Hepatocyte growth factor gene therapy enhances infiltration of macrophages and may induce kidney repair in db/db mice as a model of diabetes

Abstract

Aims/hypothesisWe previously demonstrated hepatocyte growth factor (HGF) gene therapy was able to induce regression of glomerulosclerosis in diabetic nephropathy through local reparative mechanisms. The aim of this study was to test whether bone-marow-derived cells are also involved in this HGF-induced reparative process.MethodsWe have created chimeric db/db mice as a model of diabetes that produce enhanced green fluorescent protein (EGFP) in bone marrow cells. We performed treatment with HGF gene therapy either alone or in combination with granulocyte-colony stimulating factor, in order to induce mobilisation of haematopoietic stem cells in these diabetic and chimeric animals.ResultsWe find HGF gene therapy enhances renal expression of stromal-cell-derived factor-1 and is subsequently associated with an increased number of bone-marrow-derived cells getting into the injured kidneys. These cells are mainly monocyte-derived macrophages, which may contribute to the renal tissue repair and regeneration consistently observed in our model. Finally, HGF gene therapy is associated with the presence of a small number of Bowman’s capsule parietal epithelial cells producing EGFP, suggesting they are fused with bone-marrow-derived cells and are contributing to podocyte repopulation.Conclusions/interpretationAltogether, our findings provide new evidence about the therapeutic role of HGF and open new opportunities for inducing renal regeneration in diabetic nephropathy.

Macrophage Overexpressing NGAL Ameliorated Kidney Fibrosis in the UUO Mice Model

“…RNA was extracted from kidney with PureLink RNA Mini Kit (Invitrogen, CA, USA) as previously described [16]. A total amount of 400 ng RNA was used to perform the reverse transcription using a High-Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Warrington, UK).…”

“…Histological cross sections of 3µm thickness were stained with Haematoxylin and eosin (H&E), Sirius Red, Fibronectin and anti-α-smooth muscle actin (α-SMA) for optical microscopy assessment. Fibronectin (1:500, Abeam, Madrid, Spain) and α-SMA (1:100, Thermo Scientific, CA, USA) were stained as described previously [16]. …”

“…In a murine model of diabetic kidney disease, we have previously demonstrated that hepatocyte growth factor (HGF) gene therapy increases the presence of bone marrow-derived M2 macrophages, which seem to contribute to the renal tissue repair and regeneration [16]. However, it is unclear what the role of "M2" macrophages are in UUO renal fibrosis, though some descriptive studies would suggest that "M2" macrophages are associated with fibrosis in the UUO context [9].…”

Correlation between the decrease of cholesterol efflux from macrophages in patients with type II diabetes mellitus and down-regulated CYP7A1 expression

“…The results of this study did not find abnormal CYP7A1 expression in the macrophages of patients with type II DM. The reasons for the prior inconsistent study results might include the following aspects: 1) a difference in the selection of animal species and cell lines leading to differences in gene expression; 2) individual differences between subjects, and 3) the functional impairment of CYP7A1 in some patients might be effected instead by post-translational regulation (Huang et al, 2011;Flaquer et al, 2012;Liu et al, 2012). Furthermore, some researchers have found a reduction of CYP7A1 expression in patients with hypertriglyceridemia, but no difference was found in the blood lipid levels among the patients in each group in this study, which might be the reason for the inconsistency between our results and those mentioned above (Dinneen and O'Donnell, 2012;Pérez de Isla et al, 2012).…”

Importance of diabetic nephropathy in childhood. Clinical findings and basic research in the past decades

“…Négy hónap múlva az állatokban enyhébb szövettani károsodást ész-leltek és alacsonyabb volt a fi broticus (TGF-β, kollagén), illetve a gyulladásos (TNF-α, IL-6) markerek expresszió-ja is, míg a proteinuria nem változott [62]. További vizsgálatok zajlanak hepatocyta növekedési faktor bejuttatá-sával is, amelyről ismert, hogy befolyásolja a makrofágok infi ltrációját, azonban a hatásmechanizmus még tisztá-zásra vár [63].…”