Alteration of p38 MAPK activity in lung tissue in diabetic rats

AIM: To observe the pathologic changes in lung and the role of p38 MAPKinase signal pathways in pulmonary alteration in diabetic rats. METHODS: Diabetic rats were induced by intraperitoneally injected streptozotozin (STZ). After 4 weeks, we observed the pathologic changes in lungs, tested protein kinase C (PKC) activities by isotope in lungs of model rats, tested transforming growth factor (TGF-β₁) by Western blotting and immunohistochemical analysis, and determined the expression of p38 MAPKinase mRNA using in situ hybridization.RESULTS: After STZ administration for 4 weeks, we observed thickened pulmonary capillary basal lamina and increased number of fibre in Diabetes mellitus (DM) rats. TGF-β₁ levels, PKC and p38 MAPK activities were also found increased. CONCLUSION: The increased activities of TGF-β₁ and p38 MAPK suggeste that TGF-β₁ may play an important role in diabetic lung, and hyperglycemia-PKC-p38 MAPK signal pathways may be involved in the pathogenesis of diabetes.     

Nontypeable haemophilus influenzae induces IL-8 expression in alveolar epithelial cells in a p38 MAPK and NF-κB dependent manner

AIM:To investigate the key molecular mechanism of inflammatory response in alveolar epithelial cells induced by nontypeable haemophilus influenzae (NTHi). METHODS: A549 cells were co-cultured with NTHi (multiplicity of infection, MOI: 10) and harvested 15 min and 30 min after stimulation. The phosphorylation of p38 mitogen activated protein kinase (p38 MAPK) in A549 cells was detected by Western blotting. The intracellular expression of nuclear factor-κB (NF-κB) p65 was examined by flow cytometry 4 h after stimulation. A549 cells were preincubated with p38 inhibitor (SB203580) or NF-κB inhibitor (PDTC) for 1 h and then stimulated with NTHi for 24 h. The level of interleukin 8 (IL-8) in the supernatants was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The phosphorylation of p38 MAPK was rapidly induced by NTHi stimulation. The expression of NF-κB p65 in A549 cells after NTHi stimulation was significantly up-regulated compared with control group (P<0.05). The level of IL-8 in the supernatants was increased 24 h after bacterial stimulation compared with control group (P<0.05). Blockage of p38 MAPK or NF-κB remarkably decreased IL-8 secretion in A549 cells (P<0.05). CONCLUSION:NTHi induces inflammatory response in alveolar epithelial cells in a p38 MAPK and NF-κB dependent manner.     

Effect of CCK-8 on signal mechanisms of IL-12 secretion in LPS-induced mice

AIM:To study the effects of CCK-8 on IL-12 secretion in LPS-induced mice and to investigate the signal transduction mechanisms involving NF-κB and p38 MAPK. METHODS:Female BALB/c mice were induced by LPS in the presence or absence of CCK-8, CCK-A or B receptor antagonist. The productions of IL-12p40 and p70 in the sera, lung and spleen tissues were evaluated by ELISA. Changes of pIκB, p-p38 protein expression and the NF-κB/DNA binding activity were examined by Western blotting and EMSA, respectively. RESULTS:CCK-8 increased the expressions of IL-12p40, p70 in the serum, lung and spleen tissues of LPS-induced mice, inhibited IκB phosphorylation and NF-κB/DNA binding activity, increased p38 phosphorylation. CONCLUSION:CCK-8 increases the production of IL-12 in LPS-induced mice probably via activating p38 MAPK. NF-κB might not mediate the activating effect of CCK-8 on IL-12 production.     

Renal protective effect of spirinolactone and cilazapril on diabetic rats

AIM: To assess the renal protective effect of the combination use of spirinolactone and cilazapril on streptozotocin(STZ)-induced diabetic rats with single nephrectomy. METHODS: Diabetic nephropathies were induced by intraperitoneal injection of STZ in the rats with single nephrectomy. The rats were randomly divided into 5 groups: normal control; diabetes; diabetes treated with spirinolactone; diabetes treated with cilazapril; diabetic rats treated with spirinolactone and cilazapril. The expression of NF-κB and PAI-1 in the glomeruli was detected by immunohistochemical staining. RT-PCR was performed to evaluate the mRNA expression of AT-1R. RESULTS: Increased 24 h urinary protein, decreased Ccr and the pathological injury of the renal tissues were improved by the treatment with either spirinolactone or cilazapril alone and further ameliorated by using the combination of the two drugs. The activity of NF-κB and PAI-1 was higher in the renal tissues of diabetic rats than that in control group, and further attenuated by the combination therapy in both cases (P<0.05). The over-expression of AT-1R mRNA observed in the diabetic rats was attenuated by treating with spirinolactone or cilazapril and further reduced by the combination use of the two drugs (P<0.05).CONCLUSION: The combination use of spirinolactone and cilazapril confers superiority over monotherapy on the effect of renal protection. The mechanism may be partly correlated with synergistic suppression of the increasing activity of NF-κB and PAI-1 as well as the over-expression of AT-1R mRNA in renal tissues.     

Expression of myocardial NF-κB,iNOS and COX-2 in diabetic rats

AIM: To investigate the expression of nuclear factor-κB (NF-κB), inducable nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in diabetic myocardium. METHODS: Thirty SD rats were randomly divided into control and experimental groups. Diabetes was induced by a single intraperitoneal injection of STZ. The weight, blood glucose level and heart weight index (HWI) were measured 24 weeks after injection. The myocardial NF-κB, iNOS and COX-2 were stained at the same time. Furthermore, NF-κB activation in myocardium was investigated by electrophoretic mobility shift assay (EMSA).RESULTS: (1) Compared to the normal rats, the NF-κB-positive cells in the myocardium in diabetic rats significantly increased. (2) NF-κB activation in myocardium by EMSA was significantly higher in the diabetic rats than that in the normal rats. (3) The iNOS was not expressed in normal rat myocardium and was significantly expressed in the diabetic rat myocardium. (4) The COX-2 was rarely expressed in normal rat myocardium and was significantly expressed in the diabetic rat myocardium.CONCLUSION: The expressions of NF-κB, iNOS and COX-2 are significantly enhanced in the diabetic myocardium.     

Relationship of p38MAPK,NF-κB and HO-1 in LPS-induced acute lung injury in rats

AIM: To investigate the relationship of p38 mitogen-activated protein kinases (p38MAPK), nuclear factor-kappa B (NF-κB) and heme oxygenase-1 (HO-1) in acute lung injury (ALI) in rats.METHODS: Forty male Wistar rats were divided into 5 groups (n=8) at random: control group or normal saline group (NS group), lipopolysaccharide group (LPS group), Hemin (inducer of HO-1)+LPS group, ZnPPIX (inhibitor of HO-1)+LPS group and SB203580 (inhibitor of p38MAPK)+LPS group (SB+LPS group). Six hours after endotracheal instillation of LPS or NS, the ratio of neutrophils and the protein contents in bronchoalveolar lavage fluid (BALF) of right lung, the ratio of wet/dry weight (W/D) of the superior lobe of right lung, and arterial blood gas analysis (ABG) were examined. The protein levels of p38MAPK and NF-κB in the lower lobe of right lung were detected by Western blotting. The protein expression of HO-1 in the middle lobe of right lung was measured by the method of immunohistochemisty. The structure of the lung was evaluated under light microscope. RESULTS: Compared with NS group, the ratio of neutrophils and protein contents in BALF, the ratio of W/D, the protein levels of HO-1, p38MAPK and NF-κB were obviously higher, and arterial oxygen pressure (PaO₂), partial pressure of carbon dioxide in artery (PaCO₂) and bicarbonate content (HCO^-₃) were significantly lower in LPS group, Hemin+LPS group, ZnPPIX+LPS group and SB+LPS group (P<0.05 or P<0.01). The ratio of neutrophils and proteins in BALF, the ratio of W/D, the protein levels of p38MAPK and NF-κB were significantly lower, the protein level of HO-1 was obviously higher in Hemin+LPS group and SB+LPS group than those in LPS group (P<0.05), while the changes of the parameters in ZnPPIX+LPS group were in a contrary manner (P<0.05). No significant difference of the parameters between Hemin+LPS group and SB+LPS group (P>0.05) was found. The structures of the lung tissues in LPS group were severely damaged and even severer damages were observed in ZnPPIX+LPS group. The structural changes of the lung tissues in Hemin+LPS group and SB+LPS group were slighter. CONCLUSION: p38MAPK/NF-κB and HO-1 are inhibited by each other and the effects of them are independent on the acute lung injury.     

黄瓜CsSUN和CsLNG1调控果实大小的机理分析

对黄瓜Q30（CsSUN/CsLNG1）及以其为遗传背景的3个近等基因系材料，即Q30（CsSUN/CsLNG1）、QK1.2-S（Cssun/CsLNG1）、QK2.1-S（CsSUN/Cslng1）、QK1.2+2.1-S（Cssun/Cslng1）进行组织形态、内源激素和转录水平的分析结果表明：与QK1.2-S和QK2.1-S相比，Q30果实最为细长，茎粗最小，植株最高。在果实各发育期，Q30的细胞最小，而细胞密度最大。Q30在开花前6 d的BR/ABA及GA3/ABA显著低于3个近等基因系，随着果实发育差异逐渐缩小。各材料ZT/ABA和IAA/ABA在果实发育各时期基本无显著差异。开花前6 d和开花当天Q30的CsSUN表达量均显著高于QK1.2-S和QK1.2+2.1-S，CsLNG1表达量显著高于QK1.2-S，整体来看也高于QK1.2+2.1-S；与细胞膨胀相关的基因Csa1G422480（木葡聚糖内转葡糖基酶基因）、Csa6G014540（扩张蛋白基因）、BR生物合成基因Csa1G524640和GA3调节基因Csa3G872170的定量分析结果却相反，在子房期Q30中的表达量显著低于3个近等基因系。随着果实发育，Q30的CsSUN表达水平与QK1.2-S和QK1.2+2.1-S差异逐渐缩小，CsLNG1与QK2.1-S和QK1.2+2.1-S差异也逐渐缩小，而Csa1G422480、Csa6G014540、Csa1G524640、Csa3G872170表达水平反而逐渐上升，后期甚至显著高于3个近等基因系。综上所述，CsSUN和CsLNG1控制Q30黄瓜细长果实是由于子房期抑制了细胞增大，导致细胞体积小，细胞密度增大；进入果实迅速增长期后该基因对细胞大小的抑制作用减弱，在原有数量基础上细胞逐渐变大，果实持续增长。     

High glucose induces down-regulation of BMP-7 expression in renal tubular epithelial cells through p38 MAPK pathway

AIM: To observe the BMP-7 expression in primary renal tubular epithelial cells cultured with high glucose and to investigate the role of p38MAPK signaling pathway.METHODS: The primary renal tubular epithelial cells were randomly treated with normal glucose, high glucose, co-incubation of high glucose with specific p38MAPK inhibitor SB202190 or D-mannitol for 72 h. The protein expression of BMP-7 and fibronectin (FN) in all the cells was assessed by the method of immunocytochemistry. The protein expression of p38MAPK and p-p38MAPK was determined by Western blotting. The mRNA expression of BMP-7 and FN was detected by RT-PCR.RESULTS: In normal glucose group, BMP-7 was highly expressed in the cytoplasm of tubular epithelial cells, and only small amounts of p38MAPK and FN, but not p-p38MAPK, were observed. High glucose was able to activate p38MAPK, and therefore the protein of p-p38MAPK increased remarkably in high glucose-treated cells. High glucose also enhanced FN production. Meanwhile, the expression of BMP-7 decreased. Co-incubation of high glucose with SB202190 for 72 h reduced the activity of p38MAPK by 80% and the FN expression was also decreased, while the BMP-7 expression significantly increased. No significant difference of the BMP-7 or FN expression between control group and D-mannitol group was observed.CONCLUSION: The expression of BMP-7 at mRNA and protein levels in renal tubular epithelial cells is decreased under the condition of high-glucose cultivation. Suppression of p38MAPK signaling pathway stimulates endogenous BMP-7 expression, indicating that p38MAPK pathway may be involved in the down-regulation of BMP-7 in renal tubular epithelial cells by high glucose.     

Protective effects of riboflavin on diabetic nephropathy in STZ-induced diabetic rats

AIM: To explore the protective effects of riboflavin on the kidney in streptozotocin (STZ)-induced diabetic rats. METHODS: Male Sprague-Dawley rats were randomly divided into 3 groups: normal control group, diabetic model group and riboflavin-treated group. Diabetes was induced by a single injection of STZ (dissolved in 0.01 mol/L citrate buffer, pH 4.5, 65 mg/kg, ip) in rats. The biochemical methods were used to measure the contents of urine protein and malondialdehyde in the kidney, and the activities of superoxide dismutase (SOD) and catalase (CAT) in serum and renal tissues. Furthermore, the protein expression of TGF-β1 and plasminogen activator inhibitor-1(PAI-1) in renal cortex was detected by Western blotting. The morphological changes of renal tissue were observed under microscope.RESULTS: Compared to the diabetic model group, riboflavin significantly increased the activities of SOD and CAT (P<0.01) in the serum and renal tissues, and decreased the contents of urine protein and MDA (P<0.01) in the renal tissues in riboflavin-treated group. The levels of TGF-β1 and PAI-1 in the renal cortex were dramatically decreased in the treated diabetic rats compared to the diabetic model rats (P<0.01).CONCLUSION: Riboflavin inhibits the protein expression of TGF-β1 and PAI-1 in renal tissue of STZ-induced diabetic rats. Riboflavin may alleviate the pathologic changes and play an important protective role in diabetic kidneys.     

Effects of rosiglitazone on expressions of peroxisome proliferator-activated receptor gamma and TGF-β1 in rats with adriamycin nephrosis

AIM: To investigate the expression of renal peroxisome proliferator-activated receptor gamma (PPARγ) in rats with adrimycine nephrosis (ADR), and the effect of rosiglitazone on the activation of NF-κB p65 in renal tissue rats with ADR. METHODS: The rats were randomly assigned to following groups: control (CTR) group, adrimycine nephrosis (ADR) group, and ADR treated with rosiglitazone (5 mg·kg^-1·d^-1) group（RGL）. The levels of urinary protein, albumin, total cholesterol, triglyceride and renal function change in rats were measured after 12 weeks. The nuclear-translocation of cortical NF-κB p65 was detected by immunohistochemistry. The activity of cortical NF-κB p65 was measured by sandwich ELISA. The mRNA levels of cortical PPARγ and TGF-β₁ were detected by RT-PCR. The protein expressions of PPARγ and TGF-β₁ in the rat kidney tissues were detected by Western blotting. RESULTS: As compared to ADR group, the urinary protein excretion in RGL treatment group was decreased and the serum albumin levels were increased, but the serum total cholesterol and triglyceride were decreased and the renal pathological lesion was ameliorated. The activity of NF-κB p65 and the expressions of TGF-β₁ mRNA and protein were significantly decreased in rosiglitazone group, while the expression of PPARγ mRNA and protein was increased in RGL group (P<0.01). The correlation analysis was manifested: in ADR and RGL group, a negative correlation between the activity of NF-κB p65 and the expression of PPARγ in renal tissue (r=-0.8305, P<0.01) was observed. There was a negative correlation between the expression of TGF-β₁ and PPARγ in renal tissues (r=－0.7938, P<0.01). CONCLUSION: The expression of renal cortical PPARγ is up-regulated in rats with adrimycine nephrosis by rosiglitazone. Rosiglitazone inhibits the activation of renal cortical NF-κB p65 in part, so it inhibits the gene expression of renal TGF-β₁ and relieves the renal pathological lesion.     

Grape seed proanthocyanidin regulates expression of GSTM through Nrf2 in renal tissues of STZ-induced diabetic rats

AIM: To investigate the potential mechanisms of renoprotective effect of grape seed proanthocyanidin (GSP) on diabetic nephropathy.METHODS: Male Wistar rats were injected with 1% streptozotocin (STZ) intravenously to induce diabetes mellitus (DM). The diabetic rats were randomly divided into 2 groups: diabetes group (DM group) and GSP treatment group (GSP group, GSP 250 mg·kg^-1·d^-1). The normal Wistar rats served as control (C group). Body weight (BW), systolic pressure, kidney weight/body weight (KW/BW), fasting plasma glucose (FPG), blood urea nitrogen (BUN), serum creatinine (SCr), glycosylated hemoglobin (HbA1c) and 24 h urine protein were determined 24 weeks after STZ intervention. The pathological changes of the renal tissues were observed. The protein levels of glutathione S-transferase mu (GSTM) and nuclear factor-erythroid 2-related factor 2 (Nrf2) in the renal tissues were determined by Western blotting and immunohistochemistry. RESULTS: Compared with C group, BW in diabetic rats decreased (P<0.01). The levels of systolic pressure, FPG, HbA1c, KW/BW, 24 h urine protein, BUN and SCr in DM group were higher than those in C group (P<0.01). After treated with GSP, the levels of systolic pressure, KW/BW, 24 h urine protein, BUN and SCr in DM rats were lower than those in DM rats without treatment (P<0.01 or P<0.05). The pathological changes were ameliorated in GSP group. The expression of GSTM and Nrf2 was up-regulated in the kidneys of diabetic rats and down-regulated to the normal levels after GSP treatment. CONCLUSION: The renoprotective effect of GSP is associated with the down-regulation of GSTM through modulating the expression of Nrf2.     

Role of focal adhesion kinase expression in renal tissues of type 2 diabetic rats

AIM：To explore the dynamic change of focal adhesion kinase (FAK) in renal tissues of rats with type 2 diabetes mellitus (T2DM), and to investigate its role in the pathogenesis of diabetic nephropathy (DN). METHODS：The rat model of T2DM was established and the diabetic rats were randomly divided into 8-week DM (DM8), 12-week DM (DM12) and 16-week DM (DM16) groups. Meanwhile, normal control (NC) and high-fat high-sucrose control (HC) groups were also established. The protein expression of FAK, transforming growth factor β1 (TGF-β1), extracellular signal-regulated kinase 1/2 (ERK1/2), p-ERK1/2 and fibronectin (FN) was detected by immunohistochemical staining. The protein levels of FAK and p-FAK (Tyr397) were detected by Western blotting. The mRNA level of FAK in the renal cortex was examined by RT-PCR. RESULTS：The expression of FAK protein in renal tubular epithelial cells in DM12 and DM16 groups was significantly higher than that in NC, HC and DM8 groups (P<0.05). Moreover, TGF-β1, p-ERK1/2 and FN protein expression in DM groups was significantly increased compared with NC and HC groups (P<0.05). The levels of FAK and p-FAK (Tyr397) in the renal cortex in DM12 and DM16 groups were significantly up-regulated compared with NC, HC and DM8 groups (P<0.05), and the expression trend of p-FAK in different groups was in accordance with that of total FAK. The FAK protein expression was positively correlated with the expression of TGF-β1, p-ERK1/2 and FN proteins (P<0.01). Compared with NC, HC and DM8 groups, the expression of FAK mRNA increased remarkably in DM12 and DM16 groups (P<0.05). CONCLUSION: There is a possibility that FAK is activated as a downstream effector of TGF-β1 in T2DM, which enhances the expression of FN protein through activating ERK1/2, and therefore plays an important role in the pathogenesis of type 2 diabetic nephropathy.     

Expression of zinc-finger transcription factor Snail 1 in the kidney of diabetic rats

AIM: To explore the expression of Snail 1 in renal tissues of diabetic rats, and to investigate its contribution to the progression of diabetic nephropathy. METHODS: Streptozotocin-induced diabetic rats were randomly divided into 2, 4, 8, 12, 16, 20, 24 weeks groups and 16 week A, 20 week A and 24 week A groups. A groups were treated with insulin to control blood glucose to normal level from the 13th week. Control groups were set up in age-matched time points. Blood glucose, 24 h urine protein, serum creatinine (Scr) and kidney index of rats were measured. Periodic acid-silver (PAS) staining was used to observe the renal pathological changes. The mRNA and protein expressions of Snail 1 and FN in renal cortex were detected by RT-PCR and immunohistochemical staining, respectively. Western blotting was employed to detect the expression of Snail 1 protein in the renal cortex. RESULTS: The levels of blood glucose, Scr, kidney weight index were increased remarkably in diabetic rats as compared with those in control groups (P<0.05, P<0.01), and decreased remarkably in the insulin-treated rats as compared with those in the diabetic rats (P<0.05, P<0.01). The Snail 1 protein was not detected by immunohistochemical staining in normal renal tissues. However, strongly positive staining was observed in renal tubules of diabetic rats. A time-dependent loss of Snail 1 expression was detected in the kidney in insulin-treated rats. The Snail 1 protein and mRNA of Snail 1 and FN were significantly up-regulated in the diabetic rats as compared with those in controls (P<0.01), while down-regulated in the insulin-treated diabetic rats (P<0.01). A close positive relationship existed between the mRNA expression of Snail 1 and FN (r=0.800, P<0.01). The level of Snail 1 protein expression was positively correlated with blood glucose, urine protein, Scr, kidney index (r=0.877, 0.694, 0.522, 0.875, P<0.01).CONCLUSION: These findings suggest that Snail 1 gene and protein expression are up-regulated in the kidney of rats with diabetes and may be involved in the pathogenesis of diabetic nephropathy.     

p38MAPK expression and apoptosis in the rat unilateral ureteral obstruction model

AIM: To investigate the expression of p38 mitogen-activated protein kinase (p38MAPK) in the kidney after unilateral ureteral obstruction (UUO) in rats and the functional role of it on apoptosis and fibrosis.METHODS: Eighteen Wistar rats underwent UUO were killed at 3, 7, 14 days. Additional 7 rats were sham operated. Histological changes were observed by HE and Masson staining. Immunohistochemistry study was performed on renal tissue for proliferating cell nuclear antigen (PCNA). Apoptotic cells were determined by terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling (TUNEL) and the electrophoresis analysis of genomic DNA. Western blotting of cysteinyl aspartate specific proteinase-3 (caspase-3), p38MAPK and p-p38MAPK were measured.RESULTS: UUO induced a significant increase in renal tubular and interstitial cell apoptosis, immunohistochemistry of PCNA and Western blotting of caspase-3, p-p38MAPK as well as severe morphology changes. However, there was no significant difference between UUO and the control in Western blotting of p38MAPK.CONCLUSION: An in vivo model of renal fibrosis after UUO demonstrates that activated or phosphorylated p38MAPK plays a role in apoptosis of renal tubulointerstitial cells.     

Expression and activation of NF-κB and carcinogenesis of cervical cancer

AIM:To evaluate the significance of NF-κB p65 protein expression in the development of human cervical squmous cell cancer.METHODS:Immunohistochemical analysis was done in 125 casas of paraffin-embedded cervical tissue specimens of different histological grades (32 LSILs,33 HSILs,38 SCCs and 22 normal) to evaluate the expression of RelA.Western blotting was used to analyze the level of NF-κB p65 protein.RESULTS:① By using immunohistochemical analysis,RelA was mainly localized in cytosol in normal cervical tissue and low-grade squamous intraepithelial lesions,whereas in high-grade lesions and squamous cell carcinomas,RelA translocated into the nucleus.② By Western blotting analysis,RelA was detected in the cytosolic extracts in normal or LSILs.In cancer tissues,the expression of RelA increased in nuclear extracts while their expression in the cytosolic extracts was relatively less.CONCLUSIONS:Constitutive activation of NF-κB p65 may lead to oncogenesis.NF-κB p65 may be a new target for the treatment of human cervical squmous cancer.     

Effects of PDS on rat brain cortical nuclear factor kappa B in LPS shock

AIM:To explore the molecular mechanism of brain tissue injury induced by lipopolysaccharide (LPS),the effects of panaxadiol (PDS) on the expression of nuclear factor kappa B (NF-κB) in cerebral cortex of rat with LPS shock were studied. METHODS:Rats were randomly divided into LPS roup,LPS+dexamethasone group,LPS+PDS group and control group. The DNA binding activity and protein expression of NF-κB were observed. These indices were assayed at 1 h and 4 h after intravenous injection of LPS (4 mg·kg^-1). RESULTS:EMSA showed that PDS inhibited NF-κB DNA-binding activity in nuclear extracts at both 1 h and 4 h after LPS injection,compared with the LPS group (P<0.01). Western blotting showed that PDS down-regulated the expression of p65 and p50 protein in the nuclear extracts compared with the LPS group. However,the expression of p65 and p50 protein from cytosolic extracts did not show any significant change. CONCLUSION:PDS may alleviate brain injury by inhibiting NF-κB activation.     

Expression and role of SnoN in kidney tissue of diabetic rats

AIM: To observe the changes of SnoN expression in renal tissues of diabetic rats, and to elucidate the role of co-repressor SnoN protein in the diabetic nephropathy. METHODS: Diabetic nephropathy was induced by intravenous injection of streptozotocin in male Sprague-Dawley rats. The model animals were divided into 2 weeks, 4 weeks and 8 weeks groups randomly. Meanwhile other 3 age-matched normal control groups were set up. The expressions of SnoN, TGF-β₁, Smad2/3, APC were detected by immunohistochemistry staining. The SnoN proteins in renal cortex were detected by Western blotting. Blood glucose, serum creatinine and 24 h urine protein were examined by biochemistry methods. The renal morphology was checked on PAS staining sections under light microscopy. RESULTS: The results of immunohistochemistry and Western blotting showed that the expression of SnoN in diabetic renal tissues at 2 weeks was the same as the normal kidney. There was a significant decrease in DM 4 weeks (P<0.01). A time dependent increases in TGF-β₁, Smad2/3 and APC were detected in the kidney of diabetic mellitus rats. The degree of SnoN down-regulation had close relation with the increases in TGF-β₁, Smad2/3 and APC. CONCLUSION: These results suggest that in the DM, renal increase in TGF-β₁ expression may down-regulate the SnoN expression through APC dependent degradation, indicating a key role in the mechanism of diabetic nephropathy.     

The expression of NF-κB and ICAM-1 in rat brain of experimental intracerebral hemorrhage and cerebral microvascular endothelial cells injured by hydrogen peroxide

AIM: To discuss the possible mechanism of the inflammation after intracerebral hemorrhage (ICH) and the relationship of nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM-1). METHODS: The expression of NF-κB and ICAM-1 were detected by immunohistochemistry, in situ hybridization, immunocytochemistry and Western blotting techniques in rat brain of experimental ICH and cerebral microvascular endothelial cells (RCMECs) injured by hydrogen peroxide. RESULTS: The expression of NF-κB p65 and ICAM-1 were up-regulated in rat brain after ICH. The ICAM-1 reached the peak at 1 day while the NF-κB at 4th day. NF-κB p65 expressed remarkably in cultured RCMECs immediately after injured by hydrogen peroxide, while ICAM-1 expressed remarkably　2 hours later. PDTC, an inhibitor of NF-κB, down-regulated the expression of NF-κB and ICAM-1. CONCLUSION: NF-κB induces the expression of ICAM-1 in RCMECs injured by reactive oxygen species (ROS).