Complement system is overactivated in patients with IgA nephropathy after COVID-19.

IgA nephropathy (IgAN), which has been confirmed as a complement mediated autoimmune disease, is also one form of glomerulonephritis associated with COVID-19. Here, we aim to investigate the clinical and immunological characteristics of patients with IgAN after COVID-19. The level of plasma level of C5a (p < 0.001), soluble C5b-9 (p = 0.018), FHR5 (p < 0.001) were all significantly higher in Group CoV (33 patients with renal biopsy-proven IgAN experienced COVID-19) compared with Group non-CoV (44 patients with IgAN without COVID-19), respectively. Compared with Group non-CoV, the intensity of glomerular C4d (p = 0.017) and MAC deposition (p < 0.001) and Gd-IgA1 deposition (p = 0.005) were much stronger in Group CoV. Our finding revealed that for IgAN after COVID-19, mucosal immune responses to SARS-CoV-2 infection may result in the overactivation of systemic and renal local complement system, and increased glomerular deposition of Gd-IgA1, which may lead to renal dysfunction and promote renal progression in IgAN patients.

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.

Corrigendum to "CD36-Mediated Lipid Accumulation and Activation of NLRP3 Inflammasome Lead to Podocyte Injury in Obesity-Related Glomerulopathy".

[This corrects the article DOI: 10.1155/2019/3172647.].

CD36-Mediated Lipid Accumulation and Activation of NLRP3 Inflammasome Lead to Podocyte Injury in Obesity-Related Glomerulopathy.

Podocyte injury critically contributes to the pathogenesis of obesity-related glomerulopathy (ORG). Recently, lipid accumulation and inflammatory responses have been found to be involved in podocyte injury. This study is to explore their role and relationship in podocyte injury of ORG. In animal experiments, the ORG mice developed proteinuria, podocyte injury, and hypertriglyceridemia, accompanied with deregulated lipid metabolism, renal ectopic lipid deposition, activation of NOD-like receptor protein 3 (NLRP3) inflammasome, and secretion of IL-1ß of the kidney. The expression of adipose differentiation-related protein (ADRP), CD36, sterol regulatory element-binding protein 1 (SREBP-1), and peroxisome proliferator-activated receptor α (PPARα) in renal tissue were increased. In in vitro cell experiments, after cultured podocytes were stimulated with leptin, similar to ORG mice, we found aggravated podocyte injury, formatted lipid droplet, increased expression of ADRP and CD36, activated NLRP3 inflammasome, and released IL-1ß. In addition, after blocking CD36 with inhibitor sulfo-N-succinimidyl oleate (SSO) or CD36 siRNA, activation of NLRP3 inflammasome and release of IL-1ß are downregulated, and podocyte injury was alleviated. However, after blocking NLRP3 with MCC950, although podocyte injury was alleviated and release of IL-1ß was decreased, there was no change in the expression of CD36, ADRP, and intracellular lipid droplets. Taken together, our study suggests that CD36-mediated lipid accumulation and activation of NLRP3 inflammasome may be one of the potential pathogeneses of ORG podocyte injury.

[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.

Characterization of patients with IgA nephropathy with and without associated minimal change disease.

Introduction: Immunoglobulin A nephropathy (IgAN) presents various clinical manifestations and pathological phenotypes. Approximately 5% of patients with IgAN present with early onset nephrotic syndrome, mild mesangial lesions, and diffuse foot process effacement of podocytes, which resemble minimal change disease (MCD). These patients are defined as MCD-IgAN. Whether MCD-IgAN is a special type of IgAN or simply MCD accompanied by IgA deposition remains controversial. Methods: A total of 51 patients diagnosed with MCD-IgAN at Beijing Anzhen Hospital from January 2010 to September 2022 were recruited. The clinical and pathological characteristics of IgA-MCD were analyzed. Patients with IgAN but without MCD (non-MCD-IgAN) and healthy participants were enrolled as controls. Galactose-deficient immunoglobulin A1 (Gd-IgA1) and complement C3 were detected both in the circulation and in renal tissues. Results: We found that the levels of serum Gd-IgA1 were lower in participants with MCD-IgAN than in those with non-MCD-IgAN, but higher than in healthy participants. Gd-IgA1 was rarely deposited in the glomeruli of participants with MCD-IgAN, with a positive rate of only 13.7% (7/51); in contrast, the positive rate in participants with non-MCD-IgAN was 82.4% (42/51). Among renal Gd-IgA1-positive patients, Gd-IgA1 and immunoglobulin A (IgA) colocalized along the glomerular mesangial and capillary areas. Interestingly, we found that the circulating levels of complement C3 were significantly higher in participants with MCD-IgAN than in participants with non-MCD-IgAN. In addition, the intensity of C3c in glomeruli in participants with MCD-IgAN was significantly weaker than in participants with non-MCD-IgAN. Conclusions: Our study suggests that, in MCD-IgAN, most of the IgA that is deposited on glomeruli is not the same pathogenic Gd-IgA1 as found in general IgAN. Complement activation both in the circulation and in the renal locality was much weaker in MCD-IgAN than in non-MCD-IgAN. Our study suggests that IgAN with MCD might be MCD with coincidental IgA deposition.

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.

Overactivation of the complement system may be involved in intrarenal arteriolar lesions in IgA nephropathy.

Introduction: IgA nephropathy (IgAN) encompasses a wide range of clinical and histology features. Some patients present without hematuria, with or without hypertension, still rapidly progress in renal function. Renal pathology of this part of patients were predominant intrarenal arteriolar lesions, rarely presented glomerular proliferative lesions. We aim to investigate the clinical and pathological characteristics and prognosis of these IgAN patients and initially explore whether the abnormal activation of complement is involved in the intrarenal arteriolar lesions of IgAN. Methods: A total of 866 patients with renal biopsy-proven IgAN diagnosed at Beijing Anzhen Hospital were recruited. IgAN patients without intrarenal arteriolar lesions and proliferative lesions were excluded (n = 115), the rest were divided into arteriolar lesions group (n = 202) and proliferative lesions group (n = 549). Among them, 255 patients were regularly followed up for at least 1 year. Renal biopsy tissues of 104 IgAN patients were stained for complement components by immunohistochemistry and immunofluorescence. Results: Compared with proliferative lesions group, the arteriolar lesions group experienced high percentage of hypertension (p = 0.004), low percentage of gross hematuria (p = 0.001), microscopic hematuria (p < 0.001) and less initial proteinuria (p = 0.033). Renal survival between the two groups was not significantly different (p = 0.133). MBL, C4d, FH and FHR5, C3c, and MAC deposited on intrarenal arteriole in arteriolar lesions group. Compare with the proliferative lesion group, the arteriolar lesions group exhibited a higher intensity of C3c deposition on the intrarenal arterioles (p = 0.048). C3c and CD31 co-deposited on intrarenal arterioles area in patients with intrarenal arteriolar lesions. Conclusion: Renal survival of the IgAN patients in arteriolar lesions group was not better than those in proliferative lesions group. Abnormal activation of complement may be involved in the pathogenesis of arteriolar damage through the injury of endothelial cells in this clinical phenotype of IgAN.

Glomerular Complement Factor H-Related Protein 5 is Associated with Histologic Injury in Immunoglobulin A Nephropathy.

INTRODUCTION: Immunoglobulin A nephrology (IgAN), characterized by co-deposition of IgA and complement components, is an activation of complement system involved disease. Factor H-related protein 5 (FHR-5) antagonized the ability of factor H to negatively regulate C3 activation, which leads to overactivation of the alternative pathway. Here we explore the relationship of intensity of glomerular FHR-5 deposition and severity of IgAN. METHODS: Renal staining of FHR-5 was detected by immunofluorescence, and plasma FHR-5 was detected by enzyme-linked immunosorbent assay in 56 patients with IgAN. The relationship of intensity of glomerular FHR-5 and clinical and pathologic features of these patients were further analyzed. RESULTS: Glomerular staining for FHR-5 was observed in a predominantly mesangial pattern in 32 biopsy specimens (57.1%). FHR-5 co-deposited with IgA and C3c in glomerular mesangial and capillary area in patients with IgAN. Patients with IgAN with Oxford endocapillary hypercellularity (P = 0.007) and segmental glomerulosclerosis (P = 0.049) presented with greater intensity of FHR-5 deposition. There were more cases with 2+ and 3+ FHR-5 staining in cohorts of 2+ and 3-4+ mesangial C3 deposition (P = 0.034) and IgA deposition (P = 0.019). Interestingly, the glomerular FHR-5 depositions were more abundant in male versus female in patients with IgAN (P = 0.002). Besides, circulating FHR-5 levels were elevated in patients with IgAN compared with healthy control subjects. Plasma FHR-5 levels were significantly higher in patients with mesangial hypercellularity at diagnosis than those with nonmesangial hypercellularity. CONCLUSIONS: We found that glomerular intensity of FHR-5 deposition could indicate the severity of histologic lesions of IgAN.

SMRT sequencing revealed to be an effective method for ADTKD-MUC1 diagnosis through follow-up analysis of a Chinese family.

We reported a large Chinese family diagnosed with autosomal dominant tubulointerstitial kidney disease caused by MUC1 mutation (ADTKD-MUC1). Cytosine duplication within a string of 7 cytosines in the variable-number tandem repeats (VNTR) region of the MUC1 gene was detected by long-read single-molecule real-time (SMRT) sequencing. MUC1 frameshift protein (MUC1fs) was found to be expressed in renal tubules and urinary exfoliated cells by pathological examination. The family, which consisted of 5 generations including 137 individuals, was followed for 5 years. Genetic testing was performed in thirty-four individuals, 17 of whom carried MUC1 mutations. The ADTKD-MUC1-affected individuals had an elevated incidence of hyperuricaemia without gout attack. Within five years, higher baseline levels of urinary α1-microglobulin were detected in affected individuals with rapidly progressing renal failure than in affected individuals with stable renal function, and the increases manifested even before increases in serum creatinine. This study demonstrates that SMRT sequencing is an effective method for the identification of MUC1 mutations. The pathological examination of MUC1fs expression in renal tissue and urinary exfoliated cells can contribute to early screening of family members suspected to be affected. It is suggested that affected individuals with elevated urinary α1-microglobulin levels should be closely monitored for renal function.

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.

IgG4-related sialadenitis complicated with type III mixed cryoglobulinemia: A case report.

RATIONALE: IgG4-related disease (IgG4-RD) is a systemic autoimmune disease and mixed cryoglobulinemia may be caused by autoimmune diseases. However, so far only 1 case of IgG4-RD complicated with mixed cryoglobulinemia is reported. Our case further confirms the close relationship between these 2 diseases. PATIENT CONCERNS: A 55-year-old female was admitted because of dry mouth and teeth falling off. DIAGNOSES: The patient was diagnosed as IgG4-related sialadenitis (IgG4-RS) complicated with type III mixed cryoglobulinemia. IgG4-RS was confirmed by elevated serum IgG4 levels and diffuse IgG4 plasmocyte infiltration and storiform fibrosis in the interstitium of labial gland. Type III mixed cryoglobulinemia was confirmed by positive serum cryoglobulins and no monoclonal immunoglobulin in serum and urine. INTERVENTIONS AND OUTCOMES: After treatment with prednisone and cyclophosphamide, serum cryoglobulins rapidly turned negative with the remission of IgG4-RS. LESSONS: Type III mixed cryoglobulinemia can be caused by IgG4-RS, and the underlying mechanisms need to be further explored.

Purinergic 2X7 Receptor is Involved in the Podocyte Damage of Obesity-Related Glomerulopathy via Activating Nucleotide-Binding and Oligomerization Domain-Like Receptor Protein 3 Inflammasome.

BACKGROUND: The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R). This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation of NLRP3 inflammasome. METHODS: A mouse model of ORG was established by high-fat diet feeding. The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079). The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3, ASC, and caspase-1, as well as the podocyte-associated molecules including nephrin, podocin, and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Western blot analysis, respectively. RESULTS: The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo, which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules. Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression of podocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro, and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079. CONCLUSIONS: P2X7R could trigger the activation of NLRP3 inflammasome, and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.

Artificially Cultivated Ophiocordyceps sinensis Alleviates Diabetic Nephropathy and Its Podocyte Injury via Inhibiting P2X7R Expression and NLRP3 Inflammasome Activation.

BACKGROUND/AIMS: It is known that chronic low-grade inflammation contributes to the initiation and development of both diabetes and diabetic nephropathy (DN), so we designed this study to investigate the role of P2X7R and NLRP3 inflammasome in DN pathogenesis and the antagonistic effects of artificially cultivated Ophiocordyceps sinensis (ACOS). METHODS: A rat model of DN caused by high-fat-diet feeding and low-dose streptozotocin injection and a mouse podocyte injury model induced by high-glucose (HG) stimulation were established, and the intervention effects of ACOS on them were observed. The biological parameters of serum and urine and the pathological manifestations of kidney tissue were examined. The expression of mRNA and protein of P2X7R and NLRP3 inflammasome (NLRP3, ASC, and caspase-1) and downstream effectors (IL-1ß and IL-18), as well as podocyte-associated molecules, was determined by real-time quantitative PCR and Western blot assay, respectively. RESULTS: The DN rats showed to have developed insulin resistance, elevated fasting blood glucose, increased urinary protein excretion, and serum creatinine level as well as corresponding glomerular pathological alterations including podocyte damages. ACOS significantly antagonized the above changes. The experiments in vivo and in vitro both displayed that the mRNA and protein expression of P2X7R, NLRP3, ASC, caspase1 (procaspase-1 mRNA in the gene level and active caspase-1 subunit P10 in the protein level), IL-1ß, and IL-18 was significantly upregulated and the mRNA and protein expression of podocyte-associated molecules was significantly changed (downregulation of nephrin, podocin, and WT-1 expression and upregulation of desmin expression) indicating podocyte injury in the kidney tissue of DN rats and in the HG-stressed mouse podocytes, respectively. ACOS also significantly antagonized all the above changes. CONCLUSION: Our research work suggests that P2X7R and NLRP3 inflammasome are involved in the pathogenesis of DN, and ACOS can effectively inhibit the high expression of P2X7R and the activation of NLRP3 inflammasome, which may contribute to the therapeutic effects of Ophiocordyceps sinensis.

Aldosterone is involved in the pathogenesis of obesity-related glomerulopathy through activation of Wnt/ß-catenin signaling in podocytes.

Obesity-related glomerulopathy (ORG) is morphologically characterized by glomerulomegaly with or without observable focal segmental glomerulosclerosis under light microscope, with decreased podocyte density and number, and with increased foot­process width observed under electron microscope. The severity of podocyte injury is correlated with the degree of proteinuria and renal dysfunction. However, the pathogenesis of ORG is not well understood. The aim of the present study was to explore the possible pathogenic role of aldosterone (ALDO) in ORG. In the in vivo animal experiments, body weight, Lee's obesity index, abdominal fat index, urinary protein excretion, average glomerular diameter were significantly increased, the mRNA and protein expression of podocyte­associated molecules including nephrin, podocin, podoplanin and podocalyxin were significantly reduced, and the Wnt/ß­catenin signaling pathway was activated in ORG model mice compared with the Control mice, whereas the administration of spironolactone significantly ameliorated these effects. In the in vitro experiments on cultured podocytes, the mRNA and protein expression levels of the aforementioned podocyte­associated molecules were significantly downregulated and the Wnt/ß­catenin signaling pathway was activated following ALDO stimulation, whereas eplerenone significantly attenuated all the above effects. Dickkopf­related protein 1 (DKK1), an inhibitor of Wnt/ß­catenin signaling pathway, also reduced the effects of ALDO exposure on the expression of podocyte­associated molecules. The present study hypothesized that ALDO may be involved in the pathogenesis of ORG through the activation of Wnt/ß­catenin signaling pathway in podocytes.

[Protective effects of Hirsutella sinensis on renal interstitial fibrosis: experiment with rat model of chronic aristolochic acid nephropathy].

OBJECTIVE: To study the protective effects of Hirsutella sinensis on renal interstitial fibrosis in chronic aristolochic acid nephropathy (CAAN). METHODS: Eighteen male SD rats were divided into 3 equal groups: model group, given the extract of Aristolochia manshuriensis Kom (AmK) by gavage in the morning everyday for 12 weeks, intervention group, given the extract of Amk in the morning and suspension of Hirsutella sinensis in the afternoon by gavage once a day for 12 weeks, and control group, receiving tap water only by gavage. Bodyweight, urinary glucose, 24 h urinary protein excretion, and serum creatinine (SCr) were measured at the ends of the 1st, 4th, 8th, and 12th weeks respectively. At the end of the 12th week, all the rats were sacrificed with their kidneys taken out to undergo pathological examination. RT-PCR and immunohistochemistry were used to detect the mRNA and protein 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 (ColI) in the kidney tissues. RESULTS: Since the 1st week, the urinary protein excretion and SCr levels in the model group were significantly higher than those in the control group (P < 0.01 or 0.05). At the end of the 12th week, the relative area of interstitial fibrosis of the model group was significantly enlarged (P < 0.01). The mRNA expression levels of TGF-beta1, CTGF, PAI-1, TIMP-1, and ColI in the model group were up-regulated by 4.19, 2.66, 6.12, 3.09, and 7.03 times respectively, and their protein expression levels were up-regulated by 2.31, 3.53, 3.17, 3.18, and 6.87 times respectively (all P < 0.01). By the end of the 12th week, the urinary protein excretion, SCr level and the relative area of interstitial fibrosis in the intervention group were all significantly lower than those in the model group (all P < 0.05). The mRNA expression levels of TGF-beta, CTGF, PAI-1, TIMP-1, and ColIof the intervention group were all significantly lower than those of the model group (all P < 0.05) with the inhibition rates of 45%, 41%, 47%, 48%, and the protein expression levels of TGF-beta, CTGF, PAI-1, TIMP-1, and ColI of the intervention group were all significantly lower than those of the model group (all P < 0.05) with the inhibition rates of 38%, 39%, 49%, 46%, and 61% respectively. CONCLUSION: Hirsutella sinensis can inhibit the production of TGF-beta1 and CTGF, factors that promote the extracellular matrix (ECM) synthesis and TIMP-1 and PAI-1, factors that antagonize ECM degradation in kidney tissues, thus alleviating renal interstitial fibrosis and improving renal function in CAAN.

Hirsutella sinensis Attenuates Aristolochic Acid-Induced Renal Tubular Epithelial-Mesenchymal Transition by Inhibiting TGF-ß1 and Snail Expression.

OBJECTIVE: To investigate the inhibitory effect of Hirsutella sinensis (HS) on epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells induced by aristolochic acid (AA) and its possible mechanism. METHODS: 18 male Sprague-Dawley rats were randomly and equally divided into the following 3 groups: AA group, AA+HS group and control group. Urinary protein excretion and creatinine clearance (CCr) were measured. All rats were sacrificed at the end of 12th week. The pathological examination of renal tissue was performed and the mRNA and protein expression of transforming growth factor-ß1 (TGF-ß1), α-smooth muscle actin (α-SMA), cytokeratin-18 and Snail in renal cortex were determined by real time quantitative PCR and immunohistochemical staining respectively. In addition, human renal proximal tubule epithelial cells line (HKC) was divided into the following 4 groups: AA group, AA+HS group, HS control group and control group. The above mRNA and protein expression in HKC was determined by real time quantitative PCR and Western blot respectively. RESULTS: (1) CCr was significantly decreased, and the urinary protein excretion and relative area of renal interstitial fibrosis were significantly increased in the rats of AA and AA+HS group compared to those in control group (P<0.05 or P<0.01); all the above abnormalities significantly lightened in the rats of AA+HS group compared to those in AA group (P<0.05). (2) The mRNA and protein expression of TGF-ß1, α-SMA and Snail was significantly up-regulated and the expression of cytokeratin-18 was significantly down-regulated in the rat renal cortex as well as in the cultured HKC cells in AA and AA+HS groups compared to those in control group (P<0.05 or P<0.01); all the above abnormalities significantly alleviated in AA+HS group compared to those in AA group (P<0.05 or P<0.01). (3) Knockdown endogenous Snail expression by siRNA could ameliorate AA-induced EMT of HKC cells, while overexpression of Snail by plasmid transfection diminished the antagonistic effect of HS on AA-induced EMT. These results suggest Snail might be a potential target of HS effect. CONCLUSION: HS is able to antagonize, to some extent, tubular EMT and renal interstitial fibrosis caused by AA, which might be related to its inhibitory effects on the TGF-ß1 and Snail expression.

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.

[The therapeutic effects of bosentan and valsartan on renal interstitial fibrosis of chronic aristolochic acid nephropathy].

OBJECTIVE: To investigate the therapeutic effects of endothelin receptor antagonist (bosentan) and angiotensin II type 1 receptor antagonist (valsartan) on renal interstitial fibrosis of rats with chronic aristolochic acid nephropathy (CAAN). METHODS: A rat model of CAAN was established by gavage with extract of Aristolochia manshuriensis Kom intermittently, and then they were divided into the following three groups, i.e. model group, bosentan group (100 mg.kg(-1).d(-1) by gavage) and valsartan group (30 mg .kg(-1).d(-1) by gavage). Control group (CTR) only received tap water by gavage. Each group consisted of 6 rats. At the end of 1st, 4 th, 8 th, 12 th and 16 th week, urinary protein excretion, urinary beta2 microglobulin (beta2-mG) and serum creatinine (SCr) were measured. Afterwards the rats were sacrificed. The relative area of renal interstitial fibrosis on pathological section was semi-quantitatively determined. The mRNA and the protein 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 collagen I (ColI) in kidney tissue was semi-quantitatively determined with reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical staining, respectively. RESULTS: Compared with CTR, urinary protein excretion, urinary beta2-mG and Scr were significantly increased (P < 0.05 or 0.01) and relative area of interstitial fibrosis was also significantly enlarged in the model group (3.964 +/- 0.739%, CTR 0.158 +/- 0.059%, P < 0.01). Compared with CTR, the expression of TGF-beta1, CTGF, PAI-1, TIMP-1 and Col I mRNA and protein was significantly up-regulated in the model group (P < 0.01). After intervention with bosentan or valsartan the up-regulating above mentioned parameters were all significantly inhibited (P < 0.05 or 0.01). However, there was no difference between bosentan group and valsartan group. CONCLUSION: Bosentan and valsartan both can ameliorate renal interstitial fibrosis and improve renal function in rats with CAAN. These responses may result from the inhibition effects on the promoting factors of ECM synthesis (TGF-beta1, CTGF) and the antagonistic factors of ECM degradation (PAI-1, TIMP-1).