Chemokines as potential markers in pediatric renal diseases

A case of chronic kidney disease with refractory periodic vomiting and hypertension in a pediatric patient

Patients with chronic kidney disease (CKD) sometimes experience gastrointestinal symptoms, such as nausea and vomiting. In addition, hypertension and CKD are closely linked, and sustained hypertension in children is associated with the progression of CKD, leading to early cardiomyopathy and premature atherosclerosis. These symptoms substantially affect the quality of daily life of CKD patients, and particularly in children with CKD, they may cause growth retardation. Therefore, establishing effective management methods to alleviate these symptoms is very important. Here, we report a case of a male patient who was born at 34 weeks of gestation weighing 1400 g. At birth, abdominal ultrasonography displayed left multicystic dysplastic kidney. From 6 months after birth, he was frequently hospitalized owing to refractory periodic vomiting. At 9 months old, he was diagnosed as having stage 3a CKD, and at 20 months old, he presented with stage 2 high blood pressure. In Japan, the uremic toxin adsorbent AST-120 and angiotensin-converting enzyme inhibitor-I (ACE-I) are not strongly recommended for CKD patients. However, after the patient underwent combination therapy of AST-120 and ACE-I, his frequent hospitalizations for refractory periodic vomiting ceased, and his blood pressure decreased. These results indicate that AST-120 and ACE-I are effective for refractory periodic vomiting and hypertension associated with CKD. The patient's height, weight, and mental development are catching up smoothly. The cause of the patient's refractory periodic vomiting remains unclear. However, his impaired kidney function owing to congenital anomalies of the kidney and urinary tract may have caused the refractory periodic vomiting and dehydration. The production of uremic toxins in CKD patients is thought to lead to the secretion of proinflammatory cytokines into the circulation. However, our patient had low serum levels of proinflammatory cytokines, and his serum levels of the chemokines CX3CL1 and CCL2 decreased with age, together with improvement in his clinical course. Therefore, some specific chemokines might be diagnostic and/or prognostic biomarkers of CKD.

Hemostasis and oxidative stress in chronic kidney disease in children and adolescents

Chronic kidney disease (CKD) can be defined as the progressive loss of renal function, characterized by decreased glomerular filtration rate (GFR). The etiology of CKD in childhood is mainly associated with congenital anomalies of the kidneys and urinary tract (CAKUT) and to glomerular diseases. The goal of this study was to investigate the hemostasis and oxidative stress in pediatric CKD of different etiologies. 54 CKD children and adolescents and 52 controls were enrolled in this study. The evaluation of hemostasis was carried out by determination of D-Dimer (D-Di) and plasminogen activator inhibitor (PAI-1) plasma levels, while oxidative stress by thiobarbituric acid reactive substances (TBARS) levels, protein carbonyl content, plasma antioxidant capacity (MTT) and ascorbate. The D-Di was increased in CAKUT stage 3 or 4 patients compared to those with glomerular disease. PAI-1 was increased in patients with glomerular disease compared to CAKUT. Carbonyl protein content was higher in the control group compared to glomerular disease stage 3 or 4 patients. Our findings showed that the reduction in GFR is associated with a state of hypercoagulability. The analysis of integrated networks showed an expansion of connections among hemostatic and oxidative stress markers in CKD children and adolescents comparing to controls.

Exploring protective effect of Glycine tabacina aqueous extract against nephrotic syndrome by network pharmacology and experimental verification

Background

Glycine tabacina (Labill.) Benth, one of the traditional Chinese herbal medicines, has been used for treatment of nephritis, osteoporosis, rheumatism, and menopausal syndrome. The aim of this study was to illuminate the therapeutic effect and mechanism of Glycine tabacina aqueous extract (GATE) in the treatment of nephrotic syndrome (NS).

Methods

UHPLC-DAD-MS/MS was used to analyze the chemical profile of GATE. Adriamycin (ADR)-induced NS mouse model and network pharmacology methods were conducted to explore the protective effect and mechanism of GATE on NS treatment.

Results

GATE administration significantly ameliorated symptoms of proteinuria and hyperlipidemia in NS mice, as evidenced by reduced excretion of urine protein and albumin, and decreased plasma levels of total cholesterol and triglyceride. Decreased blood urea nitrogen (BUN) and creatinine levels in NS mice suggested that GATE could prevent renal function decline caused by ADR. GATE treatment also inhibited ADR-induced pathological lesions of renal tissues as indicated by periodic acid Schiff staining. Six flavonoids of GATE were identified by using UHPLC-DAD-MS/MS. Network pharmacology analysis indicated that the protection of GATE in treating NS might be associated with the regulation of oxidative stress and inflammation. In addition, the in vivo experiment validated that treatment with GATE markedly decreased reactive oxygen species production, malonaldehyde level, and increased superoxide dismutase activity both in plasma and renal tissues. TNF-α level in plasma and protein expression in kidney were significantly decreased in GATE treatment groups.

Conclusions

Combination of network pharmacology analysis and experimental verification revealed that GATE exerts anti-NS effect possibly through modulating oxidative stress and inflammation, suggesting the potential application of GATE or its derivatives in the prevention and treatment of NS and other related kidney diseases.

Soluble tumor necrosis factor receptors are associated with severity of kidney dysfunction in pediatric chronic kidney disease

BACKGROUND

In adult chronic kidney disease (CKD) patients, there is a positive association between inflammation and progressive renal dysfunction. Higher levels of soluble receptors of tumor necrosis factor (sTNFR) have been related to worst prognosis of adult CKD patients. Therefore, the present study aimed to evaluate soluble TNF receptors in children and adolescents with CKD and to search for an association with clinical and laboratory features.

METHODS

Demographic, clinical, anthropometric, and laboratory data were evaluated in 34 pediatric patients with CKD and in 34 healthy sex- and age-matched controls. Blood samples were collected in both groups to measure sTNFR by enzyme-linked immunosorbent assay. The modified Schwartz formula was used to estimate glomerular filtration rate (GFR).

RESULTS

Pediatric patients with CKD had significantly higher plasma concentrations of soluble TNF receptors types 1 and 2 (sTNFR1 and sTNFR2) in comparison to sex- and age-matched healthy controls. Plasma levels of sTNFR1 and sTNFR2 increased progressively as renal function worsened, being inversely and significantly correlated with GFR (r = - 0.853 for sTNFR1 and GFR, r = - 0.729 for sTNFR2 and GFR).

CONCLUSIONS

Children and adolescents with CKD exhibited higher plasma levels of sTNFR1 and sTNFR2 than healthy controls, which increased in relation to renal function deterioration. Plasma levels of sTNFR1 and sTNFR2 emerge as markers of progressive CKD in pediatric patients.

MMP9 overexpression is associated with good surgical outcome in children with UPJO: Preliminary results

BACKGROUND

Ureteropelvic junction obstruction (UPJO) diagnosed prenatally occurs in 1:150 - 1:1200 pregnancies. Although many studies investigating the molecular changes of this obstructed segment have been performed, the underlying mechanisms are still unclear. The role of extracellular matrix (ECM) components remains controversial, and the investigations in the field of ECM changes, might help the better understanding of the pathogenesis of this common condition. The aim of the present study was to investigate for the first time in the literature whether MMP9 and its specific inhibitors, TIMP1 and RECK, are expressed in a reproducible, specific pattern in UPJ.

METHODS

UPJO specimens were obtained from 16 children at the time of dismembered pyeloplasty due to intrinsic UPJ stenosis. Expression levels of the three genes (MMP9, TIMP1 and RECK) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Then correlated the expression levels of the genes according to grade study population that was divided in 2 categories according to Society of Fetal Urology classification, grade 3 (moderate) and 4 (severe). For DTPA we subdivided the childrens in 2 groups, obstructive (T 1/2 more than 20 min) and partial obstructive (T 1/2 between 10 and 20 min) and success in a surgery was defined as decrease in T 1/2 to less than 20 min, absence of symptoms, improving renal function and decreasing dilatation on successive exams.

RESULTS

MMP9 was underexpressed and TIMP1 and RECK were overexpressed in children with obstructive DTPA but the differences were not statistically significant. Overexpression of MMP9 was higher among patients with severe grade of UPJ compared to those with moderate grade. Surprisingly expression levels of MMP-9 was three times higher in children who were successfully treated by surgery (n = 10) (p = 0.072), so those who were followed for at least 1 year after surgery and remained with improvement in renal function and decreasing dilation on intravenous urogram and TIMP-1 was underexpressed in 100 % of this cases (p = 0.00).

CONCLUSIONS

We showed an increase in expression of MMP9 and a decrease in expression of TIMP1 in children who improving renal function and decreasing dilation after surgery. We believe that the higher expression of MMP9 in these cases can reflect an increase in degradation and remodeling process that could be used as a marker for surgical outcome.