Effect of selenium-deficient diet on tubular epithelium in normal rats

Major and Trace Elements in Human Kidney Stones: A Preliminary Investigation in Beijing, China

Kidney stone disease affects people globally, with its prevalence on the rise. Given the importance of elements’ function in formation of kidney stones, this study investigated major and trace element content in thirty kidney stone samples from patients in Beijing. The kidney stone samples included inorganic components (calcium oxalate and carbonate apatite) and organic components (uric acid). Results showed that Ca is much higher in inorganic components than organic components. Compared to inorganic components, uric acid has a very low content of elements except for Cu and Se, which may be derived from the liver. Carbonate apatite stones have a higher element content (such as Na, K, Sr, Zn, Rb, Ba, Li, and Ti) than calcium oxalate stones, especially enrichment of Mg. The principal components analysis (PCA) extracted three principal components (PCs) with total variances of 91.91%, including the PC1 (45.08%): Na-Li-Ti-Ba-Sr-Zn, PC2 (30.05%): Rb, K, Mg, and PC3 (16.78%): Cu-Se, indicating that there are co-precipitated processes of these elements by their specific properties. A different distribution of stone types in the three components indicates a significant discrepancy in their element content, which can be an essential reference for patient intake elements.

Kidney stone analysis techniques and the role of major and trace elements on their pathogenesis: a review

Kidney stone disease is a polygenic and multifactorial disorder with a worldwide distribution, and its incidence and prevalence are increasing. Although significant progress has been made in recent years towards identifying the specific factors that contribute to the formation of kidney stone, many questions on the pathogenesis of kidney stones remain partially or completely unanswered. However, none of the proposed mechanisms specifically consider the role(s) of the trace elements and, consequently, the contribution of trace constituents to the pathogenesis of kidney stones remains unclear and under debate. The findings of some studies seem to support a role for some major and trace elements in the initiation of stone crystallization, including as a nucleus or nidus for the formation of the stone or simply as a contaminant of the stone structure. Thus, the analysis of kidney stones is an important component of investigations on nephrolithiasis in order to understand the role of trace constituents in the formation of kidney stones and to formulate future strategies for the treatment and prevention of stone formation and its recurrence. The aim of this review is to compare and evaluate the methods/procedures commonly used in the analysis of urinary calculi. We also highlight the role of major and trace elements in the pathogenesis of kidney stones.

Trace elements in children suffering from idiopathic nephrotic syndrome

OBJECTIVE

Trace elements play a significant role in several metabolic processes and often circulate in the blood binding to protein. The purpose of this study was to determine the status of selenium, zinc, and boron in idiopathic nephrotic syndrome patients in active and remission phases.

MATERIALS AND METHODS

Fourteen patients and fourteen healthy age-matched controls were included in the study. The selenium, zinc and boron level in plasma and urine were measured by the inductively coupled plasma mass spectrometry.

RESULTS

The plasma levels of zinc and selenium were significantly lower in both active and remission patients (for all p=0.0001). The plasma boron level was significantly lower only in patients in active phase (p=0.0002 vs control). The concentrations of urinary boron and selenium were significantly higher during active phase compared with remission (p=0.0003 and 0.0001, respectively).

CONCLUSION

Supplementation with zinc, selenium and boron may be justified in patients suffering with this disease.

Association between serum trace element concentrations and the disease activity of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with a complex, incompletely understood, etiology. Several genetic and environmental factors are suspected to be involved in its aetiology. Oxidative stress may be implicated in the pathogenesis of SLE and may be affected by trace element status. Zinc (Zn), copper (Cu) and selenium (Se) are essential components of several anti-oxidative enzymes and are also involved in several immune functions. The current study aimed to assess the relationship between serum concentrations of these trace elements and the clinical disease activity of SLE assessed using the SLE disease activity index (SLEDAI). Serum concentrations of albumin (Alb) (p = 0.001), Se (p = 0.001), Zn (p = 0.001) and the Zn to Cu ratio (Zn/Cu R) (p = 0.001) were lower in patients with SLE than the age- and sex-matched healthy controls. However, only Alb (p = 0.001) and Cu (p = 0.03) were negatively correlated with disease activity, which was supported by regression analysis. In summary, lower serum values of Alb, Zn, Se and Zn/Cu R were found in SLE patients compared with healthy controls; however, in addition to serum Alb concentrations, serum Cu concentrations were also negatively correlated with lupus disease activity.

Effect of sodium selenite and vitamin E on the renal cortex in rats: an ultrastructure study

This study examined the use of vitamin E to alleviate toxic effects of sodium selenite. Adult male albino rats (n=50) was divided into five groups. Group 1 was control, Groups 2 and 4 were treated with sodium selenite (2 mg/kg) for 2 and 4 weeks, respectively, Groups 3 and 5 were treated with sodium selenite (2 mg/kg) and vitamin E (100 mg/kg) for 2 and 4 weeks, respectively. Renal tissues were studied using anti-BCL2 and examined ultrastructurally. Positive Bax immunoreactivity was detected after 2 and more positive after 4 weeks and nearly all groups improved with co-administration of vitamin E. Ultrastructural study revealed lesions in Bowman's capsule and proximal convoluted tubules. The submicroscopic study revealed damage and necrosis of cortical structures after 2 and 4 weeks, respectively. After 4 weeks, cellular changes were seen, such as vacuolation and moderate degeneration of cells, widening of the urinary space scattered through the cortex with loss of cellular details, formation of apical buds, degeneration, and cellular rupture. Present findings disclosed an ameliorative effect of adding vitamin E to sodium selenite-induced changes in cortical tissues. Clinically, it is advised to add vitamin E to avoid selenium overdose hazards.

Hepatocyte nuclear factor 1 and hypertensive nephropathy

Hypertension in spontaneously hypertensive rat (SHR) is associated with renal redox stress, and we hypothesized that nephropathy arises in SHR-A3 from altered capacity to mitigate redox stress compared with nephropathy-resistant SHR lines. We measured renal expression of redox genes in distinct lines of the spontaneously hypertensive rat (SHR-A3, SHR-B2, SHR-C) and the normotensive Wistar-Kyoto (WKY) strain. The SHR lines differ in either resisting (SHR-B2, SHR-C) or experiencing hypertensive nephropathy (SHR-A3). Immediately before the emergence of hypertensive renal injury expression of redox genes in SHR-A3 was profoundly altered compared with the injury-resistant SHR lines and WKY. This change appeared to arise in antioxidant genes where 16 of 28 were expressed at 34.3% of the level in the reference strain (WKY). No such change was observed in the injury-resistant SHR lines. We analyzed occurrence of transcription factor matrices in the promoters of the downregulated antioxidant genes. In these genes, the hepatocyte nuclear factor 1 (HNF1) transcription factor matrix was found to be nearly twice as likely to be present and the overall frequency of HNF1 sites was nearly 5 times higher, compared with HNF1 transcription factor matrices in antioxidant genes that were not downregulated. We identified 35 other (nonredox) renal genes regulated by HNF1. These were also significantly downregulated in SHR-A3, but not in SHR-B2 or SHR-C. Finally, expression of genes that comprise HNF1 (Tcf1, Tcf2, and Dcoh) was also downregulated in SHR-A3. The present experiments uncover a major change in transcriptional control by HNF1 that affects redox and other genes and precedes emergence of hypertensive renal injury.