Mitochondrial dysfunction and oxidative stress: Role in chronic kidney disease

Mito-TEMPO Mitigates Fibromyalgia Induced by Reserpine in Rats: Orchestration Between SIRT1, Mitochondrial Dynamics, Endoplasmic Reticulum and miRNA-320

Fibromyalgia (FM) is a chronic disorder that lacks both well-defined underlying causes and effective treatments. Mito-TEMPO (MIT) is a mitochondrial-specific antioxidant that has demonstrated benefits in many cancerous, renal, cardiovascular, and neurodegenerative disorders. However, the therapeutic effect of MIT on FM remains ambiguous. The objective of the current work is to illuminate the use of MIT for FM and its prospective mechanisms. Here, we used the FM rat model induced by three days of subcutaneous reserpine injection (1 mg/kg) and examined the role of MIT on SIRT1 activation and other implicated molecular pathways. Behavioral tests showed that MIT (0.7 mg/kg) can effectively alleviate the locomotor, nociceptive, and depressive-like behaviors in reserpinized rats, an effect that simultaneously reconciles the balance of monoamines in the rat brain. Western blot analysis showed that MIT up-regulates SIRT1 and improves the expression of mitochondrial dynamics proteins (DRP1 and OPA1) and the endoplasmic reticulum protein (CHOP). Furthermore, MIT treatment significantly enhanced the SOD and CAT activities and decreased the brain contents of NF-κB, TNF-α, and BAX, but significantly enriching the Bcl-2 content. Lastly, MIT treatment significantly reduced the genetic expression of miRNA-320 following RES treatment. All the measured parameters showed a significant correlation with SIRT1 expression. Our results suggest that MIT provides antioxidant, anti-apoptotic, and anti-inflammatory impacts on the FM rat model, with proposed mechanisms involved activating the SIRT1 pathway to regulate mitochondrial dynamics, endoplasmic reticulum stress, as well as miRNA-320. Thus, MIT has the potential to be an effectual drug candidate for FM treatment.

The status of studies on the mechanism of microcirculatory dysfunction in the process of diabetic kidney injury

Diabetic nephropathy (DN) is one of the most common and serious microvascular complications of diabetes mellitus (DM) and is the main cause of end-stage renal disease. Endothelial dysfunction caused by persistent hyperglycemia occurs at the initial stage of vascular disease. Moreover, persistent hyperglycemia is also a critical factor causing renal microcirculatory dysfunction. In recent years, many studies have confirmed that chronic hypoxia caused by microcirculatory dysfunction is one of the main mechanisms of kidney injury in patients with DM. Similarly, microcirculatory dysfunction damages renal tissue through interactions with other pathophysiological processes, thereby promoting the occurrence and development of DN. Thus, this article reviews the pathogenesis of renal microcirculatory dysfunction in DM and its interaction with stress, energy metabolism, and immunologic inflammation. Furthermore, a new idea was proposed to analyze the mechanism of kidney injury in DM from the perspective of microcirculatory dysfunction.

Research dynamics and drug treatment of renal fibrosis from a mitochondrial perspective: a historical text data analysis based on bibliometrics

Renal fibrosis (RF) represents a significant public health challenge, necessitating the urgent identification of effective and safe therapeutic agents. Mitochondrial-targeted strategies have demonstrated considerable promise in restoring renal function and mitigating fibrosis. This study aims to examine the evolution of research and therapeutic interventions for RF from a mitochondrial perspective through bibliometric analysis. Literature retrieval was primarily conducted using the Web of Science Core Collection. Visual analysis was performed utilizing the Bibliometrix package (R- 4.4.2), CiteSpace 6.3.R1, and VOSviewer 1.6.19. A total of 819 documents were included for analysis. Significant contributions were made by researchers from China and the USA, with Nanjing Medical University leading in publication volume. Zhang Aihua and Huang Songming emerge as key scholars in the field, while the International Journal of Molecular Sciences is the journal with the highest publication output. Key research themes include oxidative stress, expression, injury, activation, mechanisms, and mitochondrial dysfunction. Mitochondrial-targeted approaches for treating RF can be categorized into six main strategies: mitochondrial biogenesis regulators, mitochondrial dynamics modulators, mitophagy inducers, oxidative stress regulators, NLRP3 inhibitors, and other mitochondrial-targeted therapeutic approaches. This study comprehensively examines the current state of RF research from a mitochondrial standpoint, summarizing key drugs and potential mechanisms of mitochondrial regulation. The findings aim to enhance scholarly understanding of the ongoing research trends and provide valuable insights for the development of targeted therapeutic agents.

Mechanism of Mitophagy to Protect Yak Kidney from Hypoxia-Induced Fibrosis Damage by Regulating Ferroptosis Pathway

Renal fibrosis is a critical pathological feature of various chronic kidney diseases, with hypoxia being recognized as an important factor in inducing fibrosis. Yaks have long inhabited high-altitude hypoxic environments and do not exhibit fibrotic damage under chronic hypoxia. However, the underlying protective mechanisms remain unclear. This study compared the renal tissue structure and collagen volume between low-altitude cattle and high-altitude yaks, revealing that yaks possess a significantly higher number of renal tubules than cattle, though collagen volume showed no significant difference. Under hypoxic treatment, we observed that chronic hypoxia induced renal fibrosis in cattle, but did not show a significant effect in yaks, suggesting that the hypoxia adaptation mechanisms in yaks may have an anti-fibrotic effect. Further investigation demonstrated a significant upregulation of P-AMPK/AMPK, Parkin, PINK1, LC3Ⅱ/Ⅰ, and BECN1, alongside a downregulation of P-mTOR/mTOR in yak kidneys. Additionally, hypoxia-induced renal tubular epithelial cells (RTECs) showed increased expression of mitophagy-related proteins, mitochondrial membrane depolarization, and an increased number of lysosomes, indicating that hypoxia induces mitophagy. By regulating the mitophagy pathway through drugs, we found that under chronic hypoxia, activation of mitophagy upregulated E-cadherin protein expression while downregulating the expression of Vimentin, α-SMA, Collagen I, and Fibronectin. Simultaneously, there was an increase in SLC7A11, GPX4, and GSH levels, and a decrease in ROS, MDA, and Fe2⁺ accumulation. Inhibition of mitophagy produced opposite effects on protein expression and cellular markers. Further studies identified ferroptosis as a key mechanism promoting renal fibrosis. Moreover, in renal fibrosis models, mitophagy reduced the accumulation of ROS, MDA, and Fe2⁺, thereby alleviating ferroptosis-induced renal fibrosis. These findings suggest that chronic hypoxia protects yaks from hypoxia-induced renal fibrosis by activating mitophagy to inhibit the ferroptosis pathway.

Inflammation in glomerular diseases

The structural and functional integrity of glomerular cells is critical for maintaining normal kidney function. Glomerular diseases, which involve chronic histological damage to the kidney, are related to injury to glomerular cells such as endothelial cells, mesangial cells (MCs), and podocytes. When faced with pathogenic conditions, these cells release pro-inflammatory cytokines such as chemokines, inflammatory factors, and adhesion factors. These substances interact with glomerular cells through specific inflammatory pathways, resulting in damage to the structure and function of the glomeruli, ultimately causing glomerular disease. Although the role of inflammation in chronic kidney diseases is well known, the specific molecular pathways that result in glomerular diseases remain largely unclear. For a long time, it has been believed that only immune cells can secrete inflammatory factors. Therefore, targeted therapies against immune cells were considered the first choice for treating inflammation in glomerular disease. However, emerging research indicates that non-immune cells such as glomerular endothelial cells, MCs, and podocytes can also play a role in renal inflammation by releasing inflammatory factors. Similarly, targeted therapies against glomerular cells should be considered. This review aims to uncover glomerular diseases related to inflammation and pathways in glomerular inflammation, and for the first time summarized that non-immune cells in the glomerulus can participate in glomerular inflammatory damage by secreting inflammatory factors, providing valuable references for future strategies to prevent and treat glomerular diseases. More importantly, we emphasized targeted glomerular cell therapy, which may be a key direction for the future treatment of glomerular diseases.

Global research trends on the associations between chronic kidney disease and mitochondria: insights from the bibliometric analysis

BACKGROUND

Chronic kidney disease (CKD) is a global health burden characterized by a progressive and irreversible loss of kidney function. Mitochondrial dysfunction has emerged as a pivotal factor in CKD pathogenesis, contributing to renal cell injury, inflammation, and fibrosis through mechanisms such as oxidative stress and impaired bioenergetics. This study aimed to provide a comprehensive bibliometric analysis of global research trends on the associations between CKD and mitochondria over the past two decades.

METHODS

A bibliometric analysis was conducted using the Web of Science Core Collection database, focusing on publications from 2004 to 2024. Data were analyzed using Citespace and VOSviewer to visualize publication trends, key contributors, keyword co-occurrences, and collaboration networks.

RESULTS

A total of 2,870 publications were identified, with a significant increase in annual output observed after 2010. The United States, China, and Japan were the leading contributors, fostering strong international collaborations. Institutional analysis highlighted the prominent roles of the US Department of Veterans Affairs and the University of California System. Key authors, such as Jose Pedraza-Chaverri and HM Kang, and influential studies addressing mitochondrial quality control and metabolic reprogramming were identified. Keyword analysis revealed major research themes, including oxidative stress, ischemia-reperfusion injury, and fatty acid oxidation, with recent trends emphasizing mitochondrial dynamics and autophagy.

CONCLUSIONS

This analysis underscored the growing recognition of mitochondrial dysfunction in CKD pathogenesis and highlighted the interdisciplinary nature of this field. The findings revealed key research trends, influential contributors, and emerging topics, providing a foundation for future studies and the development of targeted mitochondrial therapies. These insights hold promise for advancing the understanding and treatment of CKD through precision medicine approaches. Specifically, therapeutic strategies aimed at enhancing mitochondrial biogenesis, promoting mitophagy, and restoring metabolic balance may offer novel avenues for delaying CKD progression and mitigating renal dysfunction. Integrating these mitochondrial-targeted interventions into current clinical practice could improve patient outcomes and guide the development of more effective treatment protocols.

Relationship between renal oxidative stress levels and disease severity in patients with chronic kidney disease assessed by [Cu-64]ATSM PET/MRI

The purpose of the study was to investigate renal oxidative stress (OS) and its relationship with disease severity in patients with chronic kidney disease (CKD) using positron emission tomography coupled with magnetic resonance imaging (PET/MRI), employing 64Cu-diacetyl-bis(N4-methylthiosemicarbazonate) (64Cu-ATSM) as the PET tracer for OS imaging. Thirty patients with CKD (66.4 ± 8.2 y.o.) and seven healthy controls (HC) subjects (58.3 ± 3.8 y.o.) underwent 64Cu-ATSM PET/MRI. Participants were categorized into three groups based on their estimated glomerular filtration rate (eGFR): HC, mild CKD (stages 2-3a), and advanced CKD (stages 3b-5). All subjects underwent 30-min dynamic PET/MRI starting with the injection of 64Cu-ATSM to evaluate renal blood flow (RBF) and OS levels. RBF (mL/min/100 g) images were calculated from the first 3 min PET data, and standardized uptake value (SUV) images were obtained from delayed frames of 15-30 min after injection. The 64Cu-ATSM SUV images were corrected to RBF-adjusted SUV using individual RBF images to estimate the OS levels of individual kidneys using the following equation: adjusted OS index (aOSi) = (SUV/RBF)x100. Significant correlation was observed between eGFR and RBF (r = 0.81, P < 0.001). RBF in patients with advanced CKD is significantly lower than that in HC (P < 0.001) and patients with mild CKD (P = 0.004). 64Cu-ATSM SUV did not differ significantly among the three groups (P = 0.171). 64Cu-ATSM SUVs did not correlate with creatinine in the HC subjects or in the patients with CKD. However, these values did correlate with eGFR (r = 0.33, P = 0.049) in all subjects, whereas the CKD patients showed no significant correlation. Following RBF correction, the aOSi demonstrated significant correlations with creatinine (r = 0.75, P < 0.001), eGFR (r= -0.65, P < 0.001), and CKD stages (r = 0.57, P < 0.001) in all subjects. This preliminary study has revealed that 64Cu-ATSM PET may provide a estimate of renal OS reasonably in CKD patients noninvasively. Increased aOSi values were correlated with the CKD stages and creatinine levels, suggesting that OS increases with the severity of renal dysfunction.

Unveiling the antiurolithiatic potentiality of two benzene sulfonamide derivatives against ethylene glycol-induced renal calculi

OBJECTIVE

Oxidative stress and inflammation play crucial roles in the onset of kidney injury and crystal formation caused by hyperoxaluria. Indapamide is a potent medication for treating renal calculi, but it has severe side effects such as hypokalemia, hypercalcemia, and hyperuricemia. Therefore, it is advisable to explore alternative treatments that do not have these side effects. The study aimed to reveal the antiurolithiatic potential of two benzene sulfonamide derivatives (SBCl and SBF; A and B, respectively) against ethylene glycol-induced kidney stones.

METHODS

The rats were divided into two main groups: the first group consisted of 20 rats with induced kidney stones, and the second group included 15 control rats. This division enabled a comparative analysis between rats with kidney stones and those without, offering insights into the effects of kidney stone induction on various physiological parameters and biochemical markers. The effectiveness of benzene sulfonamide derivatives (compounds A and B) was assessed in rats with induced kidney stones. The treatment was given orally by gavage for 21 days, administered every 48h after inducing kidney stones with 0.12ml of 5% ethylene glycol (EG).

RESULTS

The influence of compounds A and B on electrolytes, biochemical, antioxidant, and inflammatory reactions in induced kidneys underscores their potential therapeutic advantages in alleviating the advancement of kidney stone disease and related complications.

CONCLUSION

Both compounds were found to possess equal effectiveness in inhibiting the complications of stone formation. However, SBCl-EG showed superior antioxidant and inflammatory parameters effects compared to SBF-EG. Our study's findings underscore the potential benefits of derivatives in treating nephrolithiasis and related oxidative disorders, highlighting their superior effects on antioxidant and inflammatory responses compared to standard treatments.

Progress in the application of novel inflammatory indicators in chronic kidney disease

Chronic kidney disease has become a public health problem endangering the health of all humans because of its high prevalence, high mortality and high medical burden. The chronic micro-inflammatory state is recognized as a significant component of CKD, playing a key role in disease progression. Intervening in chronic inflammation during the disease course can enhance prognosis. Recent studies have demonstrated that novel inflammatory indices, such as the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammatory index are closely associated with CKD, meanwhile may serve as prognostic monitors of all-cause death and poor renal prognosis for the disease. This article comprehensively reports on the mechanisms of micro-inflammation in CKD, the relationship between inflammatory indicators and CKD, and their impact on prognosis.

Mercury(II)-Triggered Targeted and NIR-II Fluorescence/Photoacoustic Imaging Probe for High-Sensitivity Early Diagnosis and Evaluating Drug against Acute Liver and Kidney Injury

Mercury ions (Hg2+) have been found to disrupt the body's antioxidant defense mechanisms, leading to oxidative stress and physiological dysfunction. Early diagnosis and real-time monitoring of Hg2+ fluctuations in organ damage are crucial but limited due to the lack of noninvasive and deep tissue imaging probes. Herein, a Hg2+-triggered targeted and NIR-II fluorescence/photoacoustic (PA) dual-mode molecular probe (NHG-2) was developed for real-time monitoring Hg2+ fluctuations in Hg2+-induced acute liver and kidney injury mice. NHG-2 was designed through rational adjustment of the conjugated ring structure and further screening processes, enabling it to sensitively recognize Hg2+ and subsequently open mitochondrial targeting, producing NIR-II fluorescence/PA signals. This probe allowed for noninvasive NIR-II fluorescence/PA imaging for real-time monitoring of Hg2+-induced acute liver and kidney injury, demonstrating excellent detection sensitivity. Furthermore, NHG-2 can be utilized to evaluate the efficacy of N-acetylcysteine (NAC) in Hg2+-induced liver and kidney injury through dual signal indication. Mechanism studies suggested that NAC activated the antioxidant Akt/Nrf2 signaling pathway, reversed the changes of related biomarkers, and restored mitochondrial membrane potential. Thus, this study not only presents the first specific NIR-II fluorescence/PA dual-mode probe for Hg2+ but also provides a potential tool for early diagnosis and treatment evaluation and potential pathogenesis study.

Mitochondria-targeting therapeutic strategies for chronic kidney disease

Chronic kidney disease (CKD) is a multifactorial health issue characterised by kidney impairment that has significant morbidity and mortality in the global population. Current treatments for CKD fail to prevent progression to end-stage kidney disease, where management is limited to renal replacement therapy or kidney transplantation. Mitochondrial dysfunction has been implicated in the pathogenesis of CKD and can be broadly categorised into abnormalities related to excessive oxidative stress, reduced mitochondrial biogenesis, excess mitochondrial fission and dysregulated mitophagy. Mitochondria-targeting therapeutic strategies target many of the outlined mechanisms of mitochondrial dysfunction, and an overview of recent evidence for mitochondria-targeting therapeutic strategies is explored in this review, including naturally derived compounds and novel approaches such as fusion proteins. Mitochondria-targeting therapeutic strategies using these approaches show the potential to stabilise or improve renal function, and clinical studies are needed to further confirm their safety and efficacy in human contexts.

Iron oxide nanoparticles induce ferroptosis under mild oxidative stress in vitro

Iron oxide nanoparticles (IONPs) have the potential to be utilized in a multitude of fields, including biomedicine. Consequently, the potential health risks associated with their use must be carefully considered. Most biosafety evaluations of IONPs have focused on examining the impact of the material's distinctive physicochemical attributes. However, the specific attributes of individual cells are frequently disregarded, particularly under the oxidative stress conditions. This may result in an underestimation of potential risk and impede the clinical translation of IONPs. The present study thus sought to evaluate the potential cytotoxicity and underlying mechanisms of IONPs in a pathological state characterized by mild oxidative stress. A cell model of mild oxidative stress was initially established in vitro. Subsequently, a series of indicators, including cell viability, live/dead ratio, mitochondrial membrane potential, and oxidative damage, were measured to assess the cytotoxicity of IONPs. Finally, a series of ferroptosis regulators were used to elucidate the involvement of ferroptosis. Preincubation with IONPs resulted in a significant reduction in cellular viability, morphological degeneration, elevated numbers of dead cells, impaired mitochondrial function, and increased oxidative damage under mild oxidative stress conditions in vitro. The cytotoxic effects of IONPs under mild oxidative stress are largely dependent on ROS and iron ions and are strongly associated with ferroptosis, which is based on the effects of ferroptosis regulators. The present in vitro study indicated that IONPs are toxic to cells under mild oxidative stress, which is linked to ferroptosis.

GLP-1 receptor agonist liraglutide alleviates kidney injury by regulating nuclear translocation of NRF2 in diabetic nephropathy

Diabetic nephropathy (DN) is a severe renal disorder that arises as a complication of diabetes. Liraglutide, an analogue of a glucagon-like peptide 1 (GLP-1) receptor agonist, has been shown to decrease diabetes-caused renal damage. Nevertheless, the complete understanding of the roles and mechanism remains unclear. In our study, diabetic rat models were created through a single intraperitoneal injection of streptozotocin (STZ). The level of fasting blood glucose, 24-h urine protein, serum creatinine (Scr) and blood urea nitrogen (BUN) were assessed. Periodic acid-Schiff (PAS) staining was applied to examine the pathological changes in renal tissues. Reactive oxygen species (ROS) formation was measured via dichloro-dihydro-fluorescein diacetate (DCFH-DA) probes. Western blot was conducted to examine the levels of oxidative stress-related and extracellular matrix (ECM)-associated proteins. The nuclear translocation of NRF2 was investigated through immunofluorescence and Western blot assays. We demonstrated that liraglutide attenuated DN-induced oxidative stress and ECM deposition in vitro and in vivo. Liraglutide exerted a reno-protective effect by promoting nuclear translocation of NRF2 in mesangial cells. ML385, an NRF2 inhibitor, counteracted the beneficial impact of liraglutide.

PRKAA2-mediated mitophagy regulates oxygen consumption in yak renal tubular epithelial cells under chronic hypoxia

Hypoxic environments are significant factors in the induction of various kidney diseases and are closely associated with high oxygen consumption in the kidneys. Yaks live at high altitude for a long time, exhibit a unique ability to regulate kidney oxygen consumption, protecting them from hypoxia-induced damage. However, the mechanisms underlying the regulation of oxygen consumption in yak kidneys under hypoxic conditions remain unclear. To explore this hypoxia adaptation mechanism in yak kidneys, this study analyzed the oxygen consumption rate (OCR) of renal tubular epithelial cells (RTECs) under hypoxia. We found that the OCR and apoptosis rates of RTECs under chronic hypoxia (> 24 h) were lower than those under acute hypoxia (≤ 24 h). However, when oxygen consumption was promoted under chronic hypoxia, the apoptosis rate increased, indicating that reducing the cellular OCR is crucial for maintaining RTECs activity under hypoxia. High-throughput sequencing results showed that the mitophagy pathway is likely a key mechanism for inhibiting OCR of yak RTECs, with protein kinase AMP-activated catalytic subunit alpha 2 (PRKAA2) playing a significant role in this process. Further studies demonstrated that chronic hypoxia activates the mitophagy pathway, which inhibits oxidative phosphorylation (OXPHOS) while increasing glycolytic flux in yak RTECs. Conversely, when the mitophagy pathway was inhibited, there was an increase in the activity of OXPHOS enzymes and OCR. To further explore the role of PRKAA2 in the mitophagy pathway, we inhibited PRKAA2 expression under chronic hypoxia. Results showed that the downregulation of PRKAA2 decreased the expression of mitophagy-related proteins, such as p-FUNDC1/FUNDC1, LC3-II/LC3-I, BNIP3 and ULK1 while upregulating P62 expression. Additionally, there was an increase in the enzyme activities of Complex II, Complex IV, PDH, and SDH, which further promoted oxygen consumption in RTECs. These findings suggest that PRKAA2 mediated mitophagy under chronic hypoxia is crucial mechanism for reducing oxygen consumption in yak RTECs.

Association between kidney function and Parkinson's disease risk: a prospective study from the UK Biobank

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative influenced by various clinical factors. The potential relationship between renal function and the risk of PD remains poorly understood. This study aims to explore the association between kidney function and the risk of developing PD.

METHODS

A population-based cohort study was conducted using data from 400,571 UK Biobank participants. Renal function was assessed using the estimated glomerular filtration rate (eGFR), calculated from serum creatinine and cystatin C levels. The association between eGFR levels and PD risk was evaluated using univariate and multivariate Cox regression analyses, Restricted Cubic Spline (RCS) analysis, and Kaplan-Meier analysis. Additionally, a clinical prediction model was developed and its diagnostic accuracy was evaluated using ROC analysis. A heatmap was also constructed to examine the relationship between clinical factors and gray matter volume in various brain regions.

RESULTS

Over a median observation period of 13.8 years, 2740 PD events were recorded. Cox regression and Kaplan-Meier analyses revealed a significant association between decreased eGFR and increased PD risk, particularly in participants with eGFR < 30 ml/min/1.73 m2. This association was confirmed across three adjusted models. RCS analysis demonstrated a nonlinear relationship between decreasing eGFR and increasing PD risk. Furthermore, changes in eGFR were correlated with alterations in subcortical gray matter volume in regions such as the frontal cortex, striatum, and cerebellum. The clinical prediction model showed high diagnostic accuracy with AUC values of 0.776, 0.780, and 0.824 for 4-, 8-, and 16-year predictions, respectively.

CONCLUSION

Renal insufficiency is significantly associated with an increased risk of PD, highlighting the importance of maintaining good kidney function as a potential preventive measure against PD.

Mitochondrial dysfunction in kidney stones and relief of kidney stones after reducing mtROS

Mitochondria are essential organelles because they generate the energy required for cellular functions. Kidney stones, as one of the most common urological diseases, have garnered significant attention. In this study, we first collected peripheral venous blood from patients with kidney stones and used qRT-PCR to detect mitochondrial DNA (mtDNA) copy number as a means of assessing mitochondrial function in these patients. Subsequently, through Western blotting, qPCR, immunofluorescence, immunohistochemistry, and transmission electron microscopy, we examined whether calcium oxalate crystals could cause mitochondrial dysfunction in the kidney in both in vitro and in vivo. We then examined the intersection of the DEGs obtained by transcriptome sequencing of the mouse kidney stone model with mitochondria-related genes, and performed KEGG and GO analyses on the intersecting genes. Finally, we administered the mitochondrial ROS scavenger Mito-Tempo in vivo and observed its effects. Our findings revealed that patients with kidney stones had a reduced mtDNA copy number in their peripheral venous blood compared to the control group, suggesting mitochondrial dysfunction in this population. This conclusion was further validated through in vitro and in vivo experiments. Enrichment analyses revealed that the intersecting genes were closely related to metabolism. We observed that after mitochondrial function was preserved, the deposition of calcium oxalate crystals decreased, and the kidney damage and inflammation caused by them were also alleviated. Our research indicates that kidney stones can cause mitochondrial dysfunction. After clearing mtROS, the damage and inflammation caused by kidney stones are reversed, providing new insights into the prevention and treatment of kidney stones.

The Mitochondrial-Derived Peptide MOTS-c May Refine Mortality and Cardiovascular Risk Prediction in Chronic Hemodialysis Patients: A Multicenter Cohort Study

INTRODUCTION

Uremic patients exhibit remarkably increased rates of mortality and cardiovascular (CV) events, but risk prediction in this setting remains difficult. Systemic mitochondrial dysfunction is pervasive in end-stage kidney disease and may contribute to CV complications. We tested the clinical significance of circulating MOTS-c, a small mitochondrial-derived peptide, as a biomarker for improving mortality and CV risk prediction in hemodialysis (HD) patients.

METHODS

We conducted a prospective, observational, multicenter study on 94 prevalent HD patients. The study endpoint was a composite of all-cause mortality and non-fatal CV events. The diagnostic and prognostic capacities of predictive models based on cohort-related risk factors were tested before and after the inclusion of MOTS-c.

RESULTS

MOTS-c levels were higher in HD patients than in controls (p < 0.001) and even more elevated (p = 0.01) in the 53 individuals experiencing the combined endpoint during follow-up (median duration: 26.5 months). MOTS-c was independently associated with the endpoint at either multivariate logistic (OR 1.020; 95% CI: 1.011-1.109; p = 0.03) or Cox regression analyses (HR 1.004; 95% CI: 1.000-1.025; p = 0.05) and the addition of this biomarker to prognostic models including the other cohort-related risk predictors (age, left ventricular mass, evidence of diastolic dysfunction, diabetes, pulse pressure) significantly improved the calibration, risk variability explanation, discrimination (receiver operating characteristic area under the curve from 0.727 to 0.743; C-index from 0.658 to 0.700), and particularly, the overall reclassification capacity (NRI 15.87%; p = 0.01).

CONCLUSIONS

In HD patients, the mitochondrial-derived peptide MOTS-c may impart significant information to refine CV risk prediction, beyond cohort-related risk factors. Future investigations are needed to generalize these findings in larger and more heterogeneous cohorts.

Calcium signaling crosstalk between the endoplasmic reticulum and mitochondria, a new drug development strategies of kidney diseases

Calcium (Ca2+) acts as a second messenger and constitutes a complex and large information exchange system between the endoplasmic reticulum (ER) and mitochondria; this process is involved in various life activities, such as energy metabolism, cell proliferation and apoptosis. Increasing evidence has suggested that alterations in Ca2+ crosstalk between the ER and mitochondria, including alterations in ER and mitochondrial Ca2+ channels and related Ca2+ regulatory proteins, such as sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), inositol 1,4,5-trisphosphate receptor (IP3R), and calnexin (CNX), are closely associated with the development of kidney disease. Therapies targeting intracellular Ca2+ signaling have emerged as an emerging field in the treatment of renal diseases. In this review, we focused on recent advances in Ca2+ signaling, ER and mitochondrial Ca2+ monitoring methods and Ca2+ homeostasis in the development of renal diseases and sought to identify new targets and insights for the treatment of renal diseases by targeting Ca2+ channels or related Ca2+ regulatory proteins.

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Role of Uremic Toxins, Oxidative Stress, and Renal Fibrosis in Chronic Kidney Disease

Affecting millions of people worldwide, chronic kidney disease is a serious medical problem. It results in a decrease in glomerular filtration rate below 60 mL/min/1.73 m, albuminuria, abnormalities in urine sediment and pathologies detected by imaging studies lasting a minimum of 3 months. Patients with CKD develop uremia, and as a result of the accumulation of uremic toxins in the body, patients can be expected to suffer from a number of medical consequences such as progression of CKD with renal fibrosis, development of atherosclerosis or increased incidence of cardiovascular events. Another key element in the pathogenesis of CKD is oxidative stress, resulting from an imbalance between the production of antioxidants and the production of reactive oxygen species. Oxidative stress contributes to damage to cellular proteins, lipids and DNA and increases inflammation, perpetuating kidney dysfunction. Additionally, renal fibrogenesis involving the accumulation of fibrous tissue in the kidneys occurs. In our review, we also included examples of forms of therapy for CKD. To improve the condition of CKD patients, pharmacotherapy can be used, as described in our review. Among the drugs that improve the prognosis of patients with CKD, we can include: GLP-1 analogues, SGLT2 inhibitors, Finerenone monoclonal antibody-Canakinumab and Sacubitril/Valsartan.

Arsenic exposure induced renal fibrosis via regulation of mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling pathway

Environmental arsenic exposure is one of the major global public health problems. Studies have shown that arsenic exposure can cause renal fibrosis, but the underlying mechanism is still unclear. Integrating the in vivo and in vitro models, this study investigated the potential molecular pathways for arsenic-induced renal fibrosis. In this study, SD rats were treated with 0, 5, 25, 50, and 100 mg/L NaAsO2 for 8 weeks via drinking water, and HK2 cells were treated with different doses of NaAsO2 for 48 h. The in vivo results showed that arsenic content in the rats' kidneys increased as the dose increased. Body weight decreased and kidney coefficient increased at 100 mg/L. As a response to the elevated NaAsO2 dose, inflammatory cell infiltration, renal tubular injury, glomerular atrophy, tubulointerstitial hemorrhage, and fibrosis became more obvious indicated by HE and Masson staining. The kidney transcriptome profiles further supported the protein-protein interactions involved in NaAsO2-induced renal fibrosis. The in vivo results, in together with the in vitro experiments, have revealed that exposure to NaAsO2 disturbed mitochondrial dynamics, promoted mitophagy, activated inflammation and the TGF-β1/SMAD signaling pathway, and finally resulted in fibrosis. In summary, arsenic exposure contributed to renal fibrosis via regulating the mitochondrial dynamics and the NLRP3-TGF-β1/SMAD signaling axis. This study presented an adverse outcome pathway for the development of renal fibrosis due to arsenic exposure through drinking water.

Integrated network analysis and experimental verification of the mechanisms employed by Compound Jixuecao Decoction to improve endoplasmic reticulum stress and apoptosis in chronic renal failure

ETHNOPHARMACOLOGICAL RELEVANCE

Compound Jixuecao Decoction (CJD) is a traditional Chinese herbal medicine prescribed in China to treat chronic renal failure (CRF). Previous studies have shown that CJD affects cell apoptosis and proliferation. However, the mechanism of its renal protective action has not been characterized.

AIM OF THE STUDY

To explore the mechanism(s) underlying the effect of CJD on endoplasmic reticulum stress (ERS) and apoptosis in the treatment of CRF using network pharmacology, molecular docking, molecular dynamics simulations, and in vivo studies.

MATERIALS AND METHODS

The compounds comprising CJD were extracted from the Traditional Chinese Medicine Systems Pharmacology Database. A Swiss target prediction database and similarity integration approach were employed to identify potential targets of these components. The GeneCards and DisGeNET databases were used to identify targets associated with CRF, apoptosis, and ERS. The STRING database was employed to analyze the protein-protein interactions (PPIs) associated with drug-disease crossover. A chemical composition-shared target network was established, and critical pathways were identified through gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The Protein Data Bank database was used to search key proteins, while molecular docking and dynamics simulations were performed between the top four CJD active ingredients and proteins involved in apoptosis and ERS in CRF. Subsequent in vivo studies using a 5/6 nephrectomy rat model of CRF were performed to verify the findings.

RESULTS

The 80 compounds identified in CJD yielded 875 target genes, of which 216 were potentially related to CRF. PPI network analysis revealed key targets via topology filtering. Enrichment analysis, molecular docking, and molecular dynamics simulation results suggested that CJD primarily targets mitofusin-2 (MFN2), B-cell lymphoma-2 (BCL2), BAX, protein kinase RNA-like ER kinase (PERK), and C/EBP homologous protein (CHOP) during CRF treatment. In vivo, CJD significantly increased the abundance of MFN2, BCL2, and significantly reduced the abundance of BAX, PERK, CHOP proteins in kidney tissues, indicating that CJD could improve apoptosis and ERS in CRF rats.

CONCLUSIONS

This study provides evidence that CJD effectively delays CFR through modulation of the MFN2 and PERK-eIF2α-ATF4-CHOP signaling pathways.

Limosilactobacillus fermentum Strains as Novel Probiotic Candidates to Promote Host Health Benefits and Development of Biotherapeutics: A Comprehensive Review

Fruits and their processing by-products are sources of potentially probiotic strains. Limosilactobacillus (L.) fermentum strains isolated from fruit processing by-products have shown probiotic-related properties. This review presents and discusses the results of the available studies that evaluated the probiotic properties of L. fermentum in promoting host health benefits, their application by the food industry, and the development of biotherapeutics. The results showed that administration of L. fermentum for 4 to 8 weeks promoted host health benefits in rats, including the modulation of gut microbiota, improvement of metabolic parameters, and antihypertensive, antioxidant, and anti-inflammatory effects. The results also showed the relevance of L. fermentum strains for application in the food industry and for the formulation of novel biotherapeutics, especially nutraceuticals. This review provides evidence that L. fermentum strains isolated from fruit processing by-products have great potential for promoting host health and indicate the need for a translational approach to confirm their effects in humans using randomized, double-blind, placebo-controlled trials.

The protective effect of caffeine against oxalate-induced epithelial-mesenchymal transition in renal tubular cells via mitochondrial preservation

Mitochondrial dysfunction is one of the key mechanisms for developing chronic kidney disease (CKD). Hyperoxaluria and nephrolithiasis are also associated with mitochondrial dysfunction. Increasing evidence has shown that caffeine, the main bioactive compound in coffee, exerts both anti-fibrotic and anti-lithogenic properties but with unclear mechanisms. Herein, we address the protective effect of caffeine against mitochondrial dysfunction during oxalate-induced epithelial-mesenchymal transition (EMT) in renal cells. Analyses revealed that oxalate successfully induced EMT in MDCK renal cells as evidenced by the increased expression of several EMT-related genes (i.e., Snai1, Fn1 and Acta2). Oxalate also suppressed cellular metabolic activity and intracellular ATP level, but increased reactive oxygen species (ROS). Additionally, oxalate reduced abundance of active mitochondria and induced mitochondrial fragmentation (fission). Furthermore, oxalate decreased mitochondrial biogenesis and content as evidenced by decreased expression of sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), cytochrome c oxidase subunit 4 (COX4), and total mitochondrial proteins. Nonetheless, these oxalate-induced deteriorations in MDCK cells and their mitochondria were successfully hampered by caffeine. Knockdown of Snai1 gene by small interfering RNA (siRNA) completely abolished the effects of oxalate on suppression of cellular metabolic activity, intracellular ATP and abundance of active mitochondria, indicating that these oxalate-induced renal cell deteriorations were mediated through the Snai1 EMT-related gene. These data, at least in part, unveil the anti-fibrotic mechanism of caffeine during oxalate-induced EMT in renal cells by preserving mitochondrial biogenesis and function.

A Review of Proposed Mechanisms in Rheumatoid Arthritis and Therapeutic Strategies for the Disease

Rheumatoid arthritis (RA) is characterized by synovial edema, inflammation, bone and cartilage loss, and joint degradation. Patients experience swelling, stiffness, pain, limited joint movement, and decreased mobility as the condition worsens. RA treatment regimens often come with various side effects, including an increased risk of developing cancer and organ failure, potentially leading to mortality. However, researchers have proposed mechanistic hypotheses to explain the underlying causes of synovitis and joint damage in RA patients. This review article focuses on the role of synoviocytes and synoviocytes resembling fibroblasts in the RA synovium. Additionally, it explores the involvement of epigenetic regulatory systems, such as microRNA pathways, silent information regulator 1 (SIRT1), Peroxisome proliferatoractivated receptor-gamma coactivator (PGC1-α), and protein phosphatase 1A (PPM1A)/high mobility group box 1 (HMGB1) regulators. These mechanisms are believed to modulate the function of receptors, cytokines, and growth factors associated with RA. The review article includes data from preclinical and clinical trials that provide insights into potential treatment options for RA.