Berberine alleviates cisplatin-induced acute kidney injury by regulating mitophagy via PINK 1/Parkin pathway

Role of mitochondria in reno-cardiac diseases: A study of bioenergetics, biogenesis, and GSH signaling in disease transition

Acute kidney injury (AKI) and chronic kidney disease (CKD) are global health burdens with rising prevalence. Their bidirectional relationship with cardiovascular dysfunction, manifesting as cardio-renal syndromes (CRS) types 3 and 4, underscores the interconnectedness and interdependence of these vital organ systems. Both the kidney and the heart are critically reliant on mitochondrial function. This organelle is currently recognized as a hub in signaling pathways, with emphasis on the redox regulation mediated by glutathione (GSH). Mitochondrial dysfunction, including impaired bioenergetics, redox, and biogenesis pathways, are central to the progression of AKI to CKD and the development of CRS type 3 and 4. This review delves into the metabolic reprogramming and mitochondrial redox signaling and biogenesis alterations in AKI, CKD, and CRS. We examine the pathophysiological mechanisms involving GSH redox signaling and the AMP-activated protein kinase (AMPK)-sirtuin (SIRT)1/3-peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) axis in these conditions. Additionally, we explore the therapeutic potential of GSH synthesis inducers in mitigating these mitochondrial dysfunctions, as well as their effects on inflammation and the progression of CKD and CRS types 3 and 4.

Involvement of Sirt1-FoxO3a-Bnip3 axis and autophagy mediated mitochondrial turnover in according protection to hyperglycemic NRK-52E cells by Berberine

Aberrant accumulation of dysfunctional mitochondria in renal cells during hyperglycemia signifies perturbed autophagy and mitochondrial turnover. This study aims to focus on the underlying mechanism involved in autophagy and mitophagy inducing efficacy of Berberine (isoquinoline alkaloid) in hyperglycemic NRK-52E cells. Berberine mediated protection to hyperglycemic cells prevented alteration in mitochondrial structure and function. Treatment with SRT-1720 (Sirt1 activator) enhanced autophagy, decreased apoptosis, upregulated expression of downstream moieties (FoxO3a and Bnip3) and ameliorated mitochondria related anomalies while nicotinamide (Sirt1 inhibitor) treatment exhibited reversal of the same. GFP reporter assay ascertained enhanced transcriptional activity of FoxO in Berberine-treated hyperglycemic cells, which was found to be correlated to increased expression of downstream protein Bnip3. Knocking down FoxO3a disrupted autophagy and stimulated apoptosis. N-acetyl-L-cysteine pre-treatment confirmed that generation of ROS intervened high glucose induced toxicity in NRK-52E cells. Berberine co-treatment resulted in differential expressions of key proteins involved in autophagy and mitophagy like LC3B, ATGs, Beclin1, Sirt1, Bnip3, FoxO3a and Parkin. Further, enhanced mitophagy in Berberine-treated cells was confirmed by transmission electron microscopy. Thus, our findings give evidence that the protection accorded by Berberine against hyperglycemia in renal proximal tubular cells (NRK-52E) involves instigation of Sirt1-FoxO3a-Bnip3 axis and autophagy mediated mitophagy induction.

Traditional Chinese Medicine and renal regeneration: experimental evidence and future perspectives

Repair of acute kidney injury (AKI) is a typical example of renal regeneration. AKI is characterized by tubular cell death, peritubular capillary (PTC) thinning, and immune system activation. After renal tubule injury, resident renal progenitor cells, or renal tubule dedifferentiation, give rise to renal progenitor cells and repair the damaged renal tubule through proliferation and differentiation. Mesenchymal stem cells (MSCs) also play an important role in renal tubular repair. AKI leads to sparse PTC, affecting the supply of nutrients and oxygen and indirectly aggravating AKI. Therefore, repairing PTC is important for the prognosis of AKI. The activation of the immune system is conducive for the body to clear the necrotic cells and debris generated by AKI; however, if the immune activation is too strong or lengthy, it will cause damage to renal tubule cells or inhibit their repair. Macrophages have been shown to play an important role in the repair of kidney injury. Traditional Chinese medicine (TCM) has unique advantages in the treatment of AKI and a series of studies have been conducted on the topic in recent years. Herein, the role of TCM in promoting the repair of renal injury and its molecular mechanism is discussed from three perspectives: repair of renal tubular epithelial cells, repair of PTC, and regulation of macrophages to provide a reference for the treatment and mechanistic research of AKI.

Nanodrugs based on co-delivery strategies to combat cisplatin resistance

Cisplatin (CDDP), as a broad-spectrum anticancer drug, is able to bind to DNA and inhibit cell division. Despite the widespread use of cisplatin since its discovery, cisplatin resistance developed during prolonged chemotherapy, similar to other small molecule chemotherapeutic agents, severely limits its clinical application. Cisplatin resistance in cancer cells is mainly caused by three reasons: DNA repair, decreased cisplatin uptake/increased efflux, and cisplatin inactivation. In earlier combination therapies, the emergence of multidrug resistance (MDR) in cancer cells prevented the achievement of the desired therapeutic effect even with the accurate combination of two chemotherapeutic drugs. Therefore, combination therapy using nanocarriers for co-delivery of drugs is considered to be ideal for alleviating cisplatin resistance and reducing cisplatin-related toxicity in cancer cells. This article provides an overview of the design of cisplatin nano-drugs used to combat cancer cell resistance, elucidates the mechanisms of action of cisplatin and the pathways through which cancer cells develop resistance, and finally discusses the design of drugs and related carriers that can synergistically reduce cancer resistance when combined with cisplatin.

Delta opioid peptide [D-ala2, D-leu5]-Enkephalin's ability to enhance mitophagy via TRPV4 to relieve ischemia/reperfusion injury in brain microvascular endothelial cells

BACKGROUND

Local brain tissue can suffer from ischaemia/reperfusion (I/R) injury, which lead to vascular endothelial damage. The peptide δ opioid receptor (δOR) agonist [D-ala2, D-leu5]-Enkephalin (DADLE) can reduce apoptosis caused by acute I/R injury in brain microvascular endothelial cells (BMECs).

OBJECTIVE

This study aims to explore the mechanism by which DADLE enhances the level of mitophagy in BMECs by upregulating the expression of transient receptor potential vanilloid subtype 4 (TRPV4).

METHODS

BMECs were extracted and made to undergo oxygen-glucose deprivation/reoxygenation (OGD/R) accompanied by DADLE. RNA-seq analysis revealed that DADLE induced increased TRPV4 expression. The CCK-8 method was used to assess the cellular viability; quantitative PCR (qPCR) was used to determine the mRNA expression of Drp1; western blot was used to determine the expression of TRPV4 and autophagy-related proteins; and calcium imaging was used to detect the calcium influx. Autophagosomes in in the cells' mitochondria were observed by using transmission electron microscopy. ELISA was used to measure ATP content, and a JC-1 fluorescent probe was used to detect mitochondrial membrane potential.

RESULTS

When compared with the OGD/R group, OGD/R+DADLE group showed significantly enhanced cellular viability; increased expression of TRPV4, Beclin-1, LC3-II/I, PINK1 and Parkin; decreased p62 expression; a marked rise in calcium influx; further increases in mitophagy, an increase in ATP synthesis and an elevation of mitochondrial membrane potential. These protective effects of DADLE can be blocked by a TRPV4 inhibitor HC067047 or RNAi of TRPV4.

CONCLUSION

DADLE can promote mitophagy in BMECs through TRPV4, improving mitochondrial function and relieving I/R injury.

Berberine alleviated contrast-induced acute kidney injury by mitophagy-mediated NLRP3 inflammasome inactivation in a mice model

The incidence of contrast-induced acute kidney injury (CI-AKI) has escalated to become the third most prevalent cause of hospital-acquired AKI, with a lack of efficacious interventions. Berberine (BBR) possesses diverse pharmacological effects and exhibits renoprotective properties; however, limited knowledge exists regarding its impact on CI-AKI. Therefore, our study aimed to investigate the protective effects and underlying mechanisms of BBR on CI-AKI in a mice model, focusing on the nucleotide-binding oligomerization domain-like pyrin domain-containing protein 3 (NLRP3) inflammasome and mitophagy. The CI-AKI mice model was established by administering NG-nitro-L-arginine methyl ester (L-NAME) (10 mg/kg), indomethacin (10 mg/kg), and iohexol (11 g/kg) following water deprivation. A pretreatment of 100 mg/kg of BBR was orally administered to the mice for two weeks. Renal injury markers, damage-associated molecular patterns (DAMPs), renal histopathology, mitochondrial morphology, autophagosomes, and potential mechanisms were investigated. BBR effectively reduced levels of renal injury biomarkers such as serum cystatin C, urea nitrogen, and creatinine, downregulated the protein level of kidney injury molecule 1 (KIM1), and mitigated renal histomorphological damage. Moreover, BBR reduced DAMPs, including high mobility group box-1 (HMGB1), heat shock protein 70 (HSP70), and uric acid (UA). It also alleviated oxidative stress and inflammatory factors such as monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). Furthermore, the activation of NLRP3 inflammasome was attenuated in the BBR pretreatment group, as evidenced by both mRNA and protein levels. Electron microscopy and western blotting examination revealed that BBR mitigated mitochondrial damage and enhanced mitophagy. Additionally, BBR increased the P-AMPK/AMPK ratio. These findings indicated that BBR exerted a protective effect against CI-AKI by suppressing NLRP3 inflammasome activation and modulating mitophagy, providing a potential therapeutic strategy for its prevention.

Berberine ameliorates contrast-induced acute kidney injury by regulating HDAC4-FoxO3a axis-induced autophagy: In vivo and in vitro

In hospitals, contrast-induced acute kidney injury (CI-AKI) is a major cause of renal failure. This study evaluates berberine's (BBR) renal protection and its potential HDAC4 mechanism. CI-AKI in rats was induced with 10 mL kg-1 ioversol. Rats were divided into five groups: Ctrl, BBR, CI-AKI, CI-AKI + BBR, and CI-AKI + Tasq. The renal function of CI-AKI rats was determined by measuring serum creatinine and blood urea nitrogen. Histopathological changes and apoptosis of renal tubular epithelial cells were observed by HE and terminal deoxynucleotidyl transferase (TdTase)-mediated dUTP-biotin nick end labeling (TUNEL) staining. Transmission electron microscopy was used to observe autophagic structures. In vitro, a CI-AKI cell model was created with ioversol-treated HK-2 cells. Treatments included BBR, Rapa, HCQ, and Tasq. Analyses focused on proteins and genes associated with kidney injury, apoptosis, autophagy, and the HDAC4-FoxO3a axis. BBR showed significant protective effects against CI-AKI both in vivo and in vitro. It inhibited apoptosis by increasing Bcl-2 protein levels and decreasing Bax levels. BBR also activated autophagy, as indicated by changes in autophagy-related proteins and autophagic flux. The study further revealed that the contrast agent ioversol increased the expression of HDAC4, which led to elevated levels of phosphorylated FoxO3a (p-FoxO3a) and acetylated FoxO3a (Ac-FoxO3a). However, BBR inhibited HDAC4 expression, resulting in decreased levels of p-FoxO3a and Ac-FoxO3a. This activation of autophagy-related genes, regulated by the transcription factor FoxO3a, played a role in BBR's protective effects. BBR, a traditional Chinese medicine, shows promise against CI-AKI. It may counteract CI-AKI by modulating HDAC4 and FoxO3a, enhancing autophagy, and limiting apoptosis.

Antibody-Conjugated Magnetic Nanoparticle Therapy for Inhibiting T-Cell Mediated Inflammation

Tolerance induction is critical for mitigating T cell-mediated inflammation. Treatments based on anti-CD3 monoclonal antibody (mAb) play a pivotal role in inducing such tolerance. Anti-CD3 mAb conjugated with dextran-coated magnetic nanoparticles (MNPs) may induce inflammatory tolerance is posited. MNPs conjugated with anti-CD3 mAb (Ab-MNPs) are characterized using transmission and scanning electron microscopy, and their distribution is assessed using a nanoparticle tracking analyzer. Compared to MNPs, 90% of Ab-MNPs increased in size from 54.7 ± 0.5 to 71.7 ± 2.7 nm. The in vitro and in vivo studies confirmed the therapeutic material as nontoxic and biocompatible. Mice are administered various dosages of Ab-MNPs before receiving concanavalin-A (ConA), an inflammation inducer. Preadministration of Ab-MNPs, as opposed to MNPs or anti-CD3 mAb alone, significantly reduced the serum levels of interferon-γ and interleukin-6 in ConA-treated mice. Additionally, the transdermal stamp patch as an effective delivery system for Ab-MNPs is validated. This study demonstrates the utility of the Ab-MNP complex in pathologies associated with T cell-mediated hyperinflammation, such as organ transplantation and COVID-19.

Hirudin inhibit the formation of NLRP3 inflammasome in cardiomyocytes via suppressing oxidative stress and activating mitophagy

Context

Cardiomyocyte hypertrophy due to hemodynamic overload eventually leads to heart failure. Hirudin has been widely used in the treatment of cardiovascular diseases and NLRP3 inflammasome was proven to induce cardiomyocyte pyroptosis. However, the mechanism by which it inhibits cardiomyocyte hypertrophy remains unclear.

Objective

To explore the mechanism of hirudin inhibiting cardiomyocyte hypertrophy based on NLRP3 inflammasome activation and mitophagy.

Materials & methods

1 μM AngII was used for cardiac hypertrophy modeling in H9C2 cells, and cell viability was quantified by CCK-8 assay to screen the appropriate action concentrations of hirudin. After that, we cultured AngII induced-H9C2 cells for 24 h with 0, 0.3, 0.6, and 1.2 mM hirudin, respectively. Next, we marked H9C2 cells with phalloidine and observed them using fluorescence microscope. IL-1β, IL-18, IL-6, TNF-α, ANP, BNP, β-MHC, and mtDNA were analyzed by qRT-PCR; ROS were quantified by Flow cytometry; SOD, MDA, and GSH-Px were detected by ELISA; and proteins including NLRP3, ASC, caspase-1, pro-caspase-1, IL-1β, IL-18, PINK-1, Parkin, beclin-1, LC3-Ⅰ, LC3-Ⅱ, p62, were quantified by western blotting.

Results

It was discovered that hirudin reduced the superficial area of AngII-induced H9C2 cells and inhibited the AngII-induced up-regulation of ANP, BNP, and β-MHC. Besides, hirudin down-regulated the expressions of NLRP3 inflammasome-related cytokines, containing IL-1β, IL-18, IL-6, TNF-α. It also down-regulated the expression of mtDNA and ROS, decreased the expression levels of NLRP3 inflammasome activation related proteins, including NLRP3, ASC, caspase-1, pro-caspase-1, IL-1β, IL-18; and increased the expressions of PINK-1, Parkin, beclin-1, LC3-Ⅱ/LC3-Ⅰ, p62 in AngII-induced H9C2 cells.

Discussion

Hirudin promoted the process of mitophagy, inhibited the development of inflammation and oxidative stress, and inhibited the activation of the NLRP3 inflammasome and the PINK-1/Parkin pathway.

Conclusion

Hirudin has the activity to suppress cardiac hypertrophy may benefit from the inhibition of NLRP3 inflammasome and activating of PINK-1/Parkin related-mitophagy.

Berberine Induces Mitophagy through Adenosine Monophosphate-Activated Protein Kinase and Ameliorates Mitochondrial Dysfunction in PINK1 Knockout Mouse Embryonic Fibroblasts

Mitophagy stimulation has been shown to have a therapeutic effect on various neurodegenerative diseases. However, nontoxic mitophagy inducers are still very limited. In this study, we found that the natural alkaloid berberine exhibited mitophagy stimulation activity in various human cells. Berberine did not interfere with mitochondrial function, unlike the well-known mitophagy inducer carbonyl cyanide m-chlorophenyl hydrazone (CCCP), and subsequently induced mitochondrial biogenesis. Berberine treatment induced the activation of adenosine monophosphate-activated protein kinase (AMPK), and the AMPK inhibitor compound C abolished berberine-induced mitophagy, suggesting that AMPK activation is essential for berberine-induced mitophagy. Notably, berberine treatment reversed mitochondrial dysfunction in PINK1 knockout mouse embryonic fibroblasts. Our results suggest that berberine is a mitophagy-specific inducer and can be used as a therapeutic treatment for neurodegenerative diseases, including Parkinson's disease, and that natural alkaloids are potential sources of mitophagy inducers.

Review of PINK1-Parkin-mediated mitochondrial autophagy in Alzheimer's disease

Mitochondrial autophagy plays an important role in maintaining the complexity of mitochondrial functions and removing damaged mitochondria, of which the PINK1-Parkin signal pathway is one of the most classical pathways. Thus, a comprehensive and in-depth interpretation of the PINK1-Parkin signal pathway might deepen our understanding on the impacts of mitochondrial autophagy. Alzheimer's disease (AD) is a classical example of neurodegenerative disease. Research on the pathogenesis and treatments of AD has been a focus of scientific research because of its complexity and the limitations of current drug therapies. It was reported that the pathogenesis of AD might be related to mitochondrial autophagy due to excessive deposition of Aβ protein and aggravation of the phosphorylation of Tau protein. Two key proteins in the PINK1-Parkin signaling pathway, PINK1 and Parkin, have important roles in the folding and accumulation of Aβ protein and the phosphorylation of Tau protein. In addition, the intermediate signal molecules in the PINK1-Parkin signal pathway also have certain effects on AD. In this paper, we first described the role of PINK1-Parkin signal pathway on mitochondrial autophagy, then discussed and analyzed the effect of the PINK1-Parkin signal pathway in AD and other metabolic diseases. Our aim was to provide a theoretical direction to further elucidate the pathogenesis of AD and highlight the key molecules related to AD that could be important targets used for AD drug development.

Chemical mitophagy modulators: Drug development strategies and novel regulatory mechanisms

Maintaining mitochondrial homeostasis is a potential therapeutic strategy for various diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic disorders, and cancer. Selective degradation of mitochondria by autophagy (mitophagy) is a fundamental mitochondrial quality control mechanism conserved from yeast to humans. Indeed, small-molecule modulators of mitophagy are valuable pharmaceutical tools that can be used to dissect complex biological processes and turn them into potential drugs. In the past few years, pharmacological regulation of mitophagy has shown promising therapeutic efficacy in various disease models. However, with the increasing number of chemical mitophagy modulator studies, frequent methodological flaws can be observed, leading some studies to draw unreliable or misleading conclusions. This review attempts (a) to summarize the molecular mechanisms of mitophagy; (b) to propose a Mitophagy Modulator Characterization System (MMCS); (c) to perform a comprehensive analysis of methods used to characterize mitophagy modulators, covering publications over the past 20 years; (d) to provide novel targets for pharmacological intervention of mitophagy. We believe this review will provide a panorama of current research on chemical mitophagy modulators and promote the development of safe and robust mitophagy modulators with therapeutic potential by introducing high methodological standards.

Berberine Rescues D-Ribose-Induced Alzheimer's Pathology via Promoting Mitophagy

Mitochondrial dysfunction is considered an early event of Alzheimer disease (AD). D-ribose is a natural monosaccharide that exists in cells, especially in mitochondria, and can lead to cognitive dysfunction. However, the reason for this is unclear. Berberine (BBR) is an isoquinoline alkaloid that can target mitochondria and has great prospect in the treatment of AD. The methylation of PINK1 reinforces the burden of Alzheimer's pathology. This study explores the role of BBR and D-ribose in the mitophagy and cognitive function of AD related to DNA methylation. APP/PS1 mice and N2a cells were treated with D-ribose, BBR, and mitophagy inhibitor Mdivi-1 to observe their effects on mitochondrial morphology, mitophagy, neuron histology, AD pathology, animal behavior, and PINK1 methylation. The results showed that D-ribose induced mitochondrial dysfunction, mitophagy damage, and cognitive impairment. However, BBR inhibition of PINK1 promoter methylation can reverse the above effects caused by D-ribose, improve mitochondrial function, and restore mitophagy through the PINK1-Parkin pathway, thus reducing cognitive deficits and the burden of AD pathology. This experiment puts a new light on the mechanism of action of D-ribose in cognitive impairment and reveals new insights in the use of BBR for AD treatment.

Mitochondria ROS and mitophagy in acute kidney injury

Mitophagy is an essential mitochondrial quality control mechanism that eliminates damaged mitochondria and the production of reactive oxygen species (ROS). The relationship between mitochondria oxidative stress, ROS production and mitophagy are intimately interwoven, and these processes are all involved in various pathological conditions of acute kidney injury (AKI). The elimination of damaged mitochondria through mitophagy in mammals is a complicated process which involves several pathways. Furthermore, the interplay between mitophagy and different types of cell death, such as apoptosis, pyroptosis and ferroptosis in kidney injury is unclear. Here we will review recent advances in our understanding of the relationship between ROS and mitophagy, the different mitophagy pathways, the relationship between mitophagy and cell death, and the relevance of these processes in the pathogenesis of AKI.Abbreviations: AKI: acute kidney injury; AMBRA1: autophagy and beclin 1 regulator 1; ATP: adenosine triphosphate; BAK1: BCL2 antagonist/killer 1; BAX: BCL2 associated X, apoptosis regulator; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; BH3: BCL2 homology domain 3; BNIP3: BCL2 interacting protein 3; BNIP3L/NIX: BCL2 interacting protein 3 like; CASP1: caspase 1; CAT: catalase; CCCP: carbonyl cyanide m-chlorophenylhydrazone; CI-AKI: contrast-induced acute kidney injury; CISD1: CDGSH iron sulfur domain 1; CL: cardiolipin; CNP: 2',3'-cyclic nucleotide 3'-phosphodiesterase; DNM1L/DRP1: dynamin 1 like; E3: enzyme 3; ETC: electron transport chain; FA: folic acid; FUNDC1: FUN14 domain containing 1; G3P: glycerol-3-phosphate; G6PD: glucose-6-phosphate dehydrogenase; GPX: glutathione peroxidase; GSH: glutathione; GSK3B: glycogen synthase kinase 3 beta; GSR: glutathione-disulfide reductase; HIF1A: hypoxia inducible factor 1 subunit alpha; HUWE1: HECT, UBA and WWE domain containing 1; IL1B: interleukin 1 beta; IMM: inner mitochondrial membrane; IPC: ischemic preconditioning; IRI: ischemia-reperfusion injury; LIR: LC3-interacting region; LPS: lipopolysaccharide; MA: malate-aspartate; MPT: mitochondrial permeability transition; MUL1: mitochondrial E3 ubiquitin protein ligase 1; mtROS: mitochondrial ROS; NLR: NOD-like receptor; NLRP3: NLR family pyrin domain containing 3; NOX: NADPH oxidase; OGD-R: oxygen-glucose deprivation-reperfusion; OMM: outer mitochondrial membrane; OPA1: OPA1 mitochondrial dynamin like GTPase; OXPHOS: oxidative phosphorylation; PARL: presenilin associated rhomboid like; PINK1: PTEN induced kinase 1; PLSCR3: phospholipid scramblase 3; PMP: peptidase, mitochondrial processing; PRDX: peroxiredoxin; PRKN: parkin RBR E3 ubiquitin protein ligase; RPTC: rat proximal tubular cells; ROS: reactive oxygen species; SLC7A11/xCT: solute carrier family 7 member 11; SOD: superoxide dismutase; SOR: superoxide reductase; SQSTM1/p62: sequestosome 1; TCA: tricarboxylic acid; TIMM: translocase of inner mitochondrial membrane; TOMM: translocase of outer mitochondrial membrane; TXN: thioredoxin; VDAC: voltage dependent anion channel; VCP: valosin containing protein.

Autophagy and necroptosis in cisplatin-induced acute kidney injury: Recent advances regarding their role and therapeutic potential

Cisplatin (CP) is a broad-spectrum antineoplastic agent, used to treat many different types of malignancies due to its high efficacy and low cost. However, its use is largely limited by acute kidney injury (AKI), which, if left untreated, may progress to cause irreversible chronic renal dysfunction. Despite substantial research, the exact mechanisms of CP-induced AKI are still so far unclear and effective therapies are lacking and desperately needed. In recent years, necroptosis, a novel subtype of regulated necrosis, and autophagy, a form of homeostatic housekeeping mechanism have witnessed a burgeoning interest owing to their potential to regulate and alleviate CP-induced AKI. In this review, we elucidate in detail the molecular mechanisms and potential roles of both autophagy and necroptosis in CP-induced AKI. We also explore the potential of targeting these pathways to overcome CP-induced AKI according to recent advances.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Berberine in Sepsis: Effects, Mechanisms, and Therapeutic Strategies

Sepsis is defined as a dysregulated immune response to infection that leads to multiple organ dysfunction. To date, though a growing body of knowledge has gained insight into the clinical risk factors, pathobiology, treatment response, and recovery methods, sepsis remains a significant concern and clinical burden. Therefore, further study is urgently needed to alleviate the acute and chronic outcomes. Berberine (BBR), a traditional Chinese medicine with multiple actions and mechanisms, has been investigated in cellular and rodent animal models of sepsis mainly based on its anti-inflammatory effect. However, the practical application of BBR in sepsis is still lacking, and it is imperative to systematically summarize the study of BBR in sepsis. This review summarized its pharmacological activities and mechanisms in septic-related organ injuries and the potential BBR-based therapeutic strategies for sepsis, which will provide comprehensive references for scientific research and clinical application.

Resveratrol alleviates lipopolysaccharide-induced liver injury by inducing SIRT1/P62-mediated mitophagy in gibel carp (Carassius gibelio)

Introduction

Resveratrol (RES) is a polyphenol organic compound with antioxidant and anti-inflammatory properties. This study aimed to determine whether and how RES can alleviate liver injury in lipopolysaccharide (LPS)-induced gibel carp.

Methods

Gibel carp were fed a diet with or without RES and were cultured for 8 weeks, followed by LPS injection.

Results and discussion

The results suggested that RES attenuated the resulting oxidative stress and inflammation by activating the Nrf2/Keap1 pathway and inhibiting the NF-κB pathway, as confirmed by changes in oxidative stress, inflammation-related gene expression, and antioxidant enzyme activity. Furthermore, RES cleared damaged mitochondria and enhanced mitochondrial biogenesis to mitigate reactive oxygen species (ROS) accumulation by upregulating the SIRT1/PGC-1α and PINK1/Parkin pathways and reducing p62 expression. Overall, RES alleviated LPS-induced oxidative stress and inflammation in gibel carp through mitochondria-related mechanisms.

The relationship between HMGB1 and autophagy in the pathogenesis of diabetes and its complications

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels and has become the third leading threat to human health after cancer and cardiovascular disease. Recent studies have shown that autophagy is closely associated with diabetes. Under normal physiological conditions, autophagy promotes cellular homeostasis, reduces damage to healthy tissues and has bidirectional effects on regulating diabetes. However, under pathological conditions, unregulated autophagy activation leads to cell death and may contribute to the progression of diabetes. Therefore, restoring normal autophagy may be a key strategy to treat diabetes. High-mobility group box 1 protein (HMGB1) is a chromatin protein that is mainly present in the nucleus and can be actively secreted or passively released from necrotic, apoptotic, and inflammatory cells. HMGB1 can induce autophagy by activating various pathways. Studies have shown that HMGB1 plays an important role in insulin resistance and diabetes. In this review, we will introduce the biological and structural characteristics of HMGB1 and summarize the existing knowledge on the relationship between HMGB1, autophagy, diabetes, and diabetic complications. We will also summarize potential therapeutic strategies that may be useful for the prevention and treatment of diabetes and its complications.

PTEN-induced kinase 1 enhances the reparative effects of bone marrow mesenchymal stromal cells on mice with renal ischaemia/reperfusion-induced acute kidney injury

Acute kidney injury (AKI) is a common severe acute syndrome caused by multiple factors and is characterized by a rapid decline in renal function during a short period. Bone marrow mesenchymal stromal cells (BMSCs) are effective in treating AKI. However, the mechanism of their beneficial effects remains unclear. PTEN-induced kinase 1 (PINK1) may play an important role in kidney tissue repair. In this study, we explored the effect of PINK1 overexpression on enhancing BMSC-mediated repair of AKI. In this study, ischaemia/reperfusion-induced AKI (IRI-AKI) in mice and a hypoxia-reoxygenation model in cells were established, and the indices were examined by pathology and immunology experiments. After ischaemia/reperfusion, PINK1 overexpression reduced apoptosis in injured kidney tissue cell, decreased T lymphocyte infiltration, increased macrophage infiltration, and alleviated the inflammatory response. PINK1 relieved the stress response of BMSCs and renal tubular epithelial cells (RTECs), reduced apoptosis, altered the release of inflammatory factors, and reduced the proliferation of peripheral blood mononuclear cells (PBMCs). In conclusion, BMSCs and RTECs undergo stress responses in response to hypoxia, inflammation and other conditions, and overexpressing PINK1 in BMSCs could enhance their ability to resist these stress reactions. Furthermore, PINK1 overexpression can regulate the distribution of immune cells and improve the inflammatory response. The regulation of mitochondrial autophagy during IRI-AKI maintains mitochondrial homeostasis and protects renal function. The results of this study provide new strategies and experimental evidence for BMSC-mediated repair of IRI-AKI.

Cisplatin-Induced Kidney Toxicity: Potential Roles of Major NAD+-Dependent Enzymes and Plant-Derived Natural Products

Cisplatin is an FDA approved anti-cancer drug that is widely used for the treatment of a variety of solid tumors. However, the severe adverse effects of cisplatin, particularly kidney toxicity, restrict its clinical and medication applications. The major mechanisms of cisplatin-induced renal toxicity involve oxidative stress, inflammation, and renal fibrosis, which are covered in this short review. In particular, we review the underlying mechanisms of cisplatin kidney injury in the context of NAD⁺-dependent redox enzymes including mitochondrial complex I, NAD kinase, CD38, sirtuins, poly-ADP ribosylase polymerase, and nicotinamide nucleotide transhydrogenase (NNT) and their potential contributing roles in the amelioration of cisplatin-induced kidney injury conferred by natural products derived from plants. We also cover general procedures used to create animal models of cisplatin-induced kidney injury involving mice and rats. We highlight the fact that more studies will be needed to dissect the role of each NAD⁺-dependent redox enzyme and its involvement in modulating cisplatin-induced kidney injury, in conjunction with intensive research in NAD⁺ redox biology and the protective effects of natural products against cisplatin-induced kidney injury.

Prediction of the mechanisms of action of Zhibai Dihaung Granule in cisplatin-induced acute kidney injury: A network pharmacology study and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Zhibai Dihuang Granule (ZDG) is known as traditional Chinese patent medicine with the functions of "Ziyin decrease internal heat" in Traditional Chinses medicine. In clinical, it is also used to treat various kidney diseases.

AIM OF THE STUDY

We aimed to provide a basis for the curative effect of ZDG on acute kidney injury induced by cisplatin (CIAKI).

MATERIALS AND METHODS

The active compounds and protein targets of ZDG, as well as the potential targets of the CIAKI were searched from the database. The protein-protein interaction (PPI) network diagram and the drug-compounds-targets-disease network were constructed. Enrichment analysis was performed by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, the effect of ZDG on the prevention and treatment of CIAKI was experimentally validated in vivo and in vitro.

RESULTS

From the database, we screened 22 active compounds of ZDG and 226 related targets. We obtained 498 gene targets related to CIAKI, among which 40 genes overlapped with ZDG-related targets. Go enrichment and KEGG analysis got 339 terms and 64 pathways, respectively. Based on the above study, we speculated that ZDG has the potential effect on treatment CIAKI, and the mechanism may be related to cell apoptosis and inflammation. The results in vitro experiments showed that ZDG reduced the cytotoxicity of cisplatin to HK-2 and 293T cells, but did not affect the antitumor effect of cisplatin. Moreover, in vivo experiments further proved that ZDG effectively controlled kidney damage caused by cisplatin in SD rats. The results showed that ZDG could regulate the expression of CASP3, p65 and MAPK pathway related proteins, suggesting that ZDG's prevention of CIAKI may be related to apoptosis and inflammatory response.

CONCLUSIONS

Our study showed that ZDG could prevent and treat CIAKI by inhibiting cell apoptosis and inflammation, which provided a new efficacy and clinical application for ZDG.

Transition of acute kidney injury to chronic kidney disease: role of metabolic reprogramming

Acute kidney injury (AKI) is a global public health concern associated with high morbidity and mortality. Although advances in medical management have improved the in-hospital mortality of severe AKI patients, the renal prognosis for AKI patients in the later period is not encouraging. Recent epidemiological investigations have indicated that AKI significantly increases the risk for the development of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the future, further contributing to the economic burden on health care systems. The transition of AKI to CKD is complex and often involves multiple mechanisms. Recent studies have suggested that renal tubular epithelial cells (TECs) are more prone to metabolic reprogramming during AKI, in which the metabolic process in the TECs shifts from fatty acid β-oxidation (FAO) to glycolysis due to hypoxia, mitochondrial dysfunction, and disordered nutrient-sensing pathways. This change is a double-edged role. On the one hand, enhanced glycolysis acts as a compensation pathway for ATP production; on the other hand, long-term shut down of FAO and enhanced glycolysis lead to inflammation, lipid accumulation, and fibrosis, contributing to the transition of AKI to CKD. This review discusses developments and therapies focused on the metabolic reprogramming of TECs during AKI, and the emerging questions in this evolving field.

Several Alkaloids in Chinese Herbal Medicine Exert Protection in Acute Kidney Injury: Focus on Mechanism and Target Analysis

Objectives

Acute kidney injury (AKI) is a loose set of kidney diseases accompanied by a variety of syndromes, which is a serious threat to human life and health. Some alkaloids are derived from various Chinese herbs have been widely concerned in the improvement of AKI. This review provides the research progress of alkaloids in AKI experimental models and discusses the related molecular mechanisms. Key Findings. Alkaloids can protect AKI through various mechanisms including antioxidant stress, improvement of mitochondrial damage, reduction of cell death, induction of autophagy, and inhibition of inflammation. These mechanisms are mainly related to the activation of Nrf2/HO-1 signaling pathway, inhibition of ferroptosis and apoptosis, regulation of PINK1/Parkin pathway, inhibition of TLR4/NF-κB pathway and NLRP3 inflammatory bodies, upregulation of Klotho protein level and so on. In addition, there are a few alkaloids that have certain toxicity on the kidney.

Conclusion

Alkaloids have been shown to significantly improve AKI, but only in pharmacological studies. This paper summarizes the main experimental models currently used in AKI research and describes some representative alkaloids based on recent research. Their potential roles in the prevention and treatment of AKI through different mechanisms are highlighted.

PINK1/Parkin-mediated mitophagy is activated to protect against AFB1-induced kidney damage in mice

Aflatoxin B₁ (AFB₁) is a toxic food pollutant that has extensive deleterious impacts on the kidney. Oxidative stress represents the primary mechanism of AFB₁ nephrotoxicity and can also cause mitochondrial damage. Damaged mitochondria can trigger apoptosis leading to kidney injury. PINK1/Parkin-mediated mitophagy can alleviate mitochondrial injury to maintain cellular homeostasis, however, its role in AFB₁-induced kidney damage is unknown. To investigate the effect of PINK1/Parkin-mediated mitophagy on kidney impairment triggered by AFB₁, 40 male wild-type (WT) C57BL/6N mice were first assigned to 4 groups and orally exposed to AFB₁ at 0, 0.5, 0.75, and 1 mg/kg body weight (BW) for 28 days. The results revealed that AFB₁ induced kidney damage, oxidative stress, mitochondrial damage, apoptosis and activated PINK1/Parkin-mediated mitophagy with a dose-dependent effect. Then, 20 male WT C57BL/6N mice and 20 male Parkin knockout (Parkin^-/-) C57BL/6N mice were assigned to 4 groups and orally exposed to AFB₁ at 0, 1, 0, and 1 mg/kg BW for 28 days. The results revealed that Parkin^-/- suppressed mitophagy and exacerbated kidney damage, oxidative stress, mitochondrial damage, and apoptosis under AFB₁ exposure. The aforementioned evidences demonstrate that PINK1/Parkin-mediated mitophagy is activated by AFB₁ and protects against kidney damage in mice.

Protective Effect of Gamma Aminobutyric Acid against Aggravation of Renal Injury Caused by High Salt Intake in Cisplatin-Induced Nephrotoxicity

Gamma-aminobutyric acid (GABA) is one of the inhibitory neurotransmitters. Several studies have suggested that GABA supplements can reduce blood pressure and modulate the renal immune system in vitro and in vivo. In the present study, we investigated the effect of GABA-enriched salt as an alternative to traditional salt on aggravated renal injury by high salt intake in cisplatin-induced nephrotoxicity mice. High salt intake accelerated the increase of biomarkers, such as blood urea nitrogen and serum creatinine levels for renal injury in cisplatin-induced nephrotoxicity mice. However, oral administration of GABA-contained salt notably suppressed serum BUN and creatinine levels. The efficacy of GABA salt was superior to lacto GABA salt and postbiotics GABA salt. Furthermore, GABA-enriched salt markedly restored histological symptoms of nephrotoxicity including renal hypertrophy, tubular dilation, hemorrhage, and collagen deposition aggravated by salt over-loading in cisplatin-exposed mice. Among them, GABA salt showed a higher protective effect against cisplatin-induced renal histological changes than lacto GABA salt and postbiotics GABA salt. In addition, administration of high salt significantly enhanced expression levels of apoptosis and inflammatory mediators in cisplatin-induced nephrotoxicity mice, while GABA-enriched salt greatly down-regulated the expression of these mediators. Taken together, these results demonstrate the protective effect of GABA against damage caused by high salt intake in cisplatin-induced renal toxicity. Its mechanism may be due to the suppression of hematological and biochemical toxicity, apoptosis, and inflammation. In conclusion, although the protective efficacy of GABA salt on renal injury is different depending on the sterilization and filtration process after fermentation with L. brevis BJ20 and L. plantarum BJ21, our findings suggest that GABA-enriched salt has a beneficial effect against immoderate high salt intake-mediated kidney injury in patients with cisplatin-induced nephrotoxicity.

Mitophagy in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common cause of end-stage kidney disease worldwide and is the main microvascular complication of diabetes. The increasing prevalence of diabetes has increased the need for effective treatment of DKD and identification of new therapeutic targets for better clinical management. Mitophagy is a highly conserved process that selectively removes damaged or unnecessary mitochondria via the autophagic machinery. Given the important role of mitophagy in the increased risk of DKD, especially with the recent surge in COVID-19-associated diabetic complications, in this review, we provide compelling evidence for maintaining homeostasis in the glomeruli and tubules and its underlying mechanisms, and offer new insights into potential therapeutic approaches for treatment of DKD.

Silencing Long Non-coding RNA Kcnq1ot1 Limits Acute Kidney Injury by Promoting miR-204-5p and Blocking the Activation of NLRP3 Inflammasome

Acute kidney injury (AKI) is a critical clinical disease characterized by an acute decrease in renal function. Long non-coding RNAs (LncRNAs) are important in AKI. This study aimed to explore the mechanism of lncRNA Kcnq1ot1 in AKI by sponging microRNA (miR)-204-5p as a competitive endogenous RNA (ceRNA). AKI mouse model and hypoxia/reoxygenation (H/R) model of human kidney (HK) cells were established. Kcnq1ot1 expression, cell proliferation, and apoptosis were measured. Binding relations among Kcnq1ot1, miR-204-5p, and NLRP3 were verified. Pathological changes and cell apoptosis were detected. The results showed that Kcnq1ot1 was highly expressed in the AKI model in vivo and in vitro. Kcnq1ot1 knockdown promoted cell proliferation and prevented apoptosis and inflammation. Furthermore, Kcnq1ot1 inhibited miR-204-5p expression by competitively binding to miR-204-5p in HK-2 cells. miR-204-5p targeted NLRP3 and NLRP3 overexpression averted the inhibiting effect of miR-204-5p on apoptosis and inflammation in HK-2 cells in vitro. Kcnq1ot1 knockdown in vivo promoted miR-204-5p expression, inhibited NLRP3 inflammasome activation, reduced levels of SCr, BUN, and KIM-1, and thus alleviated AKI and reduced apoptosis. In summary, silencing lncRNA Kcnq1ot1 inhibited AKI by promoting miR-204-5p and inhibiting NLRP3 inflammasome activation.

Protective effect of mitophagy against aluminum-induced MC3T3-E1 cells dysfunction

Aluminum (Al) is a ubiquitous environmental metal toxicant that causes osteoblast (OB) damage which leads to Al-related bone diseases. Mitochondrial damage plays a key role in Al-related bone diseases, and while mitophagy can clear damaged mitochondria and improve OB function, the relationship between mitophagy and Al-induced OB dysfunction is unknown. To explore the role of mitophagy in Al-induced OB dysfunction in vitro, we used 2 μM carbonyl cyanide m-chlorophenylhydrazone (CCCP) and 0.4 μM Cyclosporin A (CsA) to activate and inhibit mitophagy, respectively. MC3T3-E1 cells were treated with 0 mM AlCl₃ (control group); 2 mM AlCl₃ (Al group); 2 μM CCCP (CCCP group); 2 μM CCCP and 2 mM AlCl₃ (CCCP + Al group); 0.4 μM CsA (CsA group); 0.4 μM CsA and 2 mM AlCl₃ (CsA + Al group). The results showed that Al induced ultrastructural and functional impairment of MC3T3-E1 cells. Compared to the Al group, mitophagy activation caused mitochondrial membrane potentials to collapse, up-regulated PINK1, Parkin, and LC3 expression, down-regulated p62 expression, and increased mitophagosome numbers. Mitophagy activation also reduced Al-induced oxidative stress and MC3T3-E1 cell functional damage, as seen in improvement in cell viability, cellular calcium and phosphorus contents, and collagen I, osteocalcin, and bone alkaline phosphatase gene expression. Mitophagy inhibition had the opposite effects on activation. Overall, these results show that mitophagy can protect against Al-induced OB dysfunction.

Levosimendan in rats decreases acute kidney injury after cardiopulmonary resuscitation by improving mitochondrial dysfunction

Background

Acute kidney injury (AKI), the most common complication after cardiac resuscitation, is highly prevalent and harmful. There is increasing evidence that levosimendan can improve cardiac output, increase renal blood flow, and prevent AKI. As a novel calcium sensitizer, levosimendan may exert its protective effect via mitochondria.

Methods

Rat models of asphyxia-induced cardiac arrest and cardiopulmonary resuscitation (CPR) were set up. Thirty healthy adult male SD rats were randomly divided into CPR group (CPR group, n=10), levosimendan-treated group (levo group, n=10), and sham-operated group (sham group, n=10). Twelve hours after CPR, serum renal function indicators were measured, the kidney injury and mitochondrial morphological changes were observed. Oxygen uptake of the mitochondria, mitochondrial adenosine triphosphate (ATP) and mitochondrial free Ca²⁺ concentration were measured. Oxidative stress-related indicator levels in rat kidney tissues were further detected to analyze the differences in apoptosis rates among these three groups. Mitochondrial optic atrophy 1 (Opa1), dynamin-related protein 1 (Drp1), and apoptosis-related proteins were detected using Western blotting.

Results

Compared with the sham group, the CPR group had a significant increase in renal tissue damage. PAS staining and HE stains confirmed that CPR led to renal histopathological damage and destruction of the mitochondrial structure. Levosimendan improved the histopathological and ultrastructural damages of kidneys. Further analysis revealed that mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (CSH-Px) decreased. Free Ca²⁺ concentration and malondialdehyde (MDA) significantly increased (all P<0.05) in the kidney tissues of rats in the CPR group. However, mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, SOD, CAT, and CSH-Px increased, whereas free Ca²⁺ concentration and MDA decreased (all P<0.05) in the levo group. The apoptosis rate increased in the CPR group. There were significantly increased levels of Drp1 protein levels, and significantly decreased Opa1 expression (all P<0.05). However, the levo group showed the opposite effects (all P<0.05).

Conclusions

Levosimendan can alleviate AKI following CPR, which may be achieved by improving mitochondrial dysfunction and suppressing the mitochondrial apoptosis pathway.

Arsenic or/and antimony induced mitophagy and apoptosis associated with metabolic abnormalities and oxidative stress in the liver of mice

Arsenic and antimony are coexisting cumulative environmental pollutants that cause severe and extensive biological toxicity. However, their interactions and toxic mechanisms in the liver remain to be fully elucidated. In this study, a total of sixty 4-week-old mice were divided into four groups and treated with 4 mg/kg arsenic trioxide (ATO) or/and 15 mg/kg antimony (Sb) for 60 days. The results demonstrated that biochemical indicators of hepatotoxicity (ALT, AST, ALP) were upregulated in all treated groups. Additionally, the oxidative burden of the liver was increased in the cotreated groups compared with the individual toxicant-treated groups. Meanwhile, mitochondrial injury, autophagosomes, hepatic-congestion and karyopyknosis were obviously observed in cotreated groups. Additionally, coupled with serum biochemical index (TG, TC), histopathology examination and metabolomics results, we found that cotreatment with ATO and Sb resulted in lipid metabolism disorder and steatosis of liver tissues. Our further investigation found that the levels of pro-apoptotic (Caspase-3, Caspase-9, Bax, P53, Cytc) and mitophagy (LC3-B, P62, PINK1, Parkin) indexes in the cotreated groups were markedly increased, whereas the levels of anti-apoptosis index (Bcl-2) were decreased. Collectively, these results show that co-exposure to ATO and Sb can cause abnormal liver energy metabolism and oxidative stress. Moreover, mitophagy and apoptosis play important roles in the mechanisms of arsenic/antimony cytotoxicity to mouse livers.

Immunomodulatory Effects of Mesenchymal Stem Cells on Drug-Induced Acute Kidney Injury

Drug-induced nephrotoxicity is an important and increasing cause of acute kidney injury (AKI), which accounts for approximately 20% of hospitalized patients. Previous reviews studies on immunity and AKI focused mainly on ischemia-reperfusion (IR), whereas no systematic review addressing drug-induced AKI and its related immune mechanisms is available. Recent studies have provided a deeper understanding on the mechanisms of drug-induced AKI, among which acute tubular interstitial injury induced by the breakdown of innate immunity was reported to play an important role. Emerging research on mesenchymal stem cell (MSC) therapy has revealed its potential as treatment for drug-induced AKI. MSCs can inhibit kidney damage by regulating the innate immune balance, promoting kidney repair, and preventing kidney fibrosis. However, it is important to note that there are various sources of MSCs, which impacts on the immunomodulatory ability of the cells. This review aims to address the immune pathogenesis of drug-induced AKI versus that of IR-induced AKI, and to explore the immunomodulatory effects and therapeutic potential of MSCs for drug-induced AKI.

DUSP1 overexpression attenuates renal tubular mitochondrial dysfunction by restoring Parkin-mediated mitophagy in diabetic nephropathy

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease, and renal tubular cell dysfunction contributes to the pathogenesis of many kidney diseases. Our previous study demonstrated that dual-specificity protein phosphatase 1 (DUSP1) reduced hyperglycemia-mediated mitochondrial damage; however, its role in hyperglycemia-driven dysfunction of tubular cells is still not fully understood. In this study, we found that DUSP1 is reduced in human proximal tubular epithelial (HK-2) cells under high-glucose conditions. DUSP1 overexpression in HK-2 cells partially restored autophagic flux, improved mitochondrial function, and reduced reactive oxygen species generation and cell apoptosis under high-glucose conditions. Surprisingly, overexpressing DUSP1 abolished the decrease in mitochondrial parkin expression caused by high-glucose stimulation. In addition, knockdown of parkin in HK-2 cells reversed the effects of DUSP1 overexpression on mitophagy and apoptosis under high-glucose conditions. Overall, these data indicate that DUSP1 plays a defensive role in the pathogenesis of DN by restoring parkin-mediated mitophagy, suggesting that it may be considered a prospective therapeutic strategy for the amelioration of DN.