Reduce Kidney Damage Research Articles

Oxygenation by Intravascular Photosynthesis Reduces Kidney Damage During ex Vivo Preservation.

Several clinical issues are associated with reduced oxygen delivery to tissues due to impaired vascular perfusion; moreover, organs procured for transplantation are subjected to severe hypoxia during preservation. Consequently, alternative tissue oxygenation is an active field in biomedical research where several innovative approaches have been recently proposed. Among these, intravascular photosynthesis represents a promising approach as it relies on the intrinsic capacity of certain microorganisms to produce oxygen upon illumination. In this context, this work aims at the development of photosynthetic perfusable solutions that could be applied to preserve organs for transplantation purposes. Our findings demonstrate that a biocompatible physiological solution containing the photosynthetic microalgae Chlamydomonas reinhardtii can fulfill the metabolic oxygen demand of rat kidney slices in vitro. Furthermore, intravascular administration of this solution does not induce tissue damage in the rat kidneys. Moreover, kidney slices obtained from these algae-perfused organs exhibited significantly improved preservation after 24 h of incubation in hypoxia while exposed to light, resulting in reduced tissue damage and enhanced metabolic status. Overall, the results presented here contribute to the development of alternative strategies for tissue oxygenation, supporting the use of perfusable photosynthetic solutions for organ preservation in transplantation.

Quercetin ameliorates lupus symptoms by promoting the apoptosis of senescent Tfh cells via the Bcl-2 pathway

Systemic lupus erythematosus (SLE) is an autoimmune disorder that commonly affects the skin, kidneys, joints, and various other systemic tissues, with its development intricately linked to the process of immunosenescence. Quercetin (QC), a phytochemical that occurs naturally, demonstrates many different biological capabilities, such as antibacterial, antioxidant, and anti-inflammatory activities. Our investigation found that QC effectively reduced kidney damage and relieved mesenteric lymph nodes (mLNs) swelling in MRL/lpr lupus mice. Moreover, QC has been found to decrease the number of senescent follicular helper T (Tfh) cells, a pivotal kind of T cells that contribute to the progression of SLE. In vitro, QC exhibited the capacity to modulate mRNA expression levels, with the downregulation of IL-6, IL21-AS1, IL-27, BCL6, and BCL2L12, and the upregulation of FOXP1 and BIM. This modulation resulted in the suppression of Tfh cells differentiation and the enhancement of apoptosis in senescent CD4+ T cells. In addition, the HuProtTM Human Proteome Microarray revealed that QC can directly bind to BCL-2 protein and therefore promote the apoptosis of senescent CD4+ T cell. As a result, our investigative elucidate the potent inhibitory action of QC on the ontogeny of Tfh cells, along with its capacity to abrogate the immunosenescent phenotype. This positions QC as a promising therapeutic strategy for treating SLE.

High-Density Lipoprotein Anti-Inflammatory Capacity and Acute Kidney Injury After Cardiac and Vascular Surgery: A Prospective Observational Study.

Acute kidney injury (AKI) predicts death after cardiac and vascular surgery. Higher preoperative high-density lipoprotein (HDL) concentrations are associated with less postoperative AKI. In animals, HDL's anti-inflammatory capacity to suppress endothelial cell adhesion molecule expression reduces kidney damage due to ischemia and hemorrhagic shock. The objective of this study is to evaluate the statistical relationship between HDL anti-inflammatory capacity and AKI after major cardiac and vascular surgery. Prospective observational study. Quaternary medical center. One hundred adults with chronic kidney disease on long-term statin therapy undergoing major elective cardiac and vascular surgery. None. Apolipoprotein B-depleted serum collected at anesthetic induction was incubated with tumor necrosis factor alpha stimulated human endothelial cells. Reverse transcriptase-polymerase chain reaction was used to measure intercellular adhesion molecule-1 (ICAM-1) messenger RNA. Enzyme-linked immunosorbent assay assays were used to measure apolipoprotein A-I and postoperative soluble ICAM-1 concentrations in patient plasma. HDL concentration did not correlate with HDL ICAM-1 suppression capacity (Spearman R = 0.05; p = 0.64). Twelve patients (12%) were found to have dysfunctional, pro-inflammatory HDL. Patients with pro-inflammatory HDL had a higher rate of postoperative AKI than patients with anti-inflammatory HDL (p = 0.046). After adjustment for AKI risk factors, a higher preoperative HDL capacity to suppress endothelial ICAM-1 was independently associated with lower odds of AKI (odds ratio, 0.88; 95% CI, 0.80-0.98; p = 0.016). The association between HDL anti-inflammatory capacity and postoperative AKI was independent of HDL concentration (p = 0.018). Further, a higher long-term statin dose was associated with higher HDL capacity to suppress endothelial ICAM-1 (p = 0.045). Patients with chronic kidney disease undergoing cardiac and vascular surgery who have dysfunctional, pro-inflammatory HDL have a higher risk of postoperative AKI compared with patients with anti-inflammatory HDL. Conversely, a higher HDL anti-inflammatory capacity is associated with a lower risk of postoperative AKI, independent of HDL concentration. Higher long-term statin dose is associated with higher HDL anti-inflammatory capacity.

Protection Effect of Soy Isoflavones (Genistein and Daidzein) on Hematologic Parameters in Acute Kidney Injury

Background: Acute kidney injury (AKI) is a severe, high-morbidity condition with limited effective preventative and therapeutic strategies despite advancements in understanding and treatment. Specific Background: Rhabdomyolysis-induced acute kidney injury (AKI) presents significant challenges in renal research, but soy isoflavones, particularly GN and DZ, have shown potential in mitigating oxidative stress and inflammation. Knowledge Gap: Soy isoflavones, while potentially providing renal protection, their impact on renal and hematologic parameters in glycerol-induced AKI models has not been thoroughly studied. Aims: The study evaluated the effectiveness of soy isoflavones in regulating renal and hematologic parameters in a glycerol-induced AKI rat model, assessing their potential as therapeutic agents. Results: The study involving adult female Wistar rats showed that pretreatment with glycerol or dihydroxystilbene significantly reduced urinary β2-microglobulin, albumin, BUN, and serum creatinine levels in the AKI-induced group, reversing hematological changes. Novelty: The study explores the protective effects of soy isoflavones on renal function and hematologic parameters in AKI, highlighting GN's superior efficacy over DZ. Implications: Soy isoflavones, particularly GN, may be potential preventive or therapeutic strategies for AKI caused by rhabdomyolysis, warranting further research for clinical applications. Highlights: GN and DZ reduce kidney damage in glycerol-induced AKI. GN is more effective than DZ in kidney and blood parameters. Soy isoflavones could treat or prevent AKI. Keywords: Acute kidney injury, soy isoflavones, glycerol-induced AKI, renal protection, hematologic parameters

From computational prediction to experimental validation: Hesperidin's anti-Urolithiatic activity in sodium oxalate-induced urolithiasis models in fruit flies and mice

Kidney stones have been a long-standing health issue, contributing to renal failure, especially in co-morbid patients. There is an increasing interest in exploring natural compounds with anti-urolithiatic properties. Our study utilized in-silico techniques followed by in vivo experiments to evaluate the anti-urolithiatic potential of selected phytoconstituents. Molecular docking studies were conducted on 11 different targets, including inhibitors of kidney stone formation, antioxidant enzymes, and biomarkers of kidney injury, to explore the potential of anti-urolithiatic effects of 38 phytoconstituents from medicinal plants possessing diuretic activity. Further, the anti-urolithiatic activity of the phytoconstituent was evaluated using a sodium oxalate-induced urolithiatic fruit fly and mouse model. Hesperidin emerged as a promising candidate, exhibiting binding interactions with a specific set of 11 target proteins involved in crystal formation with minimal free energy. Hesperidin demonstrated promising anti-urolithiatic potential in mitigating urolithiasis as evidenced by reduced crystal covered area of Malpighian tubules of fruit fly and reduced blood urea nitrogen (BUN), serum creatinine and serum sodium, potassium levels in mice. Moreover, it increased urine volume, preventing crystal deposition, and reduced urine urea nitrogen, creatinine, sodium, and potassium levels, enhancing urine flow and preventing crystal accumulation. Histopathological analysis further supported its efficacy by showing minimal crystal deposition and reduced kidney damage. Hesperidin exhibited superior effectiveness in reducing various serum and urine parameters, making it promising alternatives for urolithiasis management warranting further investigation to determine its safety and optimal dosages in human.

The protective effect of hydroalcoholic Citrus aurantifolia peel extract against doxorubicin-induced nephrotoxicity

Background and purpose: Doxorubicin chemotherapy is a widely used treatment for various cancers, including breast, ovarian, and uterine cancers, among others. However, long-term use can cause nephrotoxicity side effects. Some citrus flavonoids have demonstrated nephroprotective activity; therefore, this study aimed to test the nephroprotective effectiveness of Citrus aurantifolia peel extract in protecting and reducing kidney damage caused by doxorubicin. Experimental approach: Citrus aurantifolia peel was dried, ground, and extracted by ultrasonication (70% ethanol), then the extract was dried. Twenty-five female Sprague-Dawley rats were divided into 5 groups including the normal group (control), positive control (doxorubicin) group receiving doxorubicin at the repeated intraperitoneal (i.p.) dose of 4 mg/kg/day on days 2, 6, 10, and 14, and treatment groups receiving Citrus aurantifolia peel extract (CPE) with the doses of 100, 200, and 400 mg/kg/day orally for 14 days, and doxorubicin (4 mg/kg/day, i.p.) on days 2, 6, 10 and 14. On day 15, the rats were euthanized for the measurements of MDA, superoxide dismutase (SOD), catalase, kidney function (measuring blood urea nitrogen (BUN), creatinine, albumin serum levels), and renal histopathology. Findings/Results: The CPE yield was 16.13%. CPE could significantly reduce the levels of MDA, and increase SOD and catalase activities compared with the doxorubicin-induced nephrotoxic model. CPE could increase renal function by reducing BUN and creatinine levels, increasing albumin, and improving the histopathology of the kidney. Conclusion and implications: CPE has a potential effect as nephroprotective against doxorubicin-induced toxicity in renal through antioxidant capacities and increased renal function.

Cyclic Adenosine Monophosphate Signaling in Chronic Kidney Disease: Molecular Targets and Therapeutic Potentials.

Chronic kidney disease (CKD) is characterized by a steady decline in kidney function and affects roughly 10% of the world's population. This review focuses on the critical function of cyclic adenosine monophosphate (cAMP) signaling in CKD, specifically how it influences both protective and pathogenic processes in the kidney. cAMP, a critical secondary messenger, controls a variety of cellular functions, including transcription, metabolism, mitochondrial homeostasis, cell proliferation, and apoptosis. Its compartmentalization inside cellular microdomains ensures accurate signaling. In kidney physiology, cAMP is required for hormone-regulated activities, particularly in the collecting duct, where it promotes water reabsorption through vasopressin signaling. Several illnesses, including Fabry disease, renal cell carcinoma, nephrogenic diabetes insipidus, Bartter syndrome, Liddle syndrome, diabetic nephropathy, autosomal dominant polycystic kidney disease, and renal tubular acidosis, have been linked to dysfunction in the cAMP system. Both cAMP analogs and phosphodiesterase inhibitors have the potential to improve kidney function and reduce kidney damage. Future research should focus on developing targeted PDE inhibitors for the treatment of CKD.

Inhibitory effects of Eplerenone on angiogenesis via modulating SGK1/TGF-β pathway in contralateral kidney of CKD pregnancy rats

BackgroundEplerenone is a selective aldosterone receptor blocker that is effective in preventing the progression of chroinic kidney disease (CKD). However, its mechanism and role in CKD pregnancy still remain uncertain. The aim of this study was to evaluate whether eplerenone could attenuated the fibrosis of unilateral ureteral obstruction (UUO) pregnant rats' contralateral kidney, improved pregnancy outcome and explore its therapeutic mechanisms. MethodsA pregnancy rat model of UUO established, female Wistar rats were randomly assigned into sham-operated group (Sham group),sham-operated combined pregnancy group (SP group), unilateral ureteral obstruction combined pregnancy group (UUO + Pregnancy group), unilateral ureteral obstruction combined pregnancy, administered eplerenone (UUO + Pregnancy+Eplerenone group). On the 18th day of pregnancy, the rats were placed in a metabolic cage, 24 h urine was collected and stored at −80 °C. Next day, all animals were euthanized, and serum was collected by centrifugation and stored at −20 °C. Then the right kidney was extracted, a part of the kidney was placed in 4% paraformaldehyde for morphology, immunohistochemical staining, and immunofluorescence staining, and the other part was placed in a − 80 °C refrigerator for RNA and protein extraction. In vitro, HUVECs was treated with aldosterone, progesterone and estradiol, VEGFA and its receptor blocker bevacizumab. The ability of proliferation, migration and tubularization of HUVECs was detected by CCK-8, scratch wound assay and endothelial tube formation assay. And the co-expression of CD34 and α-SMA of HUVECs was detected by Flow cytometry. ResultsImmunofluorescence results showed that the co-expression of CD34 and α-SMA increased in the UUO + Pregnancy group was significantly increased. The expression of SGK-1, TGFβ-1, Smad2, Smad3, VEGF-A, VEGFR2, CD34, α-SMA and Collagen I was significantly higher in the kidneys of the UUO + Pregnancy group compared to the Sham group and SP group. Eplerenone inhibited the expression of those results. In vitro, the ability of proliferation, migration and tubularization was increased after treated with aldosterone, aldosterone with progesterone and estradiol or VEGFA. Similarly, the expression of α-SMA on the surface of HUVECs treated with aldosterone, aldosterone with progesterone and estradiol were increased, while eplerenone supressed its expression. ConclusionEplerenone inhibits renal angiogenesis by blocking the SGK-1/TGFβ signal transduction pathway, thereby inhibiting the phenotypic transformation of endothelial cells, slowing down renal fibrosis, and reducing kidney damage caused by pregnancy.

The effect of ginger essential oil (Zingiber officinale) on catalase in rat kidney tissue

We were aimed to investigate the effect of ginger essential oil (Zingiber officinale) on catalase release in rat kidney tissue by histopathological and immunohistochemically method. This study, 21 male Wistar albino rats were used. Rats were divided into three groups: control, 100 mg/kg ginger essential oil (G100), and 500 mg/kg ginger essential oil (G500). Hematoxylin-eosin staining method was used for histopathological evaluations. Immunohistochemically localization of catalase in kidney tissue was determined by streptavidin-biotin peroxidase method. As a result of histopathological evaluations, an increase in glomerulus diameter was observed in kidney tissues of G100 and G500 groups. In addition, vacuolar degeneration was observed in the proximal and distal tubule epithelial cells in the renal cortex of the G100 group. The immunoreactivity of catalase in the renal cortex region; In the control group, it is strong in the proximal tubules and weak in the mesangial cells. While moderate severity in the proximal tubules and weak in the mesangial cells in the G100 group, very weak catalase immunoreactivity was observed in the G500 group. Strong catalase immunoreactivity was detected in the proximal and collecting ducts of the kidney medulla regions of the rats in all groups. We think that ginger essential oil can be used in appropriate doses and times to reduce kidney damage caused by oxidative stress in the kidney.

Inulin Reduces Kidney Damage in Type 2 Diabetic Mice by Decreasing Inflammation and Serum Metabolomics.

This study is aimed at assessing the impact of soluble dietary fiber inulin on the treatment of diabetes-related chronic inflammation and kidney injury in mice with type 2 diabetes (T2DM). The T2DM model was created by feeding the Institute of Cancer Research (ICR) mice a high-fat diet and intraperitoneally injecting them with streptozotocin (50 mg/kg for 5 consecutive days). The thirty-six ICR mice were divided into three dietary groups: the normal control (NC) group, the T2DM (DM) group, and the DM + inulin diet (INU) group. The INU group mice were given inulin at the dose of 500 mg/kg gavage daily until the end of the 12th week. After 12 weeks, the administration of inulin resulted in decreased serum levels of fasting blood glucose (FBG), low-density lipoprotein cholesterol (LDL-C), blood urea nitrogen (BUN), and creatinine (CRE). The administration of inulin not only ameliorated renal injury but also resulted in a reduction in the mRNA expressions of inflammatory factors in the spleen and serum oxidative stress levels, when compared to the DM group. Additionally, inulin treatment in mice with a T2DM model led to a significant increase in the concentrations of three primary short-chain fatty acids (SCFAs) (acetic acid, propionic acid, and butyric acid), while the concentration of advanced glycation end products (AGEs), a prominent inflammatory factor in diabetes, exhibited a significant decrease. The results of untargeted metabolomics indicate that inulin has the potential to alleviate inflammatory response and kidney damage in diabetic mice. This beneficial effect is attributed to its impact on various metabolic pathways, including glycerophospholipid metabolism, taurine and hypotaurine metabolism, arginine biosynthesis, and tryptophan metabolism. Consequently, oral inulin emerges as a promising treatment option for diabetes and kidney injury.

The Nephroprotective Effects of Pomegranate Juice against Lithium-Induced Kidney Damage in Rats

Background: This study aims to investigate the effect of pomegranate juice on kidney damage caused by lithium in rats. Methods: Six groups of animals were studied, group one received neither lithium nor pomegranate juice, group two received only lithium, group three received only pomegranate juice, and groups four to six received both lithium and pomegranate juice at different doses. Kidney biomarkers were investigated as indicators of acute kidney failure. Results: Comparison between the studied groups regarding the amount of creatinine in the serum of rats showed a significant relationship between serum creatinine levels of rats in the group receiving lithium and the control group, and the group receiving lithium and those receiving pomegranate juice at a dose of 100 mg/kg. A significant relationship was observed in the study of serum urea amount in rats between the control group and the group receiving lithium, and the lithium group and the group receiving pomegranate juice at a dose of 100 mg/kg. Conclusions There was no significant difference between the groups when the amount of cystatin C in the serum of rats was compared. Pomegranate juice at 100 mg/kg and lithium (25mg/kg) led to a significant decrease in serum creatinine levels, which reduced kidney damage induced by lithium. Serum urea also decreased significantly, suggesting that pomegranate has anti-toxic effects on kidneys from lithium toxicity

Time-restricted feeding does not improve nephropathy in humanized sickle cell disease mice

Sickle cell disease (SCD) is an autosomal recessive genetic disease caused by a point mutation in the hemoglobin gene. This substitution results in a “sickling” of red blood cells and subsequent vascular and organ damage. Current treatments, while increasing the lifespan of sickle cell patients, has resulted in a higher prevalence of chronic complications like SCD nephropathy. Our group has previously shown that time-restricted feeding (TRF) in chronic high fat fed mice reduces kidney damage. Given the increased kidney damage in SCD, we hypothesize that TRF in humanized SCD mice will attenuate sickle cell nephropathy. To test this hypothesis, we studied 18-22-week-old male SCD mice. Mice underwent 3 weeks of TRF, only having access to food during the active, dark period (Zeitgeber Time (ZT) 12 to 24). The control group had access to food ad libitum (ad-lib). At the end of the 3 weeks, at 21-25 week old ages, 12 hour urine was collected in metabolic cages as well as kidneys and plasma collection at ZT3 (inactive period). Excretion of urinary kidney damage markers (albumin and NGAL-1) showed no difference between TRF and ad-lib in both the active and inactive collection periods. Urinary excretion of endothelin-1 is known to be upregulated in SCD patients; however, TRF did not change this marker in SCD mice. TRF did not change plasma levels of cytokines or soluble adhesion molecules. Histological analysis of kidneys was conducted as an additional marker of kidney damage. We analyzed iron levels in the kidney with Prussian blue staining as well as fibrosis with Masson’s trichrome. TRF did not change kidney iron accumulation or kidney fibrosis. Immunohistochemical staining for CD3+ T cells did not show a difference in glomerular T cell infiltration in the TRF group compared to the ad-lib group. In conclusion, TRF does not appear to have an effect on renal inflammation or kidney function in SCD mice, but future studies need to be completed. R01 DK134562. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Exosomes From Human Umbilical Cord Stem Cells Suppress Macrophage-to-myofibroblast Transition, Alleviating Renal Fibrosis.

Renal fibrosis, a progressive scarring of the kidney, lacks effective treatment. Human umbilical cord mesenchymal stem cell-derived exosomes (HucMSC-Exos) hold promise for treating kidney diseases due to their anti-inflammatory properties. This study investigates their potential to lessen renal fibrosis by targeting macrophage-to-myofibroblast transformation (MMT), a key driver of fibrosis.We employed a mouse model of unilateral ureteral obstruction (UUO) and cultured cells exposed to transforming growth factor-β (TGF-β) to mimic MMT.HucMSC-Exos were administered to UUO mice, and their effects on kidney function and fibrosis were assessed. Additionally, RNA sequencing and cellular analysis were performed to elucidate the mechanisms by which HucMSC-Exos inhibit MMT. HucMSC-Exos treatment significantly reduced kidney damage and fibrosis in UUO mice. They downregulated markers of fibrosis (Collagen I, vimentin, alpha-smooth muscle actin) and suppressed MMT (α-SMA + F4/80 + cells). Furthermore, ARNTL, a specific molecule, emerged as a potential target of HucMSC-Exos in hindering MMT and consequently preventing fibrosis.HucMSC-Exos effectively lessen renal fibrosis by suppressing MMT, suggesting a novel therapeutic strategy for managing kidney damage and fibrosis.

Evaluation of the efficacy of silymarin and dexmedetomidine on kidney and lung tissue in the treatment of sepsis in rats with cecal perforation.

Sepsis is a systemic inflammatory response syndrome that develops in the host against microorganisms. This response develops away from the primary infection site and results in end-organ damage. The present study aimed to investigate the protective and therapeutic effects on lung and kidney tissue of silymarin (S) and dexmedetomidine (DEX) applied 1 h before and after sepsis induced by the cecal ligation and puncture (CLP) method in rats. A total of 62 rats was randomly divided into eight groups: i) Control (n=6); ii) cecal perforation (CLP; n=8); iii) S + CLP (n=8; S + CLP; S administered 1 h before CPL); iv) CLP + S (n=8; S administered 1 h after CLP); v) DEX + CLP (n=8; D + CLP; DEX administered 1 h before CLP); vi) CLP + D (n=8; DEX administered 1 h after CLP); vii) SD + CLP (n=8; S and DEX administered 1 h before CLP) and viii) CLP + SD (n=8; S and DEX administered 1 h after CLP). After the cecum filled with stool, it was tied with 3/0 silk under the ileocecal valve and the anterior surface of the cecum was punctured twice with an 18-gauge needle. A total of 100 mg/kg silymarin and 100 µg/kg DEX were administered intraperitoneally to the treatment groups. Lung and kidney tissue samples were collected to evaluate biochemical and histopathological parameters. In the histopathological examination, all parameters indicating kidney injury; interstitial edema, peritubular capillary dilatation, vacuolization, ablation of tubular epithelium from the basement membrane, loss of brush border in the proximal tubule epithelium, cell swelling and nuclear defragmentation; were increased in the CLP compared with the control group. Silymarin administration increased kidney damage, including ablation of tubular epithelium from the basement membrane, compared with that in the CLP group. DEX significantly reduced kidney damage compared with the CLP and silymarin groups. The co-administration of DEX + silymarin decreased kidney damage, although it was not as effective as DEX-alone. To conclude, intraperitoneal DEX ameliorated injury in CLP rats. DEX + silymarin partially ameliorated injury but silymarin administration increased damage. As a result, silymarin has a negative effects with this dosage and DEX has a protective effect. In the present study, it was determined that using the two drugs together had a greater therapeutic effect than silymarin and no differences in the effects were not observed any when the application times of the agents were changed.

Revolutionising CKD Care: Novel Treatment Paradigms and Cutting-edge Strategies

Chronic Kidney Disease (CKD) represents a public health crisis globally. New therapeutic horizons in CKD management encompass a diverse array of options for a more holistic and personalised approach. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors exhibit promising results in preserving kidney function and mitigating cardiovascular risks in patients with or without diabetes. Non-steroidal selective Mineralocorticoid Receptor Antagonists (MRA) present targeted strategies for CKD management. Glucagon-like peptide-1 (GLP-1) receptor agonists offer innovative approaches for glycaemic control and complication reduction. Endothelin Receptor Antagonists contribute to CKD care by modulating endothelial function and reducing kidney damage. Aldosterone synthase inhibitors offer a unique angle, targeting aldosterone production to manage CKD-related complications. Additionally, hypoxia-inducible factor (HIF) inhibitors represent a cutting-edge therapeutic class, addressing the hypoxic conditions associated with kidney damage. This diverse range of advancements underscores a transformative shift towards more personalised and effective CKD treatments, providing newfound optimism for improved patient outcomes. Beyond providing evidence-based insights into recent therapeutic advancements in CKD, this review also delineates contemporary treatment guidelines for CKD. It underscores the imperative for holistic strategies to enhance outcomes for individuals grappling with this complex condition.

Associations of environmental cadmium exposure with kidney damage: Exploring mediating DNA methylation sites in Chinese adults

Environmental exposure is widely recognized as the primary sources of Cadmium (Cd) in the human body, and exposure to Cd is associated with kidney damage in adults. Nevertheless, the role of DNA methylation in Cd-induced kidney damage remains unclear. This study aimed to investigate the epigenome-wide association of environmental Cd-related DNA methylation changes with kidney damage. We included 300 non-smoking adults from the China in 2019. DNA methylation profiles were measured with Illumina Infinium MethylationEPIC BeadChip array. Linear mixed-effect model was employed to estimate the effects of urinary Cd with DNA methylation. Differentially methylated positions (DMPs) associated with urinary Cd were then tested for the association with kidney damage indicators. The mediation analysis was further applied to explore the potential DNA methylation based mediators. The prediction model was developed using a logistic regression model, and used 1000 bootstrap resampling for the internal validation. We identified 27 Cd-related DMPs mapped to 20 genes after the adjustment of false-discovery-rate for multiple testing among non-smoking adults. 17 DMPs were found to be associated with both urinary Cd and kidney damage, and 14 of these DMPs were newly identified within the Chinese. Mediation analysis revealed that DNA methylation of cg26907612 and cg16848624 mediated the Cd-related reduced kidney damage. In addition, ten variables were selected using the LASSO regression analysis and were utilized to develop the prediction model. It found that the nomogram model predicted the risk of kidney damage caused by environmental Cd with a corrected C-index of 0.779. Our findings revealed novel DMPs associated with both environmental Cd exposure and kidney damage among non-smoking adults, and developed an easy-to-use nomogram-illustrated model using these novel DMPs. These findings could provide a theoretical basis for formulating prevention and control strategies for kidney damage from the perspective of environmental pollution and epigenetic regulation.

Astaxanthin treatment reduces kidney damage and facilitates antioxidant recovery in lithium-intoxicated rats

ObjectiveThis study aimed to evaluate the protective effects of astaxanthin against lithium-induced nephrotoxicity, focusing on histopathological changes, oxidative stress modulation, and alteration in the expression of key proteins related to apoptosis and inflammation. MethodsIn this study, 56 male rats were utilized and divided into experimental groups subjected to lithium-induced nephrotoxicity, with and without astaxanthin treatment, over 14 and 28 days. The parameters assessed included oxidative stress markers (MDA, GSH, SOD), protein expression levels of BCL-2, BAX, TNF- α, PI3K, NF-κ B-p65, IL-1β, and comprehensive histopathological examinations to evaluate the integrity of renal tissue. ResultsLithium exposure led to significant renal damage, as evidenced by histological distortions in renal architecture, increased oxidative stress indicated by elevated MDA levels, and dysregulated expressions of apoptotic and inflammatory proteins. Notably, histopathological analysis revealed glomerular and tubular degeneration in lithium-treated groups. Astaxanthin treatment effectively mitigated these effects, demonstrating its efficacy in reducing lipid peroxidation, rebalancing apoptotic proteins, suppressing pro-inflammatory cytokines, and preserving renal histological structure. The concurrent use of lithium and astaxanthin showed a considerable amelioration of lithium-induced damage, suggesting astaxanthin's role in attenuating the nephrotoxic effects of lithium, both at a molecular and structural level. ConclusionAstaxanthin demonstrates significant renoprotective effects against lithium-induced nephrotoxicity, suggesting its utility as an effective adjunctive therapy. Through its potent antioxidative, anti-inflammatory, and anti-apoptotic actions, astaxanthin effectively reduces renal damage associated with lithium treatment, underscoring its potential for enhancing renal health in patients receiving lithium therapy.

Evaluating the Effects of Kidney Preservation at 10 °C with Hemopure and Sodium Thiosulfate in a Rat Model of Syngeneic Orthotopic Kidney Transplantation.

Kidney transplantation is preferred for end-stage renal disease. The current gold standard for kidney preservation is static cold storage (SCS) at 4 °C. However, SCS contributes to renal graft damage through ischemia-reperfusion injury (IRI). We previously reported renal graft protection after SCS with a hydrogen sulfide donor, sodium thiosulfate (STS), at 4 °C. Therefore, this study aims to investigate whether SCS at 10 °C with STS and Hemopure (blood substitute), will provide similar protection. Using in vitro model of IRI, we subjected rat renal proximal tubular epithelial cells to hypoxia-reoxygenation for 24 h at 10 °C with or without STS and measured cell viability. In vivo, we preserved 36 donor kidneys of Lewis rats for 24 h in a preservation solution at 10 °C supplemented with STS, Hemopure, or both followed by transplantation. Tissue damage and recipient graft function parameters, including serum creatinine, blood urea nitrogen, urine osmolality, and glomerular filtration rate (GFR), were evaluated. STS-treated proximal tubular epithelial cells exhibited enhanced viability at 10 °C compared with untreated control cells (p < 0.05). Also, STS and Hemopure improved renal graft function compared with control grafts (p < 0.05) in the early time period after the transplant, but long-term function did not reach significance. Overall, renal graft preservation at 10 °C with STS and Hemopure supplementation has the potential to enhance graft function and reduce kidney damage, suggesting a novel approach to reducing IRI and post-transplant complications.

PSTPIP2 ameliorates aristolochic acid nephropathy by suppressing interleukin-19-mediated neutrophil extracellular trap formation.

Aristolochic acid nephropathy (AAN) is a progressive kidney disease caused by herbal medicines. Proline-serine-threonine phosphatase-interacting protein 2 (PSTPIP2) and neutrophil extracellular traps (NETs) play important roles in kidney injury and immune defense, respectively, but the mechanism underlying AAN regulation by PSTPIP2 and NETs remains unclear. We found that renal tubular epithelial cell (RTEC) apoptosis, neutrophil infiltration, inflammatory factor, and NET production were increased in a mouse model of AAN, while PSTPIP2 expression was low. Conditional knock-in of Pstpip2 in mouse kidneys inhibited cell apoptosis, reduced neutrophil infiltration, suppressed the production of inflammatory factors and NETs, and ameliorated renal dysfunction. Conversely, downregulation of Pstpip2 expression promoted kidney injury. In vivo, the use of Ly6G-neutralizing antibody to remove neutrophils and peptidyl arginine deiminase 4 (PAD4) inhibitors to prevent NET formation reduced apoptosis, alleviating kidney injury. In vitro, damaged RTECs released interleukin-19 (IL-19) via the PSTPIP2/nuclear factor (NF)-κB pathway and induced NET formation via the IL-20Rβ receptor. Concurrently, NETs promoted apoptosis of damaged RTECs. PSTPIP2 affected NET formation by regulating IL-19 expression via inhibition of NF-κB pathway activation in RTECs, inhibiting RTEC apoptosis, and reducing kidney damage. Our findings indicated that neutrophils and NETs play a key role in AAN and therapeutic targeting of PSTPIP2/NF-κB/IL-19/IL-20Rβ might extend novel strategies to minimize Aristolochic acid I-mediated acute kidney injury and apoptosis.

Colonic microflora and plasma metabolite-based comparative analysis of unilateral ureteral obstruction-induced chronic kidney disease after treatment with the Chinese medicine FuZhengHuaYuJiangZhuTongLuo and AST-120

BackgroundMany researchers have investigated the use of Chinese herbs to delay the progression of chronic kidney disease (CKD) through their effects on colonic microflora and microbiota-derived metabolites. However, whether FuZhengHuaYuJiangZhuTongLuo (FZHY) has effects that are similar to those of AST-120 on CKD needs to be elucidated. MethodsIn this study, we compared the effects of FZHY and AST-120 on the colonic microbiota and plasma metabolites in the CKD rat model. We developed a unilateral ureteral obstruction (UUO)-induced CKD rat model and then administered FZHY and AST-120 to these model rats. Non-targeted metabolomic LC-MS analysis, 16S rRNA sequencing, and histopathological staining were performed on plasma, stool, and kidney tissues, respectively, and the joint correlation between biomarkers and metabolites of candidate bacteria was analyzed. ResultsOur results showed that administering FZHY and AST-120 effectively ameliorated UUO-induced abnormal renal function and renal fibrosis and regulated the composition of microbiota and metabolites. Compared to the UUO model group, the p_Firmicutes and o_Peptostreptococcales_Tissierellales were increased, while 14 negative ion metabolites were upregulated and 21 were downregulated after FZHY treatment. Additionally, 40 positive ion metabolites were upregulated and 63 were downregulated. On the other hand, AST-120 treatment resulted in an increase in the levels of g_Prevotellaceae_NK3B31_group and f_Prevotellaceae, as well as 12 upregulated and 23 downregulated negative ion metabolites and 56 upregulated and 63 downregulated positive ion metabolites. Besides, FZHY increased the levels of candidate bacterial biomarkers that were found to be negatively correlated with some poisonous metabolites, such as 4-hydroxyretinoic acid, and positively correlated with beneficial metabolites, such as l-arginine. AST-120 increased the levels of candidate bacterial biomarkers that were negatively correlated with some toxic metabolites, such as glycoursodeoxycholic acid, 4-ethylphenol, and indole-3-acetic acid. ConclusionFZHY and AST-120 effectively reduced kidney damage, in which, the recovery of some dysregulated bacteria and metabolites are probably involved. As their mechanisms of regulation were different, FZHY might play a complementary role to AST-120 in treating CKD.