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Nature Reviews. Nephrology Feb 2023Oxalate homeostasis is maintained through a delicate balance between endogenous sources, exogenous supply and excretion from the body. Novel studies have shed light on... (Review)
Review
Oxalate homeostasis is maintained through a delicate balance between endogenous sources, exogenous supply and excretion from the body. Novel studies have shed light on the essential roles of metabolic pathways, the microbiome, epithelial oxalate transporters, and adequate oxalate excretion to maintain oxalate homeostasis. In patients with primary or secondary hyperoxaluria, nephrolithiasis, acute or chronic oxalate nephropathy, or chronic kidney disease irrespective of aetiology, one or more of these elements are disrupted. The consequent impairment in oxalate homeostasis can trigger localized and systemic inflammation, progressive kidney disease and cardiovascular complications, including sudden cardiac death. Although kidney replacement therapy is the standard method for controlling elevated plasma oxalate concentrations in patients with kidney failure requiring dialysis, more research is needed to define effective elimination strategies at earlier stages of kidney disease. Beyond well-known interventions (such as dietary modifications), novel therapeutics (such as small interfering RNA gene silencers, recombinant oxalate-degrading enzymes and oxalate-degrading bacterial strains) hold promise to improve the outlook of patients with oxalate-related diseases. In addition, experimental evidence suggests that anti-inflammatory medications might represent another approach to mitigating or resolving oxalate-induced conditions.
Topics: Humans; Oxalates; Renal Dialysis; Kidney; Hyperoxaluria; Renal Insufficiency, Chronic; Renal Insufficiency; Homeostasis
PubMed: 36329260
DOI: 10.1038/s41581-022-00643-3 -
International Journal of Surgery... Dec 2016Nephrolithiasis is a complex disease of worldwide prevalence that is influenced by both genetic and environmental factors. About 75% of kidney stones are predominantly... (Review)
Review
Nephrolithiasis is a complex disease of worldwide prevalence that is influenced by both genetic and environmental factors. About 75% of kidney stones are predominantly composed of calcium oxalate and urinary oxalate is considered a crucial risk factor. Microorganisms may have a role in the pathogenesis and prevention of kidney stones and the involvement of the intestinal microbiome in this renal disease has been a recent area of interest. Oxalobacter formigenes is a gram negative bacteria that degrades oxalate in the gut decreasing urinary oxalate excretion. In this review, we examine the data studying the role of Oxalobacter formigenes in kidney stone disease in humans and animals, the effect of antibiotics on its colonization, and the potential role of probiotics and whole microbial communities as therapeutic interventions.
Topics: Animals; Anti-Bacterial Agents; Calcium Oxalate; Gastrointestinal Microbiome; Humans; Kidney Calculi; Oxalates; Oxalobacter formigenes; Probiotics; Risk Factors
PubMed: 27847292
DOI: 10.1016/j.ijsu.2016.11.024 -
Oxalate-induced apoptosis through ERS-ROS-NF-κB signalling pathway in renal tubular epithelial cell.Molecular Medicine (Cambridge, Mass.) Aug 2022Kidney stones are composed of approximately 70-80% calcium oxalate. However, the exact mechanism of formation of calcium oxalate kidney stones remains unclear. In this...
BACKGROUND
Kidney stones are composed of approximately 70-80% calcium oxalate. However, the exact mechanism of formation of calcium oxalate kidney stones remains unclear. In this study, we investigated the roles of endoplasmic reticulum stress (ERS), reactive oxygen species (ROS), and the NF-κB signalling pathway in the pathogenesis of oxalate-induced renal tubular epithelial cell injury and its possible molecular mechanisms.
METHODS
We established a model to evaluate the formation of kidney stones by intraperitoneal injection of glyoxylic acid solution into mice and assessed cell morphology, apoptosis, and the expression levels of ERS, ROS, and NF-κB signalling pathway-related proteins in mouse renal tissues. Next, we treated HK-2 cells with potassium oxalate to construct a renal tubular epithelial cell injury model. We detected the changes in autophagy, apoptosis, and mitochondrial membrane potential and investigated the ultrastructure of the cells by transmission electron microscopy. Western blotting revealed the expression levels of apoptosis and autophagy proteins; mitochondrial structural and functional proteins; and ERS, ROS, and NF-κB (p65) proteins. Lastly, we studied the downregulation of NF-κB activity in HK-2 cells by lentivirus interference and confirmed the interaction between the NF-κB signalling and ERS/ROS pathways.
RESULTS
We observed swelling of renal tissues, increased apoptosis of renal tubular epithelial cells, and activation of the ERS, ROS, and NF-κB signalling pathways in the oxalate group. We found that oxalate induced autophagy, apoptosis, and mitochondrial damage in HK-2 cells and activated the ERS/ROS/NF-κB pathways. Interestingly, when the NF-κB signalling pathway was inhibited, the ERS/ROS pathway was also inhibited.
CONCLUSION
Oxalate induces HK-2 cell injury through the interaction between the NF-κB signalling and ERS/ROS pathways.
Topics: Animals; Apoptosis; Calcium Oxalate; Endoplasmic Reticulum Stress; Epithelial Cells; Kidney Calculi; Mice; NF-kappa B; Oxalates; Reactive Oxygen Species
PubMed: 35922749
DOI: 10.1186/s10020-022-00494-5 -
Molecular Medicine Reports Aug 2022The present study aimed to evaluate the role and mechanism of ferrostatin‑1 (Fer‑1) in oxalate (Ox)‑induced renal tubular epithelial cell injury, fibrosis, and...
The present study aimed to evaluate the role and mechanism of ferrostatin‑1 (Fer‑1) in oxalate (Ox)‑induced renal tubular epithelial cell injury, fibrosis, and calcium oxalate (CaOx) stone formation. A CaOx model in mice kidneys was established via intraperitoneal injection of 80 mg/kg glyoxylic acid for 14 days. The mice were randomly divided into three groups (n=6), namely, the control (Con), the CaOx group, and the CaOx + Fer‑1 group. Cultured human renal tubular epithelial cells (HK‑2 cells) were randomly divided into three groups (n=3), namely, the control (Con), the Ox group, and the Ox + Fer‑1 group. The levels of heme oxygenase 1 (HO‑1), superoxide dismutase 2 (SOD2), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11) were assessed by immunofluorescence and western blot analysis. Renal tubular injury and apoptosis were evaluated by H&E and TUNEL staining. Kidney interstitial fibrosis was evaluated by Masson and Sirius red staining, and the levels of E‑cadherin, vimentin and α‑SMA were detected by immunofluorescence or western blot analysis. Mitochondrial structure was observed using a transmission electron microscope. The levels of reactive oxygen species (ROS) were determined by flow cytometry and CaOx stone formation was evaluated by von Kossa staining. The results revealed that in comparison with the Con group, mitochondrial injury under glyoxylic acid treatment was observed by TEM. The expression of GPX4 and SLC7A11 in the CaOx and Ox groups was downregulated (P<0.05), whereas the expression of HO‑1 and SOD2 was upregulated (P<0.05). Renal tissue damage, apoptosis of renal tubular epithelial cells, and interstitial fibrosis were increased in the CaOx and Ox groups (P<0.05). In comparison with the CaOx or Ox group, the expression of GPX4 and SLC7A11 in the CaOx + Fer‑1 or Ox + Fer‑1 group was upregulated (P<0.05), whereas that of HO‑1 and SOD2 was downregulated (P<0.05). Renal tissue damage, apoptosis of renal tubular epithelial cells and interstitial fibrosis were decreased following Fer‑1 treatment (P<0.05). The ROS level was also decreased following Fer‑1 treatment. Moreover, CaOx stone formation was decreased in the CaOx + Fer‑1 group (P<0.05). In conclusion, Fer‑1 alleviated Ox‑induced renal tubular epithelial cell injury, fibrosis, and CaOx stone formation by inhibiting ferroptosis.
Topics: Animals; Calcium Oxalate; Cyclohexylamines; Epithelial Cells; Ferroptosis; Fibrosis; Kidney; Mice; Oxalates; Phenylenediamines; Reactive Oxygen Species
PubMed: 35703358
DOI: 10.3892/mmr.2022.12772 -
Drugs Jul 2022The primary hyperoxalurias are three rare inborn errors of the glyoxylate metabolism in the liver, which lead to massively increased endogenous oxalate production, thus... (Review)
Review
The primary hyperoxalurias are three rare inborn errors of the glyoxylate metabolism in the liver, which lead to massively increased endogenous oxalate production, thus elevating urinary oxalate excretion and, based on that, recurrent urolithiasis and/or progressive nephrocalcinosis. Frequently, especially in type 1 primary hyperoxaluria, early end-stage renal failure occurs. Treatment possibilities are scare, namely, hyperhydration and alkaline citrate medication. In type 1 primary hyperoxaluria, vitamin B, though, is helpful in patients with specific missense or mistargeting mutations. In those vitamin B responsive, urinary oxalate excretion and concomitantly urinary glycolate is significantly decreased, or even normalized. In patients non-responsive to vitamin B, RNA interference medication is now available. Lumasiran is already available on prescription and targets the messenger RNA of glycolate oxidase, thus blocking the conversion of glycolate into glyoxylate, hence decreasing oxalate, but increasing glycolate production. Nedosiran blocks liver-specific lactate dehydrogenase A and thus the final step of oxalate production. Similar to vitamin B treatment, where both RNA interference urinary oxalate excretion can be (near) normalized and plasma oxalate decreases, however, urinary and plasma glycolate increases with lumasiran treatment. Future treatment possibilities are on the horizon, for example, substrate reduction therapy with small molecules or gene editing, induced pluripotent stem cell-derived autologous hepatocyte-like cell transplantation, or gene therapy with newly developed vector technologies. This review provides an overview of current and especially new and future treatment options.
Topics: Glycolates; Glyoxylates; Humans; Hyperoxaluria, Primary; Oxalates; RNA, Small Interfering; Vitamins
PubMed: 35779234
DOI: 10.1007/s40265-022-01735-x -
Current Opinion in Urology Mar 2020The review of potential therapies in the treatment of hyperoxaluria is timely, given the current excitement with clinical trials and the mounting evidence of the... (Review)
Review
PURPOSE OF REVIEW
The review of potential therapies in the treatment of hyperoxaluria is timely, given the current excitement with clinical trials and the mounting evidence of the importance of oxalate in both kidney stone and chronic kidney disease.
RECENT FINDINGS
Given the significant contribution of both endogenous and dietary oxalate to urinary oxalate excretions, it is not surprising therapeutic targets are being studied in both pathways. This article covers the existing data on endogenous and dietary oxalate and the current targets in these pathways.
SUMMARY
In the near future, there will likely be therapies targeting both endogenous and dietary oxalate, especially in subsets of kidney stone formers.
Topics: Adult; Animals; Diet; Humans; Hyperoxaluria; Kidney Calculi; Mice; Oxalates; Rats; Renal Insufficiency, Chronic
PubMed: 31895888
DOI: 10.1097/MOU.0000000000000709 -
Drugs Dec 2023Nedosiran (RIVFLOZA™), a once-monthly subcutaneous small interfering RNA (siRNA) therapy, is being developed by Dicerna Pharmaceuticals, a Novo Nordisk company, for... (Review)
Review
Nedosiran (RIVFLOZA™), a once-monthly subcutaneous small interfering RNA (siRNA) therapy, is being developed by Dicerna Pharmaceuticals, a Novo Nordisk company, for the treatment of primary hyperoxaluria (PH). It reduces oxalate overproduction by inhibiting the expression of the hepatic lactate dehydrogenase (LDH) enzyme. Nedosiran received its first approval on 29 September 2023 in the USA to lower urinary oxalate levels in children aged ≥ 9 years and adults with PH type 1 (PH1) and relatively preserved kidney function [e.g. estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m]. This article summarizes the milestones in the development of nedosiran leading to this first approval for PH1.
Topics: Child; Adult; Humans; Hyperoxaluria, Primary; Oxalates; Lactate Dehydrogenases; RNA, Small Interfering
PubMed: 38060091
DOI: 10.1007/s40265-023-01976-4 -
Nutrients Sep 2020Oxalate is both a plant-derived molecule and a terminal toxic metabolite with no known physiological function in humans. It is predominantly eliminated by the kidneys... (Review)
Review
Oxalate is both a plant-derived molecule and a terminal toxic metabolite with no known physiological function in humans. It is predominantly eliminated by the kidneys through glomerular filtration and tubular secretion. Regardless of the cause, the increased load of dietary oxalate presented to the kidneys has been linked to different kidney-related conditions and injuries, including calcium oxalate nephrolithiasis, acute and chronic kidney disease. In this paper, we review the current literature on the association between dietary oxalate intake and kidney outcomes.
Topics: Animals; Diet; Disease Models, Animal; Glomerular Filtration Rate; Humans; Kidney; Nephrolithiasis; Oxalates; Randomized Controlled Trials as Topic
PubMed: 32887293
DOI: 10.3390/nu12092673 -
Clinics and Research in Hepatology and... May 2024Enteric hyperoxaluria is a metabolic disorder resulting from conditions associated with fatty acid malabsorption and characterized by an increased urinary output of... (Review)
Review
Enteric hyperoxaluria is a metabolic disorder resulting from conditions associated with fatty acid malabsorption and characterized by an increased urinary output of oxalate. Oxalate is excessively absorbed in the gut and then excreted in urine where it forms calcium oxalate crystals, inducing kidney stones formation and crystalline nephropathies. Enteric hyperoxaluria is probably underdiagnosed and may silently damage kidney function of patients affected by bowel diseases. Moreover, the prevalence of enteric hyperoxaluria has increased because of the development of bariatric surgical procedures. Therapeutic options are based on the treatment of the underlying disease, limitation of oxalate intakes, increase in calcium salts intakes but also increase in urine volume and correction of hypocitraturia. There are few data regarding the natural evolution of kidney stone events and chronic kidney disease in these patients, and there is a need for new treatments limiting kidney injury by calcium oxalate crystallization.
Topics: Humans; Hyperoxaluria; Oxalates; Calcium Oxalate; Malabsorption Syndromes
PubMed: 38503362
DOI: 10.1016/j.clinre.2024.102322 -
Current Opinion in Nephrology and... Jul 2022Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder that causes hepatic overproduction of oxalate and, often, nephrocalcinosis, nephrolithiasis, chronic kidney... (Review)
Review
PURPOSE OF REVIEW
Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder that causes hepatic overproduction of oxalate and, often, nephrocalcinosis, nephrolithiasis, chronic kidney disease, and kidney failure. The purpose of the review is to provide an update on current emerging therapies for the treatment of PH1.
RECENT FINDINGS
Use of ribonucleic acid interference (RNAi) therapeutics that target the liver to block production of key enzymes along pathways that generate oxalate is a promising approach. Available evidence supports the efficacy of both Lumasiran (targeting glycolate oxidase) and Nedosiran (targeting hepatic lactate dehydrogenase (LDHa)) to reduce urinary oxalate excretion in PH1. The efficacy of alternative approaches including stiripentol (an anticonvulsant drug that also targets LDHa), lanthanum (a potential gastrointestinal oxalate binder), and Oxalobacter formigenes (a bacterium that can degrade oxalate within the gastrointestinal tract and may also increase its secretion from blood) are all also under study. Genetic editing tools including clustered regularly interspaced short palindromic repeats/Cas9 are also in preclinical study as a potential PH1 therapeutic.
SUMMARY
Novel treatments can reduce the plasma oxalate concentration and urinary oxalate excretion in PH1 patients. Thus, it is possible these approaches will reduce the need for combined kidney and liver transplantation to significantly decrease the morbidity and mortality of affected patients.
Topics: Humans; Hyperoxaluria, Primary; Kidney Calculi; L-Lactate Dehydrogenase; Oxalates; RNA, Small Interfering
PubMed: 35266883
DOI: 10.1097/MNH.0000000000000790