Kidney-targeting Smad7 gene transfer inhibits renal TGF-β/MAD homologue (SMAD) and nuclear factor κB (NF-κB) signalling pathways, and improves diabetic nephropathy in mice

Abstract

Our results clearly demonstrate that kidney-targeting Smad7 gene transfer may be an effective therapy for type 2 diabetic nephropathy, acting via simultaneous modulation of the TGF-β/SMAD and NF-κB signalling pathways.

Thrombomodulin domain 1 ameliorates diabetic nephropathy in mice via anti-NF-κB/NLRP3 inflammasome-mediated inflammation, enhancement of NRF2 antioxidant activity and inhibition of apoptosis

“…The db/db mice injected with the empty AAV vector served as disease controls. All the mice were killed 18 weeks after the AAV or AAV-THBDD1 injections and samples were collected for individual analyses as described previously [7], with slight modifications. All animal experiments were performed after approval by the Institutional Animal Care and Use Committee of The National Defense Medical Center, Taiwan, and are consistent with the NIH Guide for the Care and Use of Laboratory Animals.…”

“…Clinical and histopathological evaluation The collection and assay of blood and urine samples were done as described previously [7]. For histopathological evaluation, mesangial expansion (increased matrix), and sclerosis and hyalinosis in the glomerulus, as well as renal interstitial inflammation were evaluated by light microscopy and scored as described previously [18].…”

“…Confocal microscopy of podocyte injury in vivo Frozen sections were stained with guinea pig anti-nephrin antibody (Acris Antibodies, Herford, Germany) and rabbit antibody against vascular endothelial growth factor (VEGF) (Santa Cruz Biotechnology, Dallas, TX, USA), followed by Alexa Fluor 488-labelled rabbit anti-guinea pig IgG antibody (Invitrogen, Grand Island, NY, USA) or phycoerythrin-labelled goat anti-rabbit IgG antibody (Jackson ImmunoResearch, West Grove, PA, USA) as described previously [7].…”

“…Although many therapeutic remedies focusing on hyperglycaemia and high blood pressure have been used, many patients still suffer progressive and severe renal injury [4], making the investigation of other pathogenic pathways and relevant therapeutic strategies worthwhile. Importantly, immune-mediated inflammatory processes [5], apoptosis [6,7] and reactive oxygen species (ROS) [5,8] in the kidney are involved in the developmental and progressive stages of DN. Thrombomodulin (THBD), a component of the anticoagulant pathway, binds to thrombin on the endothelial cell surface and catalyses activation of protein C, thus protecting cells from thrombus formation [9,10].…”

Pathophysiology of the aging kidney and therapeutic interventions

“…Gene transfer to induce smad7, an I-smad, can prevent diabetic glomerulosclerosis by inhibition of the renal TGF-b/smad signaling pathway. 128 There is as yet no such molecule with which to target I-smads, but this potential therapy may lie in the function of the ACE inhibition-associated rise in the antifibrotic peptide N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP). 100 AcSDKP, a natural inhibitor of hematopoietic stem cell proliferation, is a tetrapeptide originally isolated from fetal calf bone marrow 129 and has emerged as an anti-fibrotic molecule.…”