Netrin-3 Suppresses Diabetic Neuropathic Pain by Gating the Intra-epidermal Sprouting of Sensory Axons / 神经科学通报·英文版

Diabetic neuropathic pain (DNP) is the most common disabling complication of diabetes. Emerging evidence has linked the pathogenesis of DNP to the aberrant sprouting of sensory axons into the epidermal area; however, the underlying molecular events remain poorly understood. Here we found that an axon guidance molecule, Netrin-3 (Ntn-3), was expressed in the sensory neurons of mouse dorsal root ganglia (DRGs), and downregulation of Ntn-3 expression was highly correlated with the severity of DNP in a diabetic mouse model. Genetic ablation of Ntn-3 increased the intra-epidermal sprouting of sensory axons and worsened the DNP in diabetic mice. In contrast, the elevation of Ntn-3 levels in DRGs significantly inhibited the intra-epidermal axon sprouting and alleviated DNP in diabetic mice. In conclusion, our studies identified Ntn-3 as an important regulator of DNP pathogenesis by gating the aberrant sprouting of sensory axons, indicating that Ntn-3 is a potential druggable target for DNP treatment.

Protective effect of ginsenoside Rg_1 aganist diabetic retinopathy by inhibiting NLRP3 inflammasome in type 2 diabetic mice / 中国中药杂志

Ginsenoside Rg_1, one of the main active components of precious traditional Chinese medicine Ginseng Radix et Rhizoma, has the anti-oxidative stress, anti-inflammation, anti-aging, neuroprotection, and other pharmacological effects. Diabetic retinopathy(DR), the most common complication of diabetes, is also the main cause of impaired vision and blindness in the middle-aged and the elderly. The latest research shows that ginsenoside Rg_1 can protect patients against DR, but the protection and the mechanism are rarely studied. This study mainly explored the protective effect of ginsenoside Rg_1 against DR in type 2 diabetic mice and the mechanism. High fat diet(HFD) and streptozotocin(STZ) were used to induce type 2 diabetes in mice, and hematoxylin-eosin(HE) staining was employed to observe pathological changes in the retina of mice. The immunohistochemistry was applied to study the localization and expression of nucleotide-binding oligomerization domain-like receptors 3(NLRP3) and vascular endothelial growth factor(VEGF) in retina, and Western blot was used to detect the expression of nuclear factor-kappa B(NF-κB), p-NF-κB, NLRP3, caspase-1, interleukin-1β(IL-1β), transient receptor potential channel protein 6(TRPC6), nuclear factor of activated T-cell 2(NFAT2), and VEGF in retina. The results showed that ginsenoside Rg_1 significantly alleviated the pathological injury of retina in type 2 diabetic mice. Immunohistochemistry results demonstrated that ginsenoside Rg_1 significantly decreased the expression of NLRP3 and VEGF in retinal ganglion cells, middle plexiform layer, and outer plexiform layer in type 2 diabetic mice. According to the Western blot results, ginsenoside Rg_1 significantly lowered the expression of p-NF-κB, NLRP3, caspase-1, IL-1β, TRPC6, NFAT2, and VEGF in retina of type 2 diabetic mice. These findings suggest that ginsenoside Rg_1 can significantly alleviate DR in type 2 diabetic mice, which may be related to inhibition of NLRP3 inflammasome and VEGF. This study provides experimental evidence for the clinical application of ginsenoside Rg_1 in the treatment of DR.

Metabolomics analysis reveals the renal protective effect of Panax ginseng C. A. Mey in type 1 diabetic rats / 中国天然药物

The dry root and rhizome of Panax ginseng C. A. Mey has garnered much interest owing to its medicinal properties against diabetes and cardiovascular diseases. In this study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS)-based metabolomics approach was used to illustrate the therapeutic mechanisms of ginseng extract on the serum and urinary metabolic profiles in streptozotocin-induced type 1 diabetes mellitus (T1DM) rats. Pharmacological and renal parameters in response to the administration of ginseng were also evaluated. In total, 16 serum endogenous metabolites and 14 urine endogenous metabolites, including pyruvic acid, indoleacetic acid, and phenylacetylglycine, were identified as potential biomarkers for diabetes. Pathway enrichment and network analysis revealed that the biomarkers modulated by ginseng were primarily involved in phenylalanine and pyruvate metabolism, as well as in arginine biosynthesis. Moreover, the levels of several renal injury-related biomarkers in T1DM rats were significantly restored following treatment with ginseng. The administration of the extract helped maintain tissue structure integrity and ameliorated renal injury. The findings suggest that the regulatory effect of ginseng extract on T1DM involves metabolic management of diabetic rats, which subsequently attenuates T1DM-induced early renal dysfunction.

Fucoxanthin regulates Nrf2/Keap1 signaling to alleviate myocardial hypertrophy in diabetic rats / 南方医科大学学报

OBJECTIVE@#To investigate the protective effect of fucoxanthin (FX) against diabetic cardiomyopathy and explore the underlying mechanism.@*METHODS@#Rat models of diabetes mellitus (DM) induced by intraperitoneal injection of streptozotocin (60 mg/kg) were randomized into DM model group, fucoxanthin treatment (DM+FX) group and metformin treatment (DM+ Met) group, and normal rats with normal feeding served as the control group. In the two treatment groups, fucoxanthin and metformin were administered after modeling by gavage at the daily dose of 200 mg/kg and 230 mg/kg, respectively for 12 weeks, and the rats in the DM model group were given saline only. HE staining was used to examine the area of cardiac myocyte hypertrophy in each group. The expression levels of fibrotic proteins TGF-β1 and FN proteins in rat hearts were detected with Western blotting. In the cell experiment, the effect of 1 μmol/L FX on H9C2 cell hypertrophy induced by exposure to high glucose (HG, 45 mmol/L) was evaluated using FITC-labeled phalloidin. The mRNA expression levels of the hypertrophic factors ANP, BNP and β-MHC in H9C2 cells were detected using qRT-PCR. The protein expressions of Nrf2, Keap1, HO-1 and SOD1 proteins in rat heart tissues and H9C2 cells were determined using Western blotting. The DCFH-DA probe was used to detect the intracellular production of reactive oxygen species (ROS).@*RESULTS@#In the diabetic rats, fucoxanthin treatment obviously alleviated cardiomyocyte hypertrophy and myocardial fibrosis, increased the protein expressions of Nrf2 and HO-1, and decreased the protein expressions of Keap1 in the heart tissue (P < 0.05). In H9C2 cells with HG exposure, fucoxanthin significantly inhibited the enlargement of cell surface area, lowered the mRNA expression levels of ANP, BNP and β-MHC (P < 0.05), promoted Nrf2 translocation from the cytoplasm to the nucleus, and up-regulated the protein expressions its downstream targets SOD1 and HO-1 (P < 0.05) to enhance cellular antioxidant capacity and reduce intracellular ROS production.@*CONCLUSION@#Fucoxanthin possesses strong inhibitory activities against diabetic cardiomyocyte hypertrophy and myocardial fibrosis and is capable of up-regulating Nrf2 signaling to promote the expression of its downstream antioxidant proteins SOD1 and HO-1 to reduce the level of ROS.

Dihydromyricetin improves cardiac insufficiency by inhibiting HMGB1 in diabetic rats / 南方医科大学学报

OBJECTIVE@#To investigate the effect of dihydromyricetin (DHM) on cardiac insufficiency in diabetic rats and explore the underlying mechanism.@*METHOD@#Twenty-four male SD rats were randomized equally into normal control group, type 2 diabetes (T2DM) group fed on a high-glucose and high-fat diet for 6 weeks with low-dose streptozotocin (STZ) injection, metformin (MET) group with daily intragastric administration of MET (150 mg/kg) for 8 weeks after T2DM modeling, and dihydromyricetin (DHM) group with daily intragastric administration of DHM (250 mg/kg) for 8 weeks after modeling. The levels of fasting blood glucose, low density lipoprotein (LDL-C), triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL-C) and glycosylated hemoglobin (HbA1c) of the rats were measured, and plasma levels of insulin and high mobility group protein-1 (HMGB1) were detected with ELISA. The cardiac function of the rats was assessed using color echocardiography, ECG was measured using a biological signal acquisition system, and myocardial pathology was observed with HE staining. The protein expressions of HMGB1, nuclear factor-κB (NF-κB) p65 and phospho-NF-κB p65 (p-NF-κB p65) in the myocardial tissue were detected using Western blotting.@*RESULTS@#Compared with the control group, the rats in T2DM group showed significant anomalies in cardiac function after modeling with significantly increased plasma HMGB1 level and expressions of HMGB1, NF-κB p65 and p-NF-κB p65 proteins in the myocardial tissue (P < 0.05 or 0.01). Treatment with DHM significantly improved the indexes of cardiac function of the diabetic rats (P < 0.05 or 0.01), decreased plasma HMGB1 level and down-regulated the protein expressions of HMGB1 and p-NF-κB p65 in the myocardial tissue (P < 0.05 or 0.01).@*CONCLUSION@#DHM treatment can improve cardiac function in diabetic rats possibly by down-regulation of HMGB1 and phospho-NF-κB p65 expressions in the myocardium.

Histological investigation of experimentally induced diabetes effects on the distribution of transforming growth factor (TGF beta), nuclear factor kappa b (Nf-KB), heat schock 90 beta (Hsp beta) and E-cadherin proteins in testicular tissue / Investigación histológica de los efectos de la diabetes inducida experimentalmente en la distribución del factor de crecimiento transformante (TGFß), nuclear factor kappa b (Nf-KB), y proteinas heat schock 90ß (Hsp90ß) y E-cadherina en tejido testicular

SUMMARY: Diabetes is a metabolic disorder characterized by high blood sugar levels and it causes complications in many systems, including the reproductive system. As a result of diabetic conditions, one of the mechanisms that can cause repression of reproductive activity is testicular oxidant stress. The identification of diabetes on the cell signaling molecules axis is still under discussion. The aim of this study was to determine the effect of Transforming Growth Factor (TGFβ), Nuclear Factor kappa B (NF-kB), Heat-schock 90β (HSP90β) signal pathways and E-cadherin cell adhesion molecule on infertility in diabetic rat testicular tissue. In our study, includes histological, molecular and biochemical analysis of testicular tissue removed at the end of the 2 weeks experiment period. A total of 14 adult male rats were divided as control and diabetes. No intervention was given to 7 male rats in the control group. For the diabetic group, 7 male rats were injected by intraperitoneal with a single dose of 55 mg/kg streptozotocin (STZ). TGFβ, NF-kB, HSP90β and E-cadherin proteins were immunohistochemically studied to investigate possible tissue damage, inflammatory process, cell stabilization and integrity due to diabetes. In order to determine oxidant stress, lipid peroxidation product malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GPx) analyzes were performed. Fibrosis, inflammatory changes and loss of spermatogenetic series are prominent findings in the diabetic group. On analysis of all the samples with immunostaining, in the diabetic group, TGFβ and NF-kB immunoexpression significantly increased, while Hsp90β and E-cadherin immunoexpression significantly decreased compared with control groups. Experimental diabetes was found to cause fibrosis, inflammation, disrupting cell adhesion and stabilization in testicular tissue. These results suggest that cellular therapy studies are needed for possible damage.

RESUMEN: La diabetes es una enfermedad metabólica caracterizada por niveles altos de azúcar en sangre y causa complicaciones en muchos sistemas, incluido el sistema reproductivo. Como resultado de las condiciones diabéticas, uno de los mecanismos que puede causar alteraciones en la actividad reproductiva es el estrés oxidativo testicular. La identificación de la diabetes en el eje de las moléculas de señalización celular aún está en discusión. El objetivo de este estudio fue determinar el efecto del factor de crecimiento transformante (TGFβ), el factor nuclear kappa B (NF-kB), las vías de señalización de Heat-Schock 90b (HSP90β) y la molécula de adhesión celular de E-cadherina sobre la infertilidad en testículo de rata diabética. Al término de dos semanas se realizaron análisis histológico, molecular y bioquímico del tejido testicular extraído. Las 7 ratas macho del grupo control no fueron intervenidas. Para el grupo de diabéticos, 7 ratas macho fueron inyectadas por vía intraperitoneal con una dosis única de 55 mg / kg de estreptozotocina (STZ). Se estudiaron inmunohistoquímicamente las proteínas TGFβ, NF-kB, HSP90β y E-cadherina para investigar el posible daño tisular, el proceso inflamatorio, la estabilización celular y la integridad debido a la diabetes. Para determinar el estrés oxidativo, se realizaron análisis del producto de peroxidación lipídica malondialdehído (MDA), glutatión (GSH) y glutatión peroxidasa (GPx). La fibrosis, los cambios inflamatorios y la pérdida de series espermatogenéticas son hallazgos destacados en el grupo de ratas diabéticas. En el análisis de todas las muestras con inmunotinción, en el grupo diabético, la inmunoexpresión de TGFβ y NF-kB aumentó significativamente, mientras que la inmunoexpresión de Hsp90β y e-cadherina disminuyó significativamente en comparación con los grupos control. Se encontró que la diabetes experimental causa fibrosis, inflamación, alteración de la adhesión celular y estabilización en el tejido testicular. Estos resultados sugieren que son necesarios estudios de terapia celular para verificar posibles daños.

Role of adiponectin in diabetes myocardial ischemia-reperfusion injury and ischemic postconditioning

Abstract Purpose Patients with diabetes are vulnerable to myocardial I/R (ischaemia/reperfusion) injury, but are not responsive to IPO (ischaemic post-conditioning). We hypothesized that decreased cardiac Adiponectin (APN) is responsible for the loss of diabetic heart sensitivity to IPO cardioprotecton. Methods Diabetic rats were subjected to I/R injury (30 min of LAD occlusion followed by 120 min of reperfusion). Myocardial infarct area was determined by TTC staining. Cardiac function was monitored by a microcatheter. ANP, 15-F2t-isoprostane, nitrotyrosine and MDA were measured by assay kits. Levels of p-Akt, total-Akt and GAPDH were determined by Western Blot. Results Diabetic rats subjected to myocardial IR exhibited severe myocardial infarction and oxidative stress injury, lower APN in the plasma and cardiac p-Akt expression ( P <0.05). IPO significantly attenuated myocardial injury and up-regulated plasma APN content and cardiac p-Akt expression in non-diabetic rats but not in diabetic rats. Linear correlation analysis showed that the expression of adiponectin was positively correlated with p-Akt and negatively correlated with myocardial infarction area ( P <0.01). Conclusion Protective effect of IPO was tightly correlated with the expression of adiponectin, exacerbation of I/R injury and ineffectiveness of IPO was partially due to the decline of adiponectin and inactivation of Akt in diabetes mellitus.

GDF11 ameliorated myocardial ischemia reperfusion injury by antioxidant stress and up-regulating autophagy in STZ-induced type 1 diabetic rats

Abstract Purpose: To investigate whether GDF11 ameliorates myocardial ischemia reperfusion (MIR) injury in diabetic rats and explore the underlying mechanisms. Methods: Diabetic and non-diabetic rats subjected to MIR (30 min of coronary artery occlusion followed by 120 min of reperfusion) with/without GDF11 pretreatment. Cardiac function, myocardial infarct size, creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), superoxide dismutase (SOD) 15-F2tisoprostane, autophagosome, LC3II/I ratio and Belcin-1 level were determined to reflect myocardial injury, oxidative stress and autophagy, respectively. In in vitro study, H9c2 cells cultured in high glucose (HG, 30mM) suffered hypoxia reoxygenation (HR) with/without GDF11, hydrogen peroxide (H2O2) and autophagy inhibitor 3-methyladenine (3-MA) treatment, cell injury; oxidative stress and autophagy were assessed. Results: Pretreatment with GDF11 significantly improved cardiac morphology and function in diabetes, concomitant with decreased arrhythmia severity, infarct size, CK-MB, LDH and 15-F2tisoprostane release, increased SOD activity and autophagy level. In addition, GDF11 notably reduced HR injury in H9c2 cells with HG exposure, accompanied by oxidative stress reduction and autophagy up-regulation. However, those effects were completely reversed by H2O2 and 3-MA. Conclusion: GDF11 can provide protection against MIR injury in diabetic rats, and is implicated in antioxidant stress and autophagy up-regulation.

Experimentally induced diabetes mellitus influences expression of VEFGand CD68 in rat teeth pulp / La diabetes mellitus inducida experimentalmente influye en la expresión de VEGF y CD68 en la pulpa de dientes de rata

The purpose of this study was to examine the expression levels of the dental pulp to elucidate the role of Vascular Endothelial Growth Factor (VEGF) and CD68 on vascular angiogenesis, inflammation and odontoblast differentiation in the pulp tissue of diabetic rats depending on the effect of possible damage induced by diabetes. Wistar rats were used in the study, divided into two groups. Control group was fed with standard rat chow and drinking water ad libitum for 8 weeks. Single dose of streptozotocin (STZ) (55 mg/kg), was disolved in sodium citrate buffer and administered by intraperitoneal injection. Blood glucose concentration of rats exceeding 250 mg/dl were accepted as diabetic. Rats were sacrificed under anesthesia. Tissues were immediately dissected, fixed and embedded in paraffin and cut with a microtome then examined under light microscope. In the cross-sections of pulp tissue of diabetic group; the dilation of blood vessels besides hemorrhage and a significant increase in inflammatory cells were seen. The expression of VEGF in the blood vessel endothelial cells of the pulp was increased. VEGF showed positive reaction for degenerative odontoblast cells in the pulp. In this study, increase in VEGF and CD68 expressions in pulp tissue due to the effect of diabetes was thought to delay pulp treatment by inducing soft tissue damage and hypoxia.

El propósito de este estudio fue examinar los niveles de expresión en la pulpa dental para dilucidar el papel del Factor de Crecimiento Endotelial Vascular (VEGF) y el CD68 en la angiogénesis, la inflamación y la diferenciación de odontoblastos en el tejido pulpar de ratas diabéticas, dependiendo del efecto de daño inducido por la diabetes. Se utilizaron ratas Wistar divididas en dos grupos. El grupocontrol se alimentó con comida estándar para ratas y agua potable ad libitum durante 8 semanas. Se administró mediante inyección intraperitoneal dosis única de estreptozotocina (STZ) (55 mg / kg), se disolvió en tampón de citrato de sodio. La concentración de glucosa en sangre de ratas que excedían los 250 mg / dl se aceptó como diabética. Las ratas fueron sacrificadas bajo anestesia. Los tejidos se disecaron de inmediato, se fijaron en parafina y se cortaron para luego ser examinados con un microscopio óptico. En las secciones transversales del tejido pulpar del grupo diabético se observó la dilatación de los vasos sanguíneos además de hemorragia y un aumento significativo de células inflamatorias. La expresión de VEGF se incrementó en las células endoteliales de los vasos sanguíneos de la pulpa. VEGF mostró una reacción positiva para las células odontoblásticas degenerativas en la pulpa. El aumento en la expresión de VEGF y CD68 en el tejido de la pulpa debido al efecto de la diabetes puede retrasar el tratamiento de la pulpa al inducir hipoxia y daños en los tejidos blandos.

Expression of myo-inositol cotransporters in the sciatic nerve and dorsal root ganglia in experimental diabetes

The transport of myo-inositol is the main mechanism for the maintenance of its high intracellular levels. We aimed to measure the mRNA and protein levels of myo-inositol cotransporters in the sciatic nerve (SN) and dorsal root ganglia (DRG) during experimental diabetes. Streptozotocin-induced (STZ; 4, 8, and 12 weeks; 65 mg/kg; ip) diabetic rats (DB) and age-matched euglycemic (E) rats were used for the analysis of mRNA and protein levels of sodium myo-inositol cotransporters 1, 2 (SMIT1, SMIT2) or H+/myo-inositol cotransporter (HMIT). There was a significant reduction in the mRNA levels for SMIT1 in the SN and DRG (by 36.9 and 31.0%) in the 4-week DB (DB4) group compared to the E group. SMIT2 was not expressed in SN. The mRNA level for SMIT2 was up-regulated only in the DRG in the DB4 group. On the other hand, the protein level of SMIT1 decreased by 42.5, 41.3, and 44.8% in the SN after 4, 8, and 12 weeks of diabetes, respectively. In addition, there was a decrease of 64.3 and 58.0% of HMIT in membrane and cytosolic fractions, respectively, in the SN of the DB4 group. In the DRG, there was an increase of 230 and 86.3% for SMIT1 and HMIT, respectively, in the DB12 group. The levels of the main inositol transporters, SMIT1 and HMIT, were greatly reduced in the SN but not in the DRG. SMIT-1 was selectively reduced in the sciatic nerve during experimental STZ-induced diabetes.

A curcumin derivative J147 ameliorates diabetic peripheral neuropathy in streptozotocin (STZ)-induced DPN rat models through negative regulation AMPK on TRPA1

Abstract Purpose: To investigate the specific molecular mechanisms and effects of curcumin derivative J147 on diabetic peripheral neuropathy (DPN). Methods: We constructed streptozotocin (STZ)-induced DPN rat models to detected mechanical withdrawal threshold (MWT) in vivo using Von Frey filaments. In vitro, we measured cell viability and apoptosis, adenosine 5'-monophosphate-activated protein kinase (AMPK) and transient receptor potential A1 (TRPA1) expression using MTT, flow cytometry, qRT-PCR and western blot. Then, TRPA1 expression level and calcium reaction level were assessed in agonist AICAR treated RSC96cells. Results: The results showed that J147reduced MWT in vivo, increased the mRNA and protein level of AMPK, reduced TRPA1 expression and calcium reaction level in AITCR treated RSC96 cells, and had no obvious effect on cell viability and apoptosis. Besides, AMPK negative regulated TRPA1 expression in RSC96 cells. Conclusions: J147 could ameliorate DPN via negative regulation AMPK on TRPA1 in vivo and in vitro. A curcumin derivative J147might be a new therapeutic potential for the treatment of DPN.

Effect of melatonin on antioxidant capacity, inflammation and apoptotic cell death in lung tissue of diabetic rats

Abstract Purpose: To investigate the effects of melatonin on antioxidant capacity, inflammation and apoptotic cell death (through expression of cleaved-caspase 3) in lung tissue samples of diabetic rats. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control group) was made up of healthy rats. Group 2 (diabetes group) received streptozotocin at a dose of 50 mg/kg/day for 5 days.Group 3 (diabetes plus melatonin group) received streptozotocin at a dose of 50 mg/kg/day for 5 days and then they received melatonin at a dose of 20 mg/kg/day between 28thand 35thdays of the study. Results: Tissue MDA and MPO levels were found to be significantly higher in diabetes group compared to control group (p<0.05) whilst administration of melatonin was found to significantly lower this increase down to normal levels (p<0.05). Bronchus associated lymphoid tissue (BALT) was more severe in diabetics whereas administration of melatonin alleviated this hyperplasia. Cleaved caspase 3 activity was severe in hyperplastic BALT in diabetic rats however in lowered down to moderate level when melatonin was administered. Conclusion: The melatonin caused an increase in antioxidant capacity and decreased the expression of cleaved-caspase 3.

Effects on alveolar bone of diabetes mellitus induced by streptozotocin in rats: histopathologic and immunohistochemical study / Efectos de la diabetes mellitus inducida por streptozotocina en el hueso alveolar de ratas: estudio histopatológico e inmunohistoquímico

SUMMARY: The purpose of this study was to investigate effects of diabetes mellitus (DM) on the alveolar bone with histopathological and immunohistochemical methods. Wistar rats were divided into two groups, control and diabetes group. Control group was fed standard rat chow and drinking water for 8 weeks. Single dose (Streptozotocin) STZ (55 mg/kg), was dissolved in sodium citrate buffer and introduced intraperitoneal injection. Diabetes group and control group were compared in terms of glucose values. The blood glucose concentration in diabetic rats was significantly high (p <0.05). In diabetes group; periodontal membrane and the dilation of blood vessels, hemorrhage has also been a significant increase in inflammatory cells. In the diabetes group, osteonectin showed positive expression in periodontal membrane and showed negative expression in osteocytes of alveolar bone. Osteopontin expression in fibroblast cells and periodontal membrane collagen fibrils was positive, alveolar cells, osteocytes and bone matrix bone was found positive. Diabetes results showed that there formed periodontitis; due to the increase in inflammation inhibiting bone formation delaying the development of early bone cells.

RESUMEN: El objetivo de este estudio fue investigar los efectos de la diabetes mellitus (DM) sobre el hueso alveolar con métodos histopatológicos e inmunohistoquímicos. Las ratas Wistar se dividieron en dos grupos, grupo control y grupo de diabetes. El grupo control fue alimentado con comida estándar y agua potable durante 8 semanas. La dosis única Streptozotocina (STZ) (55 mg/ kg), se disolvió en tampón de citrato de sodio y se introdujo mediante inyección intraperitoneal. El grupo diabetes y el grupo control se compararon en términos de valores de glucosa. La concentración de glucosa en sangre en ratas diabéticas fue significativamente alta (p <0,05). En el grupo diabetes hubo un aumento significativo de la membrana periodontal y dilatación de los vasos sanguíneos y hemorragia, con un aumento significativo de células inflamatorias. En el grupo diabetes, la osteonectina mostró una expresión positiva en la membrana periodontal además se observó expresión negativa en los osteocitos del hueso alveolar. La expresión de osteopontina en fibroblastos y fibrillas de colágeno en membrana periodontal fue positiva, las células alveolares, osteocitos y hueso de la matriz ósea dio positivo. Los resultados de la diabetes mostraron que existía periodontitis, debido al aumento de la inflamación que inhibió la formación ósea retardando el desarrollo de células óseas tempranas.

Expression profile of endothelin receptors (ETA and ETB) and microRNAs-155 and -199 in the corpus cavernosum of rats submitted to chronic alcoholism and diabetes mellitus

Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Beetle (Ulomoides dermestoides) fat improves diabetes: effect on liver and pancreatic architecture and on PPARgamma expression

Ulomoides dermestoides is a beetle traditionally consumed to treat diabetes. In this study, we performed a composition analysis of U. dermestoides to obtain the principal fractions, which were used to assess the effect on glycemia, liver and pancreatic architecture, and PPARγ and GLUT4 expression. Normal mice and alloxan-induced diabetic mice were administered fractions of chitin, protein or fat, and the acute hypoglycemic effect was evaluated. A subacute study involving daily administration of these fractions to diabetic mice was also performed over 30 days, after which the liver and pancreas were processed by conventional histological techniques and stained with hematoxylin and eosin to evaluate morphological changes. The most active fraction, the fat fraction, was analyzed by gas chromatography-mass spectrometry (GC-MS), and PPARγ and GLUT4 mRNA expressions were determined in 3T3-L1 adipocytes. The protein and fat fractions exhibited hypoglycemic effects in the acute as well as in the 30-day study. Only the fat fraction led to elevated insulin levels and reduced glycemia, as well as lower intake of water and food. In the liver, we observed recovery of close hepatic cords in the central lobule vein following treatment with the fat fraction, while in the pancreas there was an increased density and percentage of islets and number of cells per islet, suggesting cellular regeneration. The GC-MS analysis of fat revealed three fatty acids as the major components. Finally, increased expression of PPARγ and GLUT4 was observed in 3T3-L1 adipocytes, indicating an antidiabetic effect.

MAFB mediates the therapeutic effect of sleeve gastrectomy for obese diabetes mellitus by activation of FXR expression

Farnesoid X receptor (FXR) and related pathways are involved in the therapeutic effect of sleeve gastrectomy for overweight or obese patients with diabetes mellitus. This study aimed to investigate the mechanism of FXR expression regulation during the surgical treatment of obese diabetes mellitus by sleeve gastrectomy. Diabetic rats were established by combined streptozotocin and high-fat diet induction. Data collection included body weight, chemical indexes of glucose and lipid metabolism, liver function, and the expression levels of musculoaponeurotic fibrosarcoma oncogene family B (MAFB), FXR, and related genes induced by sleeve gastrectomy. Chang liver cells overexpressing MAFB gene were established to confirm the expression of related genes. The binding and activation of FXR gene by MAFB were tested by Chip and luciferase reporter gene assays. Vertical sleeve gastrectomy induced significant weight loss and decreased blood glucose and lipids in diabetic rat livers, as well as decreased lipid deposition and recovered lipid function. The expression of MAFB, FXR, and FXR-regulated genes in diabetic rat livers were also restored by sleeve gastrectomy. Overexpression of MAFB in Chang liver cells led to FXR gene expression activation and the alteration of multiple FXR-regulated genes. Chip assay showed that MAFB could directly bind with FXR promoter, and the activation of FXR expression was confirmed by luciferase reporter gene analysis. The therapeutic effect of sleeve gastrectomy for overweight or obese patients with diabetes mellitus was mediated by activation of FXR expression through the binding of MAFB transcription factor.

Physical training reverses changes in hepatic mitochondrial diameter of Alloxan-induced diabetic rats / Treinamento físico reverte alterações no diâmetro de mitocôndrias hepáticas de ratos diabéticos induzidos pela Aloxana

ABSTRACT Objective To investigate the effects of physical training on metabolic and morphological parameters of diabetic rats. Methods Wistar rats were randomized into four groups: sedentary control, trained control, sedentary diabetic and trained diabetic. Diabetes mellitus was induced by Alloxan (35mg/kg) administration for sedentary diabetic and Trained Diabetic Groups. The exercise protocol consisted of swimming with a load of 2.5% of body weight for 60 minutes per day (5 days per week) for the trained control and Trained Diabetic Groups, during 6 weeks. At the end of the experiment, the rats were sacrificed and blood was collected for determinations of serum glucose, insulin, albumin and total protein. Liver samples were extracted for measurements of glycogen, protein, DNA and mitochondrial diameter determination. Results The sedentary diabetic animals presented decreased body weight, blood insulin, and hepatic glycogen, as well as increased glycemia and mitochondrial diameter. The physical training protocol in diabetic animals was efficient to recovery body weight and liver glycogen, and to decrease the hepatic mitochondrial diameter. Conclusion Physical training ameliorated hepatic metabolism and promoted important morphologic adaptations as mitochondrial diameter in liver of the diabetic rats.

RESUMO Objetivo Investigar os efeitos do treinamento físico nos parâmetros morfológicos e metabólicos de ratos diabéticos. Métodos Ratos Wistar foram randomizados para quatro grupos: controle sedentário, controle treinado, diabético sedentário e diabético treinado. Diabetes mellitus foi induzido por administração de Aloxana (35mg/kg) nos Grupos Diabético Sedentário e diabético treinado. O protocolo de treinamento físico incluiu natação com carga de 2,5% do peso corporal, por 60 minutos por dia (5 dias por semana) para os Grupos Controle Treinado e diabético treinado, durante 6 semanas. Ao final do experimento, os ratos foram sacrificados, e o sangue foi coletado para determinação das concentrações séricas de glicose, insulina, albumina e proteínas totais. Amostras do fígado foram coletadas para determinação do glicogênio, proteínas, DNA e diâmetro mitocondrial. Resultados O Grupo Sedentário Diabético apresentou redução no peso corporal, insulinemia e glicogênio hepático, além de maior glicemia e diâmetro mitocondrial hepático. O protocolo de treinamento físico em animais diabéticos foi eficiente para restaurar o peso corporal e o glicogênio hepático, além de reduzir o diâmetro mitocondrial hepático. Conclusão O treinamento físico melhorou o metabolismo hepático e promoveu importantes adaptações morfológicas, como no diâmetro mitocondrial no fígado de animais diabéticos.

Pulmonary oxidative stress in diabetic rats exposed to hyperoxia

Abstract Purpose: To evaluate the pulmonary oxidative stress in diabetic rats exposed to hyperoxia for 90 minutes. Methods: Forty male Wistar rats were divided into four groups, each one containing 10 animals, according to the oxygen concentration to which they were exposed: 21%, 50%, 75% and 100% (hyperoxia). In each group five animals were randomly induced to diabetes by means of at a dose of 55 mg/kg of streptozotocin (STZ). Results: Seventy two hours after diabetes induction, a significant difference was seen in blood glucose in the experimental groups in comparison with the control. In the experimental groups a significant difference was observed in the concentration of malondialdehyde (MDA) in lung tissue and blood plasma (p<0.05), except the 50% group. In the control group, significant differences in the MDA concentration in plasma and lung tissue were also observed (p<0.05), except the 75% group. The MDA concentration in lung tissue in comparison with the diabetic and non-diabetic groups showed a significant difference in the 21% group; however, no difference was seen in the 75 and 100% groups. Conclusion: In diabetic animals high oxygen concentrations (75 and 100%) do not appear to exert deleterious effects on lipid peroxidation in lung tissue.

Cardioprotective Effect of Crocin Combined with Voluntary Exercise in Rat: Role of Mir-126 and Mir-210 in Heart Angiogenesis / Efeito Cardioprotetor de Crocina Combinado com Exercício Voluntário em Ratos: Papel do Mir-126 e Mir-210 na Angiogênese Cardíaca

Abstract Background: Crocin is reported to have a wide range of biological activities such as cardiovascular protection. Recent epidemiologic studies have shown that exercise reduces cardiovascular morbidity and mortality in the general population. Objective: The aim of this study was to evaluate the effect of crocin and voluntary exercise on miR-126 and miR-210 expression levels and angiogenesis in the heart tissue. Methods: Animals were divided into 4 groups: control, exercise, crocin, and exercise-crocin. Animals received oral administration of crocin (50 mg/kg) or performed voluntary exercise alone or together for 8 weeks. Akt, ERK1/2 protein levels, miR-126 and miR-210 expression were measured in the heart tissue. Immunohistochemical method was used to detect CD31 in the heart tissue. Results: Akt and ERK1/2 levels of the heart tissue were higher in crocin treated group and voluntary exercise trained group after 8 weeks. Combination of crocin and exercise also significantly enhanced Akt and ERK1/2 levels in the heart tissue. MiR-126, miR-210 expression and CD31 in the heart increased in both crocin and voluntary exercise groups compared with control group. In addition, combination of exercise and crocin amplified their effect on miR-126 and miR-210 expression, and angiogenesis. Conclusion: Crocin and voluntary exercise improve heart angiogenesis possibly through enhancement of miR-126 and miR-210 expression. Voluntary exercise and diet supplementation with crocin could have beneficial effects in prevention of cardiovascular disease.

Resumo Fundamentos: A crocina tem uma vasta gama de atividades biológicas, tais como a proteção cardiovascular. Estudos epidemiológicos recentes demonstraram que o exercício reduz a morbidade e a mortalidade cardiovasculares na população em geral. Objetivo: O objetivo deste estudo foi avaliar o efeito da crocina e do exercício voluntário nos níveis de expressão miR-126 e miR-210 e na angiogênese no tecido cardíaco. Métodos: Os animais foram divididos em 4 grupos: controle, exercício, crocina e exercício-crocina. Os animais receberam a administração oral de crocina (50 mg/kg) ou realizaram exercício voluntário sozinhos ou em conjunto durante 8 semanas. Os níveis de proteína Akt, ERK1/2, e a expressão de miR-126 e miR-210 foram medidos no tecido cardíaco. O método imunohistoquímico foi utilizado para detectar CD31 no tecido cardíaco. Resultados: Os níveis de Akt e ERK1/2 do tecido cardíaco foram maiores no grupo tratado com crocina e no grupo de exercício voluntário após 8 semanas. A combinação de crocina e exercício também aumentou significativamente os níveis de Akt e ERK1/2 no tecido cardíaco. A expressão de MiR-126, miR-210 e CD31 no coração aumentou tanto em no grupo de crocina como no grupo de exercício voluntário em comparação com o grupo de controle. Além disso, a combinação de exercício e crocina amplificou seu efeito na expressão de miR-126 e miR-210 e angiogênese. Conclusão: A Crocina e o exercício voluntário melhoram a angiogênese cardíaca possivelmente através do aumento da expressão de miR-126 e miR-210. O exercício voluntário e a suplementação dietética com crocina podem ter efeitos benéficos na prevenção de doenças cardiovasculares.

Comparative analysis of two different models of swimming applied to pregnant rats born small for pregnant age

ABSTRACT The aim of this study was to compare two models of swimming applied to pregnant rats born small for pregnancy age (SPA). Diabetes was chemically induced in adult female rats to develop an inadequate intrauterine environment, leading to birth of a SPA offspring. In adulthood, the female SPA rats were mated and submitted to different swimming programs. The exercise program 1 (Ex1) consisted of swimming for 15 minutes, followed by 15 minutes of rest and another 15 minutes of swimming, 3 days a week before and during pregnancy. Another program (Ex2) was applied during 60 minutes uninterrupted a day, 6 days/week during pregnancy. The pregnant rats presented no interference on body weight and glycemia. The rats submitted to Ex2 model showed decreased insulin and blood glucose levels by oral glucose tolerance test, and reduction in area under curve values. The offspring from dams submitted to both exercise protocols presented an increased rate of newborns SPA. However, the offspring from Ex2 dams showed percentage twice higher of newborns SPA than Ex1 offspring. Our data suggests that continuous exercise of 60 min/day ameliorated the enhanced peripheral insulin sensitivity in growth-restricted females. However, this protocol employed at pregnancy leads to intrauterine growth restriction.