Search Results (145)

Background: Senescence, a state of permanent cell cycle arrest, is a complex cellular phenomenon closely affiliated with age-related diseases and pathological fibrosis. Cellular senescence is now recognized as a significant contributor to organ fibrosis, largely driven by transforming growth factor beta (TGF-β) signaling, such as in metabolic dysfunction-associated steatohepatitis (MASH), idiopathic pulmonary fibrosis (IPF), chronic kidney disease (CKD), and myocardial fibrosis, which can lead to heart failure, cystic fibrosis, and fibrosis in pancreatic tumors, to name a few. MASH is a progressive inflammatory and fibrotic liver condition that has reached pandemic proportions, now considered the largest non-viral contributor to the need for liver transplantation. Methods: We previously studied Oxy210, an anti-fibrotic and anti-inflammatory, orally bioavailable, oxysterol-based drug candidate for MASH, using APOE*3-Leiden.CETP mice, a humanized hyperlipidemic mouse model that closely recapitulates the hallmarks of human MASH. In this model, treatment of mice with Oxy210 for 16 weeks caused significant amelioration of the disease, evidenced by reduced hepatic inflammation, lipid deposition, and fibrosis, atherosclerosis and adipose tissue inflammation. Results: Here we demonstrate increased hepatic expression of senescence-associated genes and senescence-associated secretory phenotype (SASP), correlated with the expression of pro-fibrotic and pro-inflammatorygenes in these mice during the development of MASH that are significantly inhibited by Oxy210. Using the HepG2 human hepatocyte cell line, we demonstrate the induced expression of senescent-associated genes and SASP by TGF-β and inhibition by Oxy210. Conclusions: These findings further support the potential therapeutic effects of Oxy210 mediated in part through inhibition of senescence-driven hepatic fibrosis and inflammation in MASH and perhaps in other senescence-associated fibrotic diseases. Full article

Background: This study presents an innovative approach to cardiovascular disease (CVD) risk prediction based on a comprehensive analysis of clinical, immunological and biochemical markers using mathematical modelling and machine learning methods. Baseline data include indices of humoral and cellular immunity (CD59, CD16, IL-10, CD14, CD19, CD8, CD4, etc.), cytokines and markers of cardiovascular disease, inflammatory markers (TNF, GM-CSF, CRP), growth and angiogenesis factors (VEGF, PGF), proteins involved in apoptosis and cytotoxicity (perforin, CD95), as well as indices of liver function, kidney function, oxidative stress and heart failure (albumin, cystatin C, N-terminal pro B-type natriuretic peptide (NT-proBNP), superoxide dismutase (SOD), C-reactive protein (CRP), cholinesterase (ChE), cholesterol, and glomerular filtration rate (GFR)). Clinical and behavioural risk factors were also considered: arterial hypertension (AH), previous myocardial infarction (PICS), aortocoronary bypass surgery (CABG) and/or stenting, coronary heart disease (CHD), atrial fibrillation (AF), atrioventricular block (AB block), and diabetes mellitus (DM), as well as lifestyle (smoking, alcohol consumption, physical activity level), education, and body mass index (BMI). Methods: The study included 52 patients aged 65 years and older. Based on the clinical, biochemical and immunological data obtained, a model for predicting the risk of premature cardiovascular aging was developed using mathematical modelling and machine learning methods. The aim of the study was to develop a predictive model allowing for the early detection of predisposition to the development of CVDs and their complications. Numerical methods of mathematical modelling, including Runge–Kutta, Adams–Bashforth and backward-directed Euler methods, were used to solve the prediction problem, which made it possible to describe the dynamics of changes in biomarkers and patients’ condition over time with high accuracy. Results: HLA-DR (50%), CD14 (41%) and CD16 (38%) showed the highest association with aging processes. BMI was correlated with placental growth factor (37%). The glomerular filtration rate was positively associated with physical activity (47%), whereas SOD activity was negatively correlated with it (48%), reflecting a decline in antioxidant defence. Conclusions: The obtained results allow for improving the accuracy of cardiovascular risk prediction, and form personalised recommendations for the prevention and correction of its development. Full article

Chronic kidney disease (CKD) significantly affects canine health, but the precise cellular mechanisms of this condition remain elusive. In this study, we used single-cell RNA sequencing (scRNA-seq) to profile renal cellular gene expression in a canine model of X-linked hereditary nephropathy (XLHN). Dogs with this condition exhibit juvenile-onset CKD similar to that seen in human Alport syndrome. Post-mortem renal cortical tissues from an affected male dog and a heterozygous female dog were processed to obtain single-cell suspensions. In total, we recovered up to 13,190 cells and identified 11 cell types, including major kidney cells and immune cells. Differential gene expression analysis comparing the affected male and heterozygous female dogs identified cell-type specific pathways that differed in a subpopulation of proximal tubule cells. These pathways included the integrin signaling pathway and the pathway for inflammation mediated by chemokine and cytokine signaling. Additionally, using machine learning-empowered digital cytometry, we deconvolved bulk mRNA-seq data from a previous canine study, revealing changes in cell type proportions across CKD stages. These results underline the utility of single-cell methodologies and digital cytometry in veterinary nephrology. Full article

Background: Systemic lupus erythematosus (SLE) is a complex autoimmune disease with significant therapeutic challenges. Recent studies suggest that dihydroartemisinin (DHA), a traditional Chinese medicine known for its anti-malarial properties, may be beneficial for SLE treatment, although its precise mechanism remains unclear. This study aimed to investigate the effects of DHA on the cellular composition and molecular events of splenic T cells and B cells in MRL/lpr mice, a widely used SLE model. Methods: T cells and B cells isolated from the spleens of three DHA-treated mice and three control mice underwent single-cell RNA sequencing (scRNA-seq) using the 10× Genomics Chromium system. Comprehensive analyses included cell clustering, signaling pathway enrichment, pseudotime trajectory analysis, and cellular communication assessment using unbiased computational methods. Results: DHA treatment significantly reduced kidney inflammation and altered the proportions of splenic T cells and B cells, particularly decreasing plasma cells. Molecular profiling of effector CD4+ T cells showed a significant reduction in several inflammation-related signaling pathways in DHA-treated mice. Cellular communication analysis indicated altered interactions between effector CD4+ T cells and B cells in MRL/lpr mice after DHA treatment. Conclusions: Our findings reveal changes in cellular composition and signaling pathways in splenic T cells and B cells of MRL/lpr mice following DHA treatment. DHA may inhibit B-cell differentiation into plasma cells by modulating effector CD4+ T cells, potentially through the regulation of HIF1α and ligand–receptor interactions, enhancing our understanding of DHA’s mechanisms in SLE treatment. Full article

Oxidative stress plays a crucial role in disease pathogenesis. While reactive oxygen species (ROS) directly cause cellular injury, emerging evidence suggests oxidatively modified proteins like albumin may also contribute significantly to tissue damage. Although oxidized albumin (ox-Alb) is linked to renal pathology, the direct effects and mechanisms of ox-Alb on renal cell injury remain unclear. This study was created to address these questions. In mouse models of renal injury initiated by vitamin C/copper or ischemia/reperfusion, levels of serum ox-Alb were significantly elevated. The treatment of albumin with copper/vitamin C increased Alb carbonylation and reduced the number of sulfhydryl groups, causing Alb oxidation. In cultured renal tubular epithelial NRK-52E cells, ox-Alb triggered cell death, associated with increased intracellular albumin accumulation—enhanced cellular protein carbonylation, and p38 MAPK activation. Notably, ox-Alb induced ferroptosis, evidenced by decreased GPX4 and xCT, increased ACSL4, elevated iron and lipid peroxidation, and suppression by deferoxamine and liproxstatin-1. In vivo, administration of ox-Alb exacerbated doxorubicin-induced nephropathy, as indicated by the elevated BUN, creatinine, and proteinuria, and intensified renal ferroptotic responses, including altered GPX4 and ACSL4. Our findings demonstrate that ox-Alb induces renal cell ferroptosis and promotes renal disease progression, suggesting its pivotal pathogenic role in oxidative stress-related kidney diseases. Full article

Background/Objectives: Acute kidney injury (AKI) remains an unsolved medical problem due to the lack of effective treatments, high mortality, and increased susceptibility to progression to chronic kidney disease (CKD), especially in the elderly. Cellular senescence has been described in AKI, CKD, and aging and has been proposed as a promising therapeutic target. The senolytic drug combination of dasatinib plus quercetin (D&Q) is beneficial in some pathological conditions, including experimental CKD, but there are no data for AKI. Methods: The effect of D&Q combination was tested in folic acid-induced nephrotoxicity (FAN-AKI), a murine AKI model. Results: D&Q pretreatment did not prevent renal dysfunction in the acute phase of FAN-AKI, as determined by serum creatinine and BUN levels at 48 h. Moreover, gene expression of the kidney damage biomarkers Lcn2 and Havcr1, the Cdkn1a gene, which encodes p21, and some genes encoding components of the senescent cell secretome were significantly increased in response to D&Q treatment. The number of senescent p21-positive cells in injured kidneys was similar in untreated or D&Q-treated FAN mice. In addition, D&Q did not prevent the downregulation of the antiaging factor Klotho in damaged kidneys. Conclusions: D&Q treatment was not protective in FAN-AKI, exacerbating some deleterious responses. These results suggest caution when exploring the clinical translation of D&Q senolytic activity. Full article

The highly conserved Wnt signaling pathway, a complex network critical for embryonic development and adult tissue homeostasis, regulates diverse cellular processes, ultimately influencing tissue organization and organogenesis; its dysregulation is implicated in numerous diseases, and it is known to be affected by oxidative pathways. This report reviews the recent literature on major classes of natural products with pronounced anti-oxidant properties, such as cardiac glycosides, steroid saponins, ecdysteroids, withanolides, cucurbitacins, triterpenes, flavonoids, and iridoids, that modulate its activity in various pathological conditions, summarizing and critically analyzing their effects on the Wnt pathway in various therapeutically relevant experimental models and highlighting the role of ROS-mediated crosstalk with Wnt signaling in these studies. Models reviewed include not only cancer but also stroke, ischemia, bone or kidney diseases, and regenerative medicine, such as re-epithelialization, cardiac maintenance, and hair loss. It highlights the paramount importance of modulating this signaling by natural products to define future research directions. We also discuss controversies identified in the mode of action of several compounds in different models and directions on how to further improve the quality and depth of such studies. Full article

Subclinical chronic kidney disease (sCKD) predisposes one to acute kidney injury (AKI) and chronic kidney disease (CKD). Reduced kidney functional reserve (KFR) detects sCKD in preclinical studies and predicts AKI after cardiac surgery. We evaluated renal protection in a rat model of kidney injury where ischaemia–reperfusion injury (IRI) was induced after sCKD. Dual treatment boosting nicotinamide adenine dinucleotide (NAD) by nicotinamide riboside (NR) combined with the mitochondria-targeted antioxidant SkQR1 protected the KFR and reduced structural kidney damage, including markers of vascular integrity and the relative blood volume (rBV). The dual treatment upregulated Sirt1 and Nrf2, increased the nuclear localisation of the mitochondrial biogenesis regulator PGC-1α and the mitochondrial protein marker COX4, and upregulated the antioxidant gene NOQ1. These observations suggest mitochondrial protection and modulation of the cellular redox state provided long-term structural and functional protection against kidney injury superimposed on background sCKD. Full article

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone associated with the regulation of biological rhythms. The indoleamine is secreted by the pineal gland during the night, following a circadian rhythm. The highest plasmatic levels are reached during the night, whereas the lowest levels are achieved during the day. In addition to the pineal gland, other organs and tissues also produce melatonin, like, for example, the retina, Harderian glands, gut, ovaries, testes, skin, leukocytes, or bone marrow. The list of organs is extensive, including the cerebellum, airway epithelium, liver, kidney, adrenals, thymus, thyroid, pancreas, carotid body, placenta, and endometrium. At all these locations, the availability of melatonin is intended for local use. Interestingly, a decline of the circadian amplitude of the melatonin secretion occurs in old subjects in comparison to that found in younger subjects. Moreover, genetic and environmental factors are the primary causes of diseases, and oxidative stress is a key contributor to most pathologies. Numerous studies exist that show interesting effects of melatonin in different models of disease. Impairment in its secretion might have deleterious consequences for cellular physiology. In this regard, melatonin is a natural compound that is a carrier of a not yet completely known potential that deserves consideration. Thus, melatonin has emerged as a helpful ally that could be considered as a guard with powerful tools to orchestrate homeostasis in the body, majorly based on its antioxidant effects. In this review, we provide an overview of the widespread actions of melatonin against diseases preferentially affecting the elderly. Full article

Cellular senescence is a hallmark of aging and contributes to age-related diseases, including diabetic nephropathy (DN). Additionally, macrophage-mediated inflammation has been linked with DKD. Therefore, we investigated the effect of macrophage depletion on kidney cell senescence in DN, focusing on the relationship between the GDF-15 and Klotho signaling pathways. Wistar albino rats (n = 24) were divided into four groups: healthy control, liposomal clodronate (LC)-treated healthy, diabetic, and LC-treated diabetic groups. Rats in the LC-treated healthy, diabetic, and LC-treated diabetic groups were intravenously administered LC once a week for 4 weeks. Rat models of type 2 diabetes were successfully established via the administration of streptozotocin and a high-fat diet, as evidenced by increased blood glucose levels, kidney weight to body weight (KW/BW) ratio, serum albumin, creatinine, and urea levels, kidney damage, and oxidative stress. However, LC-mediated macrophage depletion reduced the KW/BW ratio, improved serum and oxidative parameters, decreased inflammatory markers (IL-6 and TNF-α), and ameliorated oxidative stress. Additionally, LC treatment promoted macrophage polarization towards the anti-inflammatory phenotype, downregulated GDF-15 expression, upregulated Klotho expression, and ameliorated kidney damage. In conclusion, macrophage depletion combats kidney senescence by modulating Klotho and GDF-15, indicating their potential as novel targets in DN treatment. Full article

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. Full article

Background: GM3 Synthase Deficiency (GM3SD) is a rare autosomal recessive neurodevelopmental disease characterized by recurrent seizures and neurological deficits. The disorder stems from mutations in the ST3GAL5 gene, encoding GM3 synthase (GM3S), a key enzyme in ganglioside biosynthesis. While enzyme deficiencies affecting ganglioside catabolism are well-documented, the consequences of impaired ganglioside biosynthesis remain less explored. Methods: To investigate GM3SD, we used a Human Embryonic Kidney 293-T (HEK293-T) knockout (KO) cell model generated via CRISPR/Cas9 technology. Lipid composition was assessed via high-performance thin-layer chromatography (HPTLC); glycohydrolase activity in lysosomal and plasma membrane (PM) fractions was enzymatically analyzed. Lysosomal homeostasis was evaluated through protein content analysis and immunofluorescence, and cellular bioenergetics was measured using a luminescence-based assay. Results: Lipidome profiling revealed a significant accumulation of lactosylceramide (LacCer), the substrate of GM3S, along with increased levels of monosialyl-globoside Gb5 (MSGb5), indicating a metabolic shift in glycosphingolipid biosynthesis. Lipid raft analysis revealed elevated cholesterol levels, which may impair microdomain fluidity and signal transduction. Furthermore, altered activity of lysosomal and plasma membrane (PM)-associated glycohydrolases suggests secondary deregulation of glycosphingolipid metabolism, potentially contributing to abnormal lipid patterns. In addition, we observed increased lysosomal mass, indicating potential lysosomal homeostasis dysregulation. Finally, decreased adenosine triphosphate (ATP) levels point to impaired cellular bioenergetics, emphasizing the metabolic consequences of GM3SD. Conclusions: Together, these findings provide novel insights into the molecular alterations associated with GM3SD and establish the HEK293-T KO model as a promising platform for evaluating potential therapeutic strategies. Full article

Lipotoxicity, resulting from the buildup of excess lipids in non-adipose tissues, is increasingly recognized as a major contributor to the progression of kidney disease, highlighting the need for alternative models to assess its effects on renal cells. The main aim of this study was to investigate the usefulness of Caki-1, a human proximal tubule (PT) and renal cell carcinoma (RCC) representative cell line, as a 3D model system for studying free fatty acid-induced PT lipotoxicity. Caki-1 spheroids were generated and maintained on ultra-low attachment plates and characterized regarding time-dependent morphology changes. In optimal 3D culture conditions, Caki-1 cells formed well-defined large compact spheroids with uniform morphology, good circularity, and increased diameter from days 4–12. Chronic exposure to saturated palmitate resulted in dose- and time-dependent spheroid disintegration and cell death, including dispersed and flattened spheroid morphology, with increased dead cells in the peripheral layers and decreased spheroid core. Moreover, palmitate-treated spheroids showed a significant increase in cleaved poly(ADP-ribose) polymerase (PARP) and active caspase-3. Palmitate-induced PARP cleavage, as well as endoplasmic reticulum (ER) stress and autophagy dysfunction, were blunted by triacsin C, an inhibitor of long-chain acyl-CoA synthetases. In addition, co-incubation with unsaturated oleate prevented palmitate-induced spheroid disintegration and apoptotic cell death in Caki-1 3D culture. While fatty acid overload upregulated lipid droplet protein perilipin 2 in Caki-1 cells, knockdown of perilipin 2 by siRNAs resulted in an exacerbation of palmitate-induced cell death. Together, these results indicate that the 3D Caki-1 spheroid model is a simple and reproducible in vitro system for studying renal lipotoxicity and lipid metabolism that gives useful readouts at the molecular, cellular, and multicellular levels. Full article

Cilia are highly specialized cellular projections emanating from the cell surface, whose defects contribute to a spectrum of diseases collectively known as ciliopathies. Intraflagellar transport protein 88 (IFT88) is a crucial component of the intraflagellar transport-B (IFT-B) subcomplex, a protein complex integral to ciliary transport. The absence of IFT88 disrupts the formation of ciliary structures; thus, animal models with IFT88 mutations, including the oak ridge polycystic kidney (ORPK) mouse model and IFT88 conditional allelic mouse model, are frequently employed in molecular and clinical studies of ciliary functions and ciliopathies. IFT88 plays a pivotal role in a variety of cilium-related processes, including organ fibrosis and cyst formation, metabolic regulation, chondrocyte development, and neurological functions. Moreover, IFT88 also exhibits cilium-independent functions, such as spindle orientation, planar cell polarity establishment, and actin organization. A deeper understanding of the biological events and molecular mechanisms mediated by IFT88 is anticipated to advance the development of diagnostic and therapeutic strategies for related diseases. Full article

Background/Objectives: Tuberous sclerosis complex (TSC) is a rare, autosomal dominant genetic disorder caused by mutations in the TSC1 and TSC2 genes, which disrupt the regulation of the mammalian target of rapamycin (mTOR) pathway, a critical regulator of cellular growth. The disorder presents as a multisystem condition, with benign tumors (hamartomas) developing in organs such as the brain, skin, heart, kidneys, and lungs, leading to significant clinical variability and impact on quality of life. This review aims to summarize recent advances in the understanding of TSC pathogenesis and clinical variability and evaluate the therapeutic breakthroughs in targeted treatments. Methods: A narrative review was conducted using various available databases. We applied objective evaluation metrics, such as the impact factor of the journals and the citation count, to assess the quality of the studies. Results: Targeted therapies, particularly mTOR inhibitors (mTORis), have shown efficacy in reducing hamartoma size, improving neuropsychiatric symptoms, and enhancing patient outcomes. Despite these advances, variability in disease expression poses challenges in diagnosis and individualized management strategies. Conclusions: Challenges such as early diagnosis, optimizing long-term outcomes, and addressing residual unmet needs remain critical. Future research should prioritize precision medicine approaches and patient-centered care models within centers of expertise to improve treatment efficacy and quality of life for individuals with TSC. Full article