Effect of pemafibrate, a novel selective peroxisome proliferator-activated receptor-alpha modulator (SPPARMα), on urinary protein excretion in IgA nephropathy with hypertriglyceridemia

NAD+ Protects against Hyperlipidemia-induced Kidney Injury in Apolipoprotein E-deficient Mice

Background: Hyperlipidemia is an independent risk factor for kidney injury. Several studies have shown that nicotinamide adenine dinucleotide (NAD+) is an important coenzyme involved in normal body metabolism. Therefore, this study aimed to investigate the possible protective effects of NAD+ against hyperlipidemia-induced kidney injury in apolipoprotein Edeficient (ApoE-/-) mice.

Methods: Twenty-five eight-week-old male ApoE-/- mice were randomly assigned into four groups: normal diet (ND), ND supplemented with NAD+ (ND+NAD+), high-fat diet (HFD), and HFD supplemented with NAD+ (HFD+NAD+). The mice were subjected to their respective diets for a duration of 16 weeks. Blood samples were obtained from the inferior vena cava, collected in serum tubes, and stored at -80°C until use. Kidney tissues was fixed in 10% formalin and then embedded in paraffin for histological evaluation. The remainder of the kidney tissues was snapfrozen in liquid nitrogen for Western blot analysis.

Results: Metabolic parameters (total cholesterol, triglycerides, low-density lipoprotein-cholesterol, creatinine, and blood urea nitrogen) were significantly higher in the HFD group compared to the other groups. Histological analysis revealed prominent pathological manifestations in the kidneys of the HFD group. The HFD+NAD+ group showed increased levels of oxidative stress markers (NRF2 and SOD2) and decreased levels of NOX4 compared to the HFD group. Furthermore, the HFD group exhibited higher levels of TGF-β, Smad3, Collagen I, Collagen III, Bax, and Bak compared to the other groups. NAD+ supplementation in the HFD+NAD+ group significantly increased the levels of SIRT3, HO-1, Bcl-2, and Bcl-xL compared to the HFD group. Additionally, NF-κB protein expression was higher in the HFD group than in the HFD+NAD+ group.

Conclusion: These findings demonstrated that NAD+ may hold potential as a clinical treatment for kidney injury caused by hyperlipidemia.

.

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).

Combination Therapy Using Pemafibrate and Dapagliflozin for Metabolic Dysfunction-associated Fatty Liver Disease

Metabolic syndrome, including diabetes mellitus, obesity, and dyslipidemia, is associated with the development and progression of metabolic dysfunction-associated fatty liver disease. Therapeutic strategies, particularly optimal medical therapies, for treating metabolic dysfunction-associated fatty liver disease remain unestablished. We encountered a 37-year-old man with obesity (body mass index 39.0), metabolic dysfunction-associated fatty liver disease, and nephrotic syndrome due to obesity-related focal segmental glomerulosclerosis. Combination therapy using pemafibrate and dapagliflozin, together with body weight reduction, ameliorated his hypertriglyceridemia, hyperglycemia, hepatic injury, and proteinuria. Combination therapy using selective peroxisome proliferator-activated receptor α modulator and sodium-glucose cotransporter 2 inhibitor, together with body weight reduction, might be a promising dual-medical strategy for ameliorating metabolic dysfunction-associated fatty liver disease.

The predictive value of Oxford MEST-C classification to immunosuppressive therapy of IgA nephropathy

PURPOSE

To analyze the efficacy of immunosuppressive therapy in IgA nephropathy and investigate the value of all clinicopathologic indicators.

METHOD

One hundred and one eligible IgA nephropathy patients were retrospectively studied. All the patients received immunosuppressive treatment and were then grouped according to the treatment outcome. The endpoint was a composite outcome (halving eGFR, end-stage renal disease (ESRD) or death due to kidney disease). The outcomes of immunosuppressive therapy were evaluated, and the factors influencing the outcomes of immunosuppressive therapy were analyzed by logistics regression. The independent significance of clinicopathologic indicators on renal outcome was then analyzed by multivariable Cox regression.

RESULTS

Multivariate logistic regression analysis showed that S1 and M1 were the risk factors for the immunosuppressive treatment effect in IgAN patients, and eGFR was the protective factor for the immunosuppressive treatment effect in IgAN patients. Kaplan-Meier analysis revealed that outcomes of immunosuppressive therapy were significantly associated with poor renal outcomes. Multiple Cox regression analysis further confirmed that M1, T2, and the initial level of eGFR were independent predictive factors for poor renal outcomes.

CONCLUSIONS

M, S scores and initial eGFR are independent predictors of outcomes of immunosuppressive therapy. Only M, T scores can effectively predict poor renal outcomes after immunosuppressive therapy. Nonetheless, stable eGFR and low proteinuria can protect renal outcomes.

Selective Peroxisome Proliferator-Activated Receptor Alpha Modulators (SPPARMα): New Opportunities to Reduce Residual Cardiovascular Risk in Chronic Kidney Disease?

PURPOSE OF REVIEW

Chronic kidney disease (CKD) poses a major global challenge, which is exacerbated by aging populations and the pandemic of type 2 diabetes mellitus. Much of the escalating burden of CKD is due to cardiovascular complications. Current treatment guidelines for dyslipidemia in CKD prioritize low-density lipoprotein cholesterol management, but still leave a high residual cardiovascular risk. Targeting elevated triglycerides and low plasma high-density lipoprotein cholesterol, a common feature of CKD, could offer additional benefit. There are, however, safety issues with current fibrates (peroxisome proliferator-activated receptor alpha [PPARα] agonists), notably the propensity for elevation in serum creatinine, indicating the need for new approaches.

RECENT FINDINGS

Interactions between the ligand and PPARα receptor influence the specificity and potency of receptor binding, and downstream gene and physiological effects. The peroxisome proliferator-activated receptor alpha modulator (SPPARMα) concept aims to modulate the ligand structure so as to enhance binding at the PPARα receptor, thereby improving the ligand's selectivity, potency, and safety profile. This concept has led to the development of pemafibrate, a novel SPPARMα agent. This review discusses evidence that differentiates pemafibrate from current fibrates, especially the lack of evidence for elevation in serum creatinine or worsening of renal function in high-risk patients, including those with CKD. Differentiation of pemafibrate from current fibrates aims to address unmet clinical needs in CKD. The ongoing PROMINENT study will provide critical information regarding the long-term efficacy and safety of pemafibrate in patients with type 2 diabetes mellitus, including those with CKD, and whether the favorable lipid-modifying profile translates to reduction in residual cardiovascular risk.

The role of PPARα in autosomal dominant polycystic kidney disease

PURPOSE OF REVIEW

Metabolic reprogramming is a prominent feature of cyst epithelial cells in autosomal dominant polycystic kidney disease (ADPKD). Peroxisome proliferator activated receptor alpha (PPARα) is a transcription factor that regulates many aspects of cellular metabolism. The purpose of this review is to understand the role of PPARα in ADPKD.

RECENT FINDINGS

PPARα expression is reduced in ADPKD kidneys of mice and humans. This downregulation is in part secondary to microRNA mediated translational repression and leads to impairment of fatty acid metabolism. Genetic studies demonstrate that deletion of Pparα aggravates cyst growth in a slowly progressive mouse model of ADPKD. Recent studies also show that administration of Pparα agonists ameliorates cyst burden in mice.

SUMMARY

Abnormal reduction of PPARα affects cellular metabolism in ADPKD. Pparα is a modulator of cyst progression in mouse models of ADPKD. These studies establish PPARα as an exciting new drug target for the treatment of individuals with ADPKD.