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。     

Protective effect of adiponectin on glucose and lipid metabolism by suppressing MHCⅡ expression

AIM: To investigate whether the protective effect of adiponectin on glucose and lipid metabolism is achieved through down-regulating major histocompatibility complex class Ⅱ (MHCⅡ) in the adipose tissue. METHODS: Adiponectin knockout (KO) mice and C57BL/6(WT) mice were fed with high-fat diet and standard diet for 24 weeks, respectively. The body weight, fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hepatic histology, and class Ⅱ trans-activator (CⅡTA), histocompatibility 2 class Ⅱ antigen E beta (H2-Eb1) and cluster of differentiation 74(CD74) mRNA and MHC Ⅱ protein levels in adipose tissue were measured at sacrifice. siRNA targeting MHC Ⅱ and overexpression vector was used in 3T3-L1 cells to explore the effect of adiponectin on the protein level of MHCⅡ. RESULTS: The levels of body weight, FBG, FINS, HOMA-IR, TC, TG, LDL-C, hepatic steatosis, CⅡTA, H2-Eb1 and CD74 mRNA expression, and MHCⅡ protein expression in the KO mice were higher than those in the WT mice that fed with high-fat diet or standard diet. In 3T3-L1 cells, inhibition of adiponectin reversed MHC Ⅱ protein level induced by specific siRNA. The expression of MHC Ⅱ in adipocytes decreased after adiponectin was overexpressed. CONCLUSION: Adiponectin improves glucose and lipid metabolism through suppressing the expression of MHCⅡ in the adipose tissue.     

Expression of TGF-β1 and Smad2/3 in kidney of STZ-induced diabetic nephropathy rats

AIM: To study the role of TGF-β/Smad pathway in the development of renal fibrosis in diabetic nephropathy.METHODS: Rats were induced to diabetic nephropathy by using tail intravenous injection of STZ.The expression of TGF-β₁, Smad2/3 protein and mRNA in kidney were examined at 2, 4, 8 and 16 weeks after STZ induction.CTGF, collagen-Ⅲ, PAI-1 mRNA expression in kidney at 16 weeks of STZ-induced diabetic nephropathy and normal rats were studied by RT-PCR.RESULTS: Weak TGF-β₁, Smad2/3 protein were detected in normal renal tissues while strong TGF-β₁, Smad2/3 staining were observed in renal tissues of diabetic nephropathy (0.057±0.030/0.223±0.040;0.017±0.010/0.153±0.010, respectively, P<0.05).The TGF-β₁, Smad2/3 protein expression were constantly high with the development of diabetic nephropathy and fibrosis (0.153±0.010, 0.122±0.050, 0.141±0.070 and 0.216±0.030 for 2, 4, 8 and 16 weeks, respectively).The TGF-β₁, Smad2 mRNA expression also increased with the development of diabetic nephropathy (2.86, 3.25 fold compared to control, respectively).The expression of TGF-β₁, Smad2, CTGF, collagen-Ⅲ and PAI-1 mRNA were significantly higher in kidney of 16 week diabetic nephropathy rats than that in normal ones (3.92, 2.95, 1.57, 1.95 and 1.97 folds compare to control, respectively, P<0.05).CONCLUSION: The results indicate that TGF-β₁/ Smad2 pathway activity might play an important role in pathophysiological process of diabetic nephropathy.It may be involved in diabetic renal fibrosis through up-regulation of CTGF and PAI-1 to promote extracellular matrix deposition.     

Expression of LOX-1 in type 2 diabetic rat tubular interstitial tissues

AIM： To explore the effect of lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) on type 2 diabetic nephropathy in rats. METHODS：The Sprague-Dawley (SD) rats were randomly divided into control group and model group. The animal model was established by intraperitoneal injection of low-dose streptozotocin (STZ, 30 mg/kg) plus feeding with high-fat/high-glucose diets for one month. Biochemical parameters and 24 h urine album excretion rate (UAER) were monitored. The morphological changes of the renal tissue were examined under microscope with hematoxylin-eosin (HE) and periodic acid-Schiff reaction (PAS) staining. The protein levels of LOX-1 and transforming growth factor β1 (TGF-β1) in the renal tissues were determined by the method of immunohistochemistry. The mRNA expression of LOX-1 and TGF-β1 was detected by real-time polymerase chain reaction. The serum levels of monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule (ICAM) and tumor necrosis factor α(TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). The correlation between LOX-1 and UAER, inflammatory factors and TGF-β1 was analyzed. RESULTS：Compared with normal group, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and UAER in model groups markedly increased, high-density lipoprotein (HDL) only increased at 0 week, then decreased at 4 and 8 weeks. The expression of LOX-1 and TGF-β1 at mRNA and protein levels was increased, as well as the concentration of serum inflammatory factors such as MCP-1, ICAM and TNF-α. The obvious relations between LOX-l mRNA with UAER, TNF-α and TGF-β1 were observed (r=0.509, 0.649 and 0.800, respectively, P<0.05). CONCLUSION：LOX-1 is significantly increased in type 2 diabetic rat tubular interstitial tissues and aggravates the dysfunction of renal tubules by releasing inflammatory factors and promoting inflammatory cell infiltration.     

Influence of Xiaoke keli Ji on glycemia and serum lipoprotein levels in diabetic nephropathy rats

AIM:To observe the changes of glycemia and serum cholesterol and triglyceride in diabetic nephropathy rats and therapeutic effects of Xiaoke Keli Ji.METHODS:3/4 nephrectomy was adopted firstly, three weeks later streptozotocin(STZ) was administered intraperitoneally to establish diabetic nephropathy model in rats. Animals were divided into four groups:model group, Xiaoke Keli Ji treatment group, positive control group and sham group. Changes of serum sugar and serum creatinine, cholesterol and triglyceride were examined at 1, 2, 3, 4, 5 weeks after STZ injection. Renal tissue samples were adopted at 6th week and studied by light microscopy.RESULTS:Model group demonstrated different degree of glomerular sclerosis. Lesions in treatment group were alleviated. Serum creatinine, serum sugar and serum cholesterol were higher at 1, 2, 3, 4, 5 weeks after STZ injection in model group than that of the sham group (P＜0. 05), serum triglyceride was higher at 1, 2, 3, 5 weeks after STZ injection in model group than that of the sham group(P＜0. 05). Xiaoke Keli Ji reduced those changes. Serum sugar was in positive correlation with serum lipoprotein.CONCLUSION:Diabetic nephropathy model was duplicated successfully. High serum sugar may lead to high serum lipoprotein, Xiaoke Keli Ji may treat diabetic nephropathy by reducing serum sugar and serum cholesterol and triglyceride.     

Expression and probable role of extracellular signal-regulated protein kinases in renal fibrosis associated with diabetic in mice

AIM: To investigate the expression and probable role of extracellular signal-regulated protein kinase (ERK1/2) in renal fibrosis associated with diabetic in mice.METHODS: Male homozygous C57BL/6 mice were divided at random into control group (intraperitoneally injected with citrate buffer) and diabetes group (received 5 consecutive daily intraperitoneal injections of streptozotocin at dose of 50 mg·kg^-1·d^-1).All mice were followed up for 16 weeks.Diabetes was confirmed by serum glucose levels exceeding 16.7 mmol/L.Mice were killed at 0,4,8,12 and 16 weeks respectively after streptozotocin injection.The kidney tissues were obtained from diabetic and control mice.Serum glucose,kidney weight/body weight (KW/BW),24 h albumin excretion rate (UAE) and the serum creatinine (Scr) were measured.The kidney tissue was used for histological and morphometric studies of glomerular size,glomerular matrix expansion (PAS),and the expression of TGF-β₁,phosphorylated ERK1/2 and collagen Ⅲ by immunohistochemical staining.RESULTS: The serum level of glucose in streptozotocin -induced diabetic mice increased significantly.The kidney weight/body weight ratio,glomerular volume and glomerular matrix expansion in diabetic mice were obviously higher than those in control mice.Serum creatinine and 24 h albumin excretion rate in diabetic mice increased significantly compared with control mice.TGF-β₁,phosphorylated ERK1/2 and collagen Ⅲ levels were obviously increased in the kidney of diabetic mice compared with those in control mice (P<0.01).TGF-β₁ expression was positively related to the expression of phosphorylated ERK1/2.CONCLUSION: The overexpression of phosphorylated ERK1/2 in diabetic kidney may play an important role in the development of renal fibrosis associated with diabetic nephropathy in mice.     

Effect of erlotinib on renal injury in rats with STZ-induced diabetic nephropathy

AIM: To investigate the effect of epidermal growth factor receptor (EGFR) inhibitor erlotinib on kidney injury in diabetic nephropathy (DN) rat and the underlying mechanism. METHODS: The rat model of DN was induced by intraperitoneal injection of streptozotocin (STZ) at dose of 55 mg/kg. One week after STZ injection, the rats with blood glucose level exceeding 16.7 mmol/L were identified as diabetic. Diabetic rats were randomly divided into 2 groups:STZ group and STZ+erlotinib group. In addition, the normal rats were used as control group. The rats in STZ+erlotinib group were treated with erlotinib at 100 mg·kg^-1·d^-1 for 4 weeks(5th~8th week). The fasting blood glucose (FBG), serum creatinine (SCr) and 24 h urine protein were measured. The pathological changes of the kidney were observed by HE staining and Masson staining. The protein levels of EGFR, p-EGFR, transforming growth factor β1 (TGFβ1), Smad2/3, p-Smad2/3, collagen Ⅳ (ColⅣ) and fibronectin in the kidney tissues were determined by Western blot. The reactive oxygen species (ROS) level and malondialdehyde (MDA) content in the renal tissues were futher analyzed. RESULTS: Compared with control group, the levels of FBG, 24 h urine protein and Scr were significantly increased in STZ group (P<0.01). Compared with STZ group, the levels of FBG, 24 h urine protein and SCr in STZ+erlotinib group were markedly decreased (P<0.05). In additon, the glomerular structure was restored to normal, the proliferative degree of mesangial cells markedly attenuated, and the epithelial cells were in alignment in STZ+erlotinib group. Moreover, erlotinib significantly inhibited the protein levels of p-EGFR, TGFβ1, p-Smad2/3, ColⅣ and fibronectin in the kidney tissues of STZ rats. In addition, erlotinib also significantly inhibited the levels of ROS and MDA in the kidney tissues of STZ rats. CONCLUSION: Erlotinib ameliorates STZ-induced diabetic nephropathy possibly through inhibiting the activation of EGFR/TGFβ1-Smad2/3 signaling pathway in association with suppression of fibrosis and oxidative stress.     

Renal expression of ACE/AngⅡ in ACE2 knockout mice after tourniquet shock and its relationship with renal injury

AIM: To investigate the effect of angiotensin-converting enzyme 2 (ACE2) on tourniquet shock (TS)-induced acute renal injury by observing the renal expression of angiotensin-converting enzyme/angiotensin Ⅱ (ACE/AngⅡ) and injury severity in ACE2 knockout (KO) mice. METHODS: The TS animal model was produced by bilateral tourniquet ligation in the inguinal region on both hind legs for 2 h to induce ischemia, and reperfusion was initiated by cutting latex rings for 4 h. Six-month-old male wild-type (WT) and ACE2 KO C57BL/6 mice were selected, and divided into 4 groups (6 mice in each group) including WT group, WT+TS group, KO group and KO+TS group. The expression of ACE and AngⅡ in the renal tissues was determined by Western blotting and ELISA, respectively. The renal content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD), blood urea nitrogen (BUN) and serum creatinine (Cr) were measured by chemical colorimetry. RESULTS: Compared with WT group, the expression of ACE/AngⅡ was obviously increased in WT+TS group, and significant renal oxidative stress injury was also observed. The expression of ACE/AngⅡ was elevated in KO mice, but no significant renal oxidative stress injury was found. Compared with WT+TS group, more highly increased expression of ACE/AngⅡ and more aggravated renal injury were exhibited in KO+TS group. CONCLUSION: Deletion of ACE2 gene exacerbates TS-induced renal oxidative stress injury by increasing local ACE/AngⅡ expression. The agonist targeting to ACE2 may be helpful for prevention and treatment of TS-induced acute renal injury.     

Apocynin decreases cardiac cytokines in STZ-induced diabetic cardiomyopathy

AIM: This study was to investigate the effects of apocynin on the expression of IL-1β, IL-18, TNF-α and COX-2 mRNA in the diabetic cardiomyopathy heart.METHODS: Diabetes was induced in 8-week old C57 mice with one intraperitoneal injection of streptozotocin (STZ, 100 mg/kg). The experiments were divided into 4 groups: sham (n=6), apocynin control (Apo, n=6), diabetic cardiomyopathy (STZ, n=16) and apocynin treatment (STZ+Apo, n=16). At the end of 8 weeks after induction of diabetes, cardiac functions were evaluated by echocardiography. Cardiac tissue was analyzed for the expression of IL-1β, IL-18, TNF-α, COX-2 mRNA and phosphorylated Akt by real-time RT-PCR and Western blotting, respectively.RESULTS: The expression of IL-1β, IL-18, TNF-α and COX-2 mRNA increased in diabetic cardiomyopathy heart accompanied with cardiac dysfunction. Cardiac functions were improved with decreased levels of IL-1β, IL-18, TNF-α and COX-2 mRNA expression in apocynin-treated heart. Compared with reduction of phosphorylated Akt, apocynin significantly increased phosphorylation of Akt in diabetic cardiomyopathy heart.CONCLUSION: Apocynin decreases cardiac IL-1β, IL-18, TNF-α and COX-2 mRNA expression accompanied with improved cardiac function, which associates with the increase of phosphorylated Akt in diabetic cardiomyopathy heart.     

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 Api6 in lung inflammation induced by high fat/cholesterol food in C57BL/6J mice

AIM：To investigate the function of apoptosis inhibitor 6 (Api6) in lung inflammation induced by high-fat high-cholesterol diet (HFD/HCD) in male C57BL/6J mice. METHODS：Male C57BL/6J mice (6~8 weeks old) were randomly divided into 2 groups and treated with regular diet and HFD/HCD, respectively. After 16 weeks of feeding, the lung tissues were collected and the pulmonary inflammatory status was determined by immunohistochemistry and ELISA. The mRNA and protein expression levels of Api6 were determined by real-time PCR and Western blotting. The apoptotic rate of bronchioalveolar lavage cells was examined by flow cytometry. RAW264.7 cells were cultured in vitro and the apoptosis induced by oxidized low-density lipoprotein (oxLDL) was detected by flow cytometry. RESULTS：Accumulation of macrophages and increases in both tumor necrosis factor α and monocyte chemoattractant protein 1 were observed in the lung tissues of 16-week HFD/HCD-fed C57BL/6J mice. Compared with the regular diet-fed mice, the expression of Api6 at mRNA and protein levels in the lung tissues was highly increased in the HFD/HCD-fed mice (P<0.01). Meanwhile, the apoptotic rate of bronchioalveolar lavage macrophages from the HFD/HCD-fed mice was highly inhibited (P<0.01). In vitro, 500 μg/L recombinant Api6 significantly inhibited the apoptosis of RAW264.7 cells induced by oxLDL (P<0.05). CONCLUSION：HFD/HCD feeding results in the accumulation of macrophages in the lung of C57BL/6J mice, which may partly due to the increased expression of Api6 and its anti-apoptotic role in macrophages.     

Regulatory effect of RXR/VDR agonists on atherosclerosis and NF-κB expression in diabetic ApoE knockout mice

AIM：To explore the effect of retinoid X receptor (RXR) agonist bexarotene (Bex) and vitamin D receptor (VDR) agonist calcitriol (Cal) on the expression of nuclear factor-kappa B (NF-κB) and the development of atherosclerosis in streptozotocin-induced diabetic apolipoprotein E knockout (STZ-ApoE-/-) mice. METHODS：Male mice were treated for 12 weeks as follows: (1) C57+vehicle; (2) ApoE-/-+vehicle; (3) STZ-ApoE-/-+vehicle; (4) STZ-ApoE-/-+Bex (10 mg·kg-1·d-1); (5) STZ-ApoE-/-+Cal (10 μg/kg, twice a week); (6) STZ-ApoE-/-+Bex (10 mg·kg-1·d-1)+Cal (10 μg/kg, twice a week). Intraperitoneal injection of STZ was performed to establish the diabetic animal model. Western blotting and immunohistochemical method was used to detect NF-κB level in the thoracic aorta. Plaque area in the thoracic aorta was measured using HE staining. RESULTS：Compared with the C57 mice, the fasting blood glucose in the ApoE-/- mice was not remarkably changed. The levels of total cholesterol (TC) and low-density lipoprotein (LDL) were greatly increased. The fasting blood glucose and lipid levels in STZ-ApoE-/-group were much higher than those in ApoE-/- group. Compared with STZ-ApoE-/- group, the fasting blood glucose and lipid levels in Bex group and Cal group were not significantly changed. Compared with the C57 mice, the protein expression of NF-κB in the ApoE-/- mice and the STZ-ApoE-/- mice was remarkably increased. Compared with STZ-ApoE-/- group, the levels of NF-κB in Bex group, Cal group and combination group were greatly decreased.Compared with STZ-ApoE-/- group, the thoracic artery plaque areas in Bex group and Cal group were inhibited (both P<005). Compared with Bex group, the plaque area of the thoracic artery in combination group was significantly decreased (P<005). CONCLUSION：Bexarotene or calcitriol decreases the development of atherosclerosis in streptozotocin-induced diabetic ApoE-/- mice. Bexarotene combined with calcitriol affords greater protection than monotherapy. The mechanism may be involved in down-regulating the expression of NF-κB.     

Inhibition of Rac1 protects cardiac functions in STZ-induced diabetic cardiomyopathy through decreasing pho-p38 MAPK

AIM: To investigate the effects of Rac1 inhibition on the size of cardiomyocytes and left ventricular functions in diabetic cardiomyopathy. METHODS: Type 1 diabetes was induced in 8-week old C57 mice by streptozotocin (STZ, ip injection). Diabetic mice were treated with NSC23766, a specific inhibitor of Rac1 (STZ+NSC group, n=15) or without treatment (STZ group, n=15). Nondiabetic mice were used to serve as empty control (Con group, n=10) or NSC23766 control (NSC group, n=10). The survival rate, LVHW/BW and left ventricular functions were detected at the end of 8 weeks after induction of diabetes. The expression of ANP, BNP, β-MHC and pho-p38 MAPK in the cardiac tissues were analyzed by real-time RT-PCR and Western blotting, respectively. Hematoxylin and Eosin staining (HE) was used to measure the cell size in the cardiac tissues. RESULTS: The functions of left ventricle were significantly impaired in the diabetic animals with decreased survival rate and increased LVHW/BW, which was accompanied by significant increases in ANP, BNP and β-MHC, and elevated pho-p38 MAPK expression in diabetic hearts. The increased survival rate, improved left ventricular functions and decreased LVHW/BW were observed in the diabetic animals treated with NSC. The mRNA expression of ANP, BNP, β-MHC and pho-p38 MAPK was significantly attenuated in the diabetic hearts by NSC treatment. The size of the cardiomyocytes, which increased in diabetic hearts, was decreased in the NSC-treated diabetic cardiac tissue. CONCLUSION: Rac1 inhibition protects left ventricular functions and attenuates hypertrophy, which is associated with the decrease in pho-p38 MAPK expression in diabetic heart. These data suggest that inhibition of Rac1 might be beneficial to diabetic cardiomyopathy.     

Effects of phospholipid transfer protein overexpression on content of sphingosine-1-phosphate in mouse lipoprotein

AIM：To investigate the interaction and the mechanism of sphingosine-1-phosphate (S1P) and phospholipid transfer protein (PLTP) in lipoprotein. METHODS：The S1P content in the plasma and lipoprotein from 10-week-old PLTP transgenic (PLTP-Tg) mice and wild-type (WT) mice (n=8 each) was assayed. The transport of S1P by PLTP was determined by S1P transfer assay. The content of specific S1P carrier, apolipoprotein M, was detected by Western blotting. RESULTS：Plasma S1P contents were decreased by 21.1% in PLTP-Tg mice compared with WT mice. S1P content in high-density lipoprotein (HDL) fraction (HDL-S1P) from PLTP-Tg mice was decreased by 35.1% compared with WT mice, whereas the S1P in low-density lipoprotein (LDL) fraction (LDL-S1P) was increased by 127.4%. The results of S1P transfer assay indicated that PLTP facilitated S1P transport from erythrocyte to recombinant liposome at 37 ℃ in D-Hanks buffer solution. The plasma content of apolipoprotein M was not changed in PLTP-Tg mice compared with WT mice. CONCLUSION：PLTP is a key factor to maintain plasma HDL-S1P under physical condition. Overexpression of PLTP decreases the HDL-S1P but increases LDL-S1P. The mechanism might be related to the capability of PLTP on transferring S1P from erythrocyte to lipoprotein.     

Protective effect of curcumin on myocardium in diabetic rats

AIM: To study the effects of curcumin (Cur) on diabetic cardiomyopathy (DCM) in rats. METHODS: Male Wistar rats (n=75) were divided into control group and diabetes model group, in which the rats were fed with high-fat diet and then intraperitoneally injected with streptozotocin (STZ, 40 mg/kg). Fasting blood glucose was measured 72 h and 1 week after STZ injection. The diabetic rats were diagnosed when sustained fasting blood glucose levels ≥ 11.6 mmol/L. The diabetic rats were randomly divided into DCM group, DCM+Cur 100 mg/kg group and DCM+Cur 200 mg/kg group. After treatment for 16 weeks, glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) level were measured, and the level of cardiac troponin I (cTnI) in the serum was determined by enzyme-linked immunosorbent assay. The protein expression of protein kinase C (PKC) was detected by Western blotting. RESULTS: Curcumin significantly decreased the blood glucose level, increased the body weight, inhibited MDA content and up-regulated the GSH-Px activity in the diabetic rats. Furthermore, curcumin treatment inhibited the diabetes-induced protein expression of PKC. CONCLUSION: Curcumin may have a protective effect on diabetic cardiomyopathy by attenuating oxidative stress.     

Effect of astragalus polysaccharin on expression of nephrin and podocin in podocytes of early diabetic nephropathy rats

AIM: To observe the effects of astragalus polysaccharin (APS) on the expression of nephrin and podocin in podocytes of diabetic nephropathy (DN) rats.METHODS: The rat model of diabetes was induced by intraperitoneal injection of streptozotocin (STZ).The diabetic rats were randomly divided into 2 groups by the treatment without or with APS: STZ group (n=8) and STZ+APS group (n=8).In addition, 8 non-treated rats served as control.All the rats were treated with APS or normal saline orally by gavage for 8 weeks.The concentration of blood glucose was monitored on week 2, 5 and 8 after treatment.Eight weeks later, the body weight and renal index were measured.Total urine protein in 24 h, blood urea nitrogen (BUN) and serum creatinine (SCr) were detected by biochemical methods.The pathological changes of the kidneys were also observed under light microscope.The protein levels of nephrin and podocin in the kidney tissues were also determined by Western blotting.RESULTS: After APS intervention, the levels of renal index, blood glucose concentration, 24-hour total urine protein, BUN and SCr were significantly lower and body weight was higher than those in STZ group (P<0.05).The renal pathological status in APS group was significantly improved and the expression levels of nephrin and podocin also markedly increased (P<0.05).CONCLUSION: APS might protect kidney against STZ-induced injury via increasing the expression of nephrin and podocin in podocytes.     

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.     

Expression of scavenger receptor B1 (SR-B1) in the liver of high fat and sugar diet-induced diabetic mice

AIM: To investigate serum lipid and the expression of SR-B1 in the livers of diabetic mice. METHODS: Ten normal diet, female C57BL/6J mice, fifteen high fat and sugar diet female C57BL/6J mice, five fed 8 weeks and ten fed 16 weeks were used in the experiment. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), insulin (INS) and the expression of SR-B1 in the livers were measured. RESULTS: 1. In the high fat and sugar diet mice, serum TC and FBG at 16 weeks were significantly higher than that in normal diet mice (P<0.05). 2. The expression of SR-B1 protein in the liver of high fat and sugar diet mice was the higher than that in normal mice, and the SR-B1 expression in the liver of the mouse fed 16 weeks was also higher than that fed 8 weeks. CONCLUSION: The expression of SR-B1 protein in the liver of type 2 diabetes mice is higher than that in normal mice, perhaps it is related to the decrease in serum HDL-C.     

Expression of p-p38 MAPK in partial cerebral tissues after hypoxic-ischemic brain damage in neonatal A2AR knockout mice

AIM： To study the expression of p-p38 MAPK in partial cerebral tissues after hypoxic-ischemic brain damage (HIBD) in the neonatal adenosine A2A receptor knockout (A2AR-/-) mice. METHODS：Base on the modified Rice method, the model of HIBD was established. The total 64 C57/BL6 neonatal mice (7 days old) of A2AR-/-(KO) and corresponding wild type (A2AR+/+, WT) were randomized into sham-operated group and model group. The mice in model group were divided into 3 subgroups： 1 d after HIBD, 3 d after HIBD and 7 d after HIBD (n=8 for each group). The cortex and hippocampal CA1 region were used as the study areas. The neuronal apoptosis was detected using TUNEL assay combined with Nissl staining. The expression of p-p38 MAPK and activated caspase-3 was determined by the method of immunohistochemistry. The KO mice and WT mice were also taken from sham-operated group (SKO and SWT, n=10) and model group (MKO and MWT, n=30) 1 d after HIBD to assess the early neurological behavior. RESULTS：The apoptotic neurons, activated caspase-3 and p-p38 MAPK increased after HIBD and peaked at 1 d after HIBD in the cortex and the hippocampal CA1 region. The apoptotic neurons and the expression of activated caspase-3 in KO mice were significantly higher than those in WT mice at the same time point after HIBD. The expression level of p-p38 MAPK in KO mice were significantly higher than that in WT mice at 1 d and 3 d after HIBD. The expression of activated caspase-3 was positively correlated with the expression of p-p38 MAPK in neonatal mice after HIBD (in the cortex：r=0.957, P<0.01; in the hippocampal CA1 region： r=0.939, P<0.01). CONCLUSION：p-p38 MAPK might be involved in the aggravated neuron apoptosis and brain damage induced by A2AR knockout after neonatal HIBO.     

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.