Plasma and urinary levels of cytokines in patients with idiopathic hypercalciuria

Myricetin Attenuates Ethylene Glycol-Induced Nephrolithiasis in Rats via Mitigating Oxidative Stress and Inflammatory Markers

Urolithiasis or nephrolithiasis is a condition of kidney stone formation and is considered a painful disease of the urinary tract system. In this work, we planned to discover the therapeutic roles of myricetin on the ethylene glycol (EG)-induced nephrolithiasis in rats. The experimental rats were treated with 0.75% of EG through drinking water for 4 weeks to initiate the nephrolithiasis and subsequently treated with 25 and 50 mg/kg of myricetin. The body weight and urine volume were measured regularly. After the sacrification of rats, the samples were collected, and serum and urinary biomarkers such as creatinine, urea, Ca2 + ion, and BUN, OPN, oxalate, and citrate levels were determined using assay kits. These biomarkers, the MDA level and CAT, SOD, and GPx activities, were assessed in the kidney tissue homogenates. The IL-6, IL-1β, and TNF-α levels were also quantified using respective kits. The histopathological analysis was done on the kidney tissues. Myricetin treatment did not show major changes in the body weight and kidney weight in the EG-induced rats. The treatment with 25 and 50 mg/kg of myricetin considerably reduced the urea, creatinine, BUN, Ca2 + ion, and oxalate and increased the citrate content in serum and urine samples of EG-induced rats. Further, myricetin depleted the inflammatory cytokines and MDA levels and elevated the CAT, SOD, and GPx activities in the renal tissues. The activities of ALT, AST, ALP, GGT, and LDH were also reduced by the myricetin. Furthermore, the myricetin upheld the histoarchitecture of the kidneys. The outcomes of this investigation propose that myricetin is effective in EG-induced urolithiasis probably because of its antioxidant, anti-inflammatory, and renoprotective activities. In addition, further studies are still required to verify the precise therapeutic mechanism of myricetin.

The protective role of corilagin on renal calcium oxalate crystal-induced oxidative stress, inflammatory response, and apoptosis via PPAR-γ and PI3K/Akt pathway in rats

Kidney stones, also known as calcium oxalate (CaOx) nephrolithiasis, are often asymptomatic, leading to kidney injury and renal failure complications. Corilagin is a gallotannin found in various plants and is known to elicit various biological activities. The present study aimed to elucidate the renoprotective effect of corilagin against the rats' renal stones deposition. The rats were induced for nephrolithiasis (CaOx deposition) using 0.75% ethylene glycol in their drinking water. Then, they were treated with corilagin at 50 and 100 mg/kg/day for 4 weeks. At the end of the experimental period, the rats were killed; blood and renal tissues were collected for various histological, biochemical, and gene expression analyses. The results demonstrated that the rats had renal calculi displaying a significant increase in serum creatinine (59.39 μmol/L) and blood urea nitrogen (19.03 mmol/L) levels compared with controls. Moreover, the malondialdehyde (13.29 nmol/mg) level was found to increase with a profound reduction in antioxidants' activities with upregulated inflammatory cytokines. In contrast, the RT-PCR and immunohistochemistry analysis demonstrated a substantial reduction in cell survival markers PPAR-γ and PI3K/Akt with an apparent increase in apoptosis markers genes expressions in rats suffering from renal stones. Thus, the present study results suggest that corilagin could suppress renal CaOx crystal-induced oxidative stress, inflammatory response, and apoptosis via PPAR-γ and PI3K/Akt-mediated pathway.

Prognostic value of urinary TGF-β1 in hemolytic uremic syndrome: A pilot study

BACKGROUND

Transforming growth factor β1 (TGF-β1) is the main profibrotic cytokine. Its urinary excretion reflects intrarenal production; thus, we conjectured that it is elevated during hemolytic uremic syndrome related to Shiga-toxin-producing Escherichia coli (STEC-HUS). In this pilot study, we explored the ability of baseline TGF-β1 excretion (exposure variable) to predict renal prognosis at 6 months (outcome variable). In a secondary investigation, we compared changes in cytokine levels during the study period between patients with opposite renal outcomes.

METHODS

Urinary TGF-β1 concentrations were measured prospectively in 24 children with STEC-HUS on admission, and at 15, 30, 60, 90, and 180 days. Normal values were obtained from 20 healthy subjects.

RESULTS

Baseline TGF-β1 concentrations predicted renal outcomes with an area under the curve of 1 (95%CI 0.85-1; sensitivity 100%, specificity 100%) with the best cutoff level >293.7 pg/mg uCr. All patients with high TGF-β1 levels developed persistent renal impairment, unlike none with low concentrations (4/4 vs. 20/0 respectively, P = 0.0001). The latter had higher cytokine levels (P < 0.05) at each time point without reaching normal concentrations (<45 pg/mg uCr).

CONCLUSIONS

Baseline urinary TGF-β1 levels accurately predicted short-term renal outcomes in STEC-HUS children, and cytokine excretion during the first 6 months after diagnosis was higher among those with worse evolution. Larger studies are needed to validate these findings.

Inhibiting inflammation and modulating oxidative stress in oxalate-induced nephrolithiasis with the Nrf2 activator dimethyl fumarate

Hyperoxaluria induces oxidative stress, and inflammation causes renal epithelial cell injury in nephrolithiasis, suggesting that reduced oxalate toxicity may be beneficial. This study aimed to investigate whether nuclear factor (erythroid-derived 2)-like 2 (Nrf2, also called Nfe2l2) induced by dimethyl fumarate (DMF) could protect renal epithelial cells against oxalate-mediated injury both in vivo and in vitro. Glyoxylic acid monohydrate was intraperitoneally injected into Sprague-Dawley rats with or without intragastric administration of DMF. We showed that calcium oxalate crystallisation, accompanied by overexpression of oxidant species and inflammatory cytokines and apoptosis in the rat kidney, was partially reversed by treatment with DMF. Furthermore, oxalate induced a reduction in cell viability, cell damage, oxidant species overexpression, mitochondrial dysfunction, and apoptosis in normal rat kidney epithelial-like (NRK-52E) cells, which were reversed by DMF. Pretreatment of NRK-52E cells with DMF significantly increased Nrf2 levels in the nucleus, with subsequent inhibition of the expression of the nicotinamide adenine dinucleotide phosphate subunits Nox4 and P22, canonical inflammation, and osteogenesis-associated differentiation of target genes in the cytoplasm. This effect was partially inhibited by transfection with Nrf2 siRNA and strengthened by transfection with Kelch-like ECH-associated protein 1 siRNA. These results suggest that DMF exerts beneficial effects in nephrolithiasis by inhibiting inflammation and modulating oxidative stress via regulation of Nrf2.

Urinary MCP-1、HMGB1 increased in calcium nephrolithiasis patients and the influence of hypercalciuria on the production of the two cytokines

The study aims to observe the urinary excretion of monocyte chemoattractant-1 (MCP-1) and high-mobility group box 1 (HMGB1) in patients with calcium nephrolithiasis and to determine the influence of hypercalciuria on the production of the two cytokines. 81 cases of patients with calcium nephrolithiasis (group CN) and 30 healthy controls (group C) were involved in this study. To observe the influence of urinary calcium on the excretion of those cytokines, the patients were subdivided according to their 24-h urinary calcium level: ≥4 mg/kg/day (group H) and <4 mg/kg/day (group N). MCP-1 and HMGB1 in urina sanguinis were determined for all subjects. In addition, in vitro study was done to determine the production of the two cytokines and index of apoptosis and oxidative injuries in human kidney epithelial cells (HK-2) exposed to three high levels of calcium. Data showed that both urinary MCP-1 and HMGB1 in group CN were higher than that of group C. When the patients were subdivided, comparisons among the three groups showed that both MCP-1 and HMGB1 in group H and group N were higher than group C, but there was no significant statistical difference between the two stone groups. In vitro study, the apoptosis rate of cells, the lactate dehydrogenase activities, the hydrogen peroxide, and 8-isoprostane concentrations in the medium all increased in accordance with the increased concentration of calcium supplemented. Compared with the control, mRNA expressions of MCP-1 and HMGB1 in cells and the protein concentrations of the two cytokines in the medium of calcium-supplemented groups increased significantly. Results showed that urinary MCP-1 and HMGB1 increased in calcium nephrolithiasis patients and hypercalciuria might affect the identical pathways (through the reactive oxygen species) with other factors in stimulating the production of MCP-1 and HMGB1 in vivo.

Assessment of Urine Proteomics in Type 1 Primary Hyperoxaluria

BACKGROUND

Primary hyperoxaluria type 1 (PH1) and idiopathic hypercalciuria (IHC) are stone-forming diseases that may result in the formation of calcium (Ca) oxalate (Ox) stones, nephrocalcinosis, and progressive chronic kidney disease (CKD). Poorer clinical outcome in PH1 is segregated by the highest urine (Ur)-Ox (UrOx), while IHC outcomes are not predictable by UrCa. We hypothesized that differences would be found in selected Ur-protein (PRO) patterns in PH1 and IHC, compared to healthy intra-familial sibling controls (C) of PH1 patients. We also hypothesized that the PRO patterns associated with higher UrOx levels would reflect injury, inflammation, biomineralization, and abnormal tissue repair processes in PH1.

METHODS

Twenty four-hour Ur samples were obtained from 3 cohorts: PH1 (n = 47); IHC (n = 35) and C (n = 13) and were analyzed using targeted platform-based multi-analyte profile immunoassays and for UrOx and UrCa by biochemical measurements.

RESULTS

Known stone matrix constituents, osteopontin, calbindin, and vitronectin were lowest in PH1 (C > IHC > PH1; p < 0.05). Ur-interleukin-10; chromogranin A; epidermal growth factor (EGF); insulin-like growth factor-1 (IGF-1), and macrophage inflammatory PRO-1α (MIP-1α) were higher in PH1 > C (p = 0.03 to p < 0.05). Fetuin A; IGF-1, MIP-1α, and vascular cell adhesion molecule-1 were highest in PH1 > IHC (p < 0.001 to p = 0.005).

CONCLUSION

PH1 Ur-PROs reflected overt inflammation, chemotaxis, oxidative stress, growth factors (including EGF), and pro-angiogenic and calcification regulation/inhibition compared to the C and IHC cohorts. Many of the up- and downregulated PH1-PROs found in this study are also found in CKD, acute kidney injury, stone formers, and/or stone matrices. Further data analyses may provide evidence for PH1 unique PROs or demonstrate a poorer clinical outcome.

Chemokines as potential markers in pediatric renal diseases

Glomerular diseases and obstructive uropathies are the two most frequent causes of chronic kidney disease (CKD) in children. Recently, biomarkers have become a focus of clinical research as potentially useful diagnostic tools in pediatric renal diseases. Among several putative biomarkers, chemokines emerge as promising molecules since they play relevant roles in the pathophysiology of pediatric renal diseases. The evaluation of these inflammatory mediators might help in the management of diverse renal diseases in children and the detection of patients at high risk to develop CKD. The aim of this paper is to revise general aspects of chemokines and the potential link between chemokines and the most common pediatric renal diseases by including experimental and clinical evidence.