[Effects of astragalus on renal tubulointerestitial lesions and expression of NF-kappaB and MCP-1 in renal tissues in rat experimental IgA nephropathy]

OBJECTIVE

To investigate the effects of astragalus on tubulointerstitial lesions in rats with IgA nephropathy (IgAN) and to explore the possible mechanism.

METHODS

Twenty-eight Sprague-Dawley rats were randomly assigned to three groups. The rat model of IgA nephropathy was induced by intragastric administration of bovine serum albumin and injections of LPS and CC14. Six weeks later, the rats with IgAN were randomly treated with oral astragalus (3 g/kg/d, for 6 weeks) or normal saline. Normal control rats which were not subjected to IgAN were treated with normal saline. The number of urinary erythrocytes and urinary protein and B-D-N-Acetyl glucosaminidase (NAG) contents were determined by Pan-automatic biochemistry analyzing meter. Expression of monocyte chemotactic protein-1 (MCP-1) and nuclear factor-kappa B (NF-kappaB) in tubulointerstitial tissues were analyzed by immunohistochemistry. A semiquantitative score was used to evaluate the degree of renal pathologic lesions.

RESULTS

The number of urinary erythrocytes (74.02+/-16.58 / microL vs 383.23+/-4.94 /microL) and urinary protein (13.88+/-4.94 vs 59.82+/-14.73 mg/L) and NAG contents (2.84+/-0.31 vs 5.24+/-0.80 U/L) in the astragalus-treated IgAN rats decreased remarkably compared with those in the IgAN rats without astragalus treatment (P<0.01). Expression of the NF-kappaB and MCP-1 in the renal tissues in the IgAN rats without astragalus treatment was significantly higher than that in the astragalus-treated IgAN rats and normal control rats (P<0.01). There were significant differences in the scores of renal pathologic lesions between the IgAN rats with or without astragalus treatment (6.03+/-0.46 vs 10.57+/-1.23; P<0.01).

CONCLUSIONS

Astragalus can decrease the number of urinary erythrocytes and urinary protein and NAG contents, and relieves tubulointerstitial lesions, possibly through the down-regulation of NF-kappaB and MCP-1 expression in rats with IgAN.

Retrovirus-mediated expression of enhanced green fluorescent protein in rat bone marrow stem cells

AIM: To provide basis for the study of stem cell transplantation mechanism by observing the expression of enhanced green fluorescent protein (EGFP) gene mediated by retrovirus in SD rat bone marrow stromal cells (BMSCs).

METHODS: Density gradient centrifugation was conducted to obtain rat BMSCs which were then induced in the adipogenic direction. Their surface antigen and the adipogenic-differentiation potential were detected by oil red O staining. On the basis of the above results, BMSCs were transfected with the recombinant retrovirus pLEGFP-N1 containing EGFP. The morphologic changes of the cells, the expression time and intensity of fluorescent light were observed. The transfection efficiency was calculated.

RESULTS: The morphology and purity of the obtained rat BMSCs were good. The adipocytes were obviously observed after adipogenic induction. EGFP was successfully expressed after BMSCs were transfected with the retroviral vector pLEGFP-N1. The labeled cells were easy to observe within 4 wk.

CONCLUSION: Retrovirus is an ideal vector for high transfection efficiency and long period expression of target genes.

[Role of mast cells in the development of renal interstitial fibrosis in children with Henoch-Schonlein purpura nephritis]

OBJECTIVE

To investigate the role of mast cells in the development of renal interstitial fibrosis in children with Henoch-Schonlein purpura nephritis (HSPN) and possible mechanisms.

METHODS

Paraffin-embedded renal biopsy tissue sections from 20 children with HSPN were examined for the levels of tryptase-beta and transforming growth factor-beta1 (TGF-beta1) by immunohistochemical staining. Mast cells were counted by toluidine blue staining. Masson staining was used to assess the level of renal interstitial fibrosis and renal histopathological scores. Normal renal tissue sections from 5 nephrectomized children for nephroma were used as control group.

RESULTS

The percentages of positive tryptase-beta cellsand mast cells and the TGF-beta1 expression in the HSPN group were significantly higher than those in the control group (P < 0.05). The percentages of positive tryptase-beta cells and mast cells and the TGF-beta1 expression in renal tissue were positively correlated with the glomeruli histopathological score (r =0.940, 0.920, 0.937, respectively; P < 0.05) and were also positively correlated with the histopathological score of renal interstitium (r=0.903, 0.859, 0.948, respectively; P < 0.05). The level of renal interstitial fibrosis was positively correlated with the percentages of positive tryptase-beta cells and mast cells and the expression of TGF-beta1 (r =0.790, 0.766, 0.858, respectively; P < 0.05). There was a positive correlation between the percentages of positive tryptase-beta cells and mast cells (r =0.941, P < 0.05), between the percentage of positive tryptase-beta cells and the TGF-beta1 expression (r =0.897, P < 0.05) and between the percentage of positive mast cells and the TGF-beta1 expression (r=0.942, P < 0.05).

CONCLUSIONS

Tubulointerstitial mast cell infiltration is associated with the development of renal interstitial fibrosis in children with HSPN. Mast cells together with TGF-beta1 and mast cell-derived tryptase-beta may be involved in the development of the renal interstitial fibrosis in HSPN.

[Clinicopathologic characteristics of 1,316 children with renal disease]

OBJECTIVE

To investigate the clinicopathologic characteristics of childhood renal diseases.

METHODS

A retrospective analysis of 1316 renal biopsies performed over the past 20 years was performed.

RESULTS

Of the 1316 patients, 383 (29.09% ) were diagnosed as nephrotic syndrome, 291 (22.00%) as acute nephritis syndrome, 224 (17.21%) as isolated hematuria, 209(15.87%) as purpura nephritis, and 96 (7.30% ) as hepatitis B virus-associated nephritis . Mesangial proliferation was the most common pathological change (756 cases; 57.45%), followed by IgA nephropathy (113 cases; 8.59%), endothelial capillary proliferation(112 cases; 8.51%), membranous nephropathy (66 cases; 5.02%), and various minor and minimal changes (59 cases; 4.48%). Alport syndrome, congenital nephrotic syndrome, thin basement membrane nephropathy, fibrillary glomerulopathy disease, and Fabry disease were confirmed by electronic microscopy. IgA, IgM and C1q nephropathy were definitely diagnosed using immune histochemistry or immunofluorescent. A diagnosis of primary glomerular disease was made in 69.53% of the cases (915 cases); secondary glomerular disease was noted in 26.14% (344 cases). Of the 915 cases of primary glomerular disease, 375 (41.0%) had nephrotic syndrome. Secondary glomerular disease due to purura nephritis was common (209/344; 60.8%).

CONCLUSIONS

Primiary glomerular disease predominates in children. Nephrotic syndrome is the most common clinical diagnosis. Mesangial proliferation is the most common pathological patterns in children with renal disease.

[Effect of catechin microcapsule on the repair of DNA damage in glomerular mesangial cells induced by H2O2]

OBJECTIVE

To explore the effect and possible mechanism of catechin microcapsulation on the repair of DNA damage in glumreular mesangial cells (GMCs) induced by H2O2.

METHODS

According to H2O2 concentration, the experiment GMCs were divided into 6 groups: a control group, 50 micromol/L group, 100 micromol/L group, 150 micromol/L group, 200 micromol/L group and 250 micromol/L group. Each group was sub-divided into 3 groups: 6 h group, 12 h group and 24 h group, in order to determining the optimum dose and the best time of detecting the DNA damage in GMCs. The cultured cells were divided into 8 groups as follows: the NS control group, the H2O2 group, the catechin groups (the final concentrations were 10.0, 15.0, and 20.0 mg/L respectively) and the various catechin microcapsulation groups (the final concentrations were 10.0, 15.0, and 20.0 mg/L respectively). At the end of the experiment, hydroxy radical (OH), malonydialdehyde (MDA) and total superoxide dismutase (tSOD) concentration of supernadant in GMCs were determined by biochemistry assay, the repair of DNA damage in GMCs were detected by single cell gel electrophoresis assay.

RESULTS

(1)At 6th h, H2O2 of 100 micromoL/L could cause the DNA damage of GMCs, and H2O2 of 150 micromol/L could result in DNA damage significantly. (2) No difference was found in the comet span of GMCs DNA in the catechin group and catechin microcapsulation group of different concentrations, while the DNA comet tail-long in the catechin microcapsulation group was shorter than that of the catechin group(all P(s)<0.05), and the fluorescence intensity of tail in the catechin microcapsulation group was lower than that of the catechin group(all P(s)<0.01). (3)When the concentration of catechin was 10.0 mg/L, no statistical significance was obtained in the concentration of dOH-, MDA and tSOD between the catechin microcapsulation group and the catechin group; while dOH- and MDA concentrations were lower, and the tSOD was higher in the catechin microcapsulation group than that in the catechin group when the concentration of catechin was 15.0 mg/L and 20.0 mg/L(all P(s)<0.05).

CONCLUSION

Catechin microcapsulation can enhance the GMCs ability of repairing DNA damage,which may be due to elevating the capacity of its anti-oxidation by catechin microcapsulation.

[Analysis of 94 cases of IgA nephropathy in children]

OBJECTIVE

To evaluate the clinical and pathological features of 94 children suffering from IgA nephropathy (IgAN) while estimating the prevalent situation in Hunan province.

METHODS

To summarize the annual number of hospitalized children, those with kidney diseases, those accepted biopsy, and those confirmed as IgAN in both Xiangya Hospital and Second Xiangya Hospital undertaking kidney biopsy in Hunan province during 1995 and 2004.

RESULTS

In the past 10 years, as the hospitalized population in both hospitals accrued to 9.98% each year. The rate of 7.5% was seen in those with kidney diseases. Among whom 56.3% accepted kidney biopsy and 94 of them were confirmed as IgAN. Hematuria was the main clinical presentation, seen in 71 cases, accounting to 76%, and even to 98% after excluding those with nephrotic syndrome and isolating proteinuria type of IgAN. Inflammation infiltration (91%), renal tubule degeneration (81%), and renal interstitial fibrosis (31%) were the major pathological features of 94 children, especially in nephrotic syndrome IgAN.

CONCLUSION

The number of children with IgAN synchronously accrues as hospitalized population, those with kidney diseases, and those by kidney biopsy. Hematuria is the major symptom. To routinely perform urine analysis and kidney biopsy in asymptomatic hematuria may improve the diagnosis. Inflammation infiltration, renal tubule degeneration, and renal interstitial fibrosis are the major pathological features in IgAN children, especially in nephrotic syndrome IgAN, probably relating to continuous proteinuria. Early control of proteinuria may delay or decrease renal tubule fibrosis.

[Liver lesions in children with hepatitis B virus associated glomerulonephritis]

OBJECTIVE

To investigate the pathological changes of liver in children with hepatitis B virus associated glomerulonephritis (HBV-GN).

METHODS

Thirteen children with HBV-GN (aged from 2-14 years) underwent renal and liver biopsy. The biopsy findings were analyzed.

RESULTS

Different degrees of hepatic lesions were seen in all of the 13 patients, mild lesions accounting for 69.2% (9/13). HBSAg positive was the most common in the liver tissue [76.9% (10/13)]. Among the renal lesions, membranous glomerulopathy accounted for 69.2%( 9/13), followed by membranoproliferative glomerulonephritis 30.8% (4/13). HBsAg and HBcAg positive were presented in all patients' kidney tissues. HBV antigens were detected in stroma between nephric tubule in all samples. Four patients presented with HBcAg positive in both live and kidneys.

CONCLUSIONS

The children with HBV-GN couple with liver lesions. The severity of the renal lesions is not always accord with that of the liver lesions. The appearance of HBcAg in both kidneys and liver indicates severe lesions of the two organs. It is suggested that a liver-kidney holistic treatment is necessary for children with HBV-GN.

Role of PAX2 gene polymorphisms in Henoch-Schonlein purpura nephritis

OBJECTIVE

To investigate the distribution of polymorphisms in the PAX2 gene in children with Henoch-Schonlein purpura with and without nephritis (HSPN and HSP, respectively), with particular attention to the relationship between PAX2 gene polymorphisms and the development of kidney pathology.

METHODS

Genomic DNA was extracted from the peripheral leukocytes of 39 HSPN patients, 23 HSP patients without nephritis and 100 normal children, and three known single nucleotide polymorphisms (SNP), including 1410C>T, 1521A>C and 1544C>T in exon 8 and exon 9 of the PAX2 gene were studied as the candidate polymorphisms. The above two exons were amplified, the polymerase chain reaction (PCR) products were detected by denatured high-pressure liquid chromatography and direct DNA sequencing was performed for sequences with abnormal elution peaks.

RESULTS

In all samples confirmed by direct sequencing, we identified two SNP, which present as complete linkage haplotype 1410C>T + 1521A>C, in exon 8. We did not identify any SNP in exon 9. The frequency of the PAX2 heterozygous genotype 1410CT/1521AC in the HSPN group (28.20%) was significantly higher than in the HSP without HSPN group (4.35%) or in the control group (12.00%) (P < 0.05). The odds ratio (OR) values for HSPN and HSP were 6.05 and 2.62, respectively, and the 95% confidence intervals (CI) were 1.23-29.78 and 1.09-6.30, respectively. However, no differences in the frequency distribution was found between the HSP without nephritis and normal groups. Furthermore, there was no significant correlation between the polymorphism and clinical manifestation or kidney pathology in the HSPN group (P > 0.05).

CONCLUSION

The 1410CT/1521AC PAX2 genotype does not increase susceptibility for HSP, but is likely to increase the susceptibility of kidney involvement, resulting in a HSPN diagnosis.

[Pax2 expression in children with steroid-resistant primary nephrotic syndrome]

OBJECTIVE

To investigate the difference of Pax2 and P53 expressions in children with primary nephritic syndrome (PNS) and the effect of Pax2 on glucocorsteroid (GC)-resistance.

METHODS

Renal Pax2 and P53 expressions in children with PNS (40 patients) were detected by immunohistochemistry. A semiquantitative score was used to evaluate the injury degree of the glomeruli and the tubulointerstitium, and correlation analysis was done among Pax2, P53 and pathologic score.

RESULTS

Pax2 and P53 expressions were not found in the control group. Pax2 expression of renal tubule epithelia exsisted in children with PNS and there was weak or no expression of Pax2 in the podocytes. Pax2 expressions in the proximal tubule and the distal tubule in the GC-resistant group were more intense than those in the GC-intensive group (P <0.01). The more the Pax2 expression in the tubule, the more abnormal structure such as dilation and atrophy. Pax2 expression in the tubule epithelia was positively correlated with pathologic score of tubulointerstitium (P < 0.01). There was no P53 expression in the GC-intensive group, but there exsisted P53 expression in parts of the patients from the GC-resistant group, mainly distributing in the renal tubular epithelia. P53 expression was positively correlated with P53 expression and the pathologic score of tubulointerstitium (P < 0.01).

CONCLUSION

Over-expression of Pax2 in the renal tubule epithelia may improve P53 expression to a certain degree, which may aggravate the lesion of the renal tubule. It may be one of the mechanisms resulting in GC-resistant in children with PNS.

[Studies on chemical constituents of Cistanche tubulosa (Schenk) R. Wight]

OBJECTIVE

To investigate the chemical constituents of Cistanche tubulosa.

METHOD

The chemical constituents were isolated by solvent extraction together with various chromatographic techniques including preparative HPLC. The structures were elucidated on the basis of chemical evidence and spectral data.

RESULTS

Four iridoid glycosides, one lignan glycoside and one monoterpenoid were isolated from the 95% ethanol extract from the stem of C. tubulosa and identified as adoxosidic acid(I), 8-epiloganic acid(II), geniposidic acid (III), mussaenosidic acid(IV), (+)-syringaresinol-O-beta-D-gluco pyranoside(V) and 8-hydroxygeraniol(VI).

CONCLUSION

Compounds I and VI were isolated from the genus of Cistanche for the first time. Compounds III, IV and V were isolated from this plant for the first time.