Effects of Bardoxolone Methyl on Hepatic Enzymes in Patients with Type 2 Diabetes Mellitus and Stage 4 CKD

Mitochondrial dysfunction: the hidden catalyst in chronic kidney disease progression

Chronic kidney disease (CKD) represents a global health epidemic, with approximately one-third of affected individuals ultimately necessitating renal replacement therapy or transplantation. The kidney, characterized by its exceptionally high energy demands, exhibits significant sensitivity to alterations in energy supply and mitochondrial function. In CKD, a compromised capacity for mitochondrial ATP synthesis has been documented. As research advances, the multifaceted roles of mitochondria, extending beyond their traditional functions in oxygen sensing and energy production, are increasingly acknowledged. Empirical studies have demonstrated a strong association between mitochondrial dysfunction and the pathogenesis of fibrosis and cellular apoptosis in CKD. Targeting mitochondrial dysfunction holds substantial therapeutic promise, with emerging insights into its epigenetic regulation in CKD, particularly involving non-coding RNAs and DNA methylation. This article presents a comprehensive review of contemporary research on mitochondrial dysfunction in relation to the onset and progression of CKD. It elucidates the associated molecular mechanisms across various renal cell types and proposes novel research avenues for CKD treatment.

Modulation of Lonp1 Activity by Small Compounds

The Lon protease homolog 1 (LONP1) is an ATP-dependent mitochondrial protease essential for maintaining proteostasis, bioenergetics, and cellular homeostasis. LONP1 plays a pivotal role in protein quality control, mitochondrial DNA maintenance, and oxidative phosphorylation system (OXPHOS) regulation, particularly under stress conditions. Dysregulation of LONP1 has been implicated in various pathologies, including cancer, metabolic disorders, and reproductive diseases, positioning it as a promising pharmacological target. This review examines compounds that modulate LONP1 activity, categorizing them into inhibitors and activators. Inhibitors such as CDDO and its derivatives selectively target LONP1, impairing mitochondrial proteolysis, inducing protein aggregation, and promoting apoptosis, particularly in cancer cells. Compounds like Obtusilactone A and proteasome inhibitors (e.g., MG262) demonstrate potent cytotoxicity, further expanding the therapeutic landscape. Conversely, LONP1 activators, including Artemisinin derivatives and 84-B10, restore mitochondrial function and protect against conditions such as polycystic ovary syndrome (PCOS) and acute kidney injury (AKI). Future research should focus on improving the specificity, bioavailability, and pharmacokinetics of these modulators. Advances in structural biology and drug discovery will enable the development of novel LONP1-targeted therapies, addressing diseases driven by mitochondrial dysfunction and proteostasis imbalance.

Nrf2 activators for the treatment of rare iron overload diseases: From bench to bedside

Iron overload and related oxidative damage are seen in many rare diseases, due to mutation of iron homeostasis-related genes. As a core regulator on cellular antioxidant reaction, Nrf2 can also decrease systemic and cellular iron levels by regulating iron-related genes and pathways, making Nrf2 activators very good candidates for the treatment of iron overload disorders. Successful examples include the clinical use of omaveloxolone for Friedreich's Ataxia and dimethyl fumarate for relapsing-remitting multiple sclerosis. Despite these uses, the therapeutic potentials of Nrf2 activators for iron overload disorders may be overlooked in clinical practice. Therefore, this study talks about the potential use, possible mechanisms, and precautions of Nrf2 activators in treating rare iron overload diseases. In addition, a combination therapy with Nrf2 activators and iron chelators is proposed for clinical reference, aiming to facilitate the clinical use of Nrf2 activators for more iron overload disorders.

Antioxidant-Rich Functional Foods and Exercise: Unlocking Metabolic Health Through Nrf2 and Related Pathways

This article reviews the synergistic effects of antioxidant-enriched functional foods and exercise in improving metabolic health, focusing on the underlying molecular mechanisms. The review incorporates evidence from PubMed, SCOPUS, Web of Science, PsycINFO, and reference lists of relevant reviews up to 20 December 2024, highlighting the central role of the Nrf2 pathway. As a critical regulator of oxidative stress and metabolic adaptation, Nrf2 mediates the benefits of these interventions. This article presents an innovative approach to understanding the role of Nrf2 in the regulation of oxidative stress and inflammation, highlighting its potential in the prevention and treatment of various diseases, including cancer, neurodegenerative disorders, cardiovascular and pulmonary diseases, diabetes, inflammatory conditions, ageing, and infections such as COVID-19. The novelty of this study is to investigate the synergistic effects of bioactive compounds found in functional foods (such as polyphenols, flavonoids, and vitamins) and exercise-induced oxidative stress on the activation of the Nrf2 pathway. This combined approach reveals their potential to improve insulin sensitivity and lipid metabolism and reduce inflammation, offering a promising strategy for the management of chronic diseases. However, there are significant gaps in current research, particularly regarding the molecular mechanisms underlying the interaction between diet, physical activity, and Nrf2 activation, as well as their long-term effects in different populations, including those with chronic diseases. In addition, the interactions between Nrf2 and other critical signalling pathways, including AMPK, NF-κB, and PI3K/Akt, and their collective contributions to metabolic health are explored. Furthermore, novel biomarkers are presented to assess the impact of these synergistic strategies, such as the NAD+/NADH ratio, the GSH ratio, and markers of mitochondrial health. The findings provide valuable insights into how the integration of an antioxidant-rich diet and regular exercise can improve metabolic health by activating Nrf2 and related molecular pathways and represent promising strategies for the prevention and treatment of metabolic disorders. Further studies are needed to fully understand the therapeutic potential of these interventions in diseases related to oxidative stress, such as cardiovascular disease, neurodegenerative disease, diabetes, and cancer.

Adverse Effects of Nrf2 in Different Organs and the Related Diseases

Significance: Under normal physiological conditions, Nrf2 undergoes ubiquitination and subsequent proteasome degradation to maintain its basal activity. Oxidative stress can trigger Nrf2 activation, prompting its translocation to the nucleus where it functions as a transcription factor, activating various antioxidant pathways, and conferring antioxidant properties. Recent Advances: While extensive research has shown Nrf2's protective role in various diseases, emerging evidence suggests that Nrf2 activation can also produce harmful effects. Critical Issues: This review examines the pathological contexts in which Nrf2 assumes different roles, emphasizing the mechanisms and conditions that result in adverse outcomes. Future Directions: Persistent Nrf2 activation may have deleterious consequences, necessitating further investigation into the specific conditions and mechanisms through which Nrf2 exerts its harmful effects. Antioxid. Redox Signal. 00, 000-000.

Transcription factor NF-E2-related factor 2 plays a critical role in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) by regulating ferroptosis

NRF2 is an important transcription factor that regulates redox homeostasis in vivo and exerts its anti-oxidative stress and anti-inflammatory response by binding to the ARE to activate and regulate the transcription of downstream protective protein genes, reducing the release of reactive oxygen species. Ferroptosis is a novel iron-dependent, lipid peroxidation-driven cell death mode, and recent studies have shown that ferroptosis is closely associated with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). NRF2 is able to regulate ferroptosis through the regulation of the transcription of its target genes to ameliorate ALI/ARDS. Therefore, This article focuses on how NRF2 plays a role in ALI/ARDS by regulating ferroptosis. We further reviewed the literature and deeply analyzed the signaling pathways related to ferroptosis which were regulated by NRF2. Additionally, we sorted out the chemical molecules targeting NRF2 that are effective for ALI/ARDS. This review provides a relevant theoretical basis for further research on this theory and the prevention and treatment of ALI/ARDS. The intended audience is clinicians and researchers in the field of respiratory disease.

Nrf2 Signaling Pathway as a Key to Treatment for Diabetic Dyslipidemia and Atherosclerosis

Diabetes mellitus (DM) is a chronic endocrine disorder that affects more than 20 million people in the United States. DM-related complications affect multiple organ systems and are a significant cause of morbidity and mortality among people with DM. Of the numerous acute and chronic complications, atherosclerosis due to diabetic dyslipidemia is a condition that can lead to many life-threatening diseases, such as stroke, coronary artery disease, and myocardial infarction. The nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway is an emerging antioxidative pathway and a promising target for the treatment of DM and its complications. This review aims to explore the Nrf2 pathway's role in combating diabetic dyslipidemia. We will explore risk factors for diabetic dyslipidemia at a cellular level and aim to elucidate how the Nrf2 pathway becomes a potential therapeutic target for DM-related atherosclerosis.

Investigation of Basolateral Targeting Micelles for Drug Delivery Applications in Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is a complex disorder characterized by uncontrolled renal cyst growth, leading to kidney function decline. The multifaceted nature of ADPKD suggests that single-pathway interventions using individual small molecule drugs may not be optimally effective. As such, a strategy encompassing combination therapy that addresses multiple ADPKD-associated signaling pathways could offer synergistic therapeutic results. However, severe off-targeting side effects of small molecule drugs pose a major hurdle to their clinical transition. To address this, we identified four drug candidates from ADPKD clinical trials, bardoxolone methyl (Bar), octreotide (Oct), salsalate (Sal), and pravastatin (Pra), and incorporated them into peptide amphiphile micelles containing the RGD peptide (GRGDSP), which binds to the basolateral surface of renal tubules via integrin receptors on the extracellular matrix. We hypothesized that encapsulating drug combinations into RGD micelles would enable targeting to the basolateral side of renal tubules, which is the site of disease, via renal secretion, leading to superior therapeutic benefits compared to free drugs. To test this, we first evaluated the synergistic effect of drug combinations using the 20% inhibitory concentration for each drug (IC20) on renal proximal tubule cells derived from Pkd1flox/-:TSLargeT mice. Next, we synthesized and characterized the RGD micelles encapsulated with drug combinations and measured their in vitro therapeutic effects via a 3D PKD growth model. Upon both IV and IP injections in vivo, RGD micelles showed a significantly higher accumulation in the kidneys compared to NT micelles, and the renal access of RGD micelles was significantly reduced after the inhibition of renal secretion. Specifically, both Bar+Oct and Bar+Sal in the RGD micelle treatment showed enhanced therapeutic efficacy in ADPKD mice (Pkd1fl/fl;Pax8-rtTA;Tet-O-Cre) with a significantly lower KW/BW ratio and cyst index as compared to PBS and free drug-treated controls, while other combinations did not show a significant difference. Hence, we demonstrate that renal targeting through basolateral targeting micelles enhances the therapeutic potential of combination therapy in genetic kidney disease.

Antioxidants for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD) and death. Increased oxidative stress in people with CKD has been implicated as a potential causative factor. Antioxidant therapy decreases oxidative stress and may consequently reduce cardiovascular morbidity and death in people with CKD. This is an update of a Cochrane review first published in 2012.

OBJECTIVES

To examine the benefits and harms of antioxidant therapy on death and cardiovascular and kidney endpoints in adults with CKD stages 3 to 5, patients undergoing dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies until 15 November 2022 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials investigating the use of antioxidants, compared with placebo, usual or standard care, no treatment, or other antioxidants, for adults with CKD on cardiovascular and kidney endpoints.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened independently by two authors who also performed data extraction using standardised forms. Results were pooled using random effects models and expressed as risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 95 studies (10,468 randomised patients) that evaluated antioxidant therapy in adults with non-dialysis-dependent CKD (31 studies, 5342 patients), dialysis-dependent CKD (41 studies, 3444 patients) and kidney transplant recipients (21 studies, 1529 patients). Two studies enrolled dialysis and non-dialysis patients (153 patients). Twenty-one studies assessed the effects of vitamin antioxidants, and 74 assessed the effects of non-vitamin antioxidants. Overall, the quality of included studies was moderate to low or very low due to unclear or high risk of bias for randomisation, allocation concealment, blinding, and loss to follow-up. Compared with placebo, usual care, or no treatment, antioxidant therapy may have little or no effect on cardiovascular death (8 studies, 3813 patients: RR 0.94, 95% CI 0.64 to 1.40; I² = 33%; low certainty of evidence) and probably has little to no effect on death (any cause) (45 studies, 7530 patients: RR 0.95, 95% CI 0.82 to 1.11; I² = 0%; moderate certainty of evidence), CVD (16 studies, 4768 patients: RR 0.79, 95% CI 0.63 to 0.99; I² = 23%; moderate certainty of evidence), or loss of kidney transplant (graft loss) (11 studies, 1053 patients: RR 0.88, 95% CI 0.67 to 1.17; I² = 0%; moderate certainty of evidence). Compared with placebo, usual care, or no treatment, antioxidants had little to no effect on the slope of urinary albumin/creatinine ratio (change in UACR) (7 studies, 1286 patients: MD -0.04 mg/mmol, 95% CI -0.55 to 0.47; I² = 37%; very low certainty of evidence) but the evidence is very uncertain. Antioxidants probably reduced the progression to kidney failure (10 studies, 3201 patients: RR 0.65, 95% CI 0.41 to 1.02; I² = 41%; moderate certainty of evidence), may improve the slope of estimated glomerular filtration rate (change in eGFR) (28 studies, 4128 patients: MD 3.65 mL/min/1.73 m², 95% CI 2.81 to 4.50; I² = 99%; low certainty of evidence), but had uncertain effects on the slope of serum creatinine (change in SCr) (16 studies, 3180 patients: MD -13.35 µmol/L, 95% CI -23.49 to -3.23; I² = 98%; very low certainty of evidence). Possible safety concerns are an observed increase in the risk of infection (14 studies, 3697 patients: RR 1.30, 95% CI 1.14 to 1.50; I² = 3%; moderate certainty of evidence) and heart failure (6 studies, 3733 patients: RR 1.40, 95% CI 1.11 to 1.75; I² = 0; moderate certainty of evidence) among antioxidant users. Results of studies with a low risk of bias or longer follow-ups generally were comparable to the main analyses.

AUTHORS' CONCLUSIONS

We found no evidence that antioxidants reduced death or improved kidney transplant outcomes or proteinuria in patients with CKD. Antioxidants likely reduce cardiovascular events and progression to kidney failure and may improve kidney function. Possible concerns are an increased risk of infections and heart failure among antioxidant users. However, most studies were of suboptimal quality and had limited follow-up, and few included people undergoing dialysis or kidney transplant recipients. Furthermore, the large heterogeneity in interventions hampers drawing conclusions on the efficacy and safety of individual agents.

The Evolving Profile of Idiosyncratic Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) is an infrequent but important cause of liver disease. Newly identified causes of DILI include the COVID vaccines, turmeric, green tea extract, and immune checkpoint inhibitors. DILI is largely a clinical diagnosis of exclusion that requires evaluation for more common causes of liver injury and a compatible temporal association with the suspect drug. Recent progress in DILI causality assessment includes the development of the semi-automated revised electronic causality assessment method (RECAM) instrument. In addition, several drug-specific HLA associations have been identified that can help with the confirmation or exclusion of DILI in individual patients. Various prognostic models can help identify the 5%-10% of patients at highest risk of death. Following suspect drug cessation, 80% of patients with DILI fully recover, whereas 10%-15% have persistently abnormal laboratory studies at 6 months of follow-up. Hospitalized patients with DILI with an elevated international normalized ratio or mental status changes should be considered for N-acetylcysteine therapy and urgent liver transplant evaluation. Selected patients with moderate to severe drug reaction with eosinophilia and systemic symptoms or autoimmune features on liver biopsy may benefit from short-term corticosteroids. However, prospective studies are needed to determine the optimal patients and dose and duration of steroids to use. LiverTox is a comprehensive, freely accessible Web site with important information regarding the hepatotoxicity profile of more than 1000 approved medications and 60 herbal and dietary supplement products. It is hoped that ongoing "omics" studies will lead to additional insight into DILI pathogenesis, improved diagnostic and prognostic biomarkers, and mechanism-based treatments.

Advances and challenges in therapeutic targeting of NRF2

Activation of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is emerging as an attractive therapeutic approach to counteract oxidative stress, inflammation, and metabolic imbalances. These processes underpin many chronic pathologies with unmet therapeutic needs, including neurodegenerative disorders and metabolic diseases. As the NRF2 field transitions into the clinical phase of its evolution, the need for an understanding of the factors influencing NRF2 pharmacology has never been greater. In this opinion article we describe the rationale for targeting NRF2, summarise the recent advances in drug development of NRF2 modulators, and reflect on the remaining challenges in realising the full clinical potential of NRF2 as a therapeutic target.

Combining Metformin and Drug-Loaded Kidney-Targeting Micelles for Polycystic Kidney Disease

Introduction

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease that leads to eventual renal failure. Metformin (MET), an AMP-activated protein kinase (AMPK) activator already approved for type 2 diabetes, is currently investigated for ADPKD treatment. However, despite high tolerability, MET showed varying therapeutic efficacy in preclinical ADPKD studies. Thus, newer strategies have combined MET with other ADPKD small molecule drug candidates, thereby targeting multiple ADPKD-associated signaling pathways to enhance therapeutic outcomes through potential drug synergy. Unfortunately, the off-target side effects caused by these additional drug candidates pose a major hurdle. To address this, our group has previously developed kidney-targeting peptide amphiphile micelles (KMs), which displayed significant kidney accumulation in vivo, for delivering drugs to the site of the disease.

Methods

To mitigate the adverse effects of ADPKD drugs and evaluate their therapeutic potential in combination with MET, herein, we loaded KMs with ADPKD drug candidates including salsalate, octreotide, bardoxolone methyl, rapamycin, tolvaptan, and pioglitazone, and tested their in vitro therapeutic efficacy when combined with free MET. Specifically, after determining the 40% inhibitory concentration for each drug (IC40), the size, morphology, and surface charge of drug-loaded KMs were characterized. Next, drug-loaded KMs were applied in combination with MET to treat renal proximal tubule cells derived from Pkd1flox/-:TSLargeT mice in 2D proliferation and 3D cyst model.

Results

MET combined with all drug-loaded KMs demonstrated significantly enhanced efficacy as compared to free drugs in inhibiting cell proliferation and cyst growth. Notably, synergistic effects were found for MET and KMs loaded with either salsalate or rapamycin as determined by Bliss synergy scores.

Conclusion

Together, we show drug synergy using drug-loaded nanoparticles and free MET for the first time and present a novel nanomedicine-based combinatorial therapeutic approach for ADPKD with enhanced efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-022-00753-9.

Effects of Bardoxolone Methyl in Alport Syndrome

BACKGROUND AND OBJECTIVES

Alport syndrome is an inherited disease characterized by progressive loss of kidney function. We aimed to evaluate the safety and efficacy of bardoxolone methyl in patients with Alport syndrome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We randomly assigned patients with Alport syndrome, ages 12-70 years and eGFR 30-90 ml/min per 1.73 m2, to bardoxolone methyl (n=77) or placebo (n=80). Primary efficacy end points were change from baseline in eGFR at weeks 48 and 100. Key secondary efficacy end points were change from baseline in eGFR at weeks 52 and 104, after an intended 4 weeks off treatment. Safety was assessed by monitoring for adverse events and change from baseline in vital signs, 12-lead electrocardiograms, laboratory measurements (including, but not limited to, aminotransferases, urinary albumin-creatinine ratio, magnesium, and B-type natriuretic peptide), and body weight.

RESULTS

Patients randomized to bardoxolone methyl experienced preservation in eGFR relative to placebo at 48 and 100 weeks (between-group differences: 9.2 [97.5% confidence interval, 5.1 to 13.4; P<0.001] and 7.4 [95% confidence interval, 3.1 to 11.7; P=0.0008] ml/min per 1.73 m2, respectively). After a 4-week off-treatment period, corresponding mean differences in eGFR were 5.4 (97.5% confidence interval, 1.8 to 9.1; P<0.001) and 4.4 (95% confidence interval, 0.7 to 8.1; P=0.02) ml/min per 1.73 m2 at 52 and 104 weeks, respectively. In a post hoc analysis with no imputation of missing eGFR data, the difference at week 104 was not statistically significant (1.5 [95% confidence interval, -1.9 to 4.9] ml/min per 1.73 m2). Discontinuations from treatment were more frequent among patients randomized to bardoxolone methyl; most discontinuations were due to protocol-specified criteria being met for increases in serum transaminases. Serious adverse events were more frequent among patients randomized to placebo. Three patients in each group developed kidney failure.

CONCLUSIONS

In adolescent and adult patients with Alport syndrome receiving standard of care, treatment with bardoxolone methyl resulted in preservation in eGFR relative to placebo after a 2-year study period; off-treatment results using all available data were not significantly different.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

A Phase 2/3 Trial of the Efficacy and Safety of Bardoxolone Methyl in Patients with Alport Syndrome - CARDINAL (CARDINAL), NCT03019185.

Recent advances in medicinal chemistry of oleanolic acid derivatives

Oleanolic acid (OA), a ubiquitous pentacyclic oleanane-type triterpene isolated from edible and medicinal plants, exhibits a wide spectrum of pharmacological activities and tremendous therapeutic potential. However, the undesirable pharmacokinetic properties limit its application and development. Numerous researches on structural modifications of OA have been carried out to overcome this limitation and improve its pharmacokinetic and therapeutic properties. This review aims to compile and summarize the recent progresses in the medicinal chemistry of OA derivatives, especially on structure-activity relationship in the last few years (2010-2021). It gives insights into the rational design of bioactive derivatives from OA scaffold as promising therapeutic agents.

Clinical Significance of Transient Asymptomatic Elevations in Aminotransferase (TAEAT) in Oncology

Monitoring for liver injury remains an important aspect of drug safety assessment, including for oncotherapeutics. When present, drug-induced liver injury may limit the use or result in the discontinuation of these agents. Drug-induced liver injury can exhibit with a wide spectrum of clinical and biochemical manifestations, ranging from transient asymptomatic elevations in aminotransferases (TAEAT) to acute liver failure. Numerous oncotherapeutics have been associated with TAEAT, with published reports indicating a phenomenon in which patients may be asymptomatic without overt liver injury despite the presence of grade ≥3 aminotransferase elevations. In this review, we discuss the occurrence of TAEAT in the context of oncology clinical trials and clinical practice, as well as the clinical relevance of this phenomenon as an adverse event in response to oncotherapeutics and the related cellular and molecular mechanisms that may underlie its occurrence. We also identify several gaps in knowledge relevant to the diagnosis and the management of TAEAT in patients receiving oncotherapeutics, and identify areas warranting further study to enable the future development of consensus guidelines to support clinical decision-making.

Targeting Nrf2 in ischemia-reperfusion alleviation: From signaling networks to therapeutic targeting

The nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of redox balance and it responds to various cell stresses that oxidative stress is the most well-known one. The Nrf2 should undergo nuclear translocation to exert its protective impacts and decrease ROS production. On the other hand, ischemic/reperfusion (I/R) injury is a pathological event resulting from low blood flow to an organ and followed by reperfusion. The I/R induces cell injury and organ dysfunction. The present review focuses on Nrf2 function in alleviation of I/R injury. Stimulating of Nrf2 signaling ameliorates I/R injury in various organs including lung, liver, brain, testis and heart. The Nrf2 enhances activity of antioxidant enzymes to reduce ROS production and prevent oxidative stress-mediated cell death. Besides, Nrf2 reduces inflammation via decreasing levels of pro-inflammatory factors including IL-6, IL-1β and TNF-α. Nrf2 signaling is beneficial in preventing apoptosis and increasing cell viability. Nrf2 induces autophagy to prevent apoptosis during I/R injury. Furthermore, it can interact with other molecular pathways including PI3K/Akt, NF-κB, miRNAs, lncRNAs and GSK-3β among others, to ameliorate I/R injury. The therapeutic agents, most of them are phytochemicals such as resveratrol, berberine and curcumin, induce Nrf2 signaling in I/R injury alleviation.

Nrf2 Activation in Chronic Kidney Disease: Promises and Pitfalls

The nuclear factor erythroid 2-related factor 2 (Nrf2) protects the cell against oxidative damage. The Nrf2 system comprises a complex network that functions to ensure adequate responses to redox perturbations, but also metabolic demands and cellular stresses. It must be kept within a physiologic activity range. Oxidative stress and alterations in Nrf2-system activity are central for chronic-kidney-disease (CKD) progression and CKD-related morbidity. Activation of the Nrf2 system in CKD is in multiple ways related to inflammation, kidney fibrosis, and mitochondrial and metabolic effects. In human CKD, both endogenous Nrf2 activation and repression exist. The state of the Nrf2 system varies with the cause of kidney disease, comorbidities, stage of CKD, and severity of uremic toxin accumulation and inflammation. An earlier CKD stage, rapid progression of kidney disease, and inflammatory processes are associated with more robust Nrf2-system activation. Advanced CKD is associated with stronger Nrf2-system repression. Nrf2 activation is related to oxidative stress and moderate uremic toxin and nuclear factor kappa B (NF-κB) elevations. Nrf2 repression relates to high uremic toxin and NF-κB concentrations, and may be related to Kelch-like ECH-associated protein 1 (Keap1)-independent Nrf2 degradation. Furthermore, we review the effects of pharmacological Nrf2 activation by bardoxolone methyl, curcumin, and resveratrol in human CKD and outline strategies for how to adapt future Nrf2-targeted therapies to the requirements of patients with CKD.

NLRP3 Inflammasome and Pyroptosis in Liver Pathophysiology: The Emerging Relevance of Nrf2 Inducers

Inflammasomes, particularly the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3) inflammasome, apparently serve as crucial regulators of the inflammatory response through the activation of Caspase-1 and induction of pro-inflammatory cytokines and pyroptotic cell death. Pyroptosis is a type of programmed cell death mediated by Caspase-1 cleavage of Gasdermin D and the insertion of its N-terminal fragment into the plasma membrane, where it forms pores, enabling the release of different pro-inflammatory mediators. Pyroptosis is considered not only a pro-inflammatory pathway involved in liver pathophysiology but also an important pro-fibrotic mediator. Diverse molecular mechanisms linking oxidative stress, inflammasome activation, pyroptosis, and the progression of liver pathologies have been documented. Numerous studies have indicated the protective effects of several antioxidants, with the ability to induce nuclear factor erythroid 2-related factor 2 (Nrf2) activity on liver inflammation and fibrosis. In this review, we have summarised recent studies addressing the role of the NLRP3 inflammasome and pyroptosis in the pathogenesis of various hepatic diseases, highlighting the potential application of Nrf2 inducers in the prevention of pyroptosis as liver protective compounds.

Antioxidant Response Activating nanoParticles (ARAPas) localize to atherosclerotic plaque and locally activate the Nrf2 pathway

Atherosclerotic disease is the leading cause of death world-wide with few novel therapies available despite the ongoing health burden. Redox dysfunction is a well-established driver of atherosclerotic progression; however, the clinical translation of redox-based therapies is lacking. One of the challenges facing redox-based therapies is their targeted delivery to cellular domains of redox dysregulation. In the current study, we sought to develop Antioxidant Response Activating nanoParticles (ARAPas), encapsulating redox-based interventions, that exploit macrophage biology and the dysfunctional endothelium in order to selectively accumulate in atherosclerotic plaque. We employed flash nanoprecipitation (FNP) to synthesize bio-compatible polymeric nanoparticles encapsulating the hydrophobic Nrf2 activator drug, CDDO-Methyl (CDDOMe-ARAPas). Nuclear factor erythroid 2-related factor 2 (Nrf2)-activators are a promising class of redox-active drug molecules whereby activation of Nrf2 results in the expression of several antioxidant and cyto-protective enzymes that can be athero-protective. In this study, we characterize the physicochemical properties of CDDOMe-ARAPas as well as confirm their in vitro internalization by murine macrophages. Drug release of CDDOMe was determined by Nrf2-driven GFP fluorescence. Moreover, we show that these CDDOMe-ARAPas exert anti-inflammatory effects in classically activated macrophages. Finally, we show that CDDOMe-ARAPas selectively accumulate in atherosclerotic plaque of two widely-used murine models of atherosclerosis: ApoE^-/- and LDLr^-/- mice, and are capable of increasing gene expression of Nrf2-transcriptional targets in the atherosclerotic aortic arch. Future work will assess the therapeutic efficacy of intra-plaque Nrf2 activation with CDDOMe-ARAPas to inhibit atherosclerotic plaque progression. Overall, our present studies underline that targeting of atherosclerotic plaque is an effective means to enhance delivery of redox-based interventions.

Anti-Diabetic Potential of Plant-Based Pentacyclic Triterpene Derivatives: Progress Made to Improve Efficacy and Bioavailability

Diabetes mellitus (DM) results from the inability of the pancreas to produce sufficient insulin or weakened cellular response to the insulin produced, which leads to hyperglycemia. Current treatments of DM focus on the use of oral hypoglycemic drugs such as acarbose, alpha-glucose inhibitors, sulphonylureas, thiazolidinediones, and biguanides to control blood glucose levels. However, these medications are known to have various side effects in addition to their bioavailability, efficacy, and safety concerns. These drawbacks have increased interest in the anti-diabetic potential of plant-derived bioactive compounds such as oleanolic and maslinic acids. Although their efficacy in ameliorating blood glucose levels has been reported in several studies, their bioavailability and efficacy remain of concern. The current review examines the anti-diabetic effects of oleanolic, maslinic, asiatic, ursolic, and corosolic acids and their derivatives, as well as the progress made thus far to enhance their bioavailability and efficacy. The literature for the current review was gathered from leading academic databases-including Google Scholar and PubMed-the key words listed below were used. The literature was searched as widely and comprehensively as possible without a defined range of dates.

Alterations of hepatic gluconeogenesis and amino acid metabolism in CTRP3-deficient mice

BACKGROUND

Adipose tissue secretes various adipocytokines that play important roles in lipid and glucose metabolism. C1q and tumor necrosis factor-related protein 3 (CTRP3) is a paralog of adiponectin, which has been extensively studied. Previously, we showed that epididymal white adipose tissue size is decreased in high fat diet-fed Ctrp3 knockout (KO) mice. Here, I examined metabolic roles of CTRP3 in non-obese mice under starvation conditions.

METHODS AND RESULTS

Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were increased in 20-h-fasted standard chow-fed Ctrp3 KO mice compared with wild-type (WT) controls. RT-qPCR analysis revealed that ALT1, AST2, and glucose-6-phosphatase mRNA expressions were increased in the liver of Ctrp3 KO mice after a 20-h fast. Upon intraperitoneal alanine administration, Ctrp3 KO mice showed a modest but significant increase in the conversion of alanine to glucose. To characterize hepatic metabolism in fasted Ctrp3 KO mice, I further analyzed metabolomic profiles in the liver. Unexpectedly, metabolome analysis of the liver of 20-h-fasted Ctrp3 KO mice revealed that the relative concentrations of 10 of the 20 amino acids were lower than in WT controls. The relative concentrations of ornithine and argininosuccinate, which are urea cycle intermediates, were also decreased in the Ctrp3 KO liver.

CONCLUSIONS

Taken together, my results indicate that CTRP3 has novel roles in regulating both gluconeogenesis and amino acid metabolism in the liver during starvation.

Drug-Induced Liver Injury: Highlights and Controversies in the Recent Literature

Drug-induced liver injury (DILI) remains an important, yet challenging diagnosis for physicians. Each year, additional drugs are implicated in DILI and this year was no different, with more than 1400 articles published on the subject. This review examines some of the most significant highlights and controversies in DILI-related research over the past year and their implications for clinical practice. Several new drugs were approved by the US Food and Drug Administration including a number of drugs implicated in causing DILI, particularly among the chemotherapeutic classes. The COVID-19 pandemic was also a major focus of attention in 2020 and we discuss some of the notable aspects of COVID-19-related liver injury and its implications for diagnosing DILI. Updates in diagnostic and causality assessments related to DILI such as the Roussel Uclaf Causality Assessment Method are included, mindful that there is still no single biomarker or diagnostic tool to unequivocally diagnose DILI. Glutamate dehydrogenase received renewed attention as being more specific than alanine aminotransferase. There were a few new reports of previously unrecognized hepatotoxins, including immune modulators and novel gene therapy drugs that we highlight. Updates and new developments of previously described hepatotoxins, such as immune checkpoint inhibitors and anti-tuberculosis drugs are reviewed. Finally, novel technologies such as organoid culture systems to better predict DILI preclinically may be coming of age and determinants of hepatocyte loss, such as calculating P_ALT are poised to improve our current means of estimating DILI severity and the risk of acute liver failure.

Safety and Efficacy of Omaveloxolone in Friedreich Ataxia (MOXIe Study)

OBJECTIVE

Friedreich ataxia (FA) is a progressive genetic neurodegenerative disorder with no approved treatment. Omaveloxolone, an Nrf2 activator, improves mitochondrial function, restores redox balance, and reduces inflammation in models of FA. We investigated the safety and efficacy of omaveloxolone in patients with FA.

METHODS

We conducted an international, double-blind, randomized, placebo-controlled, parallel-group, registrational phase 2 trial at 11 institutions in the United States, Europe, and Australia (NCT02255435, EudraCT2015-002762-23). Eligible patients, 16 to 40 years of age with genetically confirmed FA and baseline modified Friedreich's Ataxia Rating Scale (mFARS) scores between 20 and 80, were randomized 1:1 to placebo or 150mg per day of omaveloxolone. The primary outcome was change from baseline in the mFARS score in those treated with omaveloxolone compared with those on placebo at 48 weeks.

RESULTS

One hundred fifty-five patients were screened, and 103 were randomly assigned to receive omaveloxolone (n = 51) or placebo (n = 52), with 40 omaveloxolone patients and 42 placebo patients analyzed in the full analysis set. Changes from baseline in mFARS scores in omaveloxolone (-1.55 ± 0.69) and placebo (0.85 ± 0.64) patients showed a difference between treatment groups of -2.40 ± 0.96 (p = 0.014). Transient reversible increases in aminotransferase levels were observed with omaveloxolone without increases in total bilirubin or other signs of liver injury. Headache, nausea, and fatigue were also more common among patients receiving omaveloxolone.

INTERPRETATION

In the MOXIe trial, omaveloxolone significantly improved neurological function compared to placebo and was generally safe and well tolerated. It represents a potential therapeutic agent in FA. ANN NEUROL 2021;89:212-225.

Omaveloxolone: potential new agent for Friedreich ataxia

Friedreich ataxia is a slowly progressive neurodegenerative disorder leading to ataxia, dyscoordination, dysarthria and in many individuals vision and hearing loss. It is associated with cardiomyopathy, the leading cause of death in Friedreich ataxia (FRDA), diabetes and scoliosis. There are no approved therapies, but elucidation of the pathophysiology of FRDA suggest that agents that increase the activity of the transcription factor Nrf2 may provide a mechanism for ameliorating disease progression or severity. In this work, we review the evidence for use of omaveloxolone in FRDA from recent clinical trials. Though not at present approved for any indication, the present data suggest that this agent acting though increases in Nrf2 activity may provide a novel therapy for FRDA.