Are children with IgA nephropathy different from adult patients?

BACKGROUND: Previously, several studies have indicated that pediatric IgA nephropathy (IgAN) might be different from adult IgAN, and treatment strategies might be also different between pediatric IgAN and adult IgAN. METHODS: We analyzed two prospective cohorts established by pediatric and adult nephrologists, respectively. A comprehensive analysis was performed investigating the difference in clinical and pathological characteristics, treatment, and prognosis between children and adults with IgAN. RESULTS: A total of 1015 children and 1911 adults with IgAN were eligible for analysis. More frequent gross hematuria (88% vs. 20%, p < 0.0001) and higher proteinuria (1.8 vs. 1.3 g/d, p < 0.0001) were seen in children compared to adults. In comparison, the estimated glomerular filtration rate (eGFR) was lower in adults (80.4 vs. 163 ml/min/1.73 m2, p < 0.0001). Hypertension was more prevalent in adult patients. Pathologically, a higher proportion of M1 was revealed (62% vs. 39%, p < 0.0001) in children than in adults. S1 (62% vs. 28%, p < 0.0001) and T1-2 (34% vs. 8%, p < 0.0001) were more frequent in adults. Adjusted by proteinuria, eGFR, and hypertension, children were more likely to be treated with glucocorticoids than adults (87% vs. 45%, p < 0.0001). After propensity score matching, in IgAN with proteinuria > 1 g/d, children treated with steroids were 1.87 (95% CI 1.16-3.02, p = 0.01) times more likely to reach complete remission of proteinuria compared with adults treated with steroids. CONCLUSIONS: Children present significantly differently from adults with IgAN in clinical and pathological manifestations and disease progression. Steroid response might be better in children.

DNA methylation of IFI44L as a potential blood biomarker for childhood-onset systemic lupus erythematosus.

BACKGROUND: IFN-induced protein 44-like (IFI44L) promoter methylation has been demonstrated to serve as an effective blood diagnostic biomarker for adult-onset SLE. However, its utility as a diagnostic marker for childhood-onset SLE (cSLE) remains to be verified. METHODS: Initially, we conducted a differential analysis of gene methylation and mRNA expression patterns in cSLE whole blood samples obtained from the public GEO database to determine IFI44L gene expression and assess the methylation status at its CpG sites. Subsequently, we collected clinical whole blood samples from 49 cSLE patients and 12 healthy children, employing an HRM-qPCR-based IFI44L methylation detection technique to evaluate its diagnostic efficacy in pediatric clinical practice. RESULTS: A total of 26 hypomethylated, highly expressed genes in cSLE were identified by intersecting differentially expressed genes (DEGs) and differentially methylation genes (DMGs). GO enrichment analysis for these 26 genes indicated a robust association with type I IFN. Among the overlapping genes, IFI44L exhibited the most pronounced differential expression and methylation. In subsequent clinical validation experiments, IFI44L methylation was confirmed as an effective blood-based diagnostic biomarker for cSLE, achieving an AUC of 0.867, a sensitivity of 0.753, and a specificity of 1.000. CONCLUSIONS: IFI44L methylation is a promising blood biomarker for cSLE. IMPACT: IFI44L promoter methylation was reported to serve as a highly sensitive and specific diagnostic marker for adult-onset SLE. However, the diagnostic efficacy of IFI44L in childhood-onset SLE (cSLE) still remains to be confirmed. In this study, we utilized bioinformatics analysis and conducted clinical experiments to demonstrate that IFI44L methylation can also serve as a promising blood biomarker for cSLE. The findings of this study can facilitate the diagnosis of cSLE and broaden our understanding of its molecular mechanisms, with a particular focus on those related to type I interferons.

Clinical features and familial mutations in the coexistence of Wilson's disease and Alport syndrome: A case report.

Background: Alport syndrome (AS) and Wilson's disease (WD) are genetic diseases that could lead to kidney damage. Herein, we report the clinical features and gene variants in a patient with WD and X-linked AS. Case presentation: The proband was a 12-year-old boy diagnosed with AS coexisting with WD at the age of 11 years. The patient underwent a medical check-up when he was 4 years and 8 months. Laboratory tests revealed elevated liver enzymes, decreased serum ceruloplasmin, increased 24-h urinary copper excretion, and one variant in the ATP7B gene. Then, the patient was diagnosed with WD. After 2 months of treatment with D-penicillamine and zinc salt, his liver function had recovered to normal levels, but he presented with microscopic hematuria. The hematuria did not resolve after switching to dimercaptosuccinic acid from D-penicillamine. In addition, he presented with proteinuria 3 years later. A renal biopsy was performed more than 6 years after the patient was diagnosed with WD, and electron microscopy showed that the basement membrane thickness was uneven, layered, and focal torn. Copper staining was negative. A genetic analysis identified a hemizygous variant (c.1718G > A, p. Gly573Asp) in COL4A5 and a homozygous variant (c.2975C > T, p. Pro992leu) in ATP7B. The patient's urine protein-creatinine ratio was less than 1.0 mg/mg after a 1 year of follow-up, after enalapril was administered for treating AS. Conclusion: This case highlights a lack of improvement in renal function after conventional treatment provides a possible indication for performing renal biopsy or genetic testing to determine the etiology in order to facilitate subsequent clinical management. Clinicians should prevent the occurrence of diagnostic inaccuracies caused by diagnostic anchoring because an accurate diagnosis is essential for achieving precise treatment and improved prognosis.

Genetic Architecture of Childhood Kidney and Urological Diseases in China.

Kidney disease is manifested in a wide variety of phenotypes, many of which have an important hereditary component. To delineate the genotypic and phenotypic spectrum of pediatric nephropathy, a multicenter registration system is being implemented based on the Chinese Children Genetic Kidney Disease Database (CCGKDD). In this study, all the patients with kidney and urological diseases were recruited from 2014 to 2020. Genetic analysis was conducted using exome sequencing for families with multiple affected individuals with nephropathy or clinical suspicion of a genetic kidney disease owing to early-onset or extrarenal features. The genetic diagnosis was confirmed in 883 of 2256 (39.1%) patients from 23 provinces in China. Phenotypic profiles showed that the primary diagnosis included steroid-resistant nephrotic syndrome (SRNS, 23.5%), glomerulonephritis (GN, 32.2%), congenital anomalies of the kidney and urinary tract (CAKUT, 21.2%), cystic renal disease (3.9%), renal calcinosis/stone (3.6%), tubulopathy (9.7%), and chronic kidney disease of unknown etiology (CKDu, 5.8%). The pathogenic variants of 105 monogenetic disorders were identified. Ten distinct genomic disorders were identified as pathogenic copy number variants (CNVs) in 11 patients. The diagnostic yield differed by subgroups, and was highest in those with cystic renal disease (66.3%), followed by tubulopathy (58.4%), GN (57.7%), CKDu (43.5%), SRNS (29.2%), renal calcinosis /stone (29.3%) and CAKUT (8.6%). Reverse phenotyping permitted correct identification in 40 cases with clinical reassessment and unexpected genetic conditions. We present the results of the largest cohort of children with kidney disease in China where diagnostic exome sequencing was performed. Our data demonstrate the utility of family-based exome sequencing, and indicate that the combined analysis of genotype and phenotype based on the national patient registry is pivotal to the genetic diagnosis of kidney disease. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-021-00014-1.

Podocytic infolding in Schimke immuno-osseous dysplasia with novel SMARCAL1 mutations: a case report.

BACKGROUND: Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive disorder characterized by spondyloepiphyseal dysplasia, progressive renal insufficiency and defective cellular immunity. Podocytic infolding glomerulopathy (PIG) is a newly proposed disease entity characterized by microspheres or microtubular structures associated with podocytes infolding into the glomerular basement membrane (GBM) on electron microscopy (EM). CASE PRESENTATION: A 4-year-old boy was admitted to our ward due to proteinuria and edema lasting 1 month. He had a short trunk and demonstrated subtle dysmorphology, with a triangular shape, a broad nasal bridge and a bulbous nasal tip. The laboratory findings were as follows: lymphocytes, 0.5 × 109/L; urine protein, 3.67 g/d; albumin, 9.8 g/L; and cholesterol, 11.72 mmol/L. Skeletal X rays showed small iliac wings, small ossification centers of the capital femoral epiphyses, shallow dysplastic acetabular fossae and mildly flattened vertebrae. The specimen for light microscopy (LM) suggested focal segmental glomerulosclerosis (FSGS). EM revealed a focal thickness of the GBM with some cytoplasmic processes of podocyte infolding into the GBM. Gene sequencing showed novel compound heterozygous mutations in the SMARCAL1 gene (c.2141 + 5G > A; c.2528 + 1G > A) that were inherited from his parents. Finally, we established the diagnosis of SIOD and treated him with diuretics and angiotensin-converting enzyme inhibitors (ACEIs). CONCLUSION: The pathogenic mechanism of PIG has not been clarified. Further studies are required to understand whether gene mutations, especially those related to podocytes, contribute to the pathogenesis of podocytic infolding.

Genetic spectrum of renal disease for 1001 Chinese children based on a multicenter registration system.

To explore the approaches and diagnostic yield of genetic testing for renal disease in children, we describe the genotype and phenotype of the national cohort of children with renal disease from 13 different regions of China recruited from 2014 to 2018 by building up the multicenter registration system (Chinese Children Genetic Kidney Disease Database, CCGKDD). Genetic diagnosis was confirmed in 42.1% of our cohort of 1001 pediatric patients with clinical suspicion of a genetic renal disease. Of the 106 distinct monogenetic disorders detected, 15 accounted for 60.7% of genetic diagnoses. The diagnostic yield was 29.1% in steroid resistant nephritic syndrome (SRNS), 61.4% in cystic renal disease, 17.0% in congenital anomalies of the kidney and urinary tract (CAKUT), 62.3% in renal tubular disease/renal calcinosis, and 23.9% for chronic kidney disease (CKD) 3 to 5 stage with unknown origin. Genetic approaches of target gene sequence (TGS), singleton whole-exome sequencing (WES) and trio-WES were performed with diagnostic rates of 44.8%, 36.2%, and 42.6%, respectively. The early use of trio-WES could improve the diagnostic rate especially in renal tubular disease and calcinosis. We report the genetic spectrum of Chinese children with renal disease. Establishment of the CCGKDD will improve the genetic work on renal disease.

Green tea polyphenols protect against preglomerular arteriopathy via the jagged1/notch1 pathway.

Preglomerular arteriopathy (PA) induced by hyperuricemia contributes to the progression of chronic kidney disease (CKD). Green tea polyphenols (GTPs) are antioxidant ingredients thought to assist in preventing hyperuricemia. However, the underlying mechanism by which GTPs affect renal function remains unclear. Both normal and remnant kidney (RK) rats were administrated oxonic acid (OX) to induce hyperuricemia. The hyperuricemia RK rats were concomitantly treated with GTPs. Hematoxlyin-eosin (H&E) and periodic acid-Schiff (PAS) staining methods were used to examine renal function and arterial morphology. The expression of proteins in the Jagged1/Notch1 pathway was assessed via immunohistochemistry, in situ hybridization, the quantitative polymerase chain reaction (qPCR), and western blotting techniques. Our results showed that an RK rat model with preglomerular vascular disease had been successfully established. Treatment of the RK rats with GTPs effectively alleviated the damage due to preglomerular arteriopathy, significantly alleviated pathological symptoms, and reduced the levels of proteinuria, serum UA, BUN, and creatinine. Our results also suggested involvement of the Jagged1/Notch1 pathway in the preglomerular vascular lesions. The levels of Jagged1, Notch1-ICD, Hes5, and p-STAT3 were significantly decreased in RK + OA-treated rats when compared with those in RK rats. Treatment with GTPs upregulated the levels of Jagged1, Notch1, Hes5, p-STAT3, and MnSOD2, and downregulated xanthine oxidase (XO) expression in rats with preglomerular arteriopathy. However, the beneficial effects of GTPs were lost when the Jagged1/Notch1-STAT3 pathway was inactivated by siRNA. In conclusion, GTPs exert a therapeutic effect on perglomerular arteriopathy. Our results also revealed a novel mechanism that mediates preglomerular arteriopathy, and suggest GTPs as effective novel renal protective agents.

Lupus erythematosus panniculitis in a 10-year-old female child with severe systemic lupus erythematosus: A case report.

RATIONALE: Lupus erythematosus panniculitis (LEP) is a rare subset of lupus erythematosus. The incidence of LEP in systemic lupus erythematosus (SLE) ranges from 2% to 5%. In the previous literature, most LEP patients were women aged from 20 to 60 years, while pediatric cases were rare, all of whom appeared on their own without SLE.A rare LEP in a 10-year-old female child with severe SLE is presented. PATIENT CONCERNS: A 10-year-old girl was admitted to our hospital for marasmus and fatigue without other typical manifestations of SLE well before the appearance of skin lesions. The only proof to support the SLE is that we observed a weakly positive antinuclear antibody (ANA) in serum at the onset. DIAGNOSES: A 10-year-old girl diagnosed to the Division of Nephrology, Department of Pediatrics, the Second Xiangya Hospital, Central South University, for LEP with severe SLE. INTERVENTIONS: The patient was administered with high-dose corticosteroids and cyclophosphamide. OUTCOME: The patient died of severe lung involvement despite the use of high-dose corticosteroids and cyclophosphamide. LESSONS: This report highlights an unusual manifestation of LEP associated with SLE in a child. It also suggests that pediatricians should be aware of occult onset of SLE, such as unclear marasmus and fatigue found in this case. Repeat tests of antinuclear antibody and anti-double strand DNA antibody (anti-dsDNA) as well as renal biopsy in a timely manner will be effective to achieve early recognition and immediate treatment for saving lives.

Genetic mutational testing of Chinese children with familial hematuria with biopsy­proven FSGS.

Focal segmental glomerulosclerosis (FSGS) is a pathological lesion rather than a disease, with a diverse etiology. FSGS may result from genetic and non­genetic factors. FSGS is considered a podocyte disease due to the fact that in the majority of patients with proven­FSGS, the lesion results from defects in the podocyte structure or function. However, FSGS does not result exclusively from podocyte­associated genes, however also from other genes including collagen IV­associated genes. Patients who carry the collagen type IVA3 chain (COL4A3) or COL4A4 mutations usually exhibit Alport Syndrome (AS), thin basement membrane neuropathy or familial hematuria (FH). Previous studies revealed that long­time persistent microscopic hematuria may lead to FSGS. A case of a family is presented here where affected individuals exhibited FH with FSGS­proven, or chronic kidney disease. Renal biopsies were unhelpful and failed to demonstrate glomerular or basement membrane defects consistent with an inherited glomerulopathy, and therefore a possible underlying genetic cause for a unifying diagnosis was pursued. Genomic DNA of the siblings affected by FH with biopsy­proven FSGS was analyzed, and their father was screened for 18 gene mutations associated with FSGS [nephrin, podocin, CD2 associated protein, phospholipase C ε, actinin α 4, transient receptor potential cation channel subfamily C member 6, inverted formin, FH2 and WH2 domain containing, Wilms tumor 1, LIM homeobox transcription factor 1 ß, laminin subunit ß 2, laminin subunit ß 3, galactosida α, integrin subunit ß 4, scavenger receptor class B member 2, coenzyme Q2, decaprenyl diphosphate synthase subunit 2, mitochondrially encoded tRNA leucine 1 (UUA/G; TRNL1) and SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a like 1] using matrix­assisted laser desorption/ionization time­of­flight mass spectrometry technology. Then whole exome sequencing (WES) was performed in the two probands to ascertain whether there were other known or unknown gene mutations that segregated with the disease. Using mass array technology, a TRNL1 missense homozygous mutation (m. 3290T>C) was identified in the probands diagnosed with FH and manifested as FSGS on biopsy. In addition, a COL4A4 missense mutation c. 4195A>T (p. M1399L) in heterozygous pattern was identified using WES. None of these variants were detected in their father. In the present study, a mutation in TRNL1 (m. 3290T>C) was identified, which was the first reported variant associated with FSGS. The COL4A4 (c. 4195A>T) may co­segregate with FSGS. Screening for COL4A mutations in familial FSGS patients is suggested in the present study. Genetic investigations of families with similar clinical phenotypes should be a priority for nephrologists. The combination of mass array technology and WES may improve the detection rate of genetic mutation with a high level of accuracy.

Lupus glomerulonephritis in 788 Chinese children: a multi-centre clinical and histopathological analysis based on 549 renal biopsies.

BACKGROUND: System lupus erythematosus (SLE) is a severe multisystem autoimmune disease. OBJECTIVE: To describe the clinical and pathological features, treatment, and renal outcome in children under 18 years with lupus nephritis (LN). METHODS: The study was undertaken by a questionnaire completed in 26 Grade 3A hospitals' paediatric renal units in China. The study comprised 788 children (619 girls, 169 boys) diagnosed with SLE by the American College of Rheumatology criteria (1997) during 2005-2010. Results of renal biopsies were classified according to the guidelines of The International Association of Nephrology and the Renal Pathology Society (2003). Guidelines by the Chinese Society of Paediatric Nephrology were applied for the diagnosis and treatment (for trial implementation) in 2010 to determine inclusion. The data included the prevalence of acute kidney injury (AKI), SLE disease activity index (SLEDAI), renal histopathology and the induction of therapy mode. RESULTS: The mean (SD) age of onset of SLE was 10.9 (2.90) years (range 1-18) and at diagnosis was 11.3 (2.9) years. The mean (SD) SLEDAI score was 13.5 (5.53). The clinical classification was as follows: about 36 (4.6%) patients had isolated haematuria, 99 (12.6%) isolated proteinuria, 60 (7.6%) isolated haematuria and proteinuria, 157 (19.9%) acute glomerulonephritis, 392 (49.7%) nephrotic syndrome, 20 (2.5%) rapidly progressive glomerulonephritis, 15 (1.9%) chronic nephritis, 2 (0.3%) tubule-interstitial damage and 7 (0.9%) subclinical LN. A total of 549 children (69.7%) underwent renal biopsy. The most frequent renal histopathological findings of LN were Class IV, followed by Class II and Class V + IV. There were no significant differences between the age groups in either renal pathological types or prognosis. In 242 (30.7%) patients, LN was complicated by AKI. Those with AKI had an older mean (SD) age at onset than the non-AKI patients [11.5 (2.8) years vs 10.7 (2.9) years, respectively, p < 0.0001] and a higher SLEDAI score [14.3 (5.8) vs 13.1 (5.4), respectively, p = 0.003]. In the induction phase, cyclophosphamide (CTX) and mycophenolate mofetil (MMF) were equally effective in the patients with the same pathological type. Follow-up records were only available for 482 (61.2%) patients, with a mean (SD) follow-up time of 21.5 (18.4) months. Six of the 35 patients who deteriorated required dialysis and seven died. CONCLUSION: In LN, AKI is a risk factor for poor outcome. Owing to different times of onset and remission, the pathological types of LN cannot be estimated by clinical manifestation alone, and therefore renal biopsy should be undertaken in all LN children with AKI. In the induction phase, there was no significant difference in efficacy between CTX and MMF. Follow-up of children with LN in China needs to be improved.

Mutation spectrum of genes associated with steroid-resistant nephrotic syndrome in Chinese children.

Approximately 20% of children with idiopathic nephrotic syndrome do not respond to steroid therapy. More than 30 genes have been identified as disease-causing genes for the steroid-resistant nephrotic syndrome (SRNS). Few reports were from the Chinese population. The coding regions of genes commonly associated with SRNS were analyzed to characterize the gene mutation spectrum in children with SRNS in central China. The first phase study involved 38 children with five genes (NPHS1, NPHS2, PLCE1, WT1, and TRPC6) by Sanger sequencing. The second phase study involved 33 children with 17 genes by next generation DNA sequencing (NGS. 22 new patients, and 11 patients from first phase study but without positive findings). Overall deleterious or putatively deleterious gene variants were identified in 19 patients (31.7%), including four NPHS1 variants among five patients and three PLCE1 variants among four other patients. Variants in COL4A3, COL4A4, or COL4A5 were found in six patients. Eight novel variants were identified, including two in NPHS1, two in PLCE1, one in NPHS2, LAMB2, COL4A3, and COL4A4, respectively. 55.6% of the children with variants failed to respond to immunosuppressive agent therapy, while the resistance rate in children without variants was 44.4%. Our results show that screening for deleterious variants in some common genes in children clinically suspected with SRNS might be helpful for disease diagnosis as well as prediction of treatment efficacy and prognosis.

Intravenous transfusion of endothelial progenitor cells that overexpress vitamin D receptor inhibits atherosclerosis in apoE-deficient mice.

Endothelial progenitor cells (EPCs) are widely used for angiogenic therapies, as well as predictive biomarkers to assess cardiovascular disease risk. However, it is unknown that whether overexpressed vitamin D receptor (VDR) in EPCs could help EPCs counteracting atherosclerotic risks. Here, we study intravenous transplantation of genetically modified EPCs over-expressing VDR in regulating endothelial dysfunction and spontaneously arising atherosclerotic plaques of ApoE-deficient mice. Firstly, we found that over-expression of VDR in EPCs could reduce atherosclerotic plaque formation in transplanted ApoE-/- mice. In addition, the concentration of serum HDL-C in ovVDR-EPCs group was much higher than that in control groups (ApoE-/- mice without injection or injected with fresh medium or adenovirus vector). While concentrations of serum total cholesterol, LDL-C, apoB and Lp (a) were negatively correlated with the expression level of VDR. What's more, improved serum concentration of NO and elevated serum and vessel wall expression of eNOS were observed in ovVDR-EPCs group. Furthermore, reduced expression and activity of MMP2, and elevated expression and activity of TIMP2 were detected in ovVDR-EPCs group. Taken together, intravenous transfusion of EPCs that overexpress VDR significantly inhibited atherosclerosis in ApoE-deficient mice and could be used as a potential method for angiogenic therapy.

Distribution of infused umbilical cord mesenchymal stem cells in a rat model of renal interstitial fibrosis.

AIMS: Stem cell transplantation for the treatment of kidney diseases is dependent on choice of transplant pathway. We evaluated the safety of human umbilical cord mesenchymal stem cells through peripheral infusion and their distribution in a rat model of renal interstitial fibrosis (RIF). METHOD: Cryopreserved umbilical cord mesenchymal stem cells were infused via tail vein injection into rats with unilateral ureteral obstruction and Sham-operated. Blood, kidney, heart, liver, spleen and lung were collected at 14, 21, and 28 days after infusion. Testing included microscopic observation of kidney morphological changes and immunohistochemical testing to identify and count the number of MAB1281 (labeled human cells) positive cells in the heart, liver, spleen, lungs, and kidneys of different treatment groups. RESULTS: There was no significant difference in the Sham-operated group and Sham-operated + cell transplantation group at different time points. Human cells were identified mainly in the lungs, spleen, and kidney. The number of human umbilical cord mesenchymal stem cells in the kidney was greater in the unilateral ureteral obstruction + cell transplantation group, compared to the Sham-operated + cell transplantation group. human umbilical cord mesenchymal stem cells were mainly located in the interstitium of the left kidney. These results suggest that infused mesenchymal stem cells were primed to engraft a damaged kidney, especially damaged renal interstitium. CONCLUSIONS: Intravenous infusion of exogenous umbilical cord mesenchymal stem cells is feasible and safe. Infused mesenchymal stem cells can reach damaged kidney tissues with obstructive RIF after a vein graft.

Angiogenic effect of endothelial progenitor cells transfected with telomerase reverse transcriptase on peritubular microvessel in five out of six subtotal nephrectomy rats.

Renal disease is caused by tubular interstitial injury and renal interstitial fibrosis. Previous studies have shown that transplantation of endothelial progenitor cells (EPCs) may provide an appropriate treatment for repair and reversing renal pathology. However, EPCs are typically low in abundance and have poor replication ability. Therefore, the this study investigated the use of EPCs transfected with the telomerase reverse transcriptase (TERT) in rats that had undergone five out of six subtotal nephrectomy. This study determined the effects of EPC transplantation on renal function, renal interstitial fibrosis, and peritubular capillary angiogenesis. Five groups of rats were investigated: sham group, model group (five out of six subtotal nephrectomy), EPCs-N group (transplantation with EPCs), pZ-TERT-EPCs-N group (transplantation with EPCs transfected with TERT), and pZ-EPCs-N group (transplantation with EPCs transfected with empty plasmid). At weeks 4, 8, and 12 after transplantation, renal function, renal interstitial fibrosis, and peritubular microvessel density (MVD) were investigated. EPCs transfected with TERT gene showed decreased in vitro senescence, apoptosis, and proliferative ability was significantly enhanced (p < 0.05). Furthermore, rat transplanted with EPCs transfected with TERT showed significantly reduced renal interstitial fibrosis and increased endogenous creatinine clearance rate and peritubular MVD (p < 0.05). The transplantation of EPCs expressing TERT into five out of six subtotal nephrectomy rats was shown to improve renal function, reduce loss of peritubular microvessel, and inhibit progression of renal interstitial fibrosis. These studies provide the basis for a potential treatment of renal disease using genetically modified EPCs.

Nephroprotective effects of subcapsular transplantation of metanephric mesenchymal cells on gentamicin-induced acute tubular necrosis in rats.

BACKGROUND: The subcapsular transplantation of metanephric mesenchymal cells (MMCs) may be a new therapeutic approach for the treatment of acute tubular necrosis (ATN). To investigate this hypothesis and provide evidence for its possible use in the clinic, we evaluated the nephroprotective effects of transplanting MMCs into the renal subcaspsule of rats with ATN induced by gentamicin. METHODS: MMCs were expanded in culture. After gentamicin-induced ATN was established, fluorescently-labeled cells were transplanted and traced in kidney tissues by fluorescence microscopy. Serum creatinine (Cr), urea nitrogen (BUN), and N-acetyl-b-D-glucosaminidase (NAG) levels were determined at different time points. Kidney pathology was studied by hematoxylin-eosin staining. Apoptosis was examined by the TUNEL assay. RESULTS: In the MMCs-treated group, the mortality rate decreased; BUN, Cr, and NAG levels peaked at 8 days, and were significantly lower than those in the other groups at 11 and 14 days. RIMM-18 cells locally recruited through precise tropism to sites of injury had the ability to migrate into the tubuli from the renal subcapsule. Damage to the cell-treated kidneys was reduced. The pathologic lesion scores of tubular damage reached the highest values at 8 days in the treated kidneys and 11 days in the untreated ones. The apoptotic index showed that the peaks of apoptosis occurred at earlier stages of the injury process in cell-treated than in untreated kidney and thereafter declined in a time-dependent manner. CONCLUSION: The subcapsular transplantation of MMCs could ameliorate renal function and repair kidney injury.

Differences in tissue expression of HBV markers in children with HBV-associated glomerulonephritis.

BACKGROUND/AIMS: Hepatitis B virus-associated glomerulonephritis (HBV-GN) is recognized as one of the major secondary nephropathies in HBV high-risk areas. To determine possible differences in the expression of HBV immune markers in tissues, we retrospectively examined HBV immune markers in the serum, renal tissues, and liver tissues in 132 HBV-GN children. METHODS: All 132 patients had biopsy-proven HBV-GN including the presence of positive HBV antigens in the kidney. Serum-HBV immune markers were tested by an enzyme-linked immunosorbent assay. Renal and liver biopsies were done in 26 patients. All renal tissues were examined for HBV immune markers by immunofluorescence, and liver tissues were examined by immunohistochemistry. RESULTS: Among the 132 patients, all showed varying degrees of kidney injury. Serum hepatitis B envelope antigen (HBeAg) was positive in 80 patients and negative in 52 patients. The positivity rate of Hepatitis B core antigen in renal tissue was statistically higher in serum HBeAg (-) than in serum HBeAg (+) patients (96.2% vs. 55.0%). Furthermore, there was no relationship between the presence of hepatitis B surface antigen and HBcAg in liver and renal tissue. CONCLUSION: HBV markers are not consistently present in serum, renal tissues, and liver tissues in children with HBV-GN.

[Expression of vascular endothelial growth factor is related to microvessel injury of renal interstitium in children with Henoch Schönlein purpura nephritis].

OBJECTIVE: To investigate the relationship between vascular endothelial growth factor (VEGF) expression and microvessel injury of renal interstitium in children with Henoch-Schönlein purpura nephritis (HSPN). METHODS: Thirty-two children with HSPN and who had not received glucocorticoid or immunodepressants treatment before hospitalization were enrolled. Five children undergoing nephrectomy due to renal trauma were used as the control group. Renal samples were stained by hematoxylin and eosin and renal pathological changes were evaluated semi-quantitatively. CD34 and VEGF expression was detected by immunohistochemistry. CD34 was used as the marker for endothelial cells of renal microvessels. The microvessel density (MVD) was calculated by CD34 immunostaining. RESULTS: Compared with the control and the renal pathological grade II HSPN groups, MVD in the grade III and above HSPN groups decreased significantly, with an obvious reduction in MVD with the increased renal pathological grade (p<0.05). The renal microvessel score in the grades IIIa, IIIb, IV, and V HSPN groups decreased obviously compared with that in the control group. The renal microvessel score decreased with the increased renal pathological grade (p<0.05). VEGF expression in the grade II HSPN group was higher (p<0.05), while that in the grades IV and V HSPN group was lower than that in the control group (p<0.05). VEGF expression in the HSPN group showed a significant reduction with the increased renal pathological grade (p<0.05). There was a positive correlation between VEGF expression and MVD in renal tissue in the HSPN group (r=0.935, p<0.01). CONCLUSIONS: The decreased expression of VEGF may be responsible for the renal pathological damage and microvessel injury in HSPN.

[Protective effects of catechin on apoptosis of endothelial progenitor cells induced by H2O2 in rats].

OBJECTIVE: To study the effect of H2O2 on the proliferation and apoptosis of endothelial progenitor cells (EPCs) and the antogonistic effects of catechin on the cell apoptosis induced by H2O2 in rats. METHODS: Immuno-fluoreascence assay was applied to detect CD34, CD133 and VEGFR-2 expression. EPCs of generation 2 were divided into control cells, H2O2-treated cells and catechin-H2O2-treated cells (H2O2: 100 mg/L; catechin: 10 mg/L). Genomic DNA was extracted by the conventional method after intervention for the analysis of apoptosis ladder pattern. The MTT assay was applied to detect proliferation rate of EPCs. RESULTS: The cultured cells at day 10 expressed CD34, CD133 and VEGFR-2. DNA apoptosis ladder pattern appeared in H2O2-treated cells 2 days after intervention. After 3 days of intervention DNA apoptosis ladder pattern appeared in both H2O2-treated cells and H2O2-catechinjtreated cells, with more ladders and grayer scale in H2O2 -treated cells. Compared with the controls, H2O2-treated cells and H2O2-catechin-treated cells showed significantly decreased proliferation rate (p<0.01), with the lowest proliferation rate at the 2nd day (p<0.05). The H2O2-catechin-treated cells showed increased proliferation rate than H2O2-treated cells at the 1st, 2nd and 3rd days. CONCLUSIONS: H2O2 may impair EPCs proliferation and induce EPCs apoptosis. Catechin may increase the capacity of EPCs for the resistance to apoptosis induced by H2O2.