title: Urinary serum- and glucocorticoid-inducible kinase SGK1 reflects renal injury in patients with immunoglobulin A nephropathy.
abstract: OBJECTIVE
  Serum- and glucocorticoid-inducible kinase SGK1 functions as an important regulator of transepithelial sodium transport by activating epithelial sodium channel in renal tubules. Considerable evidence demonstrated that SGK1 was associated with hypertension and fibrosing diseases, such as diabetic nephropathy and glomerulonephritis. The present study was performed to evaluate the role of SGK1 played in immunoglobulin A (IgA) nephropathy.
  
  
  METHODS
  Seventy-six patients of biopsy-proven IgA nephropathy and 33 healthy volunteers were enrolled in this study. All patients and healthy volunteers' urinary and serum samples were tested for SGK1 expression by indirect enzyme-linked immunosorbent assay. Meanwhile all patients' renal tissues were semi-quantified for SGK1 expression by immunohistochemistry assay. The relationships between SGK1 expressions and clinical or pathological parameters were also assessed.
  
  
  RESULTS
  SGK1 expression was upregulated in urine and renal tubules in patients of Oxford classification T1 and T2, whereas its expression in serum did not increase significantly. Relationship analysis indicated that urinary and tissue SGK1 expressions were associated with heavy proteinuria and renal insufficiency in patients with IgA nephropathy. On the other hand, RAS blockades would reduce the SGK1 levels both in urine and renal tissues.
  
  
  CONCLUSIONS
  These results suggested that urinary SGK1 should be a good indicator of tubulointerstitial damage in patients of IgA nephropathy. SGK1 expressions in urine and renal tissues were associated with the activity of renin-angiotensin-aldosterone system.
authors.affiliation: Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China; Kidney Disease Immunology Laboratory, The Third Grade Laboratory, State Administration of Traditional Chinese Medicine of China, Hangzhou, China; Key Laboratory of Multiple Organ Transplantation, Ministry of Health of China, Hangzhou, China; Key Laboratory of Nephropathy of Zhejiang Province, Hangzhou, China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Lu
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.forename: Lijia
authors.initials: L
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.forename: Huiping
authors.initials: H
authors.lastname: Wang
authors.forename: Jianghua
authors.initials: J
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D005260:Female; D005922:Glomerulonephritis, IGA / Q000145:classification / Q000188:drug therapy / Q000378:metabolism*; D005938:Glucocorticoids / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000097:blood* / Q000652:urine*; D008297:Male; D008875:Middle Aged; D017346:Protein Serine-Threonine Kinases / Q000097:blood* / Q000652:urine*; D011507:Proteinuria / Q000145:classification / Q000188:drug therapy / Q000378:metabolism*; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D049971:Thiazides / Q000627:therapeutic use; D055815:Young Adult; D000099184:Serum-Glucocorticoid Regulated Kinases
chemical_list: D015415:Biomarkers; D005938:Glucocorticoids; D017874:Immediate-Early Proteins; D017346:Protein Serine-Threonine Kinases; D049971:Thiazides; D000099184:Serum-Glucocorticoid Regulated Kinases
keywords: Immunoglobulin A nephropathy; Oxford classification; SGK1; proteinuria; renal failure