OBJECTIVETo investigate the expression and function of PKD1 and PKD2 in different kidney tissues and cell lines.

METHODSImmunoprecipitation, Western blotting, In situ hybridization and immunohistochemical staining methods were used to observe the expression of PKD1 mRNA and PKD2 mRNA and their protein abundance in different kidney tissues and cell lines.

RESULTSCoordinate expressions of PKD1 and PKD2 were found in all kidney tissues and cell lines. Distribution of PKD1 mRNA and PKD2 mRNA and their protein polycystin-1 and polycystin-2 in normal human adult kidney tissue were mainly expressed in the medullary collecting ducts and distal tubules. Positive staining was also found in the majority of cyst-lining epithelial cells of PKD1 cystic kidney tissue, PKD1 cyst-lining epithelia cell line and LLC-PK1. The expression level of them in cystic epithelia of ADPKD kidney tissue was much higher than that in adult renal tubules (P < 0.01).

CONCLUSIONSSimilar expression pattern of PKD1 and PKD2 and their different tissue distribution in different kidney tissues show that the molecular mutuality of PC-1 and PC-2 might be the base of their functional correlation. Polycystins might play an important role in the maintenance of tubular architecture.

Adult ; Animals ; Cell Line ; Gene Expression ; Humans ; Kidney ; metabolism ; Kidney Tubules, Collecting ; metabolism ; Kidney Tubules, Distal ; metabolism ; Kidney Tubules, Proximal ; cytology ; Polycystic Kidney, Autosomal Dominant ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Swine ; TRPP Cation Channels ; metabolism

Renal ammonium metabolism is the primary component of net acid excretion and thereby is critical for acid - base homeostasis. Briefly, ammonium is produced from glutamine in the proximal tubule in a series of biochemical reactions that result in equimolar bicarbonate. Ammonium is predominantly secreted into the luminal fluid via the apical Na++xchanger, NHE3. The thick ascending limb of the loop of Henle reabsorbs luminal ammonium, predominantly by transport of NH4+y the apical Na++Cl - cotransporter, BSC1/NKCC2. This process results in renal interstitial ammonium accumulation. Finally, the collecting duct secretes ammonium from the renal interstitium into the luminal fluid. Although in past ammonium was believed to move across epithelia entirely by passive diffusion, an increasing number of studies demonstrated that specific proteins contribute to renal ammonium transport. Recent studies have yielded important new insights into the mechanisms of renal ammonium transport. In this review, we will discuss renal handling of ammonium, with particular emphasis on the transporters involved in this process.
Ammonia ; Diffusion ; Extremities ; Glutamine ; Handling (Psychology) ; Homeostasis ; Kidney ; Kidney Tubules, Collecting ; Loop of Henle ; Phenobarbital ; Proteins ; Quaternary Ammonium Compounds

OBJECTIVETo study the clinicopathologic features of collagen III glomerulopathy and its cause, pathogenesis and prognosis.

METHODSFive cases of collagen III glomerulopathy that collected from 2005 to 2014 were observed by renal biopsy. The morphologic characteristics were studied by light microscopy, immunofluorescence, immunohistochemical and electron microscopy.

RESULTSThe glomerular mesangium became expansion but no hypercellularity, basement membrane appeared thickened. The glomeruli showed collagen type III deposit by immunohistochemistry method, and collagen fibers increased by electron microscopy. The patients often show serious proteinuria, nephrotic syndrome and renal function damage.

CONCLUSIONSCollagen III glomerulopathy is an idiopathic glomerular disease, characterized by massive accumulation of collagen type III within the glomerular mesangial areas and basement membrane. Collagen III glomerulopathy is extremely rare. The etiology and pathogenesis may relate to the abnormality of collagen III gene. There is no specific treatment for it and its prognosis is poor.

Basement Membrane ; metabolism ; Biopsy ; Collagen Type III ; genetics ; metabolism ; Female ; Fluorescent Antibody Technique ; Glomerular Mesangium ; metabolism ; Humans ; Immunohistochemistry ; Kidney Diseases ; etiology ; pathology ; Kidney Glomerulus ; pathology ; Microscopy, Electron ; Prognosis ; Proteinuria ; diagnosis

OBJECTIVETo study the clinicopathologic features of membranous nephropathy coexisting with IgA nephropathy.

METHODSThe renal biopsies performed in Peking University First Hospital during the period from January, 1998 to April, 2006 were retrospectively reviewed. The clinicopathologic features of 11 cases of membranous nephropathy coexisting with IgA nephropathy were studied. Electron microscopy with immunogold labeling for IgG and IgA were also performed.

RESULTSThe mean age of patients was 39.9 years. The male-to-female ratio was 1:2.9. The patients mainly presented with proteinuria. Proteinuria of nephrotic level was seen in 7 cases (63.6%). Seven cases also had associated microscopic hematuria. None of them showed evidence of renal insufficiency. Cases with secondary diseases, such as hepatitis virus infection and systemic lupus erythematosus, were excluded from the study. Histologically, vacuolation and thickening of glomerular basement membrane was seen. There was also mild mesangial hypercellularity and increase in mesangial matrix. Occasional glomeruli with crescent formation were identified in 2 cases. Immunofluorescence study showed granular staining for IgG and C3 along glomerular capillary walls, in addition to clumps of IgA deposits in mesangium. Electron microscopy revealed subepithelial and mesangial electron-dense deposits. Immunogold labeling showed IgG and IgA localized in the subepithelial and mesangial deposits respectively.

CONCLUSIONMembranous nephropathy coexisting with IgA nephropathy possesses the clinicopathologic features of both components. It might be caused by independent occurrence of the two entities.

Adult ; Female ; Glomerular Basement Membrane ; immunology ; pathology ; ultrastructure ; Glomerular Mesangium ; immunology ; pathology ; ultrastructure ; Glomerulonephritis, IGA ; complications ; immunology ; pathology ; Glomerulonephritis, Membranous ; complications ; immunology ; pathology ; Humans ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; metabolism ; Kidney Glomerulus ; immunology ; pathology ; ultrastructure ; Male ; Middle Aged ; Retrospective Studies

Transplant glomerulopathy is a late complication of renal transplantation. The characteristic morphology of transplant glomerulopathy includes thickening of glomerular capillary loops with double contour, and duplication of glomerular basement membrane on electron microscopy. Clinical and experimental evidences support the role of antibody-mediated immune mechanism in the development of transplant glomerulopathy. Antibody-induced endothelial cell injury is the key pathogenesis of transplant glomerulopathy. The evolution of transplant glomerulopathy in the context of immunologic injury is briefly reviewed.
Capillaries ; Endothelial Cells ; Glomerular Basement Membrane ; Graft Rejection ; Immunity, Humoral ; Kidney Glomerulus ; Kidney Transplantation ; Microscopy, Electron ; Transplants

Cystinuria is an autosomal recessive disease characterized by impaired transport of cystine and dibasic amino acids in the proximal renal tubule, resulting in the formation of cystine stones. It is believed to account for about 1% of all kidney stones and up to 10% of pediatric stones. Here we report a case of cystinuria with multiple renal stones confirmed by genetic mutational analysis. An 8-month-old girl was admitted to AMC with persistent fever and multiple renal stones. A renal sonogram showed multiple stones at the right renal pelvis, right distal ureter, and left renal medullary portion. An approximately 1 cm renal stone was extracted spontaneously, and stone analysis revealed it to be composed entirely of cystine. Cystinuria was confirmed by increased urine dibasic amino acid levels, including cysteine, and genetic mutational analysis showed the patient to be a homozygote for the pathogenic c. 1820del (p.L607fs) of SLC3A1. Despite treatment with oral hydration and urinary alkalinization, and restricted intake of animal protein, the stones increased in size and number. The patient has since been treated with tiopronin.
Amino Acids, Diamino ; Animals ; Cysteine ; Cystine ; Cystinuria* ; Female* ; Fever ; Homozygote ; Humans ; Infant* ; Kidney Calculi ; Kidney Pelvis ; Kidney Tubules, Proximal ; Tiopronin ; Ureter ; Urolithiasis

OBJECTIVE: To investigate the relationship between the expression of nephrin and the infiltration of macrophages in renal tissues in patients with lupus nephritis (LN), and to provide the evidence of potential mechanism of podocyte injury in LN. METHODS: In the study, 60 patients who were first diagnosed with LN by pathology were selected including 38 active LN patients with r-SLEDAI≥4, and another 10 patients of normal renal tissue were excised as a normal control group. The renal tissue and podocyte injury were observed through light and transmission electron microscope. The expression of nephrin and the infiltration of macrophages (CD68+cells) in the renal tissue of the 60 LN patients and 10 normal cases were detected by immunohistochemical and immunofluorescence method. Different statistical analysis methods were used to analyze the correlation between the variables. Variance analysis was used for comparison among the groups, while LSD test was used for comparison between every two groups. Pearson correlation analysis was used to analyze the correlation between the variables. RESULTS: (1)Of all the LN patients, 24 h urinary protein [(3.94±1.76) vs. (1.56±0.68), P<0.05], erythrocyte sedimentation rate (ESR) [(79.83±6.3) vs. (40.1±10.5), P<0.05] and serum creatinine [(106.58±14.9) vs. (79.1±9.89), P<0.05] were significantly increased in active group than those in inactive group, while C3 [(0.34±0.12) vs. (0.78±0.11), P<0.05], C4 [(0.07±0.04) vs. (0.17±0.10), P<0.05 ] and eGFR [(62.42±5.16) vs. (81.33±4.53), P<0.05] were significantly decreased in active group. (2)Compared with the normal control group, the expression of nephrin in renal tissue of the LN patients was significantly decreased, and the expression of nephrin in the active patients was significantly lower than that in inactive group (P<0.05). (3)Compared with the normal control group, the number of infiltrated macrophages in the LN patients was significantly increased, especially in the active patients (P<0.05). Macrophages were mainly found in glomeruli. (4)There was a significant negative correlation between the expression of nephrin and macrophage infiltration in renal tissues of the LN patients (r=0.761, P<0.001). CONCLUSION Macrophage infiltration in renal tissues may be one of the potential mechanisms of podocyte injury in lupus nephritis.
Humans ; Kidney ; Kidney Glomerulus ; Lupus Nephritis ; Macrophages ; Podocytes

In this paper, 2 cases of collagen Type Ⅲ glomerulopathy were analyzed. The clinical manifestations mainly included nephrotic syndrome, proteinuria, hypertension and renal dysfunction. One patient showed that the complement factor H-related protein 5 (CFHR5) gene was likely a disease-causing mutation. The pathological examination of renal tissues showed hyperplasia of mesangial matrix, sub-endothelial insertion, and double-track formation. Immunohistochemistry of Type III collagen was positive. Electron microscopy revealed that massive collagen fibers (40-70 nm in diameter) deposited in the mesangial matrix and basement membrane. As for the follow-up results, the normal renal function had kept steady and the proteinuria was moderate in 1 case treated with angiotensin Ⅱ receptor blocker. Due to other system disease, another case developed into acute kidney injury and then received hemodialysis. The clinical manifestations of collagen Type Ⅲ glomerulopathy was atypical, the light microscope pathological features were various, and the disease was mainly diagnosed by electron microscopy and immunohistochemistry.
Collagen Type III ; genetics ; Glomerular Mesangium ; Humans ; Kidney Diseases ; Kidney Glomerulus ; Proteinuria

A study was performed on 60 patients, who were treated by Cockcroft- Gault, Jelliffe, Bjornsson and Gates formulas at Renal-Urinary Department of Hue Central hospital between March 2003 and May 2004. Among which, 30 patients suffered from chronic renal failure, 30 patients did not suffer from any renal disease. Results: in the patients without chronic renal failure, the mean of creatinine clearance was 107.55±11.68 ml/minute . In the patients with chronic renal failure, the mean of creatinine clearance was 12.35±13,15 ml/minute; Jelliffe: 15.57±14.47 ml/minute; Mawer: 11.41±13.26 ml/minute; Bjornsson: 15.89±14.43 ml/minute; Gates: 15.42±15.95 ml/minute.
Kidney Glomerulus ; Therapeutics

Occludin is a cell adhesion molecule that is abundantly expressed in the kidney. However, the expression pattern in various renal epithelial cells is not well established. The purpose of this study was to determine the cellular localization along the tubular epithelial cells in the kidney. Kidneys from adult pigs crossbred of Yorkshire, Landrace and Duroc (three breeds) were processed for immunohistochemistry. Thiazide sensitive sodium chloride cotransporter (TSC), Na+-KATPase bat1, calbindinD28k, and H+-ATPase were used to identify the thick ascending limb, distal convoluted tubule, connecting tubule, and collecting duct, respectively. In the pig kidney, occludin was expressed in the apical domain of the tubular epithelial cells. The immunoreactivity of occludin was strongest in the collecting duct, and then gradually decreased in the connecting tubule, distal convoluted tubule, and thick ascending limb. Occludin expression was weak in the thin limbs of the loop of henle and in the proximal tubule in the pig kidney. These results suggest that occludin may be a major adhesion molecule in distal tubular epithelial cells and play a critical role in maintaining epithelial polarity of these nephron segments.
Adult ; Cell Adhesion ; Epithelial Cells ; Extremities ; Humans ; Immunohistochemistry ; Kidney ; Loop of Henle ; Nephrons ; Occludin ; Sodium Chloride Symporters ; Swine