Targeting podocyte-associated diseases

Injury to the podocytes is the initiating cause of many renal diseases, leading to proteinuria with possible progression to end-stage renal disease. Podocytes are highly specialized cells, with an important role in maintaining the glomerular filtration barrier and producing growth factors for both mesangial cells and endothelial cells. With their foot processes they cover the glomerular basement membrane, and form slit diaphragms with neighboring podocytes.Human podocytopathies include focal and segmental glomerulosclerosis, minimal change disease, membranous nephropathy, collapsing glomerulopathy and diabetic nephropathy. Research in the last two decades has demonstrated great progress in understanding the molecular mechanisms leading to podocytopathies. These include single gene defects in slit diaphragm proteins, but also discovery of apoptotic, enzymatic and other pathways involved in podocyte injury. With this progress, a great number of animal models is now available to study either specific podocytopathies, e.g. in mouse models with single gene mutations, or more general podocyte injury patterns, such as the lipopolysaccharide or protamine sulfate model of foot process effacement.In this review, the morphology of the glomerulus will be discussed, with a focus on the podocyte, its interactions with surrounding cells, and the highly differentiated slit diaphragm separating the apical from the basal membrane. We also provide an overview of human podocytopathies and animal models to study these diseases. In the last part we discuss targeted therapies addressing pathways and proteins affected in podocyte injury.     

Expert opinion on pharmacotherapy of kidney disease in HIV-infected patients

Introduction: Human immunodeficiency virus (HIV) infection is associated with the development of a wide spectrum of kidney diseases. HIV-associated nephropathy (HIVAN) is the most common cause of chronic kidney disease (CKD) in HIV-infected individuals and predominantly affects patients of African ancestry. HIVAN is a leading cause of end-stage renal disease (ESRD) among African–Americans.

Areas covered: An overview of the spectrum of kidney disease in patients with HIV is given. Current pharmacologic interventions to treat kidney disease in HIV are discussed. This review will enhance knowledge regarding the most common causes of kidney disease in HIV-infected patients. An understanding of the principles related to pharmacotherapy in HIV-infected patients with kidney disease will also be gained.

Expert opinion: Kidney disease is an important cause of morbidity and mortality in HIV-infected patients. The most common cause of chronic kidney disease in this population is HIV-associated nephropathy, which is caused by viral infection of the renal epithelium. Several medications that are commonly used in HIV-infected patients can have adverse effects on the kidneys and the doses of many antiretroviral medications need to be adjusted in patients with impaired renal function.     

筛查某家族性局灶节段硬化性肾小球肾炎家庭的NPHS2基因

目的 为某个有两个儿童患者死于局灶节段硬化性肾小球肾炎的家庭查找致病原因.方法 取孕18周后的羊水进行染色体检查,同时提取夫妇静脉血DNA、死亡男童肾组织DNA及胎儿羊水DNA,进行NPHS2基因检测.结果 胎儿染色体未见异常;孕妇NPHS2基因检测发现c.954C＞T变异,此改变位于第8外显子,不引起氨基酸的改变,为...     

Endogenous asymmetrical dimethylarginine and hypertension associated with puromycin nephrosis in the rat

1. The present experiments were designed to investigate the role of asymmetrical N^G,N^G-dimethyl-L-arginine (ADMA) in causing hypertension associated with the focal and segmental glomerulosclerosis (FSGS) produced by a single bolus of puromycin aminonucleoside (PAN) and successive injection of protamine for 7 days in rats which had undergone unilateral nephrectomy.
2. After the unilateral nephrectomy, and administering PAN and protamine, histological examinations of the kidney revealed a typical FSGS, that is, evident abnormalities including segmental mesangial proliferation, obliteration of glomerular capillary lumens and adhesions between the glomerulus and Bowman''s capsule could be observed. Changes in the glomerular epithelial cells consisted of the swelling with bleb formation.
3. In the FSGS rats, urine volume and urinary protein were significantly (P<0.05 and P<0.005) increased throughout 4-week experimental period, while the creatinine clearance was significantly (P<0.005) and transiently decreased, and recovered 4 weeks later. These changes were associated with the sustained elevation of the systolic blood pressure.
4. ADMA levels in aortic endothelial cells, plasma and urine were significantly (P<0.05 and P<0.005) increased in the FSGS rats, but the level in the kidney remained unchanged.
5. The basal level and net production of cyclic GMP in the aortic vessel wall with endothelium when stimulated by norepinephrine and acetylcholine were significantly (P<0.05 and P<0.01) attenuated in the FSGS rats.
6. There were significant and positive correlations between systolic blood pressure (y) and ADMA levels (x) in endothelial cells (y=4.43x+122.2, r=0.979, P<0.0001), plasma (y=0.10x+71.9, r=0.921, P<0.001) and urine (y=0.48x+126.9, r=0.699, P<0.005), but not significant in the kidney (y=0.06x+102.7, r=0.252, NS).
7. These findings suggest that ADMA as an endogenous inhibitor of NO synthesis may play an important role for the pathogenesis in the hypertension associated with the experimental FSGS in the rat.

     

Early recurrent nephrotic syndrome after renal transplantation in children with focal segmental glomerulosclerosis.

BACKGROUND: We analysed risk factors to predict the recurrence of nephrotic syndrome and the therapeutic efficacy of plasmapheresis combined with oral cyclophosphamide (PE+CPM) in early recurrent nephrotic syndrome after transplantation in children with focal segmental glomerulosclerosis (FSGS). METHODS: Medical records after 1990 of 16 children with biopsy-proven idiopathic FSGS and renal transplantation before the age of 18 years were reviewed. RESULTS: Early recurrence of nephrotic syndrome developed in six cases (37. 5%). While early kidney graft biopsies, performed within the first week after the onset of recurrence, revealed diffuse effacement of foot process only, late biopsies contained segmentally sclerosed glomeruli as well. Among several possible risk factors, the mean duration from onset of original nephrotic syndrome to development of end-stage renal disease was shorter in the recurrent group (P=0.045) and the percentage of globally sclerosed glomeruli was higher in the non-recurrent group (P=0.001). PE+CPM therapy resulted in complete remission of nephrotic syndrome if it was started early and if there was no evidence of accompanying acute rejection. CONCLUSION: These results support more liberal use of living-related donors for renal transplantation of children with FSGS and ESRD, considering the shortage of cadaveric donors in our society and relatively good efficacy of the early and intensive PE+CPM therapy for early recurrent nephrotic syndrome.     

Targeting tissue-resident memory CD8+ T cells in the kidney is a potential therapeutic strategy to ameliorate podocyte injury and glomerulosclerosis

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