Glomerular hypertrophy is the main pathological characteristic in the early stage of diabetic nephropathy (DN), and its regulatory mechanism is closely related to mammalian target of rapamycin (mTOR) signaling pathway activity. mTOR includes mTOR complex 1 (mTORC1) and mTOR complex 2(mTORC2), in which, the upstream pathway of mTORC1 is phosphatidylinositol-3-kinase (PI3K)/serine-threonine kinase(Akt)/adenosine monophosphate activated protein kinase(AMPK), and the representative signaling molecules in the downstream pathway of mTORC1 are 4E-binding proteins(4EBP) and phosphoprotein 70 S6Kinase(p70S6K). Some Chinese herbal extracts could improve cell proliferation via intervening the expressions of the key molecules in the upstream or downstream of PIK/Akt/mTOR signaling pathway in vivo. As for glomerular mesangial cells(MC) and podocyte, mTOR plays an important role in regulating glomerular inherent cells, including adjusting cell cycle, energy metabolism and matrix protein synthesis. Rapamycin, the inhibitor of mTOR, could suppress glomerular inherent cell hypertrophy, cell proliferation, glomerular basement membrane (GBM) thickening and mesangial matrix deposition in model rats with DN. Some Chinese herbal extracts could alleviate glomerular lesions by intervening mTOR signaling pathway activity in renal tissue of DN animal models or in renal inherent cells in vivo and in vitro.
Animals ; Diabetic Nephropathies ; drug therapy ; enzymology ; genetics ; pathology ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Hypertrophy ; drug therapy ; enzymology ; genetics ; pathology ; Kidney Glomerulus ; drug effects ; metabolism ; pathology ; Signal Transduction ; drug effects ; TOR Serine-Threonine Kinases ; genetics ; metabolism

OBJECTIVETo investigate the effect of Tongshenluo Capsule (TSL) on the components of extracellular matrix (ECM) and their metabolism in kidney of rats with diabetic nephropathy (DN), and to explore its mechanism of kidney protecting.

METHODSThe DN model rats established by one side nephrectomy and intraperitoneal injection of streptozotocin were randomly divided into 5 groups, the sham-operation group, the model group, the Valsartan group, the Gliquidon group, and the TSL group, 10 in each group. Levels of fasting blood glucose (FBG) and 24-h urinary micro-content of albumin (24 h mAlb) were determined dynamically; the serum glycosyl hemoglobin (HbA1c)was determined after the last medication; the ultrastructural changes of kidney were observed by transmission electron microscope; the expressions of collagen IV (IV-C), fibronctin (FN), laminin(LN), and the ECM metabolism influencing factors, including MMP-2, tissue inhibitor of metalloproteinase (TIMP-2), transfer growth factor-beta1 (TGF-beta1) in renal tissue were detected by immunohistological chemistry and image collecting analytical system. Results TSL could decrease the levels of FBG, HbA1c, 24 h mAlb (P < 0.05 or P < 0.01), ameliorate the thickness of glomerular basement membrane (GBM), decrease the components of ECM, down-regulate TGF-beta1 and TIMP-2 expression, and up-regulate MMP-2 expression (P < 0.05 or P < 0.01).

CONCLUSIONTSL plays a role of kidney protection by decreasing the ECM components expression and regulate ECM metabolism.

Animals ; Capsules ; Collagen Type IV ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Nephropathies ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Extracellular Matrix ; drug effects ; metabolism ; Fibronectins ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Laminin ; metabolism ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the renal protective activity of Hsian-tsao Mesona procumbens Hemsl. water extracts in diabetic rats.

METHODSThirty Sprague-dawley female rats were randomly divided into three groups (n = 10 each), "control group" with intraperitoneal saline injection, "diabetic group" with 60 mg of intraperitoneal streptozotocin injection per kg of body weight and "Hsian-tsao group" with intragastric administration of Hsian-tsao extraction everyday for 4 weeks after intraperitoneal streptozotocin injection. The body weight and blood sugar were measured before and after model induction in the three groups. Thrombospondin-1 (TSP-1) expressions in the kidney were monitored by immunohistochemistry. Kidney ultrastructural changes were also analyzed by using transmission electron microscopy.

RESULTSBefore diabetic model induction, there were no significant differences among the three groups in body weight and blood sugar. Four weeks after the induction of diabetes, the differences became statistically significant. Electron microscopy also revealed disruption of the foot processes of the podocytes and other damages in diabetic group. These damages were significantly less severe in Hsian-tsao group when compared with the diabetic group. TSP-1 expressions in the kidney were significantly increased in both the diabetic group and Hsian-tsao group, but it was relatively lower in Hsian-tsao group than in diabetic group.

CONCLUSIONOur results showed that Hsian-tsao treatment in the diabetic rats effectively prevented the pathological alterations in the kidney and decreased the TSP-1 expression. It was suggested that Hsian-tsao had protective effect on the kidneys of the diabetic rats.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; pathology ; Diabetic Nephropathies ; metabolism ; pathology ; prevention & control ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Kidney ; drug effects ; metabolism ; pathology ; ultrastructure ; Lamiaceae ; chemistry ; Rats ; Rats, Sprague-Dawley ; Thrombospondin 1 ; metabolism

OBJECTIVETo investigate nephrin and desmin expression in rat podocytes in early diabetic nephropathy (DN) and the rale of angiotensin II receptor antagonist in renal protection.

METHODSRat models of DN established by a injection of a single dose of streptozotocin (STZ) were randomized into model group and irbesartan group, with rats without STZ injection as the normal control group. The rats in irbesartan group were subjected to daily intragastric irbesartan administration for 8 consecutive weeks, while those in the model group received only saline in the same manner. Upon completion of the treatment, the rats were sacrificed and pathological changes of the kidney were examined with optical and transmission electron microscope. Nephrin and desmin expressions in the podocytes were detected by immunohistochemistry.

RESULTSIn rats with DN, irbesartan administration alleviated podocyte injury and significantly lowered the expression of nephrin and desmin (P<0.05).

CONCLUSIONAngiotensin II receptor antagonist may offer renal protection against DN by alleviating structural and functional podocyte damage through decreasing nephrin expression in the podocytes.

Angiotensin II Type 1 Receptor Blockers ; therapeutic use ; Animals ; Biphenyl Compounds ; therapeutic use ; Desmin ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetic Nephropathies ; drug therapy ; Kidney ; pathology ; Membrane Proteins ; metabolism ; Podocytes ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Tetrazoles ; therapeutic use

OBJECTIVETo study the mechanism of Shenkangwan (SKW) in treating early diabetic nephropathy (DN).

METHODSThe effect of SKW on NO and transforming growth factor (TGF)-beta(1) production by the mesangial cells (MCs) of rats with early diabetic nephropathy was evaluated with serum pharmacological method.

RESULTSCompared with normal serum, the SKW-containing serum dose- and time-dependently inhibited TGF-beta(1) excretion and increased NO production in the MCs of rats with early DN (P<0.05 and P<0.01, respectively).

CONCLUSIONThe therapeutic effect of SKW on early DN may rely on the balance modulation of cytokine network by increasing NO production and decreasing TGF-beta(1) excretion to prevent cytokine-induced damage of the MCs.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetic Nephropathies ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Glomerular Mesangium ; metabolism ; pathology ; Male ; Nitric Oxide ; biosynthesis ; Rats ; Rats, Wistar ; Transforming Growth Factor beta ; biosynthesis

OBJECTIVETo investigate the morphological changes and expressions of desmin and podocin in podocytes of rats with diabetic nephropathy (DN) rats and renal protection mechanism of Shenkangwan.

METHODSDN model was established in rats by a single injection of streptozotocin. The rats were then randomly divided into model group, Shenkangwan treatment group, irbesartan treatment group, and Shenkangwan plus irbesartan treatment group, with normal rats as the control group. All the rats received daily gavage for 8 weeks. The urinary protein quantity in 24 h were detected, and the morphological changes of the kidneys were observed with optic and transmission electron microscopes. The expressions of desmin and podocin in the podocytes were detected by immunohistochemistry.

RESULTSShenkangwan and irbesartan reduced the urinary protein quantity in 24 h and alleviated the renal damage in DN rats, and the expression of desmin was significantly attenuated while podocin expression increased in the podocytes.

CONCLUSIONSShenkangwan can provide renal protection against DN in rats and alleviate the structural and functional damages of podocytes possibly by reducing desmin expression and increasing podocin expression in the podocytes.

Animals ; Desmin ; biosynthesis ; Diabetic Nephropathies ; drug therapy ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Immunohistochemistry ; Kidney ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Phytotherapy ; Podocytes ; drug effects ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

PURPOSE: The aim of this study was to examine the effects of all-trans retinoic acid (ATRA) on diabetic nephropathy. MATERIALS AND METHODS: We measured amounts of urinary albumin excretion (UAE) after administrating ATRA to Otsuka Long-Evans Tokushima Fatty (OLETF) rats. In order to understand the mechanism of action for ATRA, we administrated ATRA to examine its inhibitory action on the production of transforming growth factor-beta1 (TGF-beta1), protein kinase C (PKC), and reactive oxidative stress (ROS) in cultured rat mesangial cells (RMCs). RESULTS: After 16 weeks of treatment, UAE was lower in the ATRA-treated OLETF rats than in the non-treated OLETF rats (0.07+/-0.03 mg/mgCr vs. 0.17+/-0.15 mg/mgCr, p<0.01). After incubation of RMCs in media containing 30 or 5 mM of glucose, treatment with ATRA showed time- and dose-dependent decreases in TGF-beta1 levels and ROS. Moreover, ATRA treatment showed a dose-dependent decrease in PKC expression. CONCLUSION: ATRA treatment suppressed UAE and TGF-beta1 synthesis, which was mediated by significant reductions in PKC activity and ROS production. Our results suggest that ATRA has a potential therapeutic role for diabetic nephropathy.
Animals ; Diabetes Mellitus, Type 2/*complications ; Diabetic Nephropathies/*complications/*drug therapy/pathology ; Mesangial Cells/*metabolism ; Oxidative Stress/drug effects ; Rats ; Rats, Inbred OLETF ; Reactive Oxygen Species/metabolism ; Transforming Growth Factor beta1/analysis/pharmacology ; Tretinoin/*pharmacology/therapeutic use

OBJECTIVETo explore the effects and underlying mechanisms of Panax notoginoside (PNS) on the nephropathy in rats with type 1 diabetes.

METHODSA murine model of diabetic nephropathy was set up by an intravenous injection of streptozotocin (STZ). Wistar rats were randomly divided into 5 groups: the control group, the diabetic group (DM), the group treated with low-dosage PNS (PNS-L), the group treated with high-dosage PNS (PNS-H) and the group treated with catopril. Rats in the PNS-L and PNS-H groups were given different dosages of PNS while rats in the catopril group were given catopril through gastrogavage every day for the next four consecutive weeks. Serum creatinine (Cr) levels, endogenous creatinine clearance rate (CCr), and 24-h urinary microalbumin (UAlb) were examined and calculated. Meanwhile, immunohistochemistry was applied to determine the expression of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-7 (BMP-7) in the kidney tissue.

RESULTSThe levels of Cr, Ccr, and UAlb were all elevated significantly in the DM group (P<0.01). The expression of VEGF protein was increased but BMP-7 protein was decreased in the kidney tissue (P<0.01). However, the above items decreased in the PNS-L, PNS-H and catopril groups compared with the DM group (P<0.05, P<0.01). In the PNS-L, PNS-H and catopril groups, the expression of VEGF protein was decreased but BMP-7 protein was increased in the kidney tissue (P<0.05, P<0.01).

CONCLUSIONPNS shows protective effects on the kidney in type 1 diabetic rats at the early stage. The protective mechanism might be closely related to its role of inhibiting the expression of VEGF protein and enhancing the expression of BMP-7 protein in the kidney.

Animals ; Body Weight ; drug effects ; Bone Morphogenetic Protein 7 ; metabolism ; Diabetes Mellitus, Type 1 ; complications ; drug therapy ; pathology ; physiopathology ; Diabetic Nephropathies ; complications ; drug therapy ; pathology ; physiopathology ; Hypertrophy ; Immunohistochemistry ; Kidney ; drug effects ; metabolism ; pathology ; Kidney Function Tests ; Male ; Panax ; chemistry ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Proteinuria ; complications ; drug therapy ; pathology ; physiopathology ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; metabolism

Diabetic nephropathy (DN) is a common and serious clinical complication of diabetes and presently there are no effective ways to prevent its occurrence and progression. Recent studies show that pentoxifylline (PTX) can improve renal hemodynamics, reduce urinary protein excretion, and alleviate or delay renal failure in DN patients. In this study, we focused on the anti-oxidative stress effect of PTX on alleviating renal damages of DN using rat models. DN rats were established with injection of streptozotocin. Blood glucose, urinary protein excretion, serum cystatin C, renal biopsy, superoxide dismutase (SOD) and malondialdehyde (MDA) in serum and renal homogenate and renal nitrotyrosine levels were analyzed before and 12 weeks after the treatment of PTX. Before treatment, all the DN rats had elevated blood glucose, increased urinary protein excretion and elevated serum cystatin C. Morphologically, DN rats exhibited renal tissue damages, including swelling and fusions of foot processes of podocytes under electron microscope. Masson staining revealed blue collagen deposition in glomeruli and renal interstitium. With treatment of PTX, symptoms and renal pathological changes of DN rats were alleviated. Furthermore, the MDA levels were increased and the SOD levels were decreased in the serum and kidneys of DN rats, and these changes were reversed by PTX. The expression of nitrotyrosine was up-regulated in DN rat model and down-regulated by PTX, indicating that PTX was able to inhibit oxidative reactions in DN rats. PTX could alleviate renal damage in DN, which may be attributable to its anti-oxidative stress activity.
Animals ; Biomarkers ; analysis ; Diabetes Mellitus, Experimental ; drug therapy ; pathology ; Diabetic Nephropathies ; drug therapy ; metabolism ; pathology ; Gene Expression Regulation ; drug effects ; Kidney ; metabolism ; pathology ; Malondialdehyde ; blood ; Oxidative Stress ; drug effects ; Pentoxifylline ; administration & dosage ; pharmacology ; Rats ; Streptozocin ; Superoxide Dismutase ; metabolism ; Tyrosine ; analogs & derivatives ; metabolism

PURPOSE: Diabetic nephropathy is a serious complication of type 2 diabetes mellitus, and delaying the development of diabetic nephropathy in patients with diabetes mellitus is very important. In this study, we investigated inflammation, oxidative stress, and lipid metabolism to assess whether curcumin ameliorates diabetic nephropathy. MATERIALS AND METHODS: Animals were divided into three groups: Long-Evans-Tokushima-Otsuka rats for normal controls, Otsuka-Long-Evans-Tokushima Fatty (OLETF) rats for the diabetic group, and curcumin-treated (100 mg/kg/day) OLETF rats. We measured body and epididymal fat weights, and examined plasma glucose, adiponectin, and lipid profiles at 45 weeks. To confirm renal damage, we measured albumin-creatinine ratio, superoxide dismutase (SOD), and malondialdehyde (MDA) in urine samples. Glomerular basement membrane thickness and slit pore density were evaluated in the renal cortex tissue of rats. Furthermore, we conducted adenosine monophosphate-activated protein kinase (AMPK) signaling and oxidative stress-related nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling to investigate mechanisms of lipotoxicity in kidneys. RESULTS: Curcumin ameliorated albuminuria, pathophysiologic changes on the glomerulus, urinary MDA, and urinary SOD related with elevated Nrf2 signaling, as well as serum lipid-related index and ectopic lipid accumulation through activation of AMPK signaling. CONCLUSION: Collectively, these findings indicate that curcumin exerts renoprotective effects by inhibiting renal lipid accumulation and oxidative stress through AMPK and Nrf2 signaling pathway.
Albuminuria ; Animals ; Anti-Inflammatory Agents, Non-Steroidal/*therapeutic use ; Curcumin/*pharmacology ; Diabetes Mellitus, Type 2/*metabolism/urine ; Diabetic Nephropathies/complications/*drug therapy/metabolism/pathology ; Gene Expression/drug effects ; Inflammation ; Kidney/drug effects/metabolism/physiopathology ; Kidney Glomerulus/metabolism/physiopathology ; Lipid Metabolism/*drug effects ; Male ; Malondialdehyde/metabolism/urine ; Oxidative Stress/*drug effects ; Rats ; Rats, Inbred OLETF ; Rats, Long-Evans ; Superoxide Dismutase/metabolism