Genistein modulates NF-κB-associated renal inflammation, fibrosis and podocyte abnormalities in fructose-fed rats
Authors: Carani Venkataraman Anuradha
Nallasamy Palanisamy
Sriramajayam Kannappan
Journal: European Journal of Pharmacology (2011)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: genistein; inflammatory status; NF-κB p65; TGF-β1; RAGE
Affiliations: Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalai Nagar-608 002, Tamil Nadu, India.

Abstract:  The study determines the effect of genistein on inflammatory status and expression of nuclear factor-kappa B (NF-κB p65), transforming growth factor-β1 (TGF-β1) and receptor for advanced glycation end products (RAGE) in kidney of fructose-fed rats. Adult male Wistar rats were fed a diet containing either starch or fructose as the source of carbohydrate. Fifteen days later, after confirming the development of insulin resistance in fructose-fed rats, the rats in each dietary group were divided into two and treated with either genistein (1 mg/kg/day) in 30% dimethylsulfoxide (DMSO) or 30% DMSO alone for the next 45 days. The expression of NF-κB P(65), TGF-β1 and RAGE, histochemical localization of α-smooth muscle actin (α-SMA), levels of tumour necrosis factor-α (TNF-α) and interleukin-6(IL-6) and ultrastructural analysis were performed at the end of the experimental period. Fructose-fed rats displayed inflammatory changes in kidney. Increased expression of TGF-β1 and RAGE in cytosol and NF-κB p65 in nuclear fraction were observed. α-SMA expression was higher in fructose-fed rat kidney. Proliferation of connective tissue was evident from increased collagen deposition in perivascular and intraglomerular regions. Administration of genistein to fructose-fed rats reduced inflammation, fibrogenesis and NF-κB activation. Genistein also mitigated the structural changes such as basement membrane thickening, reduction in podocyte number and loss of glomerular filtration barrier integrity. These findings suggest that genistein prevents inflammation, fibrosis and early nephropathic changes in fructose-fed insulin resistant rats secondary to the attenuation of NF-κB activation. 

Retracted: No

PubPeer comments:
  Fig. 3. Representative immunoblots showing the expression of RAGE (A). ![file] Unexpected similarities between RAGE and Actin blobs. Below, with increased contrast and equalised lightness. ![file] , 
 Fig 1B.  Analysis of NF-u03baB p65 expression in kidney of experimental rats by confocal imaging. Tissue sections were immunostained with antiNF-u03baB p65 antibody and FITC-conjugated secondary antibody (green). Counterstaining was performed using a nuclear stain propidium iodide (PI) (red). Images were visualized using a confocal microscope at magnification 40u00d7. Panel I u2013 background immunofluorescence of NF-u03baB-FITC (green), Panel II u2013 PI staining (red) and Panel III u2013 overlay of I and II. (Scale bar-250 u03bcm). In CON, NF-u03baB is predominantly found in cytoplasm (a, b and c) while in fructose-fed rats, NF-u03baB is translocated into the nucleus (d, e and f). Genistein inhibited the NF-u03baB translocation as there is less nuclear stain for NF-u03baB (g, h and i). (i) CON u2013 control rats; (ii) FRU u2013 fructose-fed rats; (iii) FRU+G u2013 fructose fed rats treated with genistein (1 mg kg b.w); CON+G u2013 Control rats treated with genistein (1 mg kg b.w). ![file] I would expect more difference between the Control and FRU+G slides. , 
  Fig. 4. Histology of kidney stained with Masson s trichrome. Control group show normal quantum of collagen in glomeruli and tubules (A). Sections of fructose-fed group show collagen deposition (white arrows pointing out blue color) in perivascular and intraglomerular region (B). Section from genistein-treated fructose-fed group shows marked reduction of collagen deposition (C). Genistein-treated control group shows negligible collagen deposition (D) ![file] A and D are unlikely to have come from differently-treated rats, since they overlap. , 
 [Above] Fig. 1. A.  Representative immunoblots showing the expression of NF-u03baB p65 in kidney cytosol (a) and **nuclear fraction (b)**. [Below] Fig 3 (C) from [Palanisamy et al (2010)] .  Representative immunoblots of PKCBetaII isoensyme in... **total lysate (C)**... 1. CCD; 2. FCD; 3. FSD; 4. CSD. ![file] The beta-actin loading control appears to be the same (after darkening and a vertical stretch). Could the authors clarify whether the blot was for nuclear fraction or total lysate? And whether the conditions involved fructose genistein combinations, or fructose soy protein? , 
 Much of the present data was repurposed to appear in  Soy protein prevents renal damage in a fructose-induced model of metabolic syndrome via inhibition of NF-kB in male rats [(Palanisamy Anuradha (2011)] , according to the [2013 Erratum Retraction notice] for that later-retracted paper. ,