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

PURPOSE: Proliferation of vascular smooth muscle cells (VSMCs) plays a crucial role in atherosclerosis. Rutin is a major representative of the flavonol subclass of flavonoids and has various pharmacological activities. Currently, data are lacking regarding its effects on VSMC proliferation induced by intermittent hyperglycemia. Here, we demonstrate the effects of rutin on VSMC proliferation and migration according to fluctuating glucose levels. MATERIALS AND METHODS: Primary cultures of male Otsuka Long-Evans Tokushima Fatty (OLETF) rat VSMCs were obtained from enzymatically dissociated rat thoracic aortas. VSMCs were incubated for 72 h with alternating normal (5.5 mmol/L) and high (25.0 mmol/L) glucose media every 12 h. Proliferation and migration of VSMCs, the proliferative molecular pathway [including p44/42 mitogen-activated protein kinases (MAPK), mitogen-activated protein kinase kinase 1/2 (MEK1/2), p38 MAPK, phosphoinositide 3-kinase (PI3K), c-Jun N-terminal protein kinase (JNK), nuclear factor kappa B (NF-kappaB), and Akt], the migratory pathway (big MAPK 1, BMK1), reactive oxygen species (ROS), and apoptotic pathway were analyzed. RESULTS: We found enhanced proliferation and migration of VSMCs when cells were incubated in intermittent high glucose conditions, compared to normal glucose. These effects were lowered upon rutin treatment. Intermittent treatment with high glucose for 72 h increased the expression of phospho-p44/42 MAPK (extracellular signal regulated kinase 1/2, ERK1/2), phospho-MEK1/2, phospho-PI3K, phospho-NF-kappaB, phospho-BMK1, and ROS, compared to treatment with normal glucose. These effects were suppressed by rutin. Phospho-p38 MAPK, phospho-Akt, JNK, and apoptotic pathways [B-cell lymphoma (Bcl)-xL, Bcl-2, phospho-Bad, and caspase-3] were not affected by fluctuations in glucose levels. CONCLUSION: Fluctuating glucose levels increased proliferation and migration of OLETF rat VSMCs via MAPK (ERK1/2), BMK1, PI3K, and NF-kappaB pathways. These effects were inhibited by the antioxidant rutin.
Animals ; Caspase 3/metabolism ; Cell Movement/*drug effects ; Cell Proliferation/*drug effects ; Flavonoids/*pharmacology ; Glucose/*metabolism/pharmacology ; JNK Mitogen-Activated Protein Kinases ; MAP Kinase Kinase 1 ; Male ; Mitogen-Activated Protein Kinase 3 ; Muscle, Smooth, Vascular/cytology/*drug effects/enzymology ; Myocytes, Smooth Muscle/metabolism ; NF-kappa B/metabolism ; Phosphatidylinositol 3-Kinases ; Protein Kinase Inhibitors/*pharmacology ; Rats ; Rats, Inbred OLETF ; Rats, Long-Evans ; Reactive Oxygen Species/metabolism ; Rutin/*pharmacology ; p38 Mitogen-Activated Protein Kinases/metabolism

Cartilage oligomeric matrix protein-angiopoietin-1 (COMP-Ang1) is an angiogenic factor for vascular angiogenesis. The aim was to investigate the effect of an intracavernosal injection of COMP-Ang1 on cavernosal angiogenesis in a diabetic rat model. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats made up the experimental group (1 yr old) and Long-Evans Tokushima Otsuka (LETO) rats made up the control group. The experimental group was divided into vehicle only, 10 microg COMP-Ang1, and 20 microg COMP-Ang1. COMP-Ang1 was injected into the corpus cavernosum of the penis. After 4 weeks, the penile tissues of the rats were obtained for immunohistochemistry and Western blot analysis. The immunoreactivity of PECAM-1 and VEGF was increased in the COMP-Ang1 group compared with the vehicle only group. Moreover, the expression of PECAM-1 and VEGF was notably augmented in the 20 microg Comp Ang-1 group. In the immunoblotting study, the expression of PECAM-1 and VEGF protein was significantly less in the OLEFT rats than in the control LETO rats. However, this expression was restored to control level after intracavernosal injection of COMP-Ang1. These results show that an intracavernosal injection of COMP-Ang1 enhances cavernous angiogenesis by structurally reinforcing the cavernosal endothelium.
Angiopoietin-1/genetics/*metabolism ; Animals ; Antigens, CD31/metabolism ; Blood Glucose/analysis ; Blotting, Western ; Body Weight ; Cartilage Oligomeric Matrix Protein/genetics/*metabolism ; Diabetes Mellitus, Experimental/*pathology ; Immunohistochemistry ; Male ; Neovascularization, Physiologic/*drug effects ; Penis/metabolism/pathology ; Rats ; Rats, Long-Evans ; Recombinant Fusion Proteins/biosynthesis/genetics/*pharmacology ; Vascular Endothelial Growth Factor A/metabolism

OBJECTIVETo explore electrophysiology mechanism of acupuncture for treatment and prevention of visual deprivation effect.

METHODSEighteen healthy 15-day Evans rats were randomly divided into a normal group, a model group and an acupuncture group, 6 rats in each one. Deprivation amblyopia model was established by monocular eyelid suture in the model group and acupuncture group. Acupuncture was applied at "Jingming" (BL 1), "Chengqi" (ST 1), "Qiuhou" (EX-HN 7) and "Cuanzhu" (BL 2) in the acupuncture group. The bilateral acupoints were selected alternately, one side for a day, and totally 14 days were required. The effect of acupuncture on visual evoked potential in different spatial frequencies was observed.

METHODSUnder three different kinds of spatial frequencies of 2 X 2, 4 X 4 and 8 X 8, compared with normal group, there was obvious visual deprivation effect in the model group where P1 peak latency was delayed (P<0.01) while N1 -P1 amplitude value was decreased (P<0.01). Compared with model group, P1 peak latency was obviously ahead of time (P<0.01) while N1-P1 amplitude value was increased (P<0.01) in the acupuncture group, there was no statistical significance compared with normal group (P>0.05). Under spatial frequency of 4 X 4, N1-P1 amplitude value was maximum in the normal group and acupuncture group. With this spatial frequency the rat's eye had best resolving ability, indicating it could be the best spatial frequency for rat visual system.

CONCLUSIONThe visual system has obvious electrophysiology plasticity in sensitive period. Acupuncture treatment could adjust visual deprivation-induced suppression and slow of visual response in order to antagonism deprivation effect.

Acupuncture Points ; Acupuncture Therapy ; Amblyopia ; physiopathology ; therapy ; Animals ; Evoked Potentials, Visual ; Female ; Humans ; Male ; Rats ; Rats, Long-Evans

Although peroxisome proliferator receptor (PPAR)-alpha and PPAR-gamma agonist have been developed as chemical tools to uncover biological roles for the PPARs such as lipid and carbohydrate metabolism, PPAR-delta has not been fully investigated. In this study, we examined the effects of the PPAR-delta agonist GW0742 on fatty liver changes and inflammatory markers. We investigated the effects of PPAR-delta agonist GW0742 on fatty liver changes in OLETF rats. Intrahepatic triglyceride contents and expression of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and monocyte chemo-attractant protein-1 (MCP-1) and also, PPAR-gamma coactivator (PGC)-1alpha gene were evaluated in liver tissues of OLETF rats and HepG2 cells after GW0742 treatment. The level of TNF-alpha and MCP-1 was also examined in supernatant of Raw264. 7 cell culture. To address the effects of GW0742 on insulin signaling, we performed in vitro study with AML12 mouse hepatocytes. Rats treated with GW0742 (10 mg/kg/day) from 26 to 36 weeks showed improvement in fatty infiltration of the liver. In liver tissues, mRNA expressions of TNF-alpha, MCP-1, and PGC-1alpha were significantly decreased in diabetic rats treated with GW0742 compared to diabetic control rats. We also observed that GW0742 had inhibitory effects on palmitic acid-induced fatty accumulation and inflammatory markers in HepG2 and Raw264.7 cells. The expression level of Akt and IRS-1 was significantly increased by treatment with GW0742. The PPAR-delta agonist may attenuate hepatic fat accumulation through anti-inflammatory mechanism, reducing hepatic PGC-1alpha gene expression, and improvement of insulin signaling.
Animals ; Anti-Inflammatory Agents/*pharmacology/therapeutic use ; Blood Glucose ; Cytokines/genetics/metabolism ; Diabetes Mellitus/blood/immunology/metabolism ; Fatty Liver/blood/*drug therapy/immunology ; Glucose Tolerance Test ; Hep G2 Cells ; Humans ; Insulin Resistance ; Liver/metabolism ; Male ; PPAR delta/*agonists/metabolism ; Rats ; Rats, Long-Evans ; Thiazoles/*pharmacology/therapeutic use ; Triglycerides/metabolism

This study aimed to determine whether taurine supplementation improves metabolic disturbances and diabetic complications in an animal model for type 2 diabetes. We investigated whether taurine has therapeutic effects on glucose metabolism, lipid metabolism, and diabetic complications in Otsuka Long-Evans Tokushima fatty (OLETF) rats with long-term duration of diabetes. Fourteen 50-week-old OLETF rats with chronic diabetes were fed a diet supplemented with taurine (2%) or a non-supplemented control diet for 12 weeks. Taurine reduced blood glucose levels over 12 weeks, and improved OGTT outcomes at 6 weeks after taurine supplementation, in OLETF rats. Taurine significantly reduced insulin resistance but did not improve beta-cell function or islet mass. After 12 weeks, taurine significantly decreased serum levels of lipids such as triglyceride, cholesterol, high density lipoprotein cholesterol, and low density lipoprotein cholesterol. Taurine significantly reduced serum leptin, but not adiponectin levels. However, taurine had no therapeutic effect on damaged tissues. Taurine ameliorated hyperglycemia and dyslipidemia, at least in part, by improving insulin sensitivity and leptin modulation in OLETF rats with long-term diabetes. Additional study is needed to investigate whether taurine has the same beneficial effects in human diabetic patients.
Adipokines/blood ; Animals ; Blood Glucose ; Diabetes Mellitus, Type 2/drug therapy ; Dietary Supplements ; Dyslipidemias/blood/*drug therapy ; Glucose Tolerance Test ; Hyperglycemia/blood/*drug therapy ; Hypoglycemic Agents/administration & dosage/*pharmacology ; Hypolipidemic Agents/administration & dosage/*pharmacology ; Insulin/physiology/secretion ; Insulin Resistance ; Insulin-Secreting Cells/physiology/secretion ; Leptin/*blood ; Lipid Metabolism/drug effects ; Lipids/blood ; Male ; Organ Specificity ; Rats ; Rats, Long-Evans ; Taurine/administration & dosage/*pharmacology

OBJECTIVETo investigate the association between plasma adiponectin and insulin resistance in OLETF rats.

METHODSTwenty male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and 10 male Long-evans Tokushima Otsuka (LETO) rats underwent oral glucose tolerance test (OGTT) at 13 and 40 weeks of age. At 8, 32 and 40 weeks of age, the rats were sacrificed to measure the blood glucose, plasma insulin and adiponectin levels, and serum levels of TG, CHOL and FFA.

RESULTSThe plasma adiponectin level was significantly decreased in 8-week-old OLETF rats compared with that of LETO rats (P<0.05). The plasma insulin level, TG, CHOL, and FFA were significantly higher in OLETF rats than in LETO rats at 32 and 40 weeks of age.

CONCLUSIONA decreased plasma level of adiponectin preludes insulin resistance and is inversely correlated to insulin sensitivity. Hypoadiponectinemia may be an important reason leading to insulin resistance.

Adiponectin ; blood ; Animals ; Diabetes Mellitus, Type 2 ; blood ; metabolism ; Insulin ; pharmacology ; Insulin Resistance ; Male ; Rats ; Rats, Inbred OLETF ; Rats, Long-Evans

PURPOSE: Obesity is a risk factor for asthma and type II diabetes. Peroxisome proliferator-activated receptor (PPAR)-gamma has been suggested to regulate inflammatory responses in diabetes and asthma. We investigated whether PPAR-alpha, PPAR-gamma, adiponectin receptors (AdipoR1, AdipoR2), leptin, and tumor necrosis factor (TNF)-alpha are expressed in rat lung tissues and whether the expression differs between obese Otsuka Long-Evans Tokushima Fatty (OLETF) and lean Long Evans Tokushima Otsuka (LETO) rats. MATERIALS AND METHODS: Obese and lean rats were given with a high fat diet or a 30% restricted diet for 32 weeks, and their blood glucose levels and weights were monitored. After 32 weeks, mRNA levels of PPAR-alpha, PPAR-gamma, AdipoR1, AdipoR2, leptin, and TNF-alpha in lung tissues were measured using real time PCR. RESULTS: PPAR-alpha, PPAR-gamma, AdipoR1, AdipoR2, leptin, and TNF-alpha were expressed in both obese and lean rat lung tissues. Increased serum glucose levels on intraperitoneal glucose tolerance testing and a higher weight gain at 32 weeks were observed in OLETF control rats compared to OLETF diet restricted rats. PPAR-gamma expression was markedly elevated in obese control and diet restricted rats compared to lean rats, although PPAR-gamma expression in obese rats was not affected by diet restriction. Leptin was highly expressed in OLETF rats compared to LETO rats. TNF-alpha expression was enhanced in OLETF control rats compared LETO diet restricted rats, and decreased by diet restriction. PPAR-alpha, AdipoR1, and AdipoR2 expression were not significantly different between obese and lean rats. CONCLUSION: PPAR-gamma was highly expressed in the lung tissues of obese rats and may be a novel treatment target for regulating lung inflammation associated with obesity.
Animals ; Body Weight ; Glucose Tolerance Test ; Leptin/genetics/metabolism ; Lung/*metabolism ; Male ; Obesity/genetics/*metabolism ; PPAR gamma/genetics/*metabolism ; RNA, Messenger/metabolism ; Rats ; Rats, Long-Evans ; Receptors, Adiponectin/genetics/metabolism ; Tumor Necrosis Factor-alpha/genetics/metabolism

OBJECTIVE: To observe the effects of N-acetyl-L-cysteine (L-NAC) protect hair cells in the rat cochlea from injury of exposure to styrene. METHOD: Seventeen adult Long Evans rats were used in present study. The animals were randomly assigned into test group (n=9) and control group (n=8). The animals were exposed to styrene by gavage at 400 mg/kg (2 g styrene was mixed with 1 ml olive oil). Test group animals received styrene exposure plus L-NAC 325 mg/kg (L-NAC was dissolved in physiological saline solution) by intraperitoneal injection. Treatment was performed once a day, 5 days per week for 3 weeks. Control group animals received the same volume of saline injection on an identical time schedule used for the test group. The auditory brainstem response (ABR) thresholds of both ears elicited with clicks were measured before and at the end of the 3-week styrene or styrene plus L-NAC treatment. After hearing was re-assessed, animals were sacrificed and cochleae were quickly removed from the skull. Following fixation, whole specimens comprising the basilar membrane with Corti's organ were separated from the modiolus. The organs of Corti were stained with propidium iodide (PI) and the TUNEL assay to visualize the morphologic viability of hair cell nuclei, FITC-labeled phalloidin, a F-actin intercalating fluorescent probe used to visualize the morphologic viability of cuticular plate and the stereocilia in the hair cells. Each organ of Corti was thoroughly examined using fluorescence microscopy. The numbers of damaged OHCs (apoptotic, necrotic and missing OHCs) were documented. RESULT: There was a statistically significant decrease in ABR threshold shift (P<0.05) in the styrene-plus-L-NAC treated animals. The average percentage of damaged OHCs in the styrene-treated animals was 28.3%. In contrast, the average percentage of OHC damage in the styrene-plus-L-NAC treated group was only 10.6% (P<0.01). The percentage of reduction in the number of apoptotic cells in styrene-plus-L-NAC treated group was 78% (P<0.01). However, the mean reduction of necrotic cells was only 23% (P>0.05). CONCLUSION The results indicate that the treatment with L-NAC may effectively protect against the styrene-induced hair cells damage and preferably reduce the number of apoptotic OHCs.
Acetylcysteine ; analogs & derivatives ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Cochlea ; cytology ; drug effects ; Evoked Potentials, Auditory, Brain Stem ; Hair Cells, Auditory ; drug effects ; pathology ; Lysine ; analogs & derivatives ; pharmacology ; Rats ; Rats, Long-Evans ; Styrene ; adverse effects

BACKGROUNDMany studies have suggested that the imbalance of angiogenic factor and anti-angiogenic factor expression contributes significantly to the development of choroidal neovascularization (CNV), and ultrasound microbubble combination system can increase the gene transfection efficiency successfully. This study was designed to investigate whether ultrasound-mediated microbubble destruction could effectively deliver therapeutic plasmid into the retina of rat, and whether gene transfer of pigment epithelium-derived factor (PEDF) could inhibit CNV.

METHODSHuman retinal pigment epithelial cells were isolated and treated either with ultrasound or plasmid alone, or with a combination of plasmid, ultrasound and microbubbles to approach feasibility of microbubble-enhanced ultrasound enhance PEDF gene expression; For in vivo animal studies, CNV was induced by argon lasgon laser in rats. These rats were randomly assigned to five groups and were treated by infusing microbubbles attached with the naked plasmid DNA of PEDF into the vitreous of rats followed by immediate ultrasound exposure (intravitreal injection); infusing liposomes with the naked plasmid DNA of PEDF into the vitreous (lipofectamine + PEDF); infusing microbubbles attached with PEDF into the orbit of rats with ultrasound irradiation immediately (retrobular injection); infusing microbubbles attached with PEDF into the femoral vein of rats with exposed to ultrasound immediately (vein injection). The CNV rats without any treatment served as control. Rats were sacrificed and eyes were enucleated at 7, 14, and 28 days after treatment. Gene and protein expression of PEDF was detected by quantitative real-time RT-PCR, Western blotting and immunofluorescence staining, respectively. The effect of PEDF gene transfer on CNV was examined by fluorescein fundus angiography.

RESULTSIn vitro cell experiments showed that microbubbles with ultrasound irradiation could significantly enhance PEDF delivery as compared with microbubbles or ultrasound alone. In the rat CNV model, transfection efficiency mediated by ultrasound/microbubbles was significantly higher than that by lipofectamine-mediated gene transfer at 28 days after treatment. The study also showed that with the administration of ultrasound-mediated microbubbles destruction, the CNV of rats was inhibited effectively.

CONCLUSIONSUltrasound-microbubble technique could increase PEDF gene transfer into rats' retina and chorioid, in association with a significant inhibition of the development of CNV, suggesting that this noninvasive gene transfer method may provide a useful tool for clinical gene therapy.

Animals ; Cells, Cultured ; Choroidal Neovascularization ; prevention & control ; Eye Proteins ; genetics ; Female ; Genetic Therapy ; Humans ; Microbubbles ; Nerve Growth Factors ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Long-Evans ; Retina ; metabolism ; Serpins ; genetics ; Transfection ; Ultrasonics