Low-dose of multi-glycoside of Tripterygium wilfordii Hook. f., a natural regulator of TGF-β1/Smad signaling activity improves adriamycin-induced glomerulosclerosis in vivo.
Transforming growth factor (TGF)-β1/Smad signaling pathway plays a critical role in the prolonged glomerulosclerosis (GS), which is an important determinant during the progression in chronic kidney disease (CKD). For recent 30 years, multi-glycoside of Tripterygium wilfordii Hook. f. (GTW), an extract from Chinese herbal medicine has been proved clinically effective in improving GS in CKD in China. However, therapeutic mechanisms involved in vivo are still unclear. In this study, we aimed to explain the dose-effects and molecular mechanisms of GTW on GS by regulating TGF-β1/Smad signaling activity in adriamycin (ADR)-induced nephropathy (ADRN).
Rats with ADRN, created by unilateral nephrectomy and twice adriamycin injections (ADR, 4 mg/kg and 2 mg/kg) within 4 weeks, were divided into four groups, the Sham group, the Vehicle group, the low-dose GTW-treated group, and the high-dose GTW-treated group, and that, sacrificed at the end of the 6th week after administration. Proteinuria, blood biochemical parameters, glomerulosclerotic morphological makers, podocyte shape, and nephrin expression were examined, respectively. Protein expressions of key signaling molecules in TGF-β1/Smad pathway, such as TGF-β1, Smad3, phosphorylated-Smad2/3 (p-Smad2/3), and Smad7, were also evaluated individually.
The results indicated that the characterizations of ADRN involved the typical prolonged GS, a small amount of abnormal proteinuria, and the failing renal function; TGF-β1/Smad signaling molecules, especially Smad3, p-Smad2/3, and Smad7 were activated in vivo, accompanied by the exasperation of glomerulosclerotic lesion; GTW at high-dose (100 mg/kg) and low-dose (50 mg/kg) could slightly ameliorate the prolonged GS and nephrin expression, furthermore, the anti-proliferative action of GTW at high-dose was superior to that at low-dose, but caused the significant liver injury; in ADRN model rats, protein expressions of TGF-β1, p-Smad2/3, and Smad7 in the kidneys could be regulated with the treatment of GTW at low-dose.
This study farther demonstrated that the low-dose of GTW, as a natural regulator in vivo, could effectively and safely ameliorate the prolonged GS in FSGS model, via the potential molecular mechanisms involving the reduction of ECM components and the suppression of TGF-β1 over-expression, as well as the bidirectional regulation of TGF-β1/Smad signaling activity.
Wan YG
,Che XY
,Sun W
,Huang YR
,Meng XJ
,Chen HL
,Shi XM
,Tu Y
,Wu W
,Liu YL
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Huangkui capsule, an extract from Abelmoschus manihot (L.) medic, ameliorates adriamycin-induced renal inflammation and glomerular injury via inhibiting p38MAPK signaling pathway activity in rats.
Abelmoschus manihot (L.) medic (AM) is a natural medicinal plant used for the treatment of inflammatory diseases in China. Huangkui capsule (HKC), an extract from AM, has been proved clinically effective in improving renal inflammation and glomerular injury in chronic kidney disease (CKD). However, the dose-effects and the mechanisms involved in vivo are still unclear.
This study was performed to examine the dose-effects of HKC on renal inflammation and glomerular lesion in adriamycin-induced nephropathy (ADRN), then to clarify the mechanisms in vivo of HKC by investigating its actions on modulating the activation of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway.
The rats with chronic ADRN, created by the unilateral nephrectomy and twice adriamycin injections (ADR, 4 mg/kg and 2mg/kg) within 4 weeks, were divided into four groups, a Sham group, a Vehicle group, a high-dose HKC group, and a low-dose HKC group, and that, sacrificed at the end of the 4th week after the administration. The rat's general status, renal morphological appearance, proteinuria, blood biochemical parameters, glomerular morphological changes, podocyte shape, and macrophage (ED1(+) and ED3(+) cells) infiltration in glomeruli were examined, respectively. The protein expressions of inflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-2, as well as p38MAPK signaling molecules such as transforming growth factor (TGF)-β1, p38MAPK, and phosphorylated-p38MAPK (p-p38MAPK), were also evaluated individually.
HKC at high dose of 2g/kg/d not only significantly ameliorated the rat's general status, renal morphological appearance, proteinuria, albumin, and glomerulosclerosis, but also obviously reduced the infiltrated ED1(+) and ED3(+) macrophages in glomeruli and TNF-α protein expression in the kidney, in addition to these, evidently down-regulated TGF-β1 and p-p38MAPK protein expressions in ADRN rats, but had no influence on podocyte shape and renal function.
HKC could dose-dependently ameliorate renal inflammation and glomerular injury in ADRN rats, by way of reducing the infiltration and the activation of macrophages in glomeruli, and TNF-α protein expression in the kidney, as well as inhibiting p38MAPK signaling pathway activity via the down-regulation of p-p38MAPK and TGF-β1 protein expressions in vivo.
Tu Y
,Sun W
,Wan YG
,Che XY
,Pu HP
,Yin XJ
,Chen HL
,Meng XJ
,Huang YR
,Shi XM
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