SS-31, a Mitochondria-Targeting Peptide, Ameliorates Kidney Disease

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.

Reactive Oxygen Species in Cystic Kidney Disease

Polycystic kidney disease (PKD) is a rare but significant renal condition with major implications for global acute and chronic patient care. Oxidative stress and reactive oxygen species (ROS) can significantly alter its pathophysiology, clinical outcomes, and treatment, contributing to negative outcomes, including hypertension, chronic kidney disease, and kidney failure. Inflammation from ROS and existing cysts propagate the generation and accumulation of ROS, exacerbating kidney injury, pro-fibrotic signaling cascades, and interstitial fibrosis. Early identification and prevention of oxidative stress and ROS can contribute to reduced cystic kidney disease progression and improved longitudinal patient outcomes. Increased research regarding biomarkers, the pathophysiology of oxidative stress, and novel therapeutic interventions alongside the creation of comprehensive guidelines establishing methods of assessment, monitoring, and intervention for oxidative stress in cystic kidney disease patients is imperative to standardize clinical practice and improve patient outcomes. The integration of artificial intelligence (AI), genetic editing, and genome sequencing could further improve the early detection and management of cystic kidney disease and mitigate adverse patient outcomes. In this review, we aim to comprehensively assess the multifactorial role of ROS in cystic kidney disease, analyzing its pathophysiology, clinical outcomes, treatment interventions, clinical trials, animal models, and future directions for patient care.

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.

Biological activity, limitations and steady-state delivery of functional substances for precision nutrition

Food-related functional substances with biological activity serve as a crucial material foundation for achieving precision nutrition, which has gained increasing attraction in regulating physiological functions, preventing chronic diseases, and maintaining human health. Nutritional substances typically include bioactive proteins, peptides, polysaccharides, polyphenols, functional lipids, carotenoids, probiotics, vitamins, saponins, and terpenes. These functional substances play an essential role in precise nutrition. This chapter introduces and summarizes typical functional substances to demonstrate the challenges in precision nutrition for their stability, solubility, and bioavailability. The current status of delivery systems of functional substances is described to give an insight into the development of desirable characteristics, such as food grade status, high loading capacity, site targeting, and controlled release capacity. Finally, the applications of food-borne delivery systems of functional substances for precision nutrition are emphasized to meet the requirement for precision nutrition during nutritional intervention for chronic diseases.

Mitochondrial metabolism and targeted treatment strategies in ischemic-induced acute kidney injury

Ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI). The kidney is susceptible to IRI under several clinical conditions, including hypotension, sepsis, and surgical procedures, such as partial nephrectomy and kidney transplantation. Extensive research has been conducted on the mechanism and intervention strategies of renal IRI in past decades; however, the complex pathophysiology of IRI-induced AKI (IRI-AKI) is not fully understood, and there remains a lack of effective treatments for AKI. Renal IRI involves several processes, including reactive oxygen species (ROS) production, inflammation, and apoptosis. Mitochondria, the centers of energy metabolism, are increasingly recognized as substantial contributors to the early phases of IRI. Multiple mitochondrial lesions have been observed in the renal tubular epithelial cells (TECs) of IRI-AKI mice, and damaged or dysfunctional mitochondria are toxic to the cells because they produce ROS and release cell death factors, resulting in TEC apoptosis. In this review, we summarize the recent advances in the mitochondrial pathology in ischemic AKI and highlight promising therapeutic approaches targeting mitochondrial dysfunction to prevent or treat human ischemic AKI.

A narrative review on inflammaging and late-onset hypogonadism

The increasing life expectancy observed in recent years has resulted in a higher prevalence of late-onset hypogonadism (LOH) in older men. LOH is characterized by the decline in testosterone levels and can have significant impacts on physical and mental health. While the underlying causes of LOH are not fully understood, there is a growing interest in exploring the role of inflammaging in its development. Inflammaging is a concept that describes the chronic, low-grade, systemic inflammation that occurs as a result of aging. This inflammatory state has been implicated in the development of various age-related diseases. Several cellular and molecular mechanisms have been identified as contributors to inflammaging, including immune senescence, cellular senescence, autophagy defects, and mitochondrial dysfunction. Despite the extensive research on inflammaging, its relationship with LOH has not yet been thoroughly reviewed in the literature. To address this gap, we aim to review the latest findings related to inflammaging and its impact on the development of LOH. Additionally, we will explore interventions that target inflammaging as potential treatments for LOH.

Platelet membrane-coated bio-nanoparticles of indocyanine green/elamipretide for NIR diagnosis and antioxidant therapy in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition in critically ill patients that is often associated with significant morbidity and mortality. As the lack of effective early diagnosis methods often delays AKI treatment, there is currently no definitive clinical intervention available. In this study, we aimed to address these challenges by developing a nano-system called Platelet membranes-ICG-SS31-PLGA (PISP), which was designed to selectively target to the kidney site, taking advantage of the natural tendency of platelets to accumulate at sites of vascular injury. This approach allowed for the accumulation of PISP within the kidney as the disease progresses. By incorporating ICG, the in vivo distribution of PISP can be observed for NIR diagnosis of AKI. This non-invasive imaging technique holds great promise for early detection and monitoring of AKI. Furthermore, Elamipretide (SS31) acts as a mitochondria-targeted antioxidant that protects against mitochondrial damage and reduces oxidative stress, inflammation, and apoptosis. The combination of diagnostic and therapeutic capabilities within a single nano-system makes the PISP approach a valuable tool for addressing AKI. This intervention helps to prevent the deterioration of AKI and promotes the recovery. STATEMENT OF SIGNIFICANCE.

Advances of Oxidative Stress Impact in Periodontitis: Biomarkers and Effective Targeting Options

Periodontitis is the most common inflammatory oral disease that affects around 15% of adults and contributes to severe periodontal tissue destruction with subsequent tooth loosening and loss. Among the main pathogenic mechanisms underlying periodontitis, excessive reactive oxygen species production and oxidative stress play a predominant role in inducing both local and systemic damage. Current therapeutic approaches have expanded the conventional methods combined with herbal antioxidant compounds to free radical-scavenging nanomaterials and infrared laser therapy, offering promising pre-clinical evidence in periodontitis management. Herein, we review the pathogenic mechanisms of reactive oxygen species tissue damage, along with recent advances in oxidative stress biomarkers and novel targeting options.

Elamipretide(SS-31) Attenuates Idiopathic Pulmonary Fibrosis by Inhibiting the Nrf2-Dependent NLRP3 Inflammasome in Macrophages

Idiopathic pulmonary fibrosis (IPF) is a progressive fatal lung disease with a limited therapeutic strategy. Mitochondrial oxidative stress in macrophages is directly linked to IPF. Elamipretide(SS-31) is a mitochondrion-targeted peptide that has been shown to be safe and beneficial for multiple diseases. However, whether SS-31 alleviates IPF is unclear. In the present study, we used a bleomycin (BLM)-induced mouse model followed by SS-31 injection every other day to investigate its role in IPF and explore the possible mechanism. Our results showed that SS-31 treatment significantly suppressed BLM-induced pulmonary fibrosis and inflammation, with improved histological change, and decreased extracellular matrix deposition and inflammatory cytokines release. Impressively, the expression percentage of IL-1β and IL-18 was downregulated to lower than half with SS-31 treatment. Mechanistically, SS-31 inhibited IL-33- or lipopolysaccharide(LPS)/IL-4-induced production of IL-1β and IL-18 in macrophages by suppressing NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome activation. Nuclear factor erythroid 2-related factor 2(Nrf2) was dramatically upregulated along with improved mitochondrial function after SS-31 treatment in activated macrophages and BLM-induced mice. Conversely, there was no significant change after SS-31 treatment in Nrf2-/- mice and macrophages. These findings indicated that SS-31 protected against pulmonary fibrosis and inflammation by inhibiting the Nrf2-mediated NLRP3 inflammasome in macrophages. Our data provide initial evidence for the therapeutic efficacy of SS-31 in IPF.

Mitochondria in health, disease, and aging

Mitochondria are well known as organelles responsible for the maintenance of cellular bioenergetics through the production of ATP. Although oxidative phosphorylation may be their most important function, mitochondria are also integral for the synthesis of metabolic precursors, calcium regulation, the production of reactive oxygen species, immune signaling, and apoptosis. Considering the breadth of their responsibilities, mitochondria are fundamental for cellular metabolism and homeostasis. Appreciating this significance, translational medicine has begun to investigate how mitochondrial dysfunction can represent a harbinger of disease. In this review, we provide a detailed overview of mitochondrial metabolism, cellular bioenergetics, mitochondrial dynamics, autophagy, mitochondrial damage-associated molecular patterns, mitochondria-mediated cell death pathways, and how mitochondrial dysfunction at any of these levels is associated with disease pathogenesis. Mitochondria-dependent pathways may thereby represent an attractive therapeutic target for ameliorating human disease.

The role of mtDAMPs in the trauma-induced systemic inflammatory response syndrome

Systemic inflammatory response syndrome (SIRS) is a non-specific exaggerated defense response caused by infectious or non-infectious stressors such as trauma, burn, surgery, ischemia and reperfusion, and malignancy, which can eventually lead to an uncontrolled inflammatory response. In addition to the early mortality due to the "first hits" after trauma, the trauma-induced SIRS and multiple organ dysfunction syndrome (MODS) are the main reasons for the poor prognosis of trauma patients as "second hits". Unlike infection-induced SIRS caused by pathogen-associated molecular patterns (PAMPs), trauma-induced SIRS is mainly mediated by damage-associated molecular patterns (DAMPs) including mitochondrial DAMPs (mtDAMPs). MtDAMPs released after trauma-induced mitochondrial injury, including mitochondrial DNA (mtDNA) and mitochondrial formyl peptides (mtFPs), can activate inflammatory response through multiple inflammatory signaling pathways. This review summarizes the role and mechanism of mtDAMPs in the occurrence and development of trauma-induced SIRS.

Role of oxidative stress in the relationship between periodontitis and systemic diseases

Periodontitis is a common inflammatory disease. It is characterized by destruction of the supporting structures of the teeth and could lead to tooth loss and systemic inflammation. Bacteria in inflamed gingival tissue and virulence factors are capable of entering the bloodstream to induce systemic inflammatory response, thus influencing the pathological process of many diseases, such as cardiovascular diseases, diabetes, chronic kidney disease, as well as liver injury. An increasing body of evidence show the complex interplay between oxidative stress and inflammation in disease pathogenesis. When periodontitis occurs, increased reactive oxygen species accumulation leads to oxidative stress. Oxidative stress contributes to major cellular components damage, including DNA, proteins, and lipids. In this article, the focus will be on oxidative stress in periodontal disease, the relationship between periodontitis and systemic inflammation, and the impact of periodontal therapy on oxidative stress parameters.

The Mitochondrion: A Promising Target for Kidney Disease

Mitochondrial dysfunction is important in the pathogenesis of various kidney diseases and the mitochondria potentially serve as therapeutic targets necessitating further investigation. Alterations in mitochondrial biogenesis, imbalance between fusion and fission processes leading to mitochondrial fragmentation, oxidative stress, release of cytochrome c and mitochondrial DNA resulting in apoptosis, mitophagy, and defects in energy metabolism are the key pathophysiological mechanisms underlying the role of mitochondrial dysfunction in kidney diseases. Currently, various strategies target the mitochondria to improve kidney function and kidney treatment. The agents used in these strategies can be classified as biogenesis activators, fission inhibitors, antioxidants, mPTP inhibitors, and agents which enhance mitophagy and cardiolipin-protective drugs. Several glucose-lowering drugs, such as glucagon-like peptide-1 receptor agonists (GLP-1-RA) and sodium glucose co-transporter-2 (SGLT-2) inhibitors are also known to have influences on these mechanisms. In this review, we delineate the role of mitochondrial dysfunction in kidney disease, the current mitochondria-targeting treatment options affecting the kidneys and the future role of mitochondria in kidney pathology.

SYNERGIC EFFECT OF PREPARATION WITH COORDINATION COMPLEX “TRIMETHYDRAZINIUM PROPIONATE+ETHYMTH METHYLHYDROXYPIRIDINE SUCCINATE” ON ENERGY METABOLISM AND CELL RESPIRATION

The article presents the results of an in vitro study of the synergetic effect evaluation of the combined preparation based on coordination complex ethylmethylhydroxypyridine succinate and trimethylhydrazinium propionate on energy metabolism and cell respiration.

The aim of the study was to evaluate the mitochondria-directed action of the metabolic and antioxidant preparation based on succinic acid coordination complex with trimethylhydrazinium in relation to optimizing the energy metabolism in the cells under the oxidative stress conditions, as well as against the background of ischemic processes.

Materials and methods. The study of the hydroxysuccinate complex effect of the drug Brainmax® components was carried out on isolated mouse liver mitochondria. In the course of the study, the potential of mitochondria, the generation rate of hydrogen peroxide during the respiration, the respiration rate were evaluated in the following positions: a) unstimulated by malate and pyruvate, b) stimulated by malate and pyruvate (complex I substrates), by succinate (complex II substrates), c) against the background of the initial section of the electron transport chain blockade by rotenone, d) in phosphorylation blockade by oligomycin, e) against the background of the FCCP-induced uncoupling, and f) in cyanide-blocked complex IV (cytochrome C oxidase).

Results. It has been shown that the succinic acid coordination complex with trimethylhydrazinium, which is the active principle of the Brainmax® drug, significantly reduced the transmembrane potential of mitochondria (IC50=197±5 µM), compared with the widely used preparations of ethylmethylhydroxypyridine succinate and trimethylhydrazinium propionate, which facilitates the transfer of the produced ATP into the cell and preserves a vital activity of mitochondria even under stress. In the study of the mitochondrial respiration stimulated by the substrates of complex I (NADP-coenzyme Q-oxidoreductase), pyruvate and malate, the studied drug led to a more pronounced increase in the oxygen consumption with IC50=75±6 µМ. When evaluating the effect of the complex on the production of ATP by mitochondria, the most pronounced effect was observed with the addition of studied complex, which indicated to the uncoupling of respiration and oxidative phosphorylation at the given concentrations of the studied compounds. When assessing the effect of the complex on the production of hydrogen peroxide by isolated mitochondria, a significant decrease in the peroxide production was shown in the samples containing the complex of trimethylhydrazinium propionate and EMHPS.

Conclusion. Based on totality of the results obtained, it can be assumed that a favorable conformation of the pharmacophore groups of ethylmethylhydroxypyridine succinate and trimethylhydrozinium propionate coordination complex included in the composition of Brainmax® leads to a synergetic interaction and more pronounced pharmacological effects on target cells. This complex provides stabilization of a mitochondrial function, intensification of the adenosine triphosphate energy production and the optimization of energy processes in the cell, reduces the severity of the oxidative stress and eliminates undesirable effects of an ischemic-hypoxic tissue damage.