Anti-Proliferative Actions of T-Type Calcium Channel Inhibition in Thy1 Nephritis

Abstract

Aberrant proliferation of mesangial cells (MCs) is a key finding in progressive glomerular disease. TH1177 is a small molecule that has been shown to inhibit low-voltage activated T-type Ca(2+) channels (TCCs). The current study investigates the effect of TH1177 on MC proliferation in vitro and in vivo. The effect of Ca(2+) channel inhibition on primary rat MC proliferation in vitro was studied using the microculture tetrazolium assay and by measuring bromodeoxyuridine incorporation. In vivo, rats with Thy1 nephritis were treated with TH1177 or vehicle. Glomerular injury and average glomerular cell number were determined in a blinded fashion. Immunostaining for Ki-67 and phosphorylated ERK were also performed. The expression of TCC isoforms in healthy and diseased tissue was investigated using quantitative real-time PCR. TCC blockade caused a significant reduction in rat MC proliferation in vitro, whereas L-type inhibition had no effect. Treatment of Thy1 nephritis with TH1177 significantly reduced glomerular injury (P < 0.005) and caused a 49% reduction in glomerular cell number (P < 0.005) compared to the placebo. TH1177 also reduced Ki-67-positive and pERK-positive cells per glomerulus by 52% (P < 0.01 and P < 0.005, respectively). These results demonstrate that TH1177 inhibits MC proliferation in vitro and in vivo, supporting the hypothesis that TCC inhibition may be a useful strategy for studying and modifying MC proliferative responses to injury.

Ion-Channel modulator TH1177 reduces glomerular injury and serum creatinine in chronic mesangial proliferative disease in rats

“…This agent inhibits the proliferation of cultured human and rat MCs in vitro and is also a potent antiproliferative agent in prostate cancer cells in vitro and in vivo [3,4]. We have reported that administration of TH1177 to rats with acute Thy1 nephritis reduces glomerular injury and glomerular cell proliferation in this short-term disease model [5]. This finding supports the hypothesis that TH1177 may be of benefit in renal diseases that involve excess mesangial cell proliferation.…”

Anti-inflammatory role of DPP-4 inhibitors in a nondiabetic model of glomerular injury

“…However, EPA did not reduce CD68-positive macrophage infiltration into glomeruli and failed to reduce proteinuria, suggesting that inhibition of macrophage infiltration in the glomerulus is important for reducing proteinuria and glomerular injury in the rat Thy-1 model. Indeed, many studies (3,28) have shown that reductions of proteinuria and glomerular injury are related to the reduction of macrophages in glomeruli. In our study, the number of CD68-positive macrophages in glomeruli was not decreased by treatment with alogliptin (data not shown).…”

“…Three-micrometer sections were stained with periodic acid-Schiff reagent and counterstained with hematoxylin. Quantification of renal histology was performed as previously described (3). Briefly, 30 glomeruli/section were scored using the following system: 0 ϭ normal appearance, 1 ϭ mesangial expansion and/or hypercellularity, and 2 ϭ microaneurysms, necrosis, capsular hemorrhage, or matrix or cellular crescents.…”

Effect of Huaier On the Proliferation of Mesangial Cells in Anti-Thy-1 Nephritis

“…Deparaffinized sections were stained with Periodic Acid-Schiff to examine the pathological changes under light microscopy. The degree of renal impairment was semi-quantitatively and double-blindly scored by two pathologists following a published scoring system [9]. We randomly selected 10 separate fields for each specimen to evaluate the lesions (400× magnification) and averaged the values for the histological score.…”