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[This corrects the article DOI: 10.18632/oncotarget.20170.].
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Ovarian cancer is the fifth leading cause of deaths due to cancer among women in the United States. In 2017, 22,440 women are expected to be diagnosed with ovarian cancer and 14,080 women will die with it. Currently used chemotherapies (Cisplatin or platinum/taxane combination) targets cancer cells, but spares cancer stem cells (CSCs), which are responsible for tumor relapse leading to recurrence of cancer. Aldehyde dehydrogenase I (ALDH1) positive cancer stem cells are one of the major populations in ovarian tumor and have been related to tumor progression and metastasis. In our studies, we observed expression of ALDH1 in both ovarian surface epithelium (OSE) and cortex with high levels of expression in OSE in normal ovary and benign (BN) tumor, compared to borderline (BL) and high grade (HG) ovarian tumors. In contrast, high levels of expression of ALDH1 were observed in cortex in BL and HG tumors compared to normal ovary and BN tumor. Withaferin A (WFA) alone or in combination with cisplatin (CIS) significantly inhibited the spheroid formation (tumorigenic potential) of isolated ALDH1 CSCs in vitro and significantly reduced its expression in tumors collected from mice bearing orthotopic ovarian tumor compared to control. Treatment of animals with CIS alone significantly increased the ALDH1 CSC population in tumors, suggesting that CIS targets cancer cells but spares cancer stem cells, which undergo amplification. WFA and CIS combination suppresses the expression of securin an "oncogene", suggesting that securin may serve as a downstream signaling gene to mediate the antitumor effects of WFA.
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Although type-2 diabetes (T2D) has been reported to increase the risk of cognitive dysfunction and dementia, the underlying mechanisms remain unclear. Dementia-like pathology is attributed to the accumulation of cellular prion protein (PrPc) which plays a role in cognitive dysfunction. However, its involvement and regulation in diabetic dementia-like pathology is not well understood. Using T2D db/db (leptin receptor knockout) mice subjected to object recognition and Y-maze behavioral tests, we determined that short-term memory was compromised and that the mice displayed abrupt spontaneous behaviour compared to db/m control mice. MicroRNA analysis using qRT2-PCR array demonstrated a significant reduction in the transcript expression of microRNA-146a (miR-146a) in the brain of T2D db/db mice as compared to db/m controls. The sequence matching tools validated the binding of miR-146a to a conserved domain of the PrPc gene. Administration of mouse brain endothelial cell-derived exosomes (BECDEs) loaded with miR-146a into the brain's ventricle of T2D db/db mice attenuated brain PrPc levels and restored short-term memory function though not significant. Also, we observed hyperphosphorylation of tau through decreased expression of glycogen synthase kinase-3 in T2D db/db brains that regulates microtubule organization and memory function. We conclude that underexpression of miR-146a upregulates PrPc production in T2D db/db mice and the delivery of BECDEs loaded with a miR-146a can down regulate PrPc levels and restore short term memory function up to a certain extent.
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Encéfalo/metabolismo , Demencia/etiología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/patología , Regulación de la Expresión Génica/genética , MicroARNs/metabolismo , Animales , Encéfalo/patología , Demencia/tratamiento farmacológico , Demencia/genética , Demencia/metabolismo , Diabetes Mellitus Tipo 2/genética , Modelos Animales de Enfermedad , Factores de Crecimiento Endotelial/farmacología , Factores de Crecimiento Endotelial/uso terapéutico , Regulación de la Expresión Génica/efectos de los fármacos , Glucógeno Sintasa Quinasa 3/metabolismo , Masculino , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , MicroARNs/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas Priónicas/metabolismo , ARN Mensajero/metabolismo , Receptores de Leptina/deficiencia , Receptores de Leptina/genética , Reconocimiento en Psicología/fisiología , Proteínas tau/metabolismoRESUMEN
We tested whether the combined nano-formulation, prepared with curcumin (anti-inflammatory and neuroprotective molecule) and embryonic stem cell exosomes (MESC-exocur), restored neurovascular loss following an ischemia reperfusion (IR) injury in mice. IR-injury was created in 8-10 weeks old mice and divided into two groups. Out of two IR-injured groups, one group received intranasal administration of MESC-exocur for 7days. Similarly, two sham groups were made and one group received MESC-exocur treatment. The study determined that MESC-exocur treatment reduced neurological score, infarct volume and edema following IR-injury. As compared to untreated IR group, MESC-exocur treated-IR group showed reduced inflammation and N-methyl-d-aspartate receptor expression. Treatment of MESC-exocur also reduced astrocytic GFAP expression and alleviated the expression of NeuN positive neurons in IR-injured mice. In addition, MESC-exocur treatment restored vascular endothelial tight (claudin-5 and occludin) and adherent (VE-cadherin) junction proteins in IR-injured mice as compared to untreated IR-injured mice. These results suggest that combining the potentials of embryonic stem cell exosomes and curcumin can help neurovascular restoration following ischemia-reperfusion injury in mice.
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Curcumina/farmacología , Células Madre Embrionarias/citología , Exosomas/metabolismo , Fármacos Neuroprotectores/farmacología , Daño por Reperfusión/patología , Daño por Reperfusión/terapia , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Astrocitos/patología , Moléculas de Adhesión Celular/metabolismo , Curcumina/química , Curcumina/uso terapéutico , Composición de Medicamentos , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/uso terapéutico , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/metabolismo , Proteínas de Uniones Estrechas/metabolismoRESUMEN
Activation of pulmonary C-fibers can reflexively decrease heart rate, blood pressure, and peripheral vascular resistance. However, the effects of these afferents on microvascular tone remain incompletely understood. In this study, we examined the effects of these afferents on microvascular tone in a striated muscle vascular bed. The right cremaster muscle in pentobarbital-anesthetized rats with intact circulation and innervation was suspended in a tissue bath, and diameters of small arterioles were measured by intravital video microscopy. Stimulation of pulmonary C-fibers by injecting capsaicin (5 µg/kg) or phenylbiguanide (20 µg/kg) into the right atrium dilated small arterioles and decreased blood pressure and heart rate. The effects persisted when the cervical vagus nerves were cooled to 5 to 7°C (blocking myelinated fibers), but were prevented by cooling to 0°C (blocking C-fibers and myelinated fibers), by cutting the genital femoral nerve (GFN) supplying the cremaster to block the nerve supply to the muscle, or by adding 6-hydroxydopamine to the bathing medium to selectively block sympathetic effects by depleting norepinephrine from adrenergic nerve terminals. Our results show that stimulation of pulmonary C-fibers reflexively dilates small arterioles in striated muscle by a mechanism that could involve withdrawal of sympathetic adrenergic tone. In conclusion, pulmonary C-fibers can exert an inhibitory influence on neural tone of the microcirculation at an important site where microvascular resistance and tissue blood flow are regulated.
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Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Músculo Esquelético/irrigación sanguínea , Fibras Nerviosas Amielínicas/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Biguanidas/farmacología , Presión Sanguínea/fisiología , Capsaicina/farmacología , Frecuencia Cardíaca/fisiología , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Fibras Nerviosas Amielínicas/fisiología , Conducción Nerviosa/efectos de los fármacos , Conducción Nerviosa/fisiología , Ratas , Ratas Sprague-Dawley , Estimulación Química , Vasodilatación/fisiologíaRESUMEN
Remodeling and myocardial matrix metabolism contributes to cardiac endothelium-myocyte (perivascular fibrosis), myocyte-myocyte (interstitial fibrosis), and mitochondrion-myocyte (fusion and fission) coupling. Matrix metalloproteinases (MMPs), and tissue inhibitor of metalloproteinases (TIMPs) play differential roles in different tissues and diseases. For example, although present in the heart, MMP-3 is known as stromelysin (i.e., stromal tissue enzyme). Interestingly, TIMP-3 causes apoptosis. Exercise and nutrition are synergistic in the mitigation of diseases: exercise releases exosomes containing miRNAs. Nutrition/vitamins B6 and B12 regulate the metabolism of homocysteine (an epigenetic byproduct of DNA/RNA/protein methylation). Thus, epigenetic silencing is an important therapeutic target. The statistical analysis of cohorts may be less indicative for the treatment of a disease, particularly if the 2 twins are different in terms of responding to the medicine for the same disease, therefore, personalized medicine is the future of therapy.
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Circulación Coronaria , Epigénesis Genética , Ejercicio Físico/fisiología , Matriz Extracelular/metabolismo , Miocardio/metabolismo , Fenómenos Fisiológicos de la Nutrición , Fibrosis , Humanos , Microcirculación , Miocardio/patología , RegeneraciónRESUMEN
We tested the hypothesis that exercise ameliorates contractile dysfunction by interfering with homocysteine - ß2-adrenergic receptor (AR) interactions, inducing ß2-adrenergic response and Gs (stimulatory G adenylyl cyclase dependent protein kinase), and lowering homocysteine level in diabetes. The effect of homocysteine on ß2-AR was determined by (a) scoring the ß2-AR in the cardiomyocytes treated with high dose of homocysteine using flow cytometry, and (b) co-localizing homocysteine with Gs (an inducer of ß2-AR) in the cardiomyocytes obtained from C57BL/ 6J (WT) and db/ db mice using confocal microscopy. The effect of exercise on the protein-protein interactions of homocysteine and ß2-AR in diabetes was evaluated by co-immunoprecipitation in the four groups of db/db mice: (1) sedentary, (2) treated with salbutamol (a ß2-AR agonist), (3) swimming exercise, and (4) swimming + salbutamol treatment. The effect of exercise on ß2-AR was determined by RT-PCR and Western blotting while cardiac dysfunction was assessed by echocardiography, and contractility and calcium transient of cardiomyocytes from the above four groups. The results revealed that elevated level of homocysteine decreases the number of ß2-AR and inhibits Gs in diabetes. However, exercise mitigates the interactions of homocysteine with ß2-AR and induces ß2-AR. Exercise also ameliorates cardiac dysfunction by enhancing the calcium transient of cardiomyocytes. To our knowledge, this is the first report showing mechanism of homocysteine mediated attenuation of ß2-AR response in diabetes and effect of exercise on homocysteine - ß2-AR interactions.
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BACKGROUND: Hyperhomocysteinemia (HHcy) and hyperglycemia cause diabetic cardiomyopathy by inducing oxidative stress and attenuating peroxisome proliferator- activated receptor (PPAR) gamma. However, their synergistic contribution is not clear. METHODS: Diabetic Akita (Ins2+/-) and hyperhomocysteinemic cystathionine beta synthase mutant (CBS+/-) were used for M-mode echocardiography at the age of four and twenty four weeks. The cardiac rings from WT, Akita and hybrid (Ins2+/-/CBS+/-) of Akita and CBS+/- were treated with different doses of acetylcholine (an endothelial dependent vasodilator). High performance liquid chromatography (HPLC) was performed for determining plasma homocysteine (Hcy) level in the above groups. Akita was treated with ciglitazone (CZ) - a PPAR gamma agonist and tempol-an anti-oxidant, separately and their effects on cardiac remodeling were assessed. RESULTS: At twenty four week, Akita mice were hyperglycemic and HHcy. They have increased end diastolic diameter (EDD). In their heart PPAR gamma, tissue inhibitor of metalloproteinase-4 (TIMP-4) and anti-oxidant thioredoxin were attenuated whereas matrix metalloproteinase (MMP)-9, TIMP-3 and NADPH oxidase 4 (NOX4) were induced. Interestingly, they showed synergism between HHcy and hyperglycemia for endothelial-myocyte (E-M) uncoupling. Additionally, treatment with CZ alleviated MMP-9 activity and fibrosis, and improved EDD. On the other hand, treatment with tempol reversed cardiac remodeling in part by restoring the expressions of TIMP-3,-4, thioredoxin and MMP-9. CONCLUSIONS: Endogenous homocysteine exacerbates diabetic cardiomyopathy by attenuating PPAR gamma and inducing E-M uncoupling leading to diastolic dysfunction. PPAR gamma agonist and tempol mitigates oxidative stress and ameliorates diastolic dysfunction in diabetes.
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Cardiomiopatías , Óxidos N-Cíclicos/farmacología , Diabetes Mellitus Tipo 1 , Hiperhomocisteinemia , PPAR gamma/agonistas , Tiazolidinedionas/farmacología , Animales , Antioxidantes/farmacología , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/etiología , Cardiomiopatías/metabolismo , Complicaciones de la Diabetes/tratamiento farmacológico , Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Sinergismo Farmacológico , Hiperglucemia/tratamiento farmacológico , Hiperglucemia/metabolismo , Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/tratamiento farmacológico , Hiperhomocisteinemia/metabolismo , Hipoglucemiantes/farmacología , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , NADPH Oxidasa 4 , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , PPAR gamma/genética , PPAR gamma/metabolismo , Marcadores de Spin , Inhibidor Tisular de Metaloproteinasa-3/metabolismo , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Inhibidor Tisular de Metaloproteinasa-4RESUMEN
A decrease in vascular elasticity and an increase in pulse wave velocity in hyperhomocysteinemic (HHcy) cystathionine-beta-synthase heterozygote knockout (CBS(-/+)) mice has been observed. Nitric oxide (NO) is a potential regulator of matrix metalloproteinase (MMP) activity in MMP-NO-tissue inhibitor of metalloproteinase (TIMP) inhibitory tertiary complex. However, the contribution of the nitric oxide synthase (NOS) isoforms eNOS and iNOS in the activation of latent MMP is unclear. We hypothesize that the differential production of NO contributes to oxidative stress and increased oxidative/nitrative activation of MMP, resulting in vascular remodeling in response to HHcy. The overall goal is to elucidate the contribution of the NOS isoforms, endothelial and inducible, in the collagen/elastin switch. Experiments were performed on six groups of animals [wild-type (WT), eNOS(-/-), and iNOS(-/-) with and without homocysteine (Hcy) treatment (0.67 g/l) for 8-12 wk]. In vivo echograph was performed to assess aortic timed flow velocity for indirect compliance measurement. Histological determination of collagen and elastin with trichrome and van Gieson stains, respectively, was performed. In situ measurement of superoxide generation using dihydroethidium was used. Differential expression of eNOS, iNOS, nitrotyrosine, MMP-2 and -9, and elastin were measured by quantitative PCR and Western blot analyses. The 2% gelatin zymography was used to assess MMP activity. The increase in O(2)(-) and robust activity of MMP-9 in eNOS(-/-), WT+Hcy, and eNOS(-/-)+Hcy was accompanied by the gross disorganization and thickening of the ECM along with extensive collagen deposition and elastin degradation (collagen/elastin switch) resulting in a decrease in aortic timed flow velocity. Results show that an increase in iNOS activity is a key contributor to HHcy-mediated collagen/elastin switch and resulting decline in aortic compliance.
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Aorta/fisiopatología , Colágeno/metabolismo , Elastina/metabolismo , Hiperhomocisteinemia/fisiopatología , Óxido Nítrico Sintasa de Tipo III/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Animales , Aorta/diagnóstico por imagen , Velocidad del Flujo Sanguíneo , Adaptabilidad , Matriz Extracelular/metabolismo , Hiperhomocisteinemia/diagnóstico por imagen , Masculino , Metaloproteinasa 2 de la Matriz , Metaloproteinasa 9 de la Matriz , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/deficiencia , Óxido Nítrico Sintasa de Tipo III/deficiencia , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo , UltrasonografíaRESUMEN
The rapidly increasing number of diabetes patients across the world poses a great challenge to the current therapeutic approach. The traditional method of exogenous supply of insulin has ephemeral effect and often causes lethal hypoglycemia that demands to develop a novel strategy. Recent investigations on regeneration of insulin producing cells (IPCs) revealed that in addition to primary source i.e., pancreatic beta cells, IPCs can be derived from several alternative sources including embryonic, adult, mesenchymal and hematopoietic stem cells via the process of proliferation, dedifferentiation, neogenesis, nuclear reprogramming and transdifferentiation. There is considerable success in insulin independency of diabetes patient after transplantation of whole pancreas and/or the islet cells. However, the major challenge for regenerative therapy is to obtain a large source of islet/beta cells donor. Recent advances in the directed differentiation of stem cells generated a promising hope for a better and permanent insulin independency for diabetes. In this review we discussed stem cells as a potential future therapeutic target for the treatment of diabetes and associated diseases.
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Diferenciación Celular , Diabetes Mellitus/cirugía , Células Secretoras de Insulina/citología , Células Madre/citología , Animales , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/trasplante , Modelos Biológicos , Células Madre/metabolismo , Transactivadores/genética , Transactivadores/metabolismoRESUMEN
OBJECTIVE: To examine cellular and immunologic mechanisms by which intraoperative hypothermia affects surgical patients. SUMMARY BACKGROUND DATA: Avoidance of perioperative hypothermia has recently become a focus of attention as an important quality performance measure, aimed at optimizing the care of surgical patients. Anesthetized surgical patients are particularly at risk for hypothermia, which has been directly linked to the development of sequelae, such as coagulopathy, infection, morbid myocardial events, and death after surgery. However, many of the underlying immunologic mechanisms remain unclear. METHODS: Venous blood samples from healthy volunteers were exposed for up to 4 hours to various temperatures following the addition of a 1 ng/mL lipopolysaccharide challenge. Innate immune function, assessed by the ability of monocytes to present antigen and coordinate cytokine release, was determined by qualitative and quantitative measurements of HLA-DR surface expression 2 hours following incubation, and proinflammatory tumor necrosis factor-alpha (TNF-alpha) and anti-inflammatory (IL-10) cytokine release in the first 4 hours. RESULTS: Monocyte incubation at hypothermic temperatures (34 degrees C) reduced HLA-DR surface expression, delayed TNF-alpha clearance, and increased IL-10 release. Conversely, hyperthermia (40 degrees C) increased monocyte antigen presentation and resulted in rapid decay of TNF-alpha. However, IL-10 release was also increased. Normothermia (37 degrees C) attenuated IL-10 release following the initial proinflammatory surge. CONCLUSION: Hypothermia exerts multiple effects at the cellular level, which impair innate immune function, and are associated with increased septic complications and mortality. These findings provide a physiological basis for perioperative temperature monitoring, which is a valid surgical performance measure that can be used to reduce surgical complications associated with avoidable hypothermia.
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Sangre/inmunología , Hipotermia/inmunología , Inmunidad Innata , Procedimientos Quirúrgicos Operativos/efectos adversos , Humanos , Hipotermia/etiología , Periodo Intraoperatorio , Lipopolisacáridos/inmunología , TemperaturaRESUMEN
Although congenic translocation of a segment from chromosome 10 from Lewis rat, containing an extracellular proteinase inhibitor gene, decreased blood pressure in Dahl-salt sensitive (DSS) rats, the relationship between the levels of matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), and cardiac function was unclear. In this study we investigated the cardiac effects of congenic translocation of a segment from chromosome 10 from Lewis rat, containing an extracellular proteinase inhibitor gene, in Dahl-salt sensitive rats. To test the hypothesis that left ventricular (LV) hypertrophy in DSS rats was due to high MMP and low TIMP levels and the decrease in blood pressure in congenic rats was associated with increase in proteinase inhibitor expression, cardiac function and levels of MMP and TIMP were determined in 16 weeks male DSS (D), Lewis (L) and congenic (CL-10) rats. Cardiac function was assessed by electrocardiography, echocardiography and a Millar catheter in LV cavity. LV MMP and TIMP levels were measured by Q-RT-PCR and Western blot analyses. In L, D and CL-10 rats, heart weight/body weight (g/g) were 3.73 +/- 0.06, 4.45 +/- 0.04 and 3.35 +/- 0.05 x 10(-3), respectively, suggesting significant (p < 0.05) LV hypertrophy (LVH) in D group. The ST duration was longer in D group compared with L group, suggesting coronary vasospasm, but normalized in CL-10 rats. The fractional shortening and ejection fraction were decreased in D group as compared with L group, but normalized in CL-10 groups. LV diameter was increased in D group as compared to L group, but normalized in CL-10 groups. The levels of MMP-9 were higher and TIMP were lower in D as compared to L groups, but normalized in CL-10 rats. Compared with control non-congenic Dahl rats, congenic rats exhibited lower blood pressure, amelioration of LV remodelling and dysfunction, as well as coronary abnormalities. In addition, congenic animals exhibited reduced myocardial expression of MMP-9, but increased expression of MMP-2 and TIMP-4 compared to non congenic animals. We concluded that the congenic transfer of TIMP ameliorated LV hypertrophy and cardiac dysfunction.
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Regulación de la Expresión Génica , Hipertensión/metabolismo , Hipertensión/patología , Hipertrofia Ventricular Izquierda/metabolismo , Inhibidores Tisulares de Metaloproteinasas/genética , Animales , Animales Congénicos , Electrocardiografía , Endotelio/metabolismo , Femenino , Hipertensión/diagnóstico , Hipertensión/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Masculino , Metaloproteasas/genética , Miocitos Cardíacos/metabolismo , Ratas , Ratas Endogámicas Dahl , Ratas Endogámicas Lew , UltrasonografíaRESUMEN
Although mitochondrial reduction-oxidation (redox) stress and increase in membrane permeability play an important role in diabetic-associated renal microvasculopathies, it is unclear whether the intra-renal mitochondrial oxidative stress induces mitochondrial protein modifications, leading to increase mitochondrial membrane permeability. The hypothesis is that mitochondrial oxidative stress induces mitochondrial protein modification and leakage in the mitochondrial membrane in type-2 diabetes. The present study was conducted to determine the involvement of intra-renal mitochondrial oxidative stress in mitochondrial protein modifications and modulation of membrane permeability in the setting of type-2 diabetes. Diabetes was induced by 6-week regimen of a high calorie and fat diet in C57BL/6J mice (Am J Physiol 291:F694-F701, 2006). Subcellular fractionation was carried out in kidney tissue from wild type and diabetic mice. All fractions were highly enriched in their corresponding marker enzyme. Subcellular protein modifications were determined by Western blot and 2-D proteomics. The results suggest that diabetes-induced oxidative stress parallels an increase in NADPH oxidase-4 (NOX-4) and decrease in superoxide dismutase-1, 2 (SOD-1, 2) expression, in mitochondrial compartment. We observed loss of mitochondrial membrane permeability as evidenced by leakage of mitochondrial cytochrome c and prohibitin to the cytosol. However, there was no loss in control tissue. The 2-D Western blots for mitochondrial post-translational modification showed an increase in nitrotyrosine generation in diabetes. We conclude that diabetes-induced intra-renal mitochondrial oxidative stress is reflected by an increase in mitochondrial membrane permeability and protein modifications by nitrotyrosine generation.
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Diabetes Mellitus Tipo 2/fisiopatología , Mitocondrias/patología , Estrés Oxidativo , Animales , Citosol/fisiología , Diabetes Mellitus Tipo 2/metabolismo , Angiopatías Diabéticas/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Microcirculación/patología , Membranas Mitocondriales/fisiología , Oxidación-Reducción , Permeabilidad , Valores de Referencia , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMEN
Glucose-mediated impairment of homocysteine (Hcy) metabolism and decrease in renal clearance contribute to hyperhomocysteinemia (HHcy) in diabetes. The Hcy induces oxidative stress, inversely relates to the expression of peroxisome proliferators activated receptor (PPAR), and contributes to diabetic complications. Extracellular matrix (ECM) functionally links the endothelium to the myocyte and is important for cardiac synchronization. However, in diabetes and hyperhomocysteinemia, a "disconnection" is caused by activated matrix metalloproteinase with subsequent accumulation of oxidized matrix (fibrosis) between the endothelium and myocyte (E-M). This contributes to "endothelial-myocyte uncoupling," attenuation of cardiac synchrony, leading to diastolic heart failure (DHF), and cardiac dys-synchronizatrion. The decreased levels of thioredoxin and peroxiredoxin and cardiac tissue inhibitor of metalloproteinase are in response to antagonizing PPARgamma.
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Cardiomiopatías/fisiopatología , Angiopatías Diabéticas/fisiopatología , Hiperhomocisteinemia/fisiopatología , Estrés Oxidativo , Animales , Cardiomiopatías/complicaciones , Cardiomiopatías/metabolismo , Angiopatías Diabéticas/complicaciones , Angiopatías Diabéticas/metabolismo , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Endotelio Vascular/fisiopatología , Humanos , Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/metabolismo , Modelos Biológicos , Receptores Activados del Proliferador del Peroxisoma/metabolismoRESUMEN
BACKGROUND: Coronary artery remodeling implies structural changes in the vessel wall in response to various pathophysiologic conditions. However, the classification of remodeling is unclear. We hypothesized that the adaptive, positive-outward remodeling is a reactive and compensatory response to the stress. The maladaptive negative-inward constrictive remodeling is a passive atherosclerotic condition in which the vessel becomes stiffer. METHODS: Patients with atherosclerotic lesions underwent intravascular ultrasound (IVUS) scans. The size of the vessels distal to and proximal to plaques were analyzed by IVUS. Diabetes was created in mice by an intraperitoneal injection of alloxan (65 mg/kg). To reduce remodeling, mice received ciglitazone, an agonist of peroxisome proliferators activated receptor-gamma (PPARgamma) in drinking water. After 8 weeks, atherosclerotic vessels were analyzed for collagen and elastin. RESULTS: IVUS data suggest an adaptive coronary arterial remodeling was a positive compensatory response to various pathologic stimuli; for example, with the deposition of atherosclerotic plaque, coronary arterial segments enlarged to maintain luminal area. This phenomenon was commonly observed during the initial phases of the development of atherosclerosis. However, negative coronary artery remodeling, or a decrease in vessel area with the formation of atherosclerotic plaque, was maladaptive and was associated with smoking, hypertension, hyperhomocysteinemia, diabetes mellitus, and also after percutaneous coronary interventions (restenosis). In diabetic mice, there was increased collagen and decreased elastin contents; however, treatment with ciglitazone ameliorated the decrease in elastin contents. CONCLUSION: Global enlargement of the coronary vascular tree occurs during pressure and volume overload associated with ventricular hypertrophic states such as athletic conditioning, hypertensive heart disease, and dilated cardiomyopathy. On the other hand, maladaptive coronary arterial remodeling occurs in patients with severe deconditioning, diabetes mellitus, after coronary artery bypass surgery, and in some instances, postintervention.
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Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Vasos Coronarios/diagnóstico por imagen , Complicaciones de la Diabetes , Hiperhomocisteinemia/complicaciones , Animales , Colágeno/biosíntesis , Enfermedad de la Arteria Coronaria/etiología , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/patología , Diabetes Mellitus Experimental/complicaciones , Elastina/biosíntesis , Humanos , Masculino , Ratones , PPAR gamma/antagonistas & inhibidores , Tiazolidinedionas/uso terapéutico , UltrasonografíaRESUMEN
Our hypothesis is that impairment of peroxisome proliferator-activated receptor-gamma (PPARgamma) initiates renal dysfunction by increasing renal glomerular matrix metalloproteinase-2 (MMP-2) activity because of increased renal homocysteine (Hcy) and decreased nitric oxide (NO) levels. C57BL/6J mice were made diabetic (D) by being fed a high-fat-calorie diet, and an increase in PPARgamma activity was induced by adding pioglitazone (Pi) to the diet. Mice were grouped as follows: normal calorie diet (N), D, N+Pi, and D+Pi (n = 6/group). The glomerular filtration rate (GFR), renal artery blood flow and pressure, and plasma glucose were measured. Renal glomeruli and preglomerular arterioles were isolated. Plasma and glomerular levels of NO, Hcy, and MMP activity were measured. The contractile response to phenylephrine and the dilatation response to acetylcholine in renal arteriolar rings were measured in a tissue myobath. In N, D, N+Pi, and D+Pi groups, respectively, GFR was 9.4 +/- 1.2, 3.9 +/- 1.1, 9.2 +/- 1.6, and 8.4 +/- 1.4 microl x min(-1) x g body wt(-1). Renovascular resistance was 140 +/- 3, 367 +/- 21, 161 +/- 9, and 153 +/- 10 mmHg x ml x min(-1). Levels of Hcy were increased from 5.8 +/- 1.5 in the N to 18.0 +/- 4.0 micromol/l in the D group. Glomerular levels of MMP-2 were increased in D mice compared with N mice, and there was no change in levels of MMP-9. Treatment with Pi ameliorated glomerular levels of MMP-2 and Hcy in the D group. Renal artery ring contraction and relaxation by phenylephrine and acetylcholine, respectively, were attenuated in the D groups compared with the N groups. Results suggest that a PPARgamma agonist ameliorates preglomerular arteriole remodeling in diabetes by decreasing tissue levels of Hcy and MMP-2 activity and increasing NO.
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Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Nefropatías Diabéticas/tratamiento farmacológico , Glomérulos Renales/efectos de los fármacos , Tiazolidinedionas/uso terapéutico , Animales , Arteriolas/efectos de los fármacos , Glucemia/metabolismo , Nefropatías Diabéticas/patología , Grasas de la Dieta/farmacología , Hemodinámica , Homocisteína/sangre , Glomérulos Renales/irrigación sanguínea , Glomérulos Renales/patología , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/metabolismo , Estrés Oxidativo/fisiología , Fenilefrina/farmacología , PioglitazonaRESUMEN
The agonists of peroxisome proliferator-activated receptor-gamma (PPARgamma) ameliorate cardiovascular complications associated with diabetes mellitus. We tested the hypothesis that recovery from ailing to failing myocardium in diabetes by PPARgamma agonist is in part due to decreased matrix metalloproteinase-9 (MMP-9) activation and left ventricular (LV) tissue levels of homocysteine (Hcy). C57BL/6J mice were made diabetic (D) by feeding them a high-fat calorie diet. PPARgamma was activated by adding pioglitazone (Pi) to the diet. After 6 wk, mice were grouped into: normal calorie diet (N), D, N + Pi and D + Pi (n = 6 in each group). LV variables were measured by echocardiography, endothelial-myocyte (E-M) coupling was measured in cardiac rings, and MMP-9 activation was measured by zymography. Blood glucose levels were twofold higher in D mice compared with N mice. Pi decreased the levels of glucose in D mice to the levels in N mice. LV Hcy levels were 3.5 +/- 0.5 microM in N groups compared with 12.4 +/- 0.6 microM in D groups. Treatment with Pi normalized the LV levels of Hcy but had no effect on plasma levels of Hcy. In the D group, LV contraction was reduced compared with that of the N group and was ameliorated by treatment with Pi. LV wall thickness was reduced to 0.25 +/- 0.02 mm in the D group compared with 0.42 +/- 0.01 mm in the N group. LV diastolic diameter was 3.05 +/- 0.01 mm in the D group compared with 2.20 +/- 0.02 mm in the N group. LV systolic diameter was 1.19 +/- 0.02 mm in the D group and 0.59 +/- 0.01 mm in the N group. Pi normalized the LV variables in D mice. The responses to ACh and nitroprusside were attenuated in diabetic hearts, suggesting that there was E-M uncoupling in the D group compared with the N group, which was ameliorated by Pi. Plasma and LV levels of MMP-2 and -9 activities were higher in the D group than in the N group but normalized after Pi treatment. These results suggest that E-M uncoupling in the myocardium, in part, is due to increased MMP activities secondary to suppressing PPARgamma activity in high-fat, calorie-induced Type 2 diabetes mellitus.
Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , PPAR gamma/agonistas , Tiazolidinedionas/administración & dosificación , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/prevención & control , Remodelación Ventricular/efectos de los fármacos , Animales , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/prevención & control , Grasas de la Dieta/efectos adversos , Relación Dosis-Respuesta a Droga , Ingestión de Energía , Hipoglucemiantes/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BL , Pioglitazona , Resultado del TratamientoRESUMEN
Complications associated with insulin-dependent diabetes mellitus (type-1diabetes) primarily represent vascular dysfunction that has its origin in the endothelium. While many of the vascular changes are more accountable in the late stages of type-1diabetes, changes that occur in the early or initial functional stages of this disease may precipitate these later complications. The early stages of type-1diabetes are characterized by a diminished production of both insulin and C-peptide with a significant hyperglycemia. During the last decade numerous speculations and theories have been developed to try to explain the mechanisms responsible for the selective changes in vascular reactivity and/or tone and the vascular permeability changes that characterize the development of type-1diabetes. Much of this research has suggested that hyperglycemia and/or the lack of insulin may mediate the observed functional changes in both endothelial cells and vascular smooth muscle. Recent studies suggest several possible mechanisms that might be involved in the observed decreases in vascular nitric oxide (NO) availability with the development of type-1 diabetes. In addition more recent studies have indicated a direct role for both endogenous insulin and C-peptide in the amelioration of the observed endothelial dysfunction. These results suggest a synergistic action between insulin and C-peptide that facilitates increase NO availability and may suggest new clinical treatment modalities for type-1 diabetes mellitus.
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Péptido C/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Endotelio Vascular/metabolismo , Insulina/metabolismo , Péptido C/farmacología , Endotelio Vascular/efectos de los fármacos , Humanos , Insulina/farmacología , Modelos Biológicos , Óxido Nítrico/biosíntesis , Óxido Nítrico/metabolismo , Estrés Oxidativo/fisiología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiologíaRESUMEN
Formation of homocysteine (Hcy) is the constitutive process of gene methylation. Hcy is primarily synthesized by de-methylation of methionine, in which s-adenosyl-methionine (SAM) is converted to s-adenosyl-homocysteine (SAH) by methyltransferase (MT). SAH is then hydrolyzed to Hcy and adenosine by SAH-hydrolase (SAHH). The accumulation of Hcy leads to increased cellular oxidative stress in which mitochondrial thioredoxin, and peroxiredoxin are decreased and NADH oxidase activity is increased. In this process, Ca2+-dependent mitochondrial nitric oxide synthase (mtNOS) and calpain are induced which lead to cytoskeletal de-arrangement and cellular remodeling. This process generates peroxinitrite and nitrotyrosine in contractile proteins which causes vascular dysfunction. Chronic exposure to Hcy instigates endothelial and vascular dysfunction and increases vascular resistance causing systemic hypertension. To compensate, the heart increases its load which creates adverse cardiac remodeling in which the elastin/collagen ratio is reduced, causing cardiac stiffness and diastolic heart failure in hyperhomocysteinemia.
Asunto(s)
Hiperhomocisteinemia/complicaciones , Hiperhomocisteinemia/metabolismo , Hipertensión/complicaciones , Hipertensión/metabolismo , Mitocondrias/metabolismo , Estrés Oxidativo , Homocisteína/metabolismo , Humanos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
As human males age, a decline in baroreflex-mediated elevation of blood pressure occurs due, at least in part, to a reduction in alpha-1 adrenergic vasoconstrictor function. Alpha adrenergic constriction is mediated by guanosine triphosphate binding Protein (G Protein) coupled signaling pathways. Alpha-1 A/C, B, and D adrenergic receptor expressions, measured by GeneChip array, are not reduced during aging in renal blood vessels of male or female rats. Alpha-1 A GeneChip expression is greater, at all ages studied, in females than in males. Prazosin binding by alpha-1 adrenergic receptors is greater in young adult female rats than in young adult male rats; however, it is reduced with aging in both male and female rats. G alpha q GeneChip expression declines while expression of adrenergic receptor kinase (GRK2) and tyrosine phosphatases (TyrP) increase with aging in male rats. The declines in alpha-1 adrenergic receptor binding and G alpha q expression and also the increases in GRK2 and TyrP expression likely relate to the age-related decline of vasoconstriction in male rats. The information that the expression of alpha-1 A adrenergic receptors is greater in female rats and (GRK2) expression does not increase during aging could relate to the gender differences in vasoconstrictor function with aging. Gene therapy to ameliorate the age-related decline in renal function could possibly reduce the need for renal dialysis. Signaling pathways such as those reviewed herein may provide an outline of the molecular pathways needed to move toward successful renal gene therapy for aging individuals.