Influence of HbA1c on short-term blood pressure variability in type 2 diabetic patients with diabetic nephropathy.

The aim of this study was to understand the characteristics of blood pressure (BP) variability in subjects with diabetic nephropathy (DN), and identify the probable predictors affecting BP variability. Fifty-one chronic kidney disease (CKD)-hypertensive patients without diabetes (NDN group) and sixty type 2 diabetic patients with overt DN (DN group) were enrolled in this study. The values of short-term BP variability were obtained from 24 h ambulatory BP monitoring (ABPM). Variance analysis or nonparametric analysis revealed that 24-h systolic BP variability and nighttime systolic BP variability of the DN group were significantly higher than those of the NDN group [(12.23±3.66) vs. (10.74±3.83) mmHg, P<0.05; (11.23±4.82) vs. (9.48±3.69) mmHg, P<0.05]. Then the patients of the DN group were divided into two groups according to glycated hemoglobin (HbA1c) level: Group A (HbA1c<7%) and Group B (HbA1c≥7%), and the t-test showed that patients in Group B had larger 24-h diastolic, daytime diastolic, and nighttime systolic/diastolic BP variability compared with Group A. In the DN group, partial correlation analysis revealed that HbA1c exhibited a strong association with 24-h diastolic, daytime diastolic, nighttime systolic and diastolic BP variability (P<0.001, P<0.001, P<0.05, and P<0.001, respectively). Taken together, larger short-term BP variability was detected in hypertensive type 2 diabetic patients with overt nephropathy and renal insufficiency. It may imply that the optimal BP variability level could benefit from a better glycaemic control.

Amelioration of rhabdomyolysis-induced renal mitochondrial injury and apoptosis through suppression of Drp-1 translocation.

INTRODUCTION: Mitochondrial dysfunction plays an important role in acute kidney injury (AKI). Mitochondrial fission regulated by dynamin-related protein 1 (Drp-1) impairs the function of the mitochondria and the survival of cells. This study was conducted to explore the effects of suppression of Drp-1 accumulation in the mitochondria, on mitochondrial function and renal tubular cell apoptosis in rhabdomyolysis (RM)-induced AKI. METHODS: An RM model was induced by intramuscular injection of glycerol in Sprague Dawley rats. Twenty-four and 48 hours after intraperitoneal injections of mitochondrial division inhibitor 1 (Mdivi-1), we observed the functions of the kidney, changes in pathology, expressions of Drp-1 in tubular tissues (by immunohistochemistry and Western blot) and accumulation of Drp-1 and mitofusin 2 in tubular mitochondria (by Western blot). Mitochondrial function (ATP and ROS) and tubular epithelial cell apoptosis (by TUNEL) were also measured. RESULTS: RM induced Drp-1 accumulation, decreased ATP production and increased ROS in mitochondria. With increasing cytochrome c expression, cell apoptosis increased, whereas kidney function decreased. These changes were time-dependent. At different time points, despite not significantly influencing the overall expression of Drp-1, Mdivi-1 suppressed the accumulation of Drp-1, inhibited the insertion of proapoptotic Bax in mitochondria and inhibited the release of cytochrome c, thus ameliorating cell apoptosis. CONCLUSIONS: To conclude, in RM-induced AKI, suppression of Drp-1 accumulation in mitochondria favors the maintenance of mitochondrial function and reduces the apoptosis of tubular cells. Regulation of the mitochondrial fusion-fission balance may offer a novel strategy for the prevention and treatment of RM-induced AKI.

[Relation between bone matrix proteins and monocyte chemoattractant protein-1 in renal small artery in diabetic nephropathy rats].

OBJECTIVE: To observe the expressions of bone matrix proteins and monocyte chemoattractant protein-1 ((MCP-1) in the renal arteriole of diabetic nephropathy (DN) rats and analyze their correlations and roles in diabetic nephropathy. METHODS: Adult Sprague-Dawley male rats were used to establish the animal model of diabetic nephropathy induced by peritoneal injection of 55 mg/kg of streptozocin. Calcium deposit around the renal arteriole was observed by alizarin red staining. The protein and mRNA levels of core-bind factor alpha 1 (cbfalpha1), bone morphogenetic protein 2 (BMP-2) and matrix Gla protein (MGP) in renal arteriole of DN rats were detected by immunohistochemistry, in-situ hybridization and real-time PCR. The biochemical indices were detected by routine test. RESULTS: 1. Blood glucose and Urine protein of 24 h were significantly increased in the renal arteriole of DN rats versus the control rats (P < 0.05), serum creatinine (SCr) and phosphorus were significantly increased from 12 weeks. 2. Little deposit of calcium salt was observed in the renal arteriole of DN rats at the 4th week and a large amount of deposit was observed at 24th week, but no calcium deposit was observed in control rats. 3. Cbfalpha1 and BMP-2 expressions were significantly increased in the renal arteriole of DN rats from 4 to 24 weeks vs. the control rats. MGP mRNA expression in the renal arteriole of DN rats was significantly decreased from 4 to 24 weeks. MCP-1 expression was obviously upregulated in the renal arteriole of DN rats at 24th week versus that at 4th and 12th week. No MCP-1 expression was observed in the renal arterioles of control rats. MCP-1 were positively correlated with the expression of cbfalpha1 and BMP-2. CONCLUSION: Bone matrix proteins has already expressed in renal arteriole before the formation of vascular calcification. MCP-1 can affect the expression of cbfalpha1, BMP-2; cbfalpha1, BMP-2, MGP and MCP-1 may be involved in the formation of vascular lesions of DN.

[Comparison of the effects of alpha-keto/ amino acid supplemented low protein diet and diabetes diet in patients with diabetic nephropathy].

OBJECTIVE: To investigate if a-keto/amino acid supplemented low protein diet can slow down the progression of diabetic nephrophathy in comparison with non-supplemented diabetes diet. METHODS: A prospective, randomized, controlled clinical study was conducted. Twenty three cases of type 2 diabetic nephropathy in IV stage were randomly divided into alpha-keto/amino acid supplemented diet group (trial group) and conventional diabetes diet group (control group), The treatment duration was 52 weeks. 24 h urine protein was measured at 0, 12, 20, 36 and 52 weeks. Before and after the 52 weeks treatment, all the patients received the measurement of glomerular filtration rate (GFR), blood glucose, blood lipids, inflammatory markers, as well as nutritional status. RESULTS: After the treatment for 20, 36, 52 weeks, mean 24 h urine protein decreased significantly in trial groups (P < 0.05), and 24 h urine protein in trial group were significantly decreased (P < 0.05) compared with control group in 20 weeks after treatment. Either in trial group or in control group, GFR remained relatively stable during the observation period. Nutrition status, inflammatory markers, and serum calcium, phosphorus levels between the two groups were no significantly difference. The adverse events experienced by the patients in trial group were similar and consistent with the patients underlying renal diseases. CONCLUSION: Alpha-keto/amino acid can reduce proteinuria more effectively, while improve renal function and nutritional status in diabetic nephropathy patients with well-toleration.

Spontaneous retroperitoneal hemorrhage after hemodialysis involving anticoagulant agents.

In this paper, we described the symptoms and treatment of a patient with diabetic nephropathy accompanied by spontaneous retroperitoneal hemorrhage after hemodialysis. An elderly female patient with diabetic nephropathy presented with severe pain, numbness, and an increasing swelling in the left hip and left thigh after six sessions of hemodialysis involving the use of an antiplatelet drug and an anticoagulant agent. Her hemoglobin decreased to 46 g/L. An abdominal ultrasound showed a hematoma in the left retroperitoneal space, and computed tomography (CT) findings revealed a 6 cm × 8 cm × 10 cm hematoma in the left psoas muscle. After aggressive supportive therapy [the administration of packed red blood cell transfusion, carbazochrome sodium sulfonate injection, and continuous venovenous hemofiltration (CVVH)], the patient's vital signs stabilized and her hemoglobin increased to 86 g/L. Repeat CT showed that the hematoma had been partially absorbed after two weeks. Eventually, the patient was discharged with stable vital signs. Physicians should be aware of the possibility of spontaneous retroperitoneal hemorrhage, particularly in patients with diabetic nephropathy undergoing hemodialysis involving the use of anticoagulant agents.

Early protective effect of mitofusion 2 overexpression in STZ-induced diabetic rat kidney.

Diabetic nephropathy (DN) is a serious complication of diabetes with a poorly defined etiology and limited treatment options. Early intervention is key to preventing the progression of DN. Mitofusin 2 (Mfn2) regulates mitochondrial morphology and signaling, and is involved in the pathogenesis of numerous diseases. Furthermore, Mfn2 is also closely associated with the development of diabetes, but its functional roles in the diabetic kidney remain unknown. This study investigated the effect of Mfn2 at an early stage of DN. Mfn2 was overexpressed by adenovirus-mediated gene transfer in streptozotocin-induced diabetic rats. Clinical parameters (proteinuria, albumin/creatinine ratio), pathological changes, ultra-microstructural changes in nephrons, expression of collagen IV and phosph-p38, ROS production, mitochondrial function, and apoptosis were evaluated and compared with diabetic rats expressing control levels of Mfn2. Endogenous Mfn2 expression decreased with time in DN. Compared to the blank transfection control group, overexpression of Mfn2 decreased kidney weight relative to body weight, reduced proteinuria and ACR, and improved pathological changes typical of the diabetic kidney, like enlargement of glomeruli, accumulation of ECM, and thickening of the basement membrane. In addition, Mfn2 overexpression inhibited activation of p38, and the accumulation of ROS; prevented mitochondrial dysfunction; and reduced the synthesis of collagen IV, but did not affect apoptosis of kidney cells. This study demonstrates that Mfn2 overexpression can attenuate pathological changes in the kidneys of diabetic rats. Further studies are needed to clarify the underlying mechanism of this protective function. Mfn2 might be a potential therapeutic target for the treatment of early stage DN.

[Influence of mannose binding lectin to expression of TGF-beta1 and NF-kappaB in high concentration of glucose cultured human renal glomerular endothelial cells].

OBJECTIVE: To investigate the effect of mannose binding lectin (MBL) complement pathway on expression of transforming growth factor-beta1 (TGF-beta1) and NF-kappaB in cultured human renal glomerular endothelial cells (HRGECs) stimulated by high concentration of glucose. METHODS: Human glomerular endothelial cells in culture were randomly divided into 5 groups according to different managements: normal concentration of glucose as controlled group, MBL + normal concentration of glucose group, high concentration of glucose, MBL + high glucose and MBL + high glucose + MBL blocker respectively. Flow cytometry was used to detect the depositions of MBL and C3 on the surfaces of HRGECs. Real-time PCR method was used to detect the mRNA levels of TGF-beta1. Human TGF-beta1 ELISA kit was used to detect the concentration of TGF-beta1 in supernatant fluid. ESMA was used to detect the activity of NF-kappaB in HRGECs. RESULTS: Compared with the normal glucose group and high glucose group, the depositions of MBL, C3 were apparently increased in MBL + high glucose group (P < 0.05). Expression of TGF-beta1 were significantly higher (P < 0.05) in MBL + high concentration of glucose groups than the normal glucose group and the high concentration of glucose group. Compared with the high glucose group, the activity of NF-kappaB in HRGECs was apparently increased in MBL + high glucose group, which could be significantly downregulated by MBL blocking antibody. CONCLUSION: High concentration of glucose can increase the expression of TGF-beta1 of cultured human glomerular endothelial cells. At the same time, high glucose together with MBL can up regulate the expression of TGF-beta1 and the activity of NF-kappaB in HRGECs.

[Relationship between activation of mannan-binding lectin complement and NF-kappaB in diabetic nephropathy].

OBJECTIVE: To study the activation of mannose-binding lectin (MBL) complement in STZ-induced diabetic nephropathy (DN) rats and its relationship with NF-kappaB. METHODS: Sprague-Dawley (SD) rats were randomly divided into two groups: normal control and diabetic nephropathy. Diabetes was induced by intraperitoneal injection of STZ. Five rats were sacrificed at the end of week 1, 2, 4, 8 respectively. Blood glucose, 24 h urine, 24 h urinary albumin, serum creatinine (Scr), body mass and kidney mass were examined at the same time points respectively. Creatinine clearance and renal hypertrophy index were calculated. The renal expression of MBL, membrane attack complex (MAC) and NF-kappaB were determined by immunohistochemistry. RESULT: MBL, MAC and NF-kappaB expression were significantly increased in glomerulus of diabetic nephropathy rats compared to the controls. The expression of MBL was positively correlated with NF-kappaB expression. CONCLUSION: The activation of mannose-binding lectin complement participates in the onset and development of DN.

[Influence of high glucose and mannose binding lectin complement pathway activation to IL-6 and TNF-alpha's expression by human renal glomerular endothelial cells].

OBJECTIVE: To investigate the effect of high glucose and mannose binding lectin (MBL) complement pathway activation's effect on expression of Interleukin-6 (IL-6) and Tumor necrosis factor-alpha (TNF-alpha) from human renal glomerular endothelial cells (HRGEC), to explore unknown pathogenesy of diabetic nephropathy. METHODS: Normal HRGEC was divided randomly into normal glucose group(5 mmol/L D-glucose), manicol group (5 mmol/L D-glucose+25 mmol/L manicol) and high glucose group (30 mmol/L D-glucose). Real-time PCR was used to detect IL-6 and TNF-alpha mRNA expression in each group, Euzymelinked Immunosorbent Assay (ELISA) was performed to examine the protein expression of IL-6 and TNF-alpha in supernatant after 24 hours' culture. HRGEC was then randomly divided into two groups: single high glucose group and high glucose + MBL group. After 24 hours' culture with 30 mmol/L D-glucose, 30% MBL deficiency human serum was added into two groups, 1 microg/mL MBL was only added into high glucose + MBL group, continued the culturation for another 4 hours. Flow cytometry and immunofluorescence technique were applied to evaluate MBL, C3 and membrane attacks complex (MAC) deposition on cell surface respectively. Real-time PCR and ELISA were performed to examine mRNA and protein expression of both IL-6 and TNF-alpha in each group. RESULTS: Compared with normal glucose group and manicol group, the mRNA and protein expression of IL-6 and TNF-alpha in high glucose group were increased (P < 0.05). Flow cytometry confirmed obvious MBL and C3 co-deposition and Immunofluorescence confirmed obvious MAC deposition on cell surface in high glucose+ MBL group. Compared with single high glucose group, the mRNA and protein expression of IL-6 and TNF-alpha in high glucose+ MBL group were significantly higher (P < 0.05). CONCLUSION: High glucose can bring inflammatory factors' overexpression from cultured HRGEC; high glucose together with MBL can bring MBL complement pathway activation and inflammatory factors' overexpression, this indicates that the activation of MBL complement pathway may be a potential unknown pathogenesy of diabetic nephropathy and its proinflammatory status.

[Effect of high concentration of glucose on thickness of glycocalyx and expression of syndecan-1 and glypican-1 in cultured human renal glomerular endothelial cells].

OBJECTIVE: To investigate the influence of high concentration of glucose on the thickness of Glycocalyx and expression of core protein Sydecan-1 and Glypican-1 in cultured human renal glomerular endothelial cells (HRGECs). METHODS: HRGECs in culture were randomly divided into 3 groups, high concentration of glucose (30 mmol/L D-glucose, high glucose group), normal concentration of glucose as controlled group (5 mmol/L D-glucose+25 mmol/L mannitol, normal control group), and mannitol group (30 mmol/L mannitol) respectively. After 72 hours, confocal laser scanning microscopy (CLSM) was used to observe and characterize the fully hydrated glycoalyx of HRGECs. Real time quantitative PCR and Western blot were applied to detect the mRNA levels and protein expression of Syndecan-1 and Glypican-1, and the fluorescence microscope were used to observe the immunofluorescence change of Syndecan-1 and Glypican-1. RESULTS: Compared with normal control group, the thickness of Glycocalyx on the surface of HRGECs in high glucose group decreased to 36.8% (P < 0.05). Immunofluorescence shows the depositions of Syndecan-1 and Glypican-1 were weakened in high glucose group. The mRNA and protein expression of Syndecan-1 and Glypican-1 were significantly decreased (P < 0.05) compared with normal control group and mannitol group. CONCLUSION: High concentration of glucose can reduce thickness of Glycocalyx on the surface of human glomerular endothelial cell. At the same time, high glucose can decrease the expression of core protein Sydecan-1 and Glypican-1 of HRGECs.

[Effects of high glucose on expression of core binding factor alpha1 and osteocalcin in vascular smooth muscle cells].

OBJECTIVE: To investigate the effects of high glucose on expression of core binding factor alpha1 (cbfalpha-1) and osteocalcin (OC) in vascular smooth muscle cells (VSMCs), and discuss the mechanism of small vessels calcification induced by high glucose (GS) in vitro. METHODS: The primary cultured VSMCs from rats' aortic segments were divided into three groups, including normal control group (5 mmol/L D-glucose), high glucose group (25 mmol/L D-glucose) and mannitol group (5 mmol/L D-glucose plus 25 mmol/L mannitol). We measured quantitatively the calcium deposition in VSMCs and investigated the calcium extent of VSMCs by alizarin red stain in each group. The mRNA levels of cbfalpha-1 and OC were measured by real-time PCR, and the protein expression levels of cbfalpha-1 and OC were examined by Western blot. The activity of alkaline phosphatase was measured by alkaline phosphatase activity testing kit, and the protein level of alpha-smooth muscle actin (a-SMA) was detected by immunohistochemistry. RESULTS: When compared with the normal group and mannitol group, the high glucose group showed that the calcium deposition and calcium extent of VSMCs increased obviously, the mRNA and protein levels of cbfalpha-1 and OC also increased significantly (P < 0.05), while the protein level of alpha-SMA decreased (P < 0.05), which were in a dose-dependent manner. The level of alkaline phosphatase activity of VSMCs was approximately doubled in high glucose group. CONCLUSION: The mechanism of high glucose induced calcification in VSMCs may be due to the increased expression of cbfalpha-1 and OC. High glucose decrease the expression of alpha-SMA in VSMCs, which could induce the transdifferentiation from RVSMCs to osteoblast-like cells.

[Effects of valsartan on the renal vascular endothelial growth factor and its receptor flk-1 of diabetic rats].

OBJECTIVE: To explore effects of valsartan on expression changes of vascular endothelial growth factor (VEGF) and its receptor Flk-1 in diabetic rat kidney. METHODS: To establish the diabetic nephropathy (DN) rat models and divide the experiment rats into three groups--the DN group, the valsartan group and the control group, and use the reverse transcriptase polymerase chain reaction (RT-PCR), Western Blotting and immunohistochemical techniques to detect the expression of VEGF and Flk-1, and detect the urine protein and glomerular area and volume, then analyze the relationship of the data. RESULTS: The mRNA and protein expression of VEGF and Flk-1, the urine protein and glomerular area and volume in the DN were higher than those in the control group and valsartan group (P < 0.05). VEGF and Flk-1 were positively correlated with the urine protein and glomerular area and volume (P < 0.05). CONCLUSION: VEGF and Flk-1 play an important role in the pathogenesis of DN, of which over-expression may lead to the damage of kidney. The angiotensin II receptor antagonist--valsartan can protect kidney through the non-hemodynamic mechanism of inhibiting the abnormal expression of VEGF and Flk-1.

[Effects of losartan on expressions of plasminogen activator and plasminogen activator inhibitor-1 of rat proximal tubular epithelial cells cultured with high glucose].

OBJECTIVE: To investigate the effects of high glucose on expressions of plasminogen activator (PA) and plasminogen activator inhibitor-1 (PAI-1) of rat proximal tubular epithelial cells, and the role of angiotensin II receptor antagonist Losartan. METHODS: The cultured NRK-52E cells (a renal proximal tubular epithelial cell line of rat origin) were divided into five groups: control group, mannitol group (5 mmol/L D-glucose plus 25 mmol/L mannitol), high glucose group (30 mmol/L D-glucose), losartan group (10(-3) mmol/L losartan), high glucose plus losartan group (30 mmol/L D-glucose plus 10(-3) mmol/L losartan). Semi-quantity RT-PCR was used to detect the expression of PA/PAI-1 mRNA. RESULTS: Compared with control group, the high glucose group decreased the expressions of tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) mRNAs (P < 0.01) and increased PAI-1 mRNA expression (P < 0.01) in cultured NRK-52E cells. Losartan could reverse partly the expression of PA/PAI-1 mRNA. Compared to high glucose group, the PA mRNA expression was significantly increased (P < 0.01) and the PAI-1 mRNA expression was decreased greatly (P < 0.01) to high glucose plus losartan group. CONCLUSION: The abnormal expression of PA/PAI-1 mRNA may play an important role in the accumulation of extracellular matrix (ECM) of diabetic nephropathy (DN). Losartan may keep the balance of PA/PAI-1 and have a protective effect on DN.

[Expression of VEGF in kidney of diabetic rats].

OBJECTIVE: To investigate the expression of vascular endothelial growth factor (VEGF) in the kidney of diabetic rats and probe its relationship with the development of diabetic nephropathy (DN). METHODS: Diabetes mellitus was induced in SD rats by Streptozotocin. The renal tissues of rats were taken out at 2, 4, 8, 12, 16, 20 and 24 weeks after operation. The expression of VEGF was assessed by immunohistochemistry methods. VEGF mRNA in kidney was detected by RT-PCR at the same time points. The levels of VEGF mRNA and immunostaining were quantified by computer image analysis. The relationships of VEGF with the indices of renal damage, including renal/body weight, urinary protein excretion, glomerular volume and glomerular area, were analyzed. RESULTS: The expression of VEGF mRNA in diabetic kidney was significantly up-regulated after operation from 2 weeks to 24 weeks with the peak level at 20 weeks, when compared with control at the same time-points. The positive results of VEGF staining in diabetic glomeruli was increasingly observed after operation from 2 weeks to 24 weeks, with the peak at 20 weeks. The positive results of VEGF staining in diabetic tubuli was increasingly seen from 2 weeks to 24 weeks, with the peak at 8 weeks. CONCLUSION: VEGF level is increased continuously in the diabetic kidney of rat. The increased expression of VEGF is mainly located in the glomeruli at the early and middle stages, and is in the tubuli at the middle and late stages. VEGF expression in the diabetic kidney of rat is related to the development of renal changes.

[Effect of rosiglitazone on integrin beta1 expression and apoptosis of proximal tubular cell exposed to high glucose].

OBJECTIVE: To evaluate the effect of rosiglitazone (ROS) on integrin beta1 expression and apoptosis of proximal tubular cell exposed to high glucose. METHODS: The proximal tubular cells of rats were cultured in vitro and divided into 6 groups: control group, normal glucose (5 mmol/L) group, high glucose (30 mmol/L) group, only ROS (10 micromol/L) group, glucose (30 mmol/L)+ROS (5 micromol/L) group, and glucose (30 mmol/L) +ROS (10 micromol/L) group. The cells were cultured for 48 hrs and the integrin beta1 expressions were detected by Western blot and RT-PCR; The apoptosis was evaluated by flow cytometry after the cells were cultured for 24, 48, 72 hrs. RESULTS: The expressions of integrin beta1 protein and mRNA of high glucose (30 mmol/L) group were significantly increased as compared with control group and normal glucose (5 mmol/L) group. The integrin beta1 of glucose (30 mmol/L)+ROS (5 or 10 micromol/L) group was decreased as compared with high glucose group (P < 0.05). Flow cytometry demonstrated the decreased apoptosis to be with time-dependence. CONCLUSION: ROS can strikingly inhibit the expression of integrin beta1 in proximal tubular cells exposed to high glucose, with a marked dose-dependent manner. The effect of ROS on cell apoptosis may be relevant to integrin beta1.

[The expression and significance of the angiopoietin-1 in the kidney of diabetic rats].

OBJECTIVE: To explore the expression and significance of angiopoietin-1 (Ang-1) in the renal tissue of diabetic rats. METHODS: The SD rats were divided into the diabetic and control groups. The diabetic group was treated by streptozotocin. The expression of Ang-1 in renal tissue was detected by RT-PCR and immunohisochemistry at 2, 4, 8, 12, 16, 20 and 24 weeks. The level of Ang-1 was quantified by computer image analysis. The relationship between Ang-1 and the index of renal damage including renal/body weight, urinary protein excretion, glomerular volume, and glomerular area was analyzed. RESULTS: Ang-1 mRNA in diabetic renal tissue was significantly upregulated at 4 and 8 weeks, compared with diabetic group at other time points or control group at the same time points, and then downregulated gradually after 12 weeks. The level of Ang-1 mRNA decreased significantly as compared with control group at 24 week. Ang-1 was outstandingly expressed in glomeruli. From 4-week to 24-week, the number of Ang-1 staining in diabetic glomeruli increased significantly as compared with control group, being maximal at 4 and 8 weeks, and subsequently decreased after 12 week. Ang-1 level was correlated with renal/body weight, glomerular volume, glomerular area, and urine protein excretion, respectively. CONCLUSION: The change of Ang-1, which is early upregulation and late downregulation, exists in diabetic renal tissue. The unusual expression of Ang-1 is partly connected with the renal changes of diabetic rats.

[Expression level of cubilin in the rat model of diabetic nephropathy].

OBJECTIVE: To observe the expression level of Cubilin in the renal tubules of rats with STZ-induced diabetic nephropathy, to assess its correlation with 24 hours' albuminuria, and to investigate the mechanisms of tubular dysfunction at the early stage of diabetic nephropathy. METHODS: Diabetic nephropathy was induced in Sprague-Dalwley rats by intraperitoneal injection of STZ, while the rats of normal group were injected with normal saline. Biochemical indices of blood and urine specimens were observed in both groups at weeks 2, 4 and 6 respectively. The renal expression levels of Cubilin in the two groups were determined by immunohistochemistry and RT-PCR. RESULTS: The expression level of Cubilin in the diabetic nephropathy group was significantly decreased at week 2 after operation (P < 0.05), and it continued to decrease from week 2 to week 6. Also there was significant difference between each two time-points (P < 0.05), and the Cubilin expression level was negatively correlated with albuminuria (P < 0.01). CONCLUSION: The decreased expression level of Cubilin in early-stage diabetic nephropathy rats may partly contribute to the development of microalbuminuria. Cubilin can be regarded as one of the early markers when tubular dysfunction develops in the case of diabetic nephropathy.

Modified glomerular filtration rate estimating equation for Chinese patients with chronic kidney disease.

The Modification of Diet in Renal Disease (MDRD) equations provide a rapid method of assessing GFR in patients with chronic kidney disease (CKD). However, previous research indicated that modification of these equations is necessary for application in Chinese patients with CKD. The objective of this study was to modify MDRD equations on the basis of the data from the Chinese CKD population and compare the diagnostic performance of the modified MDRD equations with that of the original MDRD equations across CKD stages in a multicenter, cross-sectional study of GFR estimation from plasma creatinine, demographic data, and clinical characteristics. A total of 684 adult patients with CKD, from nine geographic regions of China were selected. A random sample of 454 of these patients were included in the training sample set, and the remaining 230 patients were included in the testing sample set. With the use of the dual plasma sampling (99m)Tc-DTPA plasma clearance method as a reference for GFR measurement, the original MDRD equations were modified by two methods: First, by adding a racial factor for Chinese in the original MDRD equations, and, second, by applying multiple linear regression to the training sample and modifying the coefficient that is associated with each variable in the original MDRD equations and then validating in the testing sample and comparing it with the original MDRD equations. All modified MDRD equations showed significant performance improvement in bias, precision, and accuracy compared with the original MDRD equations, and the percentage of estimated GFR that did not deviate >30% from the reference GFR was >75%. The modified MDRD equations that were based on the Chinese patients with CKD offered significant advantages in different CKD stages and could be applied in clinical practice, at least in Chinese patients with CKD.