Role of PPARα in inflammatory response of C2C12 myotubes.

Recent studies have shown a role of inflammation in muscle atrophy and sarcopenia. However, no anti-inflammatory pharmacotherapy has been established for the treatment of sarcopenia. Here, we investigate the potential role of PPARα and its ligands on inflammatory response and PGC-1α gene expression in LPS-treated C2C12 myotubes. Knockdown of PPARα, whose expression was upregulated upon differentiation, augmented IL-6 or TNFα gene expression. Conversely, PPARα overexpression or its activation by ligands suppressed 2-h LPS-induced cytokine expression, with pemafibrate attenuating NF-κB or STAT3 phosphorylation. Of note, reduction of PGC-1α gene expression by LPS treatment for 24 hours was partially reversed by fenofibrate. Our data demonstrate a critical inhibitory role of PPARα in inflammatory response of C2C12 myotubes and suggest a future possibility of PPARα ligands as a candidate for anti-inflammatory therapy against sarcopenia.

Lessons from PROMINENT and prospects for pemafibrate.

The neutral result of the PROMINENT trial has led to questions about the future for pemafibrate. This commentary discusses possible reasons for the lack of benefit observed in the trial. There were, however, indicators suggesting therapeutic potential in microvascular ischaemic complications associated with peripheral artery disease, with subsequent analysis showing reduction in the incidence of lower extremity ischaemic ulceration or gangrene. Reassurance about the safety of pemafibrate, together with emerging data from PROMINENT and experimental studies, also suggest benefit with pemafibrate in non-alcoholic fatty liver disease (alternatively referred to as metabolic dysfunction-associated steatotic liver disease) and microangiopathy associated with diabetes, which merit further study.

Managing hypertriglyceridemia for cardiovascular disease prevention: Lessons from the PROMINENT trial.

BACKGROUND: Numerous epidemiological studies have shown that hypertriglyceridemia is a significant risk factor for cardiovascular diseases (CVD). However, large clinical studies on triglyceride-lowering therapy have yielded inconsistent results. In the current review, we reassess the importance of triglyceride-lowering therapy in preventing CVD based on previous literature and the recently published findings of the PROMINENT trial. METHODS: This narrative review is based on literature and public documents published up to November 2023. RESULTS: Meta-analyses of trials on peroxisome proliferator-activated receptor α agonists and triglyceride-lowering therapy, including the PROMINENT trial, have indicated that triglyceride-lowering therapy can reduce CVD events. Mendelian randomization studies have also indicated that triglyceride is indeed a true risk factor for coronary artery disease, leaving no doubt about its relationship to CVD. Meanwhile, the negative results from the PROMINENT trial were likely due to the insufficient triglyceride-lowering effect, slight increases in low-density lipoprotein cholesterol and apolipoprotein B, and the inclusion of mostly high-intensity statin users as target patients. It is unlikely that adverse events counteracted the effectiveness of pemafibrate on outcomes. Additionally, pemafibrate has shown positive effects on non-alcoholic fatty liver disease and peripheral artery disease. CONCLUSION: Although the PROMINENT trial did not demonstrate the significance of pemafibrate as a triglyceride-lowering therapy in a specific population, it does not necessarily negate the potential benefits of treating hypertriglyceridemia in reducing CVD events. It is necessary to explore appropriate populations that could benefit from this therapy, utilize data from the PROMINENT trial and other databases, and validate findings in real-world settings.

Protective Effect of Pemafibrate Treatment against Diabetic Retinopathy in Spontaneously Diabetic Torii Fatty Rats.

Diabetic retinopathy (DR) can cause visual impairment and blindness, and the increasing global prevalence of diabetes underscores the need for effective therapies to prevent and treat DR. Therefore, this study aimed to evaluate the protective effect of pemafibrate treatment against DR, using a Spontaneously Diabetic Torii (SDT) fatty rat model of obese type 2 diabetes. SDT fatty rats were fed either a diet supplemented with pemafibrate (0.3 mg/kg/d) for 16 weeks, starting at 8 weeks of age (Pf SDT fatty: study group), or normal chow (SDT fatty: controls). Normal chow was provided to Sprague-Dawley (SD) rats (SD: normal controls). Electroretinography (ERG) was performed at 8 and 24 weeks of age to evaluate the retinal neural function. After sacrifice, retinal thickness, number of retinal folds, and choroidal thickness were evaluated, and immunostaining was performed for aquaporin-4 (AQP4). No significant differences were noted in food consumption, body weight, or blood glucose level after pemafibrate administration. Triglyceride levels were reduced, and high-density lipoprotein cholesterol levels were increased. Extension of oscillatory potential (OP)1 and OP3 waves on ERG was suppressed in the Pf SDT fatty group. Retinal thickness at 1500 microns from the optic disc improved in the Pf SDT fatty group. No significant improvements were noted in choroidal thickness or number of retinal folds. Quantitative analyses showed that AQP4-positive regions in the retinas were significantly larger in the Pf SDT fatty group than in the SDT fatty group. The findings suggest that pemafibrate treatment can exert protective effects against DR.

Impact of pemafibrate on lipid profile and insulin resistance in hypertriglyceridemic patients with coronary artery disease and metabolic syndrome.

This study examined the effects of pemafibrate, a selective peroxisome proliferator-activated receptor α agonist, on the serum biochemical parameters of male patients with coronary artery disease and metabolic syndrome (MetS). This was a post hoc analysis of a randomized, crossover study that treated hypertriglyceridemia with pemafibrate or bezafibrate for 24 weeks, followed by a crossover of another 24 weeks. Of the 60 patients enrolled in the study, 55 were male. Forty-one of 55 male patients were found to have MetS. In this sub-analysis, male patients with MetS (MetS group, n = 41) and those without MetS (non-MetS group, n = 14) were compared. The primary endpoint was a change in fasting serum triglyceride (TG) levels during pemafibrate therapy, and the secondary endpoints were changes in insulin resistance-related markers and liver function parameters. Serum TG levels significantly decreased (MetS group, from 266.6 to 148.0 mg/dL, p < 0.001; non-MetS group, from 203.9 to 97.6 mg/dL, p < 0.001); however, a percent change (%Change) was not significantly different between the groups (- 44.1% vs. - 51.6%, p = 0.084). Serum insulin levels and homeostasis model assessment of insulin resistance significantly decreased in the MetS group but not in the non-MetS group. %Change in liver enzyme levels was markedly decreased in the MetS group compared with that in the non-MetS group (alanine aminotransferase, - 25.1% vs. - 11.3%, p = 0.027; gamma-glutamyl transferase, - 45.8% vs. - 36.2%, p = 0.020). In conclusion, pemafibrate can effectively decrease TG levels in patients with MetS, and it may be a more efficient drug for improving insulin resistance and liver function in such patients.

Analysis of serum levels and DNA methylation of fibroblast growth factor 21 using peripheral blood-derived genomes in patients with obesity.

Fibroblast growth factor (FGF) 21, a hormone produced by the liver, improves glucose and lipid metabolism. We recently demonstrated that the FGF21 gene (Fgf21) underwent DNA demethylation in the mouse liver via peroxisome proliferator-activated receptor (PPAR) α during the fetal to lactation periods. Furthermore, we found that the DNA methylation state of Fgf21 was involved in obesity in adult animals. In the present study, we analyzed the DNA methylation state of the FGF21 gene (FGF21) in obese patients using genomic DNA extracted from human monocytes and macrophages and investigated the pathophysiological significance of the FGF21 expression response to pemafibrate (PM), a PPARα ligand. We examined 67 patients with obesity stratified into in- and outpatient cohorts. A positive correlation was observed between serum FGF21 levels and triglyceride (TG) levels before PM administration. However, changes in serum FGF21 levels following PM administration did not correlate with the FGF21 DNA methylation rate, except at one CpG site. The body mass index (BMI) and serum TG levels positively correlated with the FGF21 DNA methylation rate, particularly at different CpG positions. A negative correlation was observed between absolute changes in serum FGF21 levels and the ratio of change in serum TG levels after PM administration. Collectively, these results indicate the potential of FGF21 DNA methylation as a surrogate indicator of BMI and serum TG levels, while absolute changes in serum FGF21 levels after PM administration may offer prognostic insights into the efficacy of reducing serum TG levels through PM administration.

Retinal degeneration induced in a mouse model of ischemia-reperfusion injury and its management by pemafibrate treatment.

Retinal ischemia-reperfusion (I/R) injury is a common cause of visual impairment. To date, no effective treatment is available for retinal I/R injury. In addition, the precise pathological mechanisms still need to be established. Recently, pemafibrate, a peroxisome proliferator-activated receptor α (PPARα) modulator, was shown to be a promising drug for retinal ischemia. However, the role of pemafibrate in preventing retinal I/R injury has not been documented. Here, we investigated how retinal degeneration occurs in a mouse model of retinal I/R injury by elevation of intraocular pressure and examined whether pemafibrate could be beneficial against retinal degeneration. Adult mice were orally administered pemafibrate (0.5 mg/kg/day) for 4 days, followed by retinal I/R injury. The mice were continuously administered pemafibrate once every day until the end of the experiments. Retinal functional changes were measured using electroretinography. Retina, liver, and serum samples were used for western blotting, quantitative PCR, immunohistochemistry, or enzyme linked immunosorbent assay. Retinal degeneration induced by retinal inflammation was prevented by pemafibrate administration. Pemafibrate administration increased the hepatic PPARα target gene expression and serum levels of fibroblast growth factor 21, a neuroprotective molecule in the eye. The expression of hypoxia-response and pro-and anti-apoptotic/inflammatory genes increased in the retina following retinal I/R injury; however, these changes were modulated by pemafibrate administration. In conclusion, pemafibrate is a promising preventive drug for ischemic retinopathies.

Safety and efficacy of switching to pemafibrate from bezafibrate in patients with chronic liver disease.

AIM: Although fibrates were developed as lipid-lowering drugs, their efficacy against liver dysfunction in patients with cholestatic liver diseases, such as primary biliary cholangitis, primary sclerosing cholangitis, and fatty liver disease, has also been reported. Although fibrates act on some peroxisome proliferator-activated receptors (PPARs), pemafibrate is a novel selective PPAR-α modulator. The present study aimed to evaluate the safety and efficacy of switching from bezafibrate to pemafibrate in patients with chronic liver disease. METHODS: We analyzed 58 patients with chronic liver disease who switched from bezafibrate to pemafibrate because of minor adverse effects and/or incomplete response. RESULTS: This study included 41 patients with cholestatic liver disease and 17 patients with non-alcoholic fatty liver disease. Reasons for switching to pemafibrate were renal function decline in 31 patients, hemoglobin decline in 17 patients, creatine kinase (CK) elevation in 11 patients, incomplete response of liver dysfunction in 39 patients, and incomplete response of hyperlipidemia in 13 patients. After 3 months, although no significant change in CK was seen, hemoglobin and estimated glomerular filtration rate were significantly increased, and creatinine was significantly decreased. Significant decreases in hepatobiliary enzymes were seen in patients with cholestatic liver diseases, but not in patients with non-alcoholic fatty liver disease. No significant changes in serum lipids were observed. No patients discontinued pemafibrate due to adverse events. CONCLUSIONS: Switching to pemafibrate could improve adverse effects due to bezafibrate, and appeared effective against liver dysfunction in cholestatic liver disease patients with incomplete response to bezafibrate.

Gamma-glutamyl transferase predicts pemafibrate treatment response in non-alcoholic fatty liver disease.

BACKGROUND AND AIM: Pemafibrate, a selective peroxisome proliferator activated receptor α modulator, has been shown to improve liver function among nonalcoholic fatty liver disease (NAFLD) patients with dyslipidemia. The aim of this retrospective study is to identify predictors of pemafibrate efficacy in NAFLD patients. METHODS: A total of 75 NAFLD patients with dyslipidemia who received pemafibrate twice per day for 48 weeks were enrolled in this study. We used the FibroScan-aspartate aminotransferase (FAST) score as a benchmark for treatment efficacy. RESULTS: Median FAST score significantly decreased from 0.96 at baseline to 0.93 at week 48 (P < 0.001). Significant improvements in levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and triglycerides were also noted. The serum level of GGT at baseline was correlated with change in FAST score (r = -0.22, P = 0.049). Changes in AST, ALT, and GGT were positively correlated with change in FAST score (r = 0.71, r = 0.61, and r = 0.38). Multivariate analyses identified age and GGT level at baseline as significantly associated with improvement of FAST score by pemafibrate therapy (odds ratio 1.11, 1.02, respectively). Patients over 50 years of age and with a GGT of 90 IU/L or higher showed significantly greater improvement in the FAST score than other groups. CONCLUSIONS: Pemafibrate improves the FAST score of NAFLD patients with complicating dyslipidemia, especially in older patients with high GGT level. GGT is useful as an indicator of optimal treatment choice for NAFLD patients with dyslipidemia.

Effect of a combination of pemafibrate and a mild low-carbohydrate diet on obese and non-obese patients with metabolic-associated fatty liver disease.

BACKGROUND AND AIM: Recently, pemafibrate and a low-carbohydrate diet (LCD) have each been reported to improve fatty liver disease. However, it is unclear whether their combination improves fatty liver disease and is equally effective in obese and non-obese patients. METHODS: In 38 metabolic-associated fatty liver disease (MAFLD) patients, classified by baseline body mass index (BMI), changes in laboratory values, magnetic resonance elastography (MRE), and magnetic resonance imaging-proton density fat fraction (MRI-PDFF) were studied after 1 year of combined pemafibrate plus mild LCD. RESULTS: The combination treatment resulted in weight loss (P = 0.002), improvement in hepatobiliary enzymes (γ-glutamyl transferase, P = 0.027; aspartate aminotransferase, P < 0.001; alanine transaminase [ALT], P < 0.001), and improvement in liver fibrosis markers (FIB-4 index, P = 0.032; 7 s domain of type IV collagen, P = 0.002; M2BPGi, P < 0.001). Vibration-controlled transient elastography improved from 8.8 to 6.9 kPa (P < 0.001) and MRE improved from 3.1 to 2.8 kPa (P = 0.017) in the liver stiffness. MRI-PDFF improved from 16.6% to 12.3% in liver steatosis (P = 0.007). In patients with a BMI of 25 or higher, improvements of ALT (r = 0.659, P < 0.001) and MRI-PDFF (r = 0.784, P < 0.001) were significantly correlated with weight loss. However, in patients with a BMI below 25, the improvements of ALT or PDFF were not accompanied by weight loss. CONCLUSIONS: Combined treatment with pemafibrate and a low-carbohydrate diet resulted in weight loss and improvements in ALT, MRE, and MRI-PDFF in MAFLD patients. Although such improvements were associated with weight loss in obese patients, the improvements were observed irrespective of weight loss in non-obese patients, indicating this combination can be effective both in obese and non-obese MAFLD patients.

Efficacy and safety of pemafibrate in patients with hypertriglyceridemia in clinical settings: A retrospective study.

BACKGROUND AND AIMS: Recently, pemafibrate, a selective PPARα modulator, has been developed as a treatment for hypertriglyceridemia and has attracted much attention. The aims of this study were to evaluate the efficacy and safety of pemafibrate in hypertriglyceridemia patients under clinical settings. METHODS AND RESULTS: We evaluated changes in lipid profiles and various parameters before and after 24-week pemafibrate administration in patients with hypertriglyceridemia who had not previously taken fibrate medications. There were 79 cases included in the analysis. 24 weeks after the treatment with pemafibrate, TG was significantly reduced from 312 ± 226 to 167 ± 94 mg/dL. In addition, lipoprotein fractionation tests using PAGE method showed a significant decrease in the ratio of VLDL and remnant fractionations, which are TG-rich lipoproteins. After pemafibrate administration, body weight, HbA1c, eGFR, and CK levels were not changed, but liver injury indices such as ALT, AST, and γ-GTP were significantly improved. CONCLUSION: In this study, pemafibrate improved the metabolism of atherosclerosis-induced lipoproteins in hypertriglyceridemia patients. In addition, it showed no off-target effects such as hepatic and renal damage or rhabdomyolysis.

Design and methods of an open-label, randomized controlled trial to evaluate the effect of pemafibrate on proteinuria in CKD patients (PROFIT-CKD).

BACKGROUND: Hypertriglyceridemia is increasingly considered a residual risk of cardiovascular disease in patients with chronic kidney disease (CKD). Pemafibrate-a novel selective peroxisome proliferator-activated receptor alpha modulator and a new treatment for hypertriglyceridemia in CKD patients-is reported to have fewer side effects in CKD patients than other fibrates. Appropriate control of hypertriglyceridemia can be expected to improve renal prognosis. However, data on the renal protective effect of pemafibrate are limited. This study aims to evaluate the effectiveness of pemafibrate on urinary protein excretion in CKD patients. METHODS: The Pemafibrate, open-label, Randomized cOntrolled study to evaluate the renal protective eFfect In hyperTriglyceridemia patients with Chronic Kidney Disease (PROFIT-CKD) study is an investigator-initiated, multi-center, open-label, parallel-group, randomized controlled trial. Participants are outpatients with hypertriglyceridemia aged 20 years and over, who have received the care of a nephrologist or a diabetologist for more than 3 months. Inclusion criteria include the following: proteinuria (urine protein/creatinine ratio of ≥ 0.15 g/gCr) within three months before allocation, and hypertriglyceridemia (triglycerides ≥ 150 mg/dL and < 1,000 mg/dL) at allocation. In the treatment group, pemafibrate is added to conventional treatment, while conventional treatment is continued with no additional treatment in the control group. Target patient enrollment is 140 patients. The primary endpoint is the change from baseline in the logarithmic urine protein/creatinine ratio at 12 months after study start. CONCLUSION: This study will provide new findings on the renal protective effect of pemafibrate in CKD patients. CLINICAL TRIAL REGISTRATION: This clinical trial was registered at the University Hospital Medical Information Network (UMIN) Center (UMIN-CTR: UMIN000042284).

Metabolic-Dysfunction-Associated Steatotic Liver Disease-Its Pathophysiology, Association with Atherosclerosis and Cardiovascular Disease, and Treatments.

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a chronic liver disease that affects more than a quarter of the global population and whose prevalence is increasing worldwide due to the pandemic of obesity. Obesity, impaired glucose metabolism, high blood pressure and atherogenic dyslipidemia are risk factors for MASLD. Therefore, insulin resistance may be closely associated with the development and progression of MASLD. Hepatic entry of increased fatty acids released from adipose tissue, increase in fatty acid synthesis and reduced fatty acid oxidation in the liver and hepatic overproduction of triglyceride-rich lipoproteins may induce the development of MASLD. Since insulin resistance also induces atherosclerosis, the leading cause for death in MASLD patients is cardiovascular disease. Considering that the development of cardiovascular diseases determines the prognosis of MASLD patients, the therapeutic interventions for MASLD should reduce body weight and improve coronary risk factors, in addition to an improving in liver function. Lifestyle modifications, such as improved diet and increased exercise, and surgical interventions, such as bariatric surgery and intragastric balloons, have shown to improve MASLD by reducing body weight. Sodium glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been shown to improve coronary risk factors and to suppress the occurrence of cardiovascular diseases. Both SGLT2i and GLP-1 have been reported to improve liver enzymes, hepatic steatosis and fibrosis. We recently reported that the selective peroxisome proliferator-activated receptor-alpha (PPARα) modulator pemafibrate improved liver function. PPARα agonists have multiple anti-atherogenic properties. Here, we consider the pathophysiology of MASLD and the mechanisms of action of such drugs and whether such drugs and the combination therapy of such drugs could be the treatments for MASLD.

Systems Approach to Discovery of Therapeutic Targets for Vein Graft Disease: PPARα Pivotally Regulates Metabolism, Activation, and Heterogeneity of Macrophages and Lesion Development.

BACKGROUND: Vein graft failure remains a common clinical challenge. We applied a systems approach in mouse experiments to discover therapeutic targets for vein graft failure. METHODS: Global proteomics and high-dimensional clustering on multiple vein graft tissues were used to identify potential pathogenic mechanisms. The PPARs (peroxisome proliferator-activated receptors) pathway served as an example to substantiate our discovery platform. In vivo mouse experiments with macrophage-targeted PPARα small interfering RNA, or the novel, selective activator pemafibrate demonstrate the role of PPARα in the development and inflammation of vein graft lesions. In vitro experiments further included metabolomic profiling, quantitative polymerase chain reaction, flow cytometry, metabolic assays, and single-cell RNA sequencing on primary human and mouse macrophages. RESULTS: We identified changes in the vein graft proteome associated with immune responses, lipid metabolism regulated by the PPARs, fatty acid metabolism, matrix remodeling, and hematopoietic cell mobilization. PPARα agonism by pemafibrate retarded the development and inflammation of vein graft lesions in mice, whereas gene silencing worsened plaque formation. Pemafibrate also suppressed arteriovenous fistula lesion development. Metabolomics/lipidomics, functional metabolic assays, and single-cell analysis of cultured human macrophages revealed that PPARα modulates macrophage glycolysis, citrate metabolism, mitochondrial membrane sphingolipid metabolism, and heterogeneity. CONCLUSIONS: This study explored potential drivers of vein graft inflammation and identified PPARα as a novel potential pharmacological treatment for this unmet medical need.

Effects of pemafibrate on primary biliary cholangitis with dyslipidemia.

AIM: The purpose of this study was to examine the effect of pemafibrate (PEM) in primary biliary cholangitis (PBC) patients with dyslipidemia. METHODS: Patients who were diagnosed with PBC between June 2018 and December 31, 2020 were included in the study if they also had dyslipidemia and their alkaline phosphatase (ALP) or gamma-glutamyl transferase (GGT) levels remained above the normal range despite taking 600 mg/day ursodeoxycholic acid (UDCA) for at least 6 months. Patients who were treated with UDCA alone were administered PEM as an add-on (PEM-add group), and patients who were treated with UDCA and bezafibrate (BEZ) for at least 6 months were given PEM instead of BEZ (PEM-switch group). Clinical parameters were compared in all patients, and the levels of ALP, GGT, the estimated glomerular filtration rate (eGFR), and creatinine (Cr) were compared between the PEM-add and PEM-switch groups. Improvement in cholangitis was also evaluated. RESULTS: In the PEM-add group, both ALP and GGT improved in 40 of 46 patients (87.0%). In the PEM-switch group, both ALP and GGT improved in 15 of 29 patients (51.7%). In the PEM-switch group, however, significant improvement was seen in eGFR and Cr. CONCLUSIONS: Administration of PEM is effective in PBC patients with dyslipidemia who are refractory to UDCA monotherapy. In patients using both UDCA and BEZ, there was an advantage in switching to PEM if they had renal damage; however, improvement of ALP and GGT occurred in about 50%.

New therapeutic approaches for the treatment of hypertriglyceridemia.

Patients with hypertriglyceridemia (> 150 mg/dl) have an increased risk for atherosclerotic cardiovascular disease, and those with severe hypertriglyceridemia (> 880 mg/dl) also for pancreatitis. The currently available medications to decrease triglyceride levels, such as fibrates, statins, and omega­3 fatty acids, are in many cases not able to achieve normal triglyceride levels. Therefore, new drugs are in development to address this unmet need. Recently, icosapent ethyl, a purified formulation of the omega-3-fatty acid eicosapentaenoic acid, was approved in Germany for the reduction of cardiovascular events in patients with hypertriglyceridemia and established cardiovascular disease or with diabetes and other risk factors on top of statins. Other new drugs in development are the more selective peroxisome proliferator-activated receptor α (PPARα) modulator, pemafibrate, already approved for the treatment of hypertriglyceridemia in Japan, and inhibitors of ApoC-III and angiopoietin-like 3 (ANGPTL3) in the form of antisense oligonucleotides or siRNAs or fully human monoclonal binding antibodies. Apolipoprotein C-III and ANGPTL3 protein seem to be quite promising targets based on solid genetic data. Larger studies of long duration, many of them currently ongoing, are needed to establish the role these medications will play in the treatment of hypertriglyceridemia in clinical practice.

Functional and Structural Insights into Human PPARα/δ/γ Subtype Selectivity of Bezafibrate, Fenofibric Acid, and Pemafibrate.

Among the agonists against three peroxisome proliferator-activated receptor (PPAR) subtypes, those against PPARα (fibrates) and PPARγ (glitazones) are currently used to treat dyslipidemia and type 2 diabetes, respectively, whereas PPARδ agonists are expected to be the next-generation metabolic disease drug. In addition, some dual/pan PPAR agonists are currently being investigated via clinical trials as one of the first curative drugs against nonalcoholic fatty liver disease (NAFLD). Because PPARα/δ/γ share considerable amino acid identity and three-dimensional structures, especially in ligand-binding domains (LBDs), clinically approved fibrates, such as bezafibrate, fenofibric acid, and pemafibrate, could also act on PPARδ/γ when used as anti-NAFLD drugs. Therefore, this study examined their PPARα/δ/γ selectivity using three independent assays-a dual luciferase-based GAL4 transactivation assay for COS-7 cells, time-resolved fluorescence resonance energy transfer-based coactivator recruitment assay, and circular dichroism spectroscopy-based thermostability assay. Although the efficacy and efficiency highly varied between agonists, assay types, and PPAR subtypes, the three fibrates, except fenofibric acid that did not affect PPARδ-mediated transactivation and coactivator recruitment, activated all PPAR subtypes in those assays. Furthermore, we aimed to obtain cocrystal structures of PPARδ/γ-LBD and the three fibrates via X-ray diffraction and versatile crystallization methods, which we recently used to obtain 34 structures of PPARα-LBD cocrystallized with 17 ligands, including the fibrates. We herein reveal five novel high-resolution structures of PPARδ/γ-bezafibrate, PPARγ-fenofibric acid, and PPARδ/γ-pemafibrate, thereby providing the molecular basis for their application beyond dyslipidemia treatment.

Effects of pemafibrate on glucose metabolism markers and liver function tests in patients with hypertriglyceridemia: a pooled analysis of six phase 2 and phase 3 randomized double-blind placebo-controlled clinical trials.

BACKGROUND: Increased risk of cardiovascular events is associated not only with dyslipidemias, but also with abnormalities in glucose metabolism and liver function. This study uses pooled analysis to explore the in-depth effects of pemafibrate, a selective peroxisome proliferator-activated receptor α modulator (SPPARMα) already known to decrease elevated triglycerides, on glucose metabolism and liver function in patients with hypertriglyceridemia. METHODS: We performed a post-hoc analysis of six phase 2 and phase 3 Japanese randomized double-blind placebo-controlled trials that examined the effects of daily pemafibrate 0.1 mg, 0.2 mg, and 0.4 mg on glucose metabolism markers and liver function tests (LFTs). Primary endpoints were changes in glucose metabolism markers and LFTs from baseline after 12 weeks of pemafibrate treatment. All adverse events and adverse drug reactions were recorded as safety endpoints. RESULTS: The study population was 1253 patients randomized to placebo (n = 298) or pemafibrate 0.1 mg/day (n = 127), 0.2 mg/day (n = 584), or 0.4 mg/day (n = 244). Participant mean age was 54.3 years, 65.4 % had BMI ≥ 25 kg/m2, 35.8 % had type 2 diabetes, and 42.6 % had fatty liver. Fasting glucose, fasting insulin, and HOMA-IR decreased significantly in all pemafibrate groups compared to placebo. The greatest decrease was for pemafibrate 0.4 mg/day: least square (LS) mean change from baseline in fasting glucose - 0.25 mmol/L; fasting insulin - 3.31 µU/mL; HOMA-IR - 1.28. ALT, γ-GT, ALP, and total bilirubin decreased significantly at all pemafibrate doses vs. placebo, with the greatest decrease in the pemafibrate 0.4 mg/day group: LS mean change from baseline in ALT - 7.6 U/L; γ-GT - 37.3 U/L; ALP - 84.7 U/L; and total bilirubin - 2.27 µmol/L. Changes in HbA1c and AST did not differ significantly from placebo in any pemafibrate groups in the overall study population. The decreases from baseline in LFTs and glucose metabolism markers except for HbA1c were notable among patients with higher baseline values. FGF21 increased significantly in all pemafibrate groups compared to placebo, with the greatest increase in the pemafibrate 0.4 mg/day group. Adverse event rates were similar in all groups including placebo. CONCLUSIONS: In patients with hypertriglyceridemia, pemafibrate can improve glucose metabolism and liver function, and increase FGF21, without increasing adverse event risk.

Selective Peroxisome Proliferator-Activated Receptor Alpha Modulators (SPPARMα) in the Metabolic Syndrome: Is Pemafibrate Light at the End of the Tunnel?

PURPOSE OF REVIEW: Adoption of poor lifestyles (inactivity and energy-dense diets) has driven the worldwide increase in the metabolic syndrome, type 2 diabetes mellitus and non-alcoholic steatohepatitis (NASH). Of the defining features of the metabolic syndrome, an atherogenic dyslipidaemia characterised by elevated triglycerides (TG) and low plasma concentration of high-density lipoprotein cholesterol is a major driver of risk for atherosclerotic cardiovascular disease. Beyond lifestyle intervention and statins, targeting the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα) is a therapeutic option. However, current PPARα agonists (fibrates) have limitations, including safety issues and the lack of definitive evidence for cardiovascular benefit. Modulating the ligand structure to enhance binding at the PPARα receptor, with the aim of maximising beneficial effects and minimising adverse effects, underlies the SPPARMα concept. RECENT FINDINGS: This review discusses the history of SPPARM development, latterly focusing on evidence for the first licensed SPPARMα, pemafibrate. Evidence from animal models of hypertriglyceridaemia or NASH, as well as clinical trials in patients with atherogenic dyslipidaemia, are overviewed. The available data set the scene for therapeutic application of SPPARMα in the metabolic syndrome, and possibly, NASH. The outstanding question, which has so far eluded fibrates in the setting of current evidence-based therapy including statins, is whether treatment with pemafibrate significantly reduces cardiovascular events in patients with atherogenic dyslipidaemia. The PROMINENT study in patients with type 2 diabetes mellitus and this dyslipidaemia is critical to evaluating this.

Pemafibrate prevents retinal neuronal cell death in NMDA-induced excitotoxicity via inhibition of p-c-Jun expression.

Excitotoxicity is involved in the retinal neuronal cell death in diabetic retinopathy. Although fenofibrate has been shown to ameliorate the progression of diabetic retinopathy, the effect of pemafibrate, which is highly selective for peroxisome proliferator-activated receptor α on retinal neuronal cell death has not been documented. Here, we investigated whether pemafibrate exerts a beneficial effect against retinal ganglion cell (RGC) death induced by N-methyl-D-aspartate (NMDA) in rats. Experiments were performed on adult male Wistar rats that received an intravitreal injection of 20 nmol NMDA. Fluoro-Gold labeled RGC morphometry showed that oral intake of pemafibrate once a day for 7 days resulted in significant protection on RGC death induced by NMDA. Phosphorylated c-Jun protein, which is involved in apoptosis, was upregulated after NMDA exposure, and this increase was significantly lessened by the systemic pemafibrate treatment. Phosphorylated c-Jun immunopositive cells were colocalized with Thy-1 immunopositive cells, and the increased these cells were ameliorated by the pemafibrate treatment. An increase in TUNEL-positive cells was significantly suppressed by the pemafibrate treatment. Phosphorylated c-Jun immunopositive cells were colocalized with TUNEL-positive cells, and they were decreased by pemafibrate treatment. These results suggest that the RGC protection achieved with pemafibrate appears to be associated with inhibition of phosphorylated c-Jun and its anti-apoptotic effect.