation by significantly increasing the levels of nerve growth factor and substance P. It also significantly increased ß-III-tubulin and reduced CDC42 mRNA expression in trigeminal ganglions. Proteomic analysis showed that neurotrophin signalling and anti-inflammation reactions were significantly up-regulated after fenofibrate treatment, whether applied topically or orally. This study concluded that both topical and oral fenofibrate ameliorate DCN, while topical fenofibrate significantly reduces neuroinflammation.

Fenofibrate reduces cardiac remodeling by mitochondrial dynamics preservation in a renovascular model of cardiac hypertrophy.

Fenofibrate, a PPAR-α agonist clinically used to lower serum lipid levels, reduces cardiac remodeling and improves cardiac function. However, its mechanism of action is not completely elucidated. In this study we examined the effect of fenofibrate on mitochondria in a rat model of renovascular hypertension, focusing on mediators controlling mitochondrial dynamics and autophagy. Rats with two-kidney one-clip (2K1C) hypertension were treated with fenofibrate 150 mg/kg/day (2K1C-FFB) or vehicle (2K1C-VEH) for 8 weeks. Systolic blood pressure and cardiac functional were in-vivo assessed, while cardiomyocyte size and protein expression of mediators of cardiac hypertrophy and mitochondrial dynamics were ex-vivo examined by histological and Western blot analyses. Fenofibrate treatment counteracted the development of hypertension and the increase of left ventricular mass, relative wall thickness and cross-sectional area of cardiomyocytes. Furthermore, fenofibrate re-balanced the expression Mfn2, Drp1 and Parkin, regulators of fusion, fission, mitophagy respectively. Regarding autophagy, the LC3-II/LC3-I ratio was increased in 2K1C-VEH and 2K1C-FFB, whereas the autophagy was increased only in 2K1C-FFB. In cultured H9C2 cardiomyoblasts, fenofibrate reversed the Ang II-induced mRNA up-regulation of hypertrophy markers Nppa and Myh7, accumulation of reactive oxygen species and depolarization of the mitochondrial membrane exerting protection mediated by up-regulation of the Uncoupling protein 2. Our results indicate that fenofibrate acts directly on cardiomyocytes and counteracts the pressure overload-induced cardiac maladaptive remodeling. This study reveals a so far hidden mechanism involving mitochondrial dynamics in the beneficial effects of fenofibrate, support its repurposing for the treatment of cardiac hypertrophy and provide new potential targets for its pharmacological function.

Fenofibrate ameliorates nitroglycerin-induced migraine in rats: Role of CGRP/p-CREB/P2X3 and NGF/PKC/ASIC3 signaling pathways.

Migraine, a debilitating neurological condition, significantly affects patients' quality of life. Fenofibrate, a peroxisome proliferator-activated receptor alpha (PPAR-α) agonist approved for managing dyslipidemia, has shown promise in treating neurological disorders. Therefore, this study aims to investigate the protective effects of fenofibrate against nitroglycerin (NTG)-induced chronic migraine in rats. Migraine was induced in rats by administering five intermittent doses of NTG (10 mg/kg, i. p.) on days 1, 3, 5, 7, and 9. Rats were treated with either topiramate (80 mg/kg/day, p. o.), a standard drug, or fenofibrate (100 mg/kg/day, p. o.) from day 1-10. Fenofibrate significantly improved mechanical and thermal hypersensitivity, photophobia, and head grooming compared to topiramate. These effects were associated with reduced serum levels of nitric oxide (NO), calcitonin gene-related peptide (CGRP), and pituitary adenylate cyclase-activating polypeptide (PACAP). Furthermore, fenofibrate down-regulated c-Fos expression in the medulla and medullary pro-inflammatory cytokine contents. Additionally, fenofibrate attenuated NTG-induced histopathological changes in the trigeminal ganglia and trigeminal nucleus caudalis. These effects were associated with the inhibition of CGRP/p-CREB/purinergic 2X receptor 3 (P2X3) and nerve growth factor (NGF)/protein kinase C (PKC)/acid-sensing ion channel 3 (ASIC3) signaling pathways. This study demonstrates that fenofibrate attenuated NTG-induced migraine-like signs in rats. These effects were partially mediated through the inhibition of CGRP/p-CREB/P2X3 and NGF/PKC/ASIC3 signaling pathways. The present study supports the idea that fenofibrate could be an effective candidate for treating migraine headache without significant adverse effects. Future studies should explore its clinical applicability.

Triglycerides: A Sensitizer but Not a Trigger for Hypertriglyceridemic Acute Pancreatitis.

BACKGROUND: The incidence of hypertriglyceridemic acute pancreatitis (HTG-AP) is increasing. Although the guideline defines the diagnostic criteria as triglyceride (TG) greater than 11.3 mmol/L, there is actually no specific threshold. Many people with hypertriglyceridemia (HTG) or obvious chyloid blood do not develop acute pancreatitis (AP). AIMS: To explore the role of HTG in the pathogenesis of AP. METHODS: Thirty-six male SD rats were randomly assigned into normal control, AP, HTG, HTG-AP, low-dose fenofibrate and high-dose fenofibrate groups. Serum indices and cytokine levels in serum, and pathological changes in pancreatic tissues were observed. The expression levels of TLR4 and NF-κBp65 in pancreatic tissues were detected by immunohistochemistry and Western blot. RESULTS: In normal rats, HTG alone did not induce AP. However, after establishing the HTG-AP model with Poloxam 407 and L-arginine, serum-free fatty acid and TG levels were positively correlated with the levels of lipase, amylase, IL-1ß, IL-6, pancreatic inflammation scores, and the expressions of TLR4 and NF-κBp65 (all P < 0.001). Expressions of TLR4 and NF-κBp65 were significantly increased in the pancreatic tissues of HTG-AP rats. Fenofibrate effectively decreased TG levels in HTG-AP rats and reduced the expression of TLR4 and NF-κBp65 (all P < 0.001). CONCLUSIONS: HTG does not directly cause AP, but rather increases the susceptibility to AP or aggravates the inflammatory response. It is more like a sensitizer of inflammation rather than an activator.

Fenofibrate Induces a Resolving Profile in Heart Macrophage Subsets and Attenuates Acute Chagas Myocarditis.

Chagas disease, caused by Trypanosoma cruzi, stands as the primary cause of dilated cardiomyopathy in the Americas. Macrophages play a crucial role in the heart's response to infection. Given their functional and phenotypic adaptability, manipulating specific macrophage subsets could be vital in aiding essential cardiovascular functions including tissue repair and defense against infection. PPARα are ligand-dependent transcription factors involved in lipid metabolism and inflammation regulation. However, the role of fenofibrate, a PPARα ligand, in the activation profile of cardiac macrophages as well as its effect on the early inflammatory and fibrotic response in the heart remains unexplored. The present study demonstrates that fenofibrate significantly reduces not only the serum activity of tissue damage biomarker enzymes (LDH and GOT) but also the circulating proportions of pro-inflammatory monocytes (CD11b+ LY6Chigh). Furthermore, both CD11b+ Ly6Clow F4/80high macrophages (MΦ) and recently differentiated CD11b+ Ly6Chigh F4/80high monocyte-derived macrophages (MdMΦ) shift toward a resolving phenotype (CD206high) in the hearts of fenofibrate-treated mice. This shift correlates with a reduction in fibrosis, inflammation, and restoration of ventricular function in the early stages of Chagas disease. These findings encourage the repositioning of fenofibrate as a potential ancillary immunotherapy adjunct to antiparasitic drugs, addressing inflammation to mitigate Chagas disease symptoms.

High-Dose Fenofibrate Stimulates Multiple Cellular Stress Pathways in the Kidney of Old Rats.

We investigated the age-related effects of the lipid-lowering drug fenofibrate on renal stress-associated effectors. Young and old rats were fed standard chow with 0.1% or 0.5% fenofibrate. The kidney cortex tissue structure showed typical aging-related changes. In old rats, 0.1% fenofibrate reduced the thickening of basement membranes, but 0.5% fenofibrate exacerbated interstitial fibrosis. The PCR array for stress and toxicity-related targets showed that 0.1% fenofibrate mildly downregulated, whereas 0.5% upregulated multiple genes. In young rats, 0.1% fenofibrate increased some antioxidant genes' expression and decreased the immunoreactivity of oxidative stress marker 4-HNE. However, the activation of cellular antioxidant defenses was impaired in old rats. Fenofibrate modulated the expression of factors involved in hypoxia and osmotic stress signaling similarly in both age groups. Inflammatory response genes were variably modulated in the young rats, whereas old animals presented elevated expression of proinflammatory genes and TNFα immunoreactivity after 0.5% fenofibrate. In old rats, 0.1% fenofibrate more prominently than in young animals induced phospho-AMPK and PGC1α levels, and upregulated fatty acid oxidation genes. Our results show divergent effects of fenofibrate in young and old rat kidneys. The activation of multiple stress-associated effectors by high-dose fenofibrate in the aged kidney warrants caution when applying fenofibrate therapy to the elderly.

Role of fenofibrate in multiple sclerosis.

Multiple sclerosis (MS) is the most frequent inflammatory and demyelinating disease of the central nervous system (CNS). The underlying pathophysiology of MS is the destruction of myelin sheath by immune cells. The formation of myelin plaques, inflammation, and injury of neuronal myelin sheath characterizes its neuropathology. MS plaques are multiple focal regions of demyelination disseminated in the brain's white matter, spinal cords, deep grey matter, and cerebral cortex. Fenofibrate is a peroxisome proliferative activated receptor alpha (PPAR-α) that attenuates the inflammatory reactions in MS. Fenofibrate inhibits differentiation of Th17 by inhibiting the expression of pro-inflammatory signaling. According to these findings, this review intended to illuminate the mechanistic immunoinflammatory role of fenofibrate in mitigating MS neuropathology. In conclusion, fenofibrate can attenuate MS neuropathology by modulating different pathways, including oxidative stress, autophagy, mitochondrial dysfunction, inflammatory-signaling pathways, and neuroinflammation.

Shen-Shuai-II-Recipe inhibits tubular inflammation by PPARα-mediated fatty acid oxidation to attenuate fibroblast activation in fibrotic kidneys.

BACKGROUND: Shen Shuai Ⅱ Recipe (SSR) is clinically used to treat chronic kidney diseases (CKDs) with remarkable efficacy and safety. In earlier research, we found the anti-inflammatory, antioxidant, and mitochondrial protective properties of SSR in hypoxic kidney injury model, which is closely related to its renal protection. Further work is needed to understand the underlying molecular mechanisms. PURPOSE: Further investigation of the mechanisms of action of SSR against renal interstitial fibrosis (RIF) building on previous research leads. METHODS: Rats receiving CKD model surgery were given with Fenofibrate or SSR once a day for eight weeks. In vitro, the NRK-52E cells were treated with SSR in the presence or absence of 10 µM Sc75741, 0.5 µM PMA, or 1 µM fenofibrate under 1% O2. The effects of SSR on NF-κB/NLRP3 inflammatory cascade, secretion of pro-inflammatory cytokines, fatty acid oxidation (FAO), and renal tubular injury were determined by immunoblotting, luminex liquid suspension chip assay, transmission electron microscopy, and Oil red O staining. Next, we delivered PPARα-interfering sequences to kidney tissue and NRK-52E cells by adeno-associated virus (AAV) injection and siRNA transfection methods. Finally, we evaluated the effect of renal tubular cells on fibroblast activation by co-culture method. RESULTS: SSR attenuated the release of IL-18, VEGF, and MCP1 cytokines, inhibited the activation of NF-κB/NLRP3 cascade, increased the PPARα, CPT-1α, CPT-2, ACADL, and MCAD protein expression, and improved the lipid accumulation. Further studies have demonstrated that one of the ways in which SSR suppresses the inflammatory response to protect renal tubular cells is through the restoration of PPARα-mediated FAO. In addition, by means of co-culture ways, the results demonstrated that SSR attenuated secretion of inflammatory mediators in NRK-52E cells by PPARα/NF-κB/NLRP3 pathway, thereby inhibiting renal fibroblast activation. CONCLUSION: SSR inhibits RIF by suppressing inflammatory response of hypoxia-exposed RTECs through PPARα-mediated FAO.

Pparα activation stimulates autophagic flux through lipid catabolism-independent route.

Autophagy is a cellular process that involves the fusion of autophagosomes and lysosomes to degrade damaged proteins or organelles. Triglycerides are hydrolyzed by autophagy, releasing fatty acids for energy through mitochondrial fatty acid oxidation (FAO). Inhibited mitochondrial FAO induces autophagy, establishing a crosstalk between lipid catabolism and autophagy. Peroxisome proliferator-activated receptor α (PPARα), a transcription factor, stimulates lipid catabolism genes, including fatty acid transport and mitochondrial FAO, while also inducing autophagy through transcriptional regulation of transcription factor EB (TFEB). Therefore, the study explores whether PPARα regulates autophagy through TFEB transcriptional control or mitochondrial FAO. In aquaculture, addressing liver lipid accumulation in fish is crucial. Investigating the link between lipid catabolism and autophagy is significant for devising lipid-lowering strategies and maintaining fish health. The present study investigated the impact of dietary fenofibrate and L-carnitine on autophagy by activating Pparα and enhancing FAO in Nile tilapia (Oreochromis niloticus), respectively. The dietary fenofibrate and L-carnitine reduced liver lipid content and enhanced ATP production, particularly fenofibrate. FAO enhancement by L-carnitine showed no changes in autophagic protein levels and autophagic flux. Moreover, fenofibrate-activated Pparα promoted the expression and nuclear translocation of Tfeb, upregulating autophagic initiation and lysosomal biogenesis genes. Pparα activation exhibited an increasing trend of LC3II protein at the basal autophagy and cumulative p62 protein trends after autophagy inhibition in zebrafish liver cells. These data show that Pparα activation-induced autophagic flux should be independent of lipid catabolism.

PPARα Agonism Enhances Immune Response to Radiotherapy While Dietary Oleic Acid Results in Counteraction.

PURPOSE: Head and neck cancer (HNC) improvements are stagnant, even with advances in immunotherapy. Our previous clinical trial data show that altered fatty acid (FA) metabolism correlates with outcome. We hypothesized that pharmacologic and dietary modulation of FA catabolism will affect therapeutic efficacy. EXPERIMENTAL DESIGN: We performed in vivo and in vitro experiments using PPARα agonism with fenofibrate (FF) or high oleic acid diets (OAD) with radiotherapy, generating metabolomic, proteomic, stable isotope tracing, extracellular flux analysis, and flow-cytometric data to investigate these alterations. RESULTS: FF improved antitumor efficacy of high dose per fraction radiotherapy in HNC murine models, whereas the OAD reversed this effect. FF-treated mice on the control diet had evidence of increased FA catabolism. Stable isotope tracing showed less glycolytic utilization by ex vivo CD8+ T cells. Improved efficacy correlated with intratumoral alterations in eicosanoid metabolism and downregulated mTOR and CD36. CONCLUSIONS: Metabolic intervention with increased FA catabolism improves the efficacy of HNC therapy and enhances antitumoral immune response.

Inhibition of tumor migration and invasion by fenofibrate via suppressing epithelial-mesenchymal transition in breast cancers.

The recurrence and metastasis in breast cancer within 3 years after the chemotherapies or surgery leads to poor prognosis with approximately 1-year overall survival. Large-scale scanning research studies have shown that taking lipid-lowering drugs may assist to reduce the risk of death from many cancers, since cholesterol in lipid rafts are essential for maintain integral membrane structure and functional signaling regulation. In this study, we examined five lipid-lowering drugs: swertiamarin, gemfibrozil, clofibrate, bezafibrate, and fenofibrate in triple-negative breast cancer, which is the most migration-prone subtype. Using human and murine triple-negative breast cancer cell lines (Hs 578 t and 4 T1), we found that fenofibrate displays the highest potential in inhibiting the colony formation, wound healing, and transwell migration. We further discovered that fenofibrate reduces the activity of pro-metastatic enzymes, matrix metalloproteinases (MMP)-9 and MMP-2. In addition, epithelial markers including E-cadherin and Zonula occludens-1 are increased, whereas mesenchymal markers including Snail, Twist and α-smooth muscle actin are attenuated. Furthermore, we found that fenofibrate downregulates ubiquitin-dependent GDF-15 degradation, which leads to enhanced GDF-15 expression that inhibits cell migration. Besides, nuclear translocation of FOXO1 is also upregulated by fenofibrate, which may responsible for GDF-15 expression. In summary, fenofibrate with anti-cancer ability hinders TNBC from migration and invasion, and may be beneficial to repurposing use of fenofibrate.