Two kinds of rare light chain cast nephropathy caused by multiple myeloma: case reports and literature review.

BACKGROUND: Light chain cast nephropathy (LCCN) is the most common renal disease caused by multiple myeloma (MM). In addition to ordinary light chain protein casts, there are a few rare casts with unique shapes, including light chain amyloid casts (LCAC) and light chain crystal casts (LCCC). CASE PRESENTATIONS: Here, we report two patients. Patient 1 is a 72-year-old man who was clinically diagnosed with MM and acute kidney injury (AKI). Pathological examination of a renal biopsy revealed that there were many amyloid casts in the distal tubules that had a lightly-stained central area and a deeply-stained burr-like edge. The marginal zone of the cast was positive for Congo red staining and contained numerous amyloid fibers, as observed by electron microscopy. No systemic amyloidosis was found. The patient received 4 courses of bortezomib-based chemotherapy, and then, his MM achieved partial remission. Patient 2 is a 57-year-old man who was also clinically diagnosed with MM and AKI. Pathological examination of a renal biopsy showed that there were many crystalline casts in the distal tubules that were fully or partially composed of crystals with different shapes, including rhomboid, needle, triangle, rectangle and other geometric shapes. Congo red staining was negative. Crystals were also detected in the urine of this patient. After 9 courses of treatment with a bortezomib-based regimen, his MM obtained complete remission and his renal function returned to normal. CONCLUSIONS: LCAC and LCCC nephropathy caused by MM are two rare types of LCCN, and both have their own unique morphological manifestations. LCAC nephropathy may not be accompanied by systemic amyloidosis. The diagnosis of these two unique LCCNs must rely on renal biopsy pathology, and the discovery of urine crystals is of great significance for indicating LCCC nephropathy.

Cryoglobulinemic vasculitis and glomerulonephritis: concerns in clinical practice.

OBJECTIVE: Cryoglobulinemia often causes systemic vasculitis, thereby damaging to skin and internal organs including kidneys, even life-threatening. This review aimed to introduce the advances in understanding, detection, and treatment of this disease in recent years, with a particular concern to clinical practice. DATA SOURCES: All the data in this review were from the English or Chinese literature in the PubMed and China National Knowledge Infrastructure databases as of March 2019. STUDY SELECTION: This review selected important original articles, meaningful reviews, and some reports on cryoglobulinemia published in recent years and in history, as well as the guidelines for treatment of underlying diseases which lead to cryoglobulinemia. RESULTS: Diagnosis of cryoglobulinemia relies on serum cryoglobulin test, in which to ensure that the blood sample temperature is not less than 37°C in the entire pre-analysis phase is the key to avoid false negative results. Cryoglobulinemic vasculitis (Cryo Vas), including cryoglobulinemic glomerulonephritis (Cryo GN), usually occurs in types II and III mixed cryoglobulinemia, and can also be seen in type I cryoglobulinemia caused by monoclonal IgG3 or IgG1. Skin purpura, positive serum rheumatoid factor, and decreased serum levels of C4 and C3 are important clues for prompting types II and III Cryo Vas. Renal biopsy is an important means for diagnosis of Cryo GN, while membranous proliferative GN is the most common pathological type of Cryo GN. In recent years, great advances have been made in the treatment of Cryo Vas and its underlying diseases, and this review has briefly introduced these advances. CONCLUSIONS: Laboratory examinations of serum cryoglobulins urgently need standardization. The recent advances in the diagnosis and treatment of Cryo Vas and GN need to be popularized among the clinicians in related disciplines.

Retrospective Study of Phospholipase A2 Receptor and IgG Subclasses in Glomerular Deposits in Chinese Patients with Membranous Nephropathy.

BACKGROUND AND OBJECTIVES: The research work in the past years showed that detection of phospholipase A2 receptor (PLA2R) antigen and its dominant IgG4 autoantibody in glomerular deposits of patients with membranous nephropathy (MN) was useful for the differentiation between primary MN (PMN) and secondary MN (SMN), but so far such research data from large Chinese patient series is little. Here, we are going to report a research work in a Chinese cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study enrolled 179 patients with PMN, 40 patients with membranous lupus nephritis (LN-MN), 26 patients with hepatitis B virus-associated MN (HBV-MN), 2 patients with malignancy-associated MN (M-MN) and one patient with IgG4-related MN (IgG4-MN). PLA2R and IgG subclasses in glomerular deposits of these patients were examined by immunofluorescence and/or immunohistochemical staining, and the potential value of the above examinations for differential diagnosis of PMN and SMN was evaluated. RESULTS: Glomerular PLA2R deposition was present in 92.2% patients with PMN and 7.7% patients with HBV-MN, but none of the patients with LN-MN. Predominant/codominant IgG4 deposition was found in 93.3% patients with PMN and 11.5% patients with HBV-MN, but none of the patients with LN-MN. The two M-MN patients both had glomerular PLA2R and predominant/codominant IgG4 deposition. The one IgG4-MN patient had deeply staining IgG4 but no PLA2R in glomeruli. CONCLUSIONS: The glomerular PLA2R and predominant/codominant IgG4 deposition is frequently observed in Chinese patients with PMN. Immunofluorescence and immunohistochemical staining of renal biopsy tissue for detection of glomerular PLA2R and IgG subclasses deposition can help to distinguish PMN from LN-MN and most of HBV-MN.

[Application of Immunohistochemistry and Immunofluorescence Staining in Detection of Phospholipase A2 Receptor on Paraffin Section of Renal Biopsy Tissue].

OBJECTIVE: To evaluate the application of immunohistochemistry and fluorescence staining method in the detection of phospholipase A2 receptor (PLA2R) on paraffin section of renal biopsy tissue,and to find an accurate and fast method for the detection of PLA2R in renal tissue. METHODS: The PLA2R of 193 cases were detected by immunohistochemical staining,and the antigen was repaired by the method of high pressure cooker (HPC) hot repair plus trypsin repair. The 193 samples including 139 cases of idiopathic membranous nephropathy (IMN), 15 cases of membranous lupus nephritis, 8 cases of hepatitis B virus associated membranous nephropathy, 18 cases of IgA nephropathy, and 13 cases of minimal change diseases. To compare the dyeing effects, 22 paraffin sections of renal biopsy tissue of IMN cases with positive PLA2R were stained by using 4 different. METHODS: of antigen repairing,which included HPC hot repair, HPC hot repair plus trypsin repair, water bath heat repair, and water bath heat repair plus trypsin repair. To compare the dyeing effects, 15 paraffin sections of renal biopsy tissue of IMN cases with positive PLA2R were stained by using 3 different. METHODS: of antigen repairing,which included water bath heat repair plus trypsin repair, protease K digestion repair, and pepsin digestion repair. RESULTS: In 193 cases, the positive rate of PLA2R in IMN cases was 90.6% (126/139), and the other 54 patients without IMN were negative. Twenty-two IMN patients were positive for PLA2R by using the HPC heat repair plus trypsin repaire or the water bath heat repair plus trypsin repair;while only a few cases of 22 IMN cases were positive by using the HPC hot repair alone or water bath heat repair alone. Fifteen IMN patients were positive for PLA2R by using water bath heat repair plus trypsin repair,protease K digestion repair,and pepsin digestion repair, but the distribution of positive deposits and the background were different. CONCLUSIONS: PLA2R immunohistochemical staining can effectively identify IMN and secondary MN. For immunohistochemical staining and immunofluorescence staining, the preferred method of antigen repair is water bath heat repair plus trypsin repair.

Clinical prediction scores for type 1 cardiorenal syndrome derived and validated in chinese cohorts.

Type 1 cardiorenal syndrome is one of the major diseases threatening human life in China. The incidence of acute kidney injury (AKI) associated with acute heart failure (AHF), acute myocardial infarction (AMI), cardiac surgery, and coronary angiography has been reported to be 32.2, 14.7, 40.2, and 4.5%, respectively. In the past 2 years, we derived and validated 4 risk scores for the prediction of AKI associated with the above acute heart diseases as well as for examination and treatment in Chinese cohorts. A univariable comparison and a subsequent multivariate logistic regression analysis of the potential predictive variables of AKI in the derivation set were conducted and used to establish the prediction scores, which were then verified in the validation set. The area under the receiver operating characteristic (ROC) curve and the Hosmer-Lemeshow goodness-of-fit statistic test were performed to assess the discrimination and calibration of the prediction scores, respectively. These 4 prediction scores all showed adequate discrimination (area under the ROC curve, ≥0.70) and good calibration (p > 0.05). Both Forman's risk score (for AKI associated with AHF) and Mehran's risk score (for AKI associated with coronary angiography) are widely applied around the world. The external validation of these 2 risk scores was performed in our patients, but their discriminative power was quite low (area under the ROC curve, 0.65 and 0.57, respectively). Therefore, these prediction scores derived from Chinese cohorts might be more accurate than those derived from different races when they are applied in Chinese patients.

Inhibition of local aldosterone by eplerenone reduces renal structural damage in a novel model of chronic cyclosporine A nephrotoxicity.

BACKGROUND AND OBJECTIVE: The fact that mineralocorticoid receptor antagonists reduce structural and functional alterations induced by cyclosporine A (CsA) indicates that aldosterone plays a key role in chronic CsA nephrotoxicity. We and other researchers have reported local renal aldosterone synthesis. To investigate local renal aldosterone's role in chronic CsA nephrotoxicity, we evaluated the effect of eplerenone (Epl) on renal structural damage and renal dysfunction in adrenalectomized (ADX) rats, and assessed whether the therapeutic benefit was associated with reduction of transforming growth factor-ß1 (TGF-ß1), connective tissue growth factor (CTGF), plasminogen activator inhibitor type 1 (PAI-1) and collagen I (COL-I) expression. METHODS: Male Sprague-Dawley rats fed a normal-sodium diet were divided in four groups: sham-ADX, ADX, CsA, or Epl. Rats in the ADX, CsA and Epl groups were adrenalectomized first. Aldosterone, sodium and potassium levels in serum and urine were measured on the second day. Two weeks later, vehicle (sham-ADX and ADX group), CsA (25mg/kg/d), or CsA and Epl (100 mg/ kg/d) combination was administrated, respectively. After six weeks, urinary protein, creatinine clearance (Ccr), tubulointerstitial fibrosis (TIF), aldosterone level in kidney, and renal aldosterone synthase CYP11B2, COL-I, TGF-ß1, CTGF and PAI-1 gene expression levels were determined. RESULTS: On the second day after surgery, adrenalectomized rats showed undetectable aldosterone with natriuresis, hyponatremia, decreased urinary potassium excretion and hyperpotassemia. CsA reduced Ccr, induced urinary proteins and up-regulated COL-I, TGF-ß1, CTGF and PAI-1 gene expression with a significant development of TIF. Eplerenone administration prevented TIF and COL-I, TGF-ß1 and PAI-1 up-regulation but did not improve renal function. CONCLUSION: Our results suggest local renal aldosterone is an important mediator of renal injury induced by CsA.

Derivation and validation of a risk score for contrast-induced nephropathy after cardiac catheterization in Chinese patients.

BACKGROUND: To derive and validate a risk score for prediction of contrast-induced nephropathy (CIN) in the Chinese patients undergoing cardiac catheterization. METHODS: The hospital medical records of 3945 patients undergoing coronary angiography or percutaneous coronary intervention were reviewed. Patients were randomly assigned into two cohorts: one was for derivation of risk score (n = 2764) and another for validation (n = 1181). The CIN was defined as an increase of serum creatinine level ≥44.2 µmol/L or ≥25 % and beyond its upper limit of normal value within 72 h following the procedure. On the basis of the odds ratio obtained from multivariate logistic regression, risk score of CIN was built up. The discrimination of the risk score was assessed using the area under the receiver operating characteristic curve and the calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test. RESULTS: The incidences of CIN in the derivation and validation cohorts were 4.6 and 4.2 %, respectively. Independent predictors included age >60 years, hypertension, acute myocardial infarction, heart failure, use of intra-aortic balloon pump, decreased glomerular filtration rate and contrast volume >100 mL. The incidence of CIN was increased with increment of risk score. Both the derivation and validation cohorts showed adequate discrimination (an area under the ROC curve, 0.76 and 0.71, respectively) and good calibration (Hosmer-Lemeshow statistic test, P = 0.50 and P = 0.54, respectively). CONCLUSION: A simple risk score for prediction of CIN development after cardiac catheterization in Chinese patients was built up by this study. Use of this risk score may help clinicians to perform early preventative strategies to minimize the risk of CIN.

Determination of normal value of glomerular size in Chinese adults by different measurement methods.

AIM: Identification of glomerulomegaly is a prerequisite for diagnosis of obesity-related glomerulopathy, so measurement of glomerular size is of critical importance. METHODS: A total 100 cases pathologically diagnosed as minor glomerular abnormalities or thin basement membrane nephropathy with normal body mass index and blood glucose level were selected as the normal value measurement group of glomerular size. The mean value of diameters of capillary tuft on the glomerular maximum profile was determined using the direct method and indirect method with the Motic Med 6.0 digital medical image analysis system. Meanwhile, 80 cases of different glomerular disease with normal body mass index and blood glucose level were also collected. Their glomerular diameters were measured and compared with those in the normal value measurement group. RESULTS: The measurement results showed that gender and age had no effects on glomerular diameter. The normal value ranges of the diameter on glomerular maximum profile were as follows. (i) Pole-containing glomerulus (the glomerulus with vascular pole or/and urinary pole): direct method, 101.3-184.9 µm; indirect method, 100.3-183.5 µm. (ii) Pole-containing glomerulus plus non-pole glomerulus (the glomerulus without poles, the maximum profile of which was larger than that in the smallest pole-containing glomerulus): direct method, 108.3-185.9 µm; indirect method, 107.4-185.4 µm. The glomerular diameters of the 80 cases with different glomerular disease were all within the aforementioned normal value ranges. CONCLUSIONS: Both methods used in the present study are feasible to measure the glomerular diameter and the normal value range of glomerular diameter in Chinese adults is established.

JNK-dependent AP-1 activation is required for aristolochic acid-induced TGF-ß1 synthesis in human renal proximal epithelial cells.

Chronic aristolochic acid nephropathy (CAAN) is a chronic and progressive tubulointerstitial nephropathy characterized by extensive interstitial fibrosis. Aristolochic acid (AA) could induce overexpression of transforming growth factor-ß1 (TGF-ß1) in a human renal proximal tubule epithelial cells line (HKC), which has been implicated in the pathogenesis of CAAN. The present studies in HKC cells showed 1) AA could activate JNK in time- and dose-dependent manners and JNK inhibitor SP600125 could inhibit AA-induced TGF-ß1 promoter activity and TGF-ß1 synthesis; 2) AA-induced JNK activation and TGF-ß1 synthesis were significantly inhibited by kinase-inactive mutants of MEKK4, MKK4, or MKK7; 3) AA could upregulate luciferase activity derived by a wild-type TGF-ß1 promoter, but not by an AP-1 binding-deficient TGF-ß1 promoter; and 4) AA could upregulate expression of c-Fos, phospho-c-Jun, and phospho-ATF2. The above data suggest AA-induced TGF-ß1 overexpression in HKC cells may be mainly mediated by the JNK signaling pathway. Both the upstream kinases of JNK including MEKK4, MKK4, and MKK7, and the downstream transcription factor of JNK, AP-1, may also participate in this process.

[Expression and regulation of adiponectin in human renal glomerular endothelial cells].

OBJECTIVE: To investigate the expression and regulation of adiponectin in human renal glomerular endothelial cells (HRGEC). METHOD: The adiponectin expression in human renal tissue was examined with immunohistochemistry assay, and the adiponectin mRNA and protein expression of HRGEC was confirmed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. PCR product was sequenced. To investigate the regulation action of TNF-alpha, the adiponectin produced by HRGEC was semi-quantitatively determined with real-time PCR in mRNA level and quantitatively measured with dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) in protein level, respectively. RESULTS: (1) Positive adiponectin staining was observed on human glomerular capillary wall with immunohistochemistry assay. (2) Adiponectin mRNA expression in HRGEC was detected by RT-PCR, and the DNA sequence of this PCR product is consistent with adiponectin DNA sequence in Gene Bank. Adiponectin protein was also found in the supernatant of cultured HRGEC by Western blot. (3) Compared with control groups, the adiponectin mRNA expression in HRGEC determined by real-time PCR was significantly up-regulated after 250 IU/ml and 500 IU/ml TNF-alpha stimulation for 24 h (P < 0.05 and P < 0.01), and the adiponectin protein levels in culture supernatant measured by DELFIA were also significantly increased in these two groups (P < 0.05 and P < 0.01). (4) Compared with control groups, the adiponectin mRNA expression in HRGEC was significantly up-regulated after 500 IU/ml TNF-alpha stimulation for 6 h, 12 h and 24 h (P < 0.05, P < 0.05 and P < 0.01), and the adiponectin protein levels in culture supernatant were also significantly increased after stimulation for 24 h and 48 h (P < 0.01). CONCLUSIONS: HRGEC is able to synthesize adiponectin, and TNF-alpha can up-regulate its mRNA and protein expression.

[Organic anion transporter system mediates the transport of aristolochic acid in tubular epithelial cells].

OBJECTIVE: To investigate whether aristolochic acid can be transported into human kidney proximal tubular cell (HKC) and its potential mechanism. METHODS: Intracellular aristolochic acid was measured by liquid chromatography-tandem mass spectrometry. The release of lactate dehydrogenase (LDH) induced by aristolochic acid in the presence of organic anion transporter inhibitor (probenecid) or organic cation transporter inhibitor (tetraethylammonium) was evaluated. The effects of probenecid on aristolochic acid induced connective tissue growth factor (CTGF) mRNA and protein expression were also examined by real time polymerase chain reaction and Western blot, respectively. RESULTS: Aristolochic acid was detected in the suspension of the denatured HKC after incubation with aristolochic acid sodium salt. The release of LDH from HKC, which was induced by 60 mg/L aristolochic acid sodium salt, was significantly inhibited by 1 mmol/L probenecid (P < 0.01), but not by 1 mmol/L tetraethylammonium. The increased CTGF mRNA and protein expression in HKC stimulated by 40 mg/L aristolochic acid sodium salt was significantly down-regulated by 1 mmol/L probenecid (P < 0.05), with an inhibition rate of 16% and 21%, respectively. CONCLUSION: Aristolochic acid can be transported into HKC by organic anion transport system, and then exerts its biological effects.

[The role of MAPK/ERK1/2 signaling pathway in aldosterone stimulated transforming growth factor-beta1 synthesis in renal tubular epithelial cells].

OBJECTIVE: Our previous study have demonstrated that the expression of transforming growth factor-beta1 (TGF-beta1) by HKC could be up-regulated by aldosterone (ALDO) in vitro. The present study was designed to evaluate the role of MAPK/ERK1/2 phosphorylation in mediating the synthesis of TGF-beta1 in renal tubular epithelial cells that was activated by aldosterone. METHODS: The following tests were performed in vitro: (1) HKC were pretreated with different concentrations of specific ERK1/2, JNK and P38 MAPK pathway inhibitors for 4h, then HKC were stimulated with 10(-7) mol/L ALDO for 48 h, finally enzyme-linked immunosorbent assay (ELISA) were performed to detect TGF-beta1 expression; (2) HKC were stimulated with ALDO at different concentrations and times, then western blot assay was performed to detect the expression of phosphorylated and total ERK1/2 in the cell lysate of HKC. (3) HKC which were co-stimulated with 10(-7) mol/L ALDO and different concentrations of spironolactone or specific glucocorticoid hormone receptor inhibitor RU486 for 30min, then western blot assay was performed to detect the expression of phosphorylated and total ERK1/2 in the cell lysate of HKC. RESULTS: (1) the production in 15 and 25 micromol/L U0126 incubated groups was (87 +/- 11) pg/ml and (75 +/- 19) pg/ml respectively, which was significantly decreased compared with that in 10(-7) mol/L ALDO incubated group (P < 0.05), however, the amount of TGF-beta1 in these groups were still significant higher than that in the control group (P < 0.05). The production of TGF-beta1 in the groups which were incubated with SP600125 and SB203580 did not appear significant decrease compared with that in 10(-7) mol/L ALDO incubated group (P > 0.05), the production of TGF-beta1 in these groups was also significant higher than that in the control group (P < 0.05). (2) The Phos/Total ERK1/2 ratio was increased in a dose-dependent manner. After HKC were stimulated with 10(-9) - 10(-7) mol/L ALDO for 30 min. Phos/TotalERK1/2 ratio was 0.67 +/- 0.06 and 0.80 +/- 0.05 respectively, which was significantly increased (vs 0 mol/L ALDO, P < 0.05 or 0.01). The expression of Phos/Total ERK1/2 ratio also had a positive correlations with the production of TGF-beta1 (R = 0.793, P < 0.01). With 10(-7) mol/L ALDO stimulated at different times, the Phos/Total ERK1/2 ratio was also significantly increased (vs 0 h, P < 0.05 or 0.01), which began to be increased and reached the peak at 15 min, the relatively ratio was 0.84 +/- 0.06, and waned till 240 min, and returned to normal level at 360 min. (3) After co-stimulated with 10(-7) mol/L ALDO and different concentration of spironolactone, Phos/TotalERK1/2 ratio was significantly decreased along with the concentrations of spironolactone, the relatively ratio of in 10(-9) - 10(-7) was 0.62 +/- 0.08 and 0.60 +/- 0.04 separately (vs 0 mol/L ALDO, or 0.01), but they were still significantly higher than that in control group (P < 0.05). The Phos/TotalERK1/2 ratio was not changed significantly along with the concentrations of RU486 (P > 0.05). CONCLUSION: The effect of aldosterone in up-regulating the expression of TGF-beta1 in HKC is mediated, at least in part, by MAPK/ERK1/2 pathway. Aldosterone may exert this effect on the conditions of binding to the mineralocorticoid receptor first.

[The effect of tubular epithelial cells activated by aldosterone on renal interstitial fibroblasts in co-culture system].

OBJECTIVE: Local aldosterone (ALDO) could be synthesized by human proximal tubular epithelial cell lines (HKC) after the stimulation of endothelin-1 (ET-1) in vitro. T to observe the effect of tubular epithelial cells activated by aldosterone (ALDO) on renal interstitial fibroblasts in co-culture system. METHODS: (1) Human Proximal tubular epithelial cells of the line HKC were stimulated with ALDO at different concentrations and times, then reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to detect TGF-beta1 expression; (2) HKC were co-stimulated with ET-1 (10(-9) mol/L) and spironolactone at different concentrations and times to evaluate the influence of endogenous ALDO on TGF-beta1 expression; (3) HKC which were activated by 10(-7) mol/L ALDO for 12 h, and hRIFs were co-cultured for 48 h with or without anti-TGF-beta1 antibody (1.0, 2.0 microg/ml) in the media, then the production of type I collagen (Col-I) in the cell layer of hRIFs was detected by ELISA. RESULTS: (1) After stimulation with ALDO, the expression of TGF-beta1 by HKC was up-regulated in a dose-and time-dependent manner. With 10(-9) or 10(-7) mol/L ALDO stimulation (mRNA determination at 12 h and protein at 48 h), the expression of TGF-beta1 was significantly increased (vs 0 mol/L ALDO, P < 0.05 or 0.01). With 10(-7) mol/L ALDO stimulated at different times (mRNA determination at 8 h, 12 h and 16 h and protein at 12 h, 24 h and 48 h), the expression of TGF-beta1 was also significantly increased (vs 0 h, P < 0.05 or 0.01). (2) After co-stimulation with ET-1 and spironolatone, the expression of TGF-beta1 by HKC was down-regulated in a dose-and-time dependent manner along with spironolatone. The expression of TGF-beta1 mRNA and protein was decreased in the 10(-9) or 10(-7) mol/L spironolatone groups compared with 0 mol/L group (P < 0.05 or 0.01). The expression of TGF-beta1 (mRNA and protein) was significantly decreased in 10(-9) mol/L ET-1 and 10(-7) mol/L spironolatone co-stimulation group compared with 10(-9) mol/L ET-1 stimulated group. (3) The production of Col-I by hRIFs which were co-cultured with activated HKC by ALDO, was significantly increased (vs control group in which hRIFs co-cultured with normal HKC, P < 0.01), and this effect was partially inhibited by 1.0 or 2.0 microg/ml anti-TGF-beta1 antibody (P < 0.05). CONCLUSION: The expression of TGF-beta1 in HKC cells can not only be up-regulated by exogenous ALDO, but also can be up-regulated by endogenous ALDO in an autocrine manner. The HKC cells activated by ALDO can promote the synthesis of Col-I in hRIFs by a "cross talking" way, and this effect is partially mediated by TGF-beta1.

[The medicinal serum of yi-shen ruan-jian san antagonized the effect of aristolochic acid on human proximal tubular epithelial cells in vitro].

OBJECTIVE: To evaluate whether the medicinal serum of Yi-shen Ruan-jian san can antagonize the fibrogenic effect of human proximal tubular epithelial cell line (HKC) activated by aristolochic acid (AA) in vitro. METHOD: The HKC was incubated in the media containing 40 mg x L(-1) aristolochic acid sodium salt (AA-Na) with or without 10% concentration of Yi-shen Ruan-jian san medicinal serum. Then the cell proliferation and cytotoxicity of HKC were determined by MTF and lactate dehydrogenase (LDH) release assay respectively, the antigen expression of cytokeratin and alpha-smooth muscle actin on HKC was detected by immunocytochemistry, the mRNA expression of transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and type I Collagen (Col I) of HKC was measured by RT-PCR, and their protein expression was measured by ELISA or Western blot. RESULT: No cytotoxic effect was found in HKC after stimulation of AA-Na with or without the medicinal serum of Yi-shen Ruan-jian san (P > 0.05). No epithelial-myofibroblast transdifferentiation was found in HKC after AA-Na stimulation. The mRNA and protein expression of TGF-beta1, CTGF, PAI-1 and TIMP-1 of HKC was significantly upregulated by AA-Na (P < 0.05). The above-mentioned enhanced mRNA and protein expression, except for PAI-1, was significantly downregulated by the medicinal serum of Yi-shen Ruan-jian san, compared with the control (normal rat serum in the same concentration) (P < 0.05). CONCLUSION: The fibrogenic effects of HKC activated by AA are antagonized by Yi-shen Ruan-jian san, through downregulating the expression of promoting excellular matrix (ECM) synthesis factors (TGF-beta1, CTGF) and inhibiting ECM degradation factor (TIMP-1).