Phosphorylation of slit diaphragm proteins NEPHRIN and NEPH1 upon binding of HGF promotes podocyte repair.

Phosphorylation (activation) and dephosphorylation (deactivation) of the slit diaphragm proteins NEPHRIN and NEPH1 are critical for maintaining the kidney epithelial podocyte actin cytoskeleton and, therefore, proper glomerular filtration. However, the mechanisms underlying these events remain largely unknown. Here we show that NEPHRIN and NEPH1 are novel receptor proteins for hepatocyte growth factor (HGF) and can be phosphorylated independently of the mesenchymal epithelial transition receptor in a ligand-dependent fashion through engagement of their extracellular domains by HGF.

Mitochondrial biogenesis induced by the β2-adrenergic receptor agonist formoterol accelerates podocyte recovery from glomerular injury.

Podocytes have limited ability to recover from injury. Here, we demonstrate that increased mitochondrial biogenesis, to meet the metabolic and energy demand of a cell, accelerates podocyte recovery from injury. Analysis of events induced during podocyte injury and recovery showed marked upregulation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a transcriptional co-activator of mitochondrial biogenesis, and key components of the mitochondrial electron transport chain.

Development of a novel cell-based assay to diagnose recurrent focal segmental glomerulosclerosis patients.

Definitive diagnosis of glomerular disease requires a kidney biopsy, an invasive procedure that may not be safe or feasible to perform in all patients. We developed a noninvasive, accurate, and economical diagnostic assay with easy commercial adaptability to detect recurrent focal segmental glomerulosclerosis (rFSGS) after kidney transplant. Since FSGS involves podocyte damage and death, our approach involved mRNA profiling of cultured podocytes treated with plasma from patients with rFSGS to identify upregulated genes involved in podocyte damage.

A Novel CLCN5 Mutation Associated With Focal Segmental Glomerulosclerosis and Podocyte Injury.

Introduction: Tubular dysfunction is characteristic of Dent's disease; however, focal segmental glomerulosclerosis (FSGS) can also be present. Glomerulosclerosis could be secondary to tubular injury, but it remains uncertain whether the gene, which encodes an endosomal chloride and/or hydrogen exchanger, plays a role in podocyte biology. Here, we implicate a role for CLCN5 in podocyte function and pathophysiology.

Deficiency of the Angiotensinase Aminopeptidase A Increases Susceptibility to Glomerular Injury.

Aminopeptidase A (APA) is expressed in glomerular podocytes and tubular epithelia and metabolizes angiotensin II (AngII), a peptide known to promote glomerulosclerosis. In this study, we tested whether APA expression changes in response to progressive nephron loss or whether APA exerts a protective role against glomerular damage and during AngII-mediated hypertensive kidney injury. At advanced stages of FSGS, fawn-hooded hypertensive rat kidneys exhibited distinctly increased APA staining in areas of intact glomerular capillary loops.

Similar dynamics of intraapheresis autologous CD34+ recruitment and collection efficiency in patients undergoing mobilization with or without plerixafor.

Background: Compared with growth factor (G) alone, the combination of G with plerixafor (G + P) increases peripheral blood CD34+ count (PB-CD34+) and improves CD34+ collection yield (yCD34+) in multiple myeloma and lymphoma patients undergoing autologous hematopoietic progenitor cell (AHPC) mobilization. It is unknown whether the improved yCD34+ with G + P results entirely from expansion of PB-CD34+ or also from increased intraapheresis CD34+ recruitment and collection efficiency.

Study Design And Methods: We retrospectively studied 192 patients who underwent AHPC mobilization and collection with G (n = 73) or G + P (n = 119) to compare the adjusted relative efficiency (aRE), the proportion of the circulating CD34+ pool that is captured for each blood volume processed.

Multiorgan system dysfunction in the chylomicronemia syndrome.

Objective: To describe an extreme presentation of the chylomicronemia syndrome resulting in multiorgan system dysfunction.

Patient: A 40-year-old African American male with no past medical history presented with multiorgan system dysfunction manifested by acute respiratory failure and acute kidney injury. He was noted to have very-high triglyceride levels (>5000 mg/dL) at admission.

Renal function and proteinuria after successful immunosuppressive therapies in patients with FSGS.

Background And Objectives: In the FSGS Clinical Trial, 22 cyclosporine-treated and 20 mycophenolate/dexamethasone-treated patients experienced a complete or partial remission after 26 weeks, completed 52 weeks of treatment, and were studied through 78 weeks. Herein, changes in the urine protein/creatinine ratio (UP/C) and estimated GFR (eGFR) throughout the entire study period are defined.

Design, Setting, Participants, And Measurements: The FSGS Clinical Trial, which was conducted from November 2004 to January 2010, enrolled patients aged 2-40 years, with eGFR ≥40 ml/min per 1.

Long-term effects of kidney donation on renal function and blood pressure in African Americans.

Background And Objectives: African Americans (AAs) have four times higher prevalence of ESRD than Caucasians. Therefore, long-term effects of kidney donation are of considerable importance in this patient population.

Design, Setting, Participants, & Measurements: GFR was measured by (125)I-iothalamate clearance, 24-hour urine albumin excretion, and 24-hour BP monitoring in 33 AAs and 11 CAs who donated kidneys for transplantation 5 to 23 years previously.

Identification of diagnostic urinary biomarkers for acute kidney injury.

Acute kidney injury (AKI) is an important cause of death among hospitalized patients. The 2 most common causes of AKI are acute tubular necrosis (ATN) and prerenal azotemia (PRA). Appropriate diagnosis of the disease is important but often difficult.

Angiotensin I is largely converted to angiotensin (1-7) and angiotensin (2-10) by isolated rat glomeruli.

Intraglomerular renin-angiotensin system enzyme activities have been examined previously using glomerular lysates and immune-based assays. However, preparation of glomerular extracts compromises the integrity of their anatomic architecture. In addition, antibody-based assays focus on angiotensin (Ang) II detection, ignoring the generation of other Ang I-derived metabolites, some of which may cross-react with Ang II.

Changes in protein profiles during course of experimental glomerulonephritis.

Better characterization of the molecular mechanisms underlying glomerular cell proliferation may improve our understanding of the pathogenesis of glomerulonephritis and yield disease-specific markers. We used two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS) to generate expression profiles of glomerular proteins in the course of anti-Thy-1 nephritis. Glomeruli were isolated from Wistar rats by sieving, and proteins were separated by 2DE.

Nephrogenic systemic fibrosis after exposure to gadolinium in patients with renal failure.

Background: Nephrogenic systemic fibrosis is a debilitating disease occurring exclusively in patients with renal failure. The aetiology of nephrogenic systemic fibrosis is unclear, but recent reports suggest that exposure to gadolinium for enhancement of magnetic resonance imaging may play a role. In the present study, we assessed the association of exposure to gadolinium with the development of nephrogenic systemic fibrosis in patients with various stages of chronic kidney disease.

Urine biomarkers predict the cause of glomerular disease.

Diagnosis of the type of glomerular disease that causes the nephrotic syndrome is necessary for appropriate treatment and typically requires a renal biopsy. The goal of this study was to identify candidate protein biomarkers to diagnose glomerular diseases. Proteomic methods and informatic analysis were used to identify patterns of urine proteins that are characteristic of the diseases.

Brain MR imaging abnormalities in kidney transplant recipients.

Background And Purpose: On the basis of limited available data, brain MR imaging abnormalities in kidney transplant recipients (KTRs) have been predominantly attributed to calcineurin inhibitors (CIs), characteristically presenting as posterior reversible encephalopathy syndrome (PRES). The goal of this study was to evaluate whether CIs play an important role in the incidence, nature, and location of MR imaging brain lesions in adult KTRs by comparing them with dialysis-dependent patients.

Methods: We retrospectively analyzed 98 brain MR imaging examinations in 77 consecutive KTRs presenting with neurologic symptoms from 1990 to 2003.

Oxidative stress in the pathogenesis of experimental mesangial proliferative glomerulonephritis.

Reactive oxygen species (ROS) are increasingly believed to be important intracellular signaling molecules in mitogenic pathways involved in the pathogenesis of glomerulonephritis (GN). We explored the effects of the antioxidants alpha-lipoic acid and N-acetyl-l-cysteine on ERK activation in cultured mesangial cells and the role of ERK activation in the severity of glomerular injury in a rat model of anti-Thy 1 GN. In cultured mesangial cells, growth factors stimulated ERK phosphorylation by 150-450%.

Hyponatremia associated with 3,4-methylenedioxymethylamphetamine ("Ecstasy") abuse.

We present a case of acute, symptomatic hyponatremia in a young woman that developed after use of 3,4-methylenedioxymethylamphetamine (MDMA), more commonly known as "ecstasy." The patient was treated with 5% saline and had complete recovery. The pathogenesis of MDMA-associated hyponatremia involves excessive water intake and inappropriately elevated antidiuretic hormone (ADH) levels.

Renal transplant in patients with Alport's syndrome.

We evaluated 52 renal grafts transplanted into 41 patients with a pretransplantation diagnosis of Alport's syndrome. Overall 1-, 5-, and 10-year patient and graft survival rates were 95.1%, 90.