The Role Of Akt And PAkt In IgA Nephropathy

Objective:Immunoglobulin A (IgA) nephropathy is the most commondisease of primary glomerulonephritis. This disease is characterized bymesangial and capillary loops deposits of IgA in the glomeruli, and thepresence of a series of clinical and pathologic change. In clinic, the presenceof recurrent episodes of macroscopic hematuria, or persistent microscopichematuria, may along with various of degrees proteinuria, hypertension andrenal dysfunction etc. On light microscopy, the most typical change is thatfocal or diffuse mesangial cell and matrix proliferation. Approximately40%ofIgAN patients develop into end-stage renal disease after20years of diseaseonset. However, few have provided specific descriptions of the molecularmechanisms associated with disease development. Akt plays important role inthe occurrence and development of renal disease, Akt involves in thefibrogenic process of various of cytokines, promote the proliferation andinhibit the apoptosis of mesangial cell, upregulate the secretion of theextracellular matrix, restraint the apoptosis of renal tubular epithelial cell thatwas caused by oxidative stress, and promote the epithelial-mesenchymaltransition of proximal tubular epithelial cells, furthermore, it participate in thedamage process of podocyte.This experiment studied the change of Akt andpAkt in renal and peripheral blood mononuclear cells which to investigate thechange of Akt. The relationship among the expression of the pathologicalchange and clinical manifestation was analyzed and explored the effection ofAkt in the pathogenesis mechanisms of IgA nephropathy in order to probe intothe significance of Akt and pAkt in the progression of IgA nephropathy, andthen to provide theory basis for prevention and treatment of the clinical renalfibrosis.Methods: The study was adopted by the Department of Nephrology, thesecond hospital of Hebei Medical University. We chosen27cases of IgA nephropathy diagnosed by renal biopsy from Nov.2010to July.2011(20malesand7females, mean age38.3±13.98years), and collected peripheralblood(People with abnormal renal function was exclued). Patients with LupusNephritis, Nephritis of Schonlein-Henoch purpura, Hepatitis B virus-associat-ed glomerulonephritis (HBV-GN), hypertension, thyropathy, renal damageinduced by polyarthritis destruens, neoplasms associated nephropathy and soon; those used glucocorticoid, immunosuppressive agents before renal biopsywere excluded from this study,furthermore patients suffering from obesity,gestation, diabetes mellitus and renal injury or acute interstitial nephritiscaused by medicine were also excluded. According to the Oxford classifyca-tion of IgA nephropathy in2009, the patients were divided into3groups bythe percent of renal tubular atrophy interstitial fibrosis: mild group T0≤25%,moderate group T126%~50%, severe group T2≥50%. Immunohistochemicalmethod was used to detection the distribution and expression of Akt and pAktin renal tissues. The semiquantitative analysis of renal tissue immunohistoche-mistry were analyzed. We collected6cases of healthy subjects(HS).Peripheral blood mononuclear cells were isolated by density gradient centri-fugation, isolated cells were lysed in buffer. The supernatants, containing totalproteins, then detected the Akt and pAkt by Western blot. All datum areapplied by SPSS13.0software for statistical analysis. At the same time wecollected clinical indicators: gender, age,24hour urinary protein quantitative(Upro), serum albumin (ALB), estimate glomerular filtration rate (eGFR).Then the expression of Akt and pAkt was analyzed with clinical and patholo-gical datum.Result:1. Clinical indicators:27cases. Among the groups the age, eGFRwas no statistical significance(P>0.05). The Upro and ALB were significantdifference among the three groups (P<0.05). The renal tubular atrophy/interstitial fibrosis proportion among the mild, moderate and severe groupswas significant differrence (P<0.05).2. The expression of Akt and pAktexpressed mainly in the proximal tubular epithelial cells of IgA nephropathy.The expression of Akt and pAkt were significant difference among the three groups.With the aggravation of tubulointerstitial atrophy, the level of Akt andpAkt was significantly increased. Akt activity(pAkt to total Akt ratios was Aktactivity) was also markedly increased following the aggravation of renaltubular atrophy/interstitial fibrosis.3. The activity of the Akt had positivecorrelation with Upro and the proportion of renal tubular atrophy/interstitialfibrosis(P<0.05). No correlation was found between the activity of Akt andALB.4. We maesured the level of Akt and pAkt in PBMCs by Western blot,We found there was no statistical signifycance of the the protein levels ofAkt(P=0.866), pAkt protein levels were significantly higher in IgAN patientscompared with HS(healthy subjects), and maintain a higher level with theprogress of the disease. Akt activity was significantly higher in IgAN patientsthan HS, There was statistical significance among groups (p<0.05).Conclusion:1The expression of Akt and pAkt expressed mainly in thetubular epithelial cells, moreover, with the aggravation of tubulointerstitialfibrosis, the trend was significantly increased. The activity of the Akt hadpositive correlation with Upro and the proportion of renal tubular atrophy/interstitial fibrosis.2In PBMCs, Akt activity significantly higher in IgAnephropathy patients.3Akt activation may contributed to the occurrence ofIgA nephropathy and participate the renal tubular damage in renal tissues.