Apoptotic mechanisms in rabbits with blast-induced acute lung injury

Abstract Purpose: To investigate the apoptotic mechanisms in rabbits with blast-induced acute lung injury (ALI). Methods: A total of 40 rabbits were randomly divided into a blank control group (A, n=10) and an experimental group (EXP, n=30). Explosion-induced chest-ALI models were prepared and sampled at different time points (4, 12, and 24h after modeling, T1-T3) to test the lung dry weight/wet weight ratio (W/D) and arterial oxygen pressure (PaO2), apoptosis of lung tissue by the TUNEL assay, and Caspase-3, Bax, and Bcl-2 levels by immunohistochemical analysis. Furthermore, lung tissue was sampled to observe pathological morphology by microscopy. Results: Under a light microscope, Group EXP exhibited obvious edema in the pulmonary interstitial substance and alveoli, a large number of red blood cells, inflammatory cells, and serous exudation in the alveolar cavity, as well as thickening of the pulmonary interstitial fluid. Compared to Group A, the W/D ratio was significantly increased in Group EXP (P<0.01), while PaO2 was significantly reduced (P<0.01). The apoptosis index was significantly increased (P<0.01), and caspase-3 and Bax/Bcl-2 levels were increased (P<0.01). Conclusion: Apoptosis plays an important role in the occurrence and development of acute lung injury in rabbits by participating in lung injury and promoting the progression of ALI.

Serum levels of melatonin may contribute to the pathogenesis of heart failure in children with median age of 1 year / Níveis séricos da melatonina podem contribuir para a patogênese de insuficiênciacardíaca em crianças com idade média de 1 ano

Abstract Objective: Melatonin has a protective role in adults with cardiovascular disease, but the effects of melatonin in children with cardiac dysfunction are not well understood. This study was designed to explore the variations in melatonin, myeloperoxidase, and caspase-3 levels in children suffering from heart failure. Methods: Seventy-two pediatric patients with heart failure and twelve healthy children were enrolled in this study. A modified Ross scoring system was used to evaluate clinical cardiac function. Patients with a score of >2 points were included in the study and were divided into three groups according to severity of heart failure: mild (score: 3-6), moderate (score: 7-9), and severe (score: 10-12). Echocardiographic parameters, laboratory data, and serum levels of melatonin, myeloperoxidase, and caspase-3 were measured and analyzed in all patients. Results: Compared with patients with mild and moderate heart failure, patients in the severe heart failure group had significantly decreased left ventricular ejection fraction (p < 0.001), and significantly increased serum melatonin levels (p = 0.013) and myeloperoxidase levels (p < 0.001). Serum melatonin levels were positively correlated with serum caspase-3 levels (p < 0.001). The optimal cutoff values of serum melatonin levels for the diagnosis of severe heart failure and primary cardiomyopathy in pediatric patients with heart failure were 54.14 pg/mL and 32.88 pg/mL, respectively. Conclusions: Serum melatonin and myeloperoxidase levels were increased in children with severe heart failure. It is likely that increasing melatonin levels may act as a compensatory mechanism in pediatric children with heart failure.

Resumo Objetivo: A melatonina possui um papel protetor em adultos com doença cardiovascular, porém os efeitos da melatonina em crianças com disfunção cardíaca não são bem entendidos. O estudo foi projetado para explorar a variação nos níveis de melatonina, mieloperoxidase e caspase 3 em crianças que sofrem de insuficiência cardíaca. Métodos: 72 pacientes pediátricos com insuficiência cardíaca e 12 crianças saudáveis foram inscritos no estudo. Um sistema de classificação de Ross modificada foi utilizado para avaliar a função cardíaca clínica. Os pacientes com escore de > 2 pontos foram incluídas no estudo e foram divididos em três grupos de acordo com a gravidade da insuficiência cardíaca: leve (escore: 3-6), moderada (escore: 7-9) e grave (escore: 10-12). Os parâmetros ecocardiográficos, dados laboratoriais e níveis séricos de melatonina, mieloperoxidase e caspase 3 foram medidos e analisados em todos os pacientes. Resultados: Em comparação com os pacientes com insuficiência cardíaca de gravidade leve e moderada, os pacientes no grupo de insuficiência cardíaca grave apresentaram redução significativa da fração de ejeção do ventrículo esquerdo (p < 0,001) e aumento significativo nos níveis séricos de melatonina (p = 0,013) e níveis de mieloperoxidase (p < 0,001). Os níveis séricos de melatonina foram positivamente correlacionados com os níveis séricos de caspase 3 (p < 0,001). Os valores de corte ideais dos níveis séricos de melatonina para diagnóstico de IC e cardiomiopatia primária em pacientes pediátricos com insuficiência cardíaca foram 54,14 pg/mL e 32,88 pg/mL, respectivamente. Conclusões: Os níveis séricos de melatonina e mieloperoxidase mostraram aumento em crianças com insuficiência cardíaca grave. Especulamos se o aumento nos níveis de melatonina pode agir como um mecanismo compensatório em crianças pediátricas com insuficiência cardíaca.

possible protective effect of exercise on liver damage following hind-limb ischemia reperfusion injury in the adult male albino rat: light and electron microscopic study

Hind-limb ischemia-reperfusion [I/R] injury is not limited to the lower extremities; it also causes damage to remote organs. This study was undertaken to investigate the role of exercise in attenuating remote hepatic damage following hind-limb I/R injury. Forty-five adult male rats were divided into three groups: the control group, the I/R group, and the exercise+I/R group. The rats were left to swim for 1 h, five times a week, for 4 weeks before I/R. Bilateral hind-limb ischemia was induced by application of rubber bands above the greater trochanter for 3 h. Blood samples were taken after 3 h of reperfusion for determination of malondialdehyde, superoxide dismutase, tumor necrosis factor-alpha, and interleukin-6. Liver specimens were processed for light and electron microscopic study. In the I/R group, the superoxide dismutase level decreased and plasma levels of malondialdehyde, tumor necrosis factor-alpha, and interleukin-6 significantly increased when compared with the control group. Light microscopic examination showed hepatocytes with vacuolated cytoplasm, dilated blood sinusoids, and portal vessels. An extensive amount of collagen fibers around portal tracts and intense immune reaction for caspase-3 were observed. The ultrastructure showed hepatocytes with swollen mitochondria and disrupted cristae and others with an electron-dense matrix. Kupffer cells showed apoptotic bodies. Ito cells appeared surrounded by wide areas of collagen fibers. The exercise+I/R group showed significant attenuation of the biochemical and histological alterations of I/R-induced liver injury. Exercise could attenuate remote liver damage following hind-limb I/R injury

Hypoglycemic and anti apoptotic effect of garlic in streptozotocin induced diabetic rats

Diabetes mellitus is caused by many factor include oxidative stress that leads to apoptosis of beta cells of the pancreas and so the antioxidant therapy strongly correlated with decrease risk of diabetes mellitus. The aim of the present study was to investigate the efficacy of an aqueous extract of raw garlic in controlling serum glucose, plasma c peptide of insulin, level of reduced glutathione and catalase activity in pancreatic tissue, also to estimate caspase 3 activity expression in pancreatic tissue in streptozotocin induced diabetic rats treated daily with garlic extract intraperitoneally [IP] for 6 weeks. This study was carried on 30 rats: grouped into 3 group. Group 1, the control normal group, was injected IP daily with 0.5 ml saline and group 2; diabetic group was injected with streptozotocin, 60 mg/Kg body weight [BWt] IP in 0.5 ml saline once and group 3; garlic-treated group, was injected IP daily with 500 mg/kg of the garlic extract 2 weeks before streptozotocin and 4 week after streptozotocin injection. There was a significant increase in blood glucose in streptozotocin group II [p = 0.001] as compared with control groups [331.3 +/- 16.15 vs 101.8 +/- 4.02 mg/dl] respectively and significantly decreased after treatment with garlic extract [161.5 +/- 5.28 mg/dl]. C peptide was significantly decreased in streptozotocin group II [p = 0.001] as compared with control groups [0.034 +/- 0.003 vs 0.053 +/- 0.001 ng/ml] respectively and significantly increased after treatment with garlic extract [0.046 +/- 0.003]. Catalase activity of pancreatic tissue was significantly decreased in streptozotocin group [p = 0.001] as compared with control groups [11.10 +/- 0.73 vs 25.7 +/- 0.55 U/gm tissue] respectively and significantly increased after treatment with garlic extract [20.3 +/- 0.66]. Reduced glutathione content of pancreatic tissue was significantly decreased in streptozotocin group [p = 0.001] as compared with control groups [0.67 +/- 0.055 vs 1.23 +/- 0.076 mg/g tissue] respectively and significantly increased after treatment with garlic extract [0.89 +/- 0.080 mg/g tissue]. Also it was observed that the expression of caspase 3 protein in the pancreatic tissue was decreased after garlic treatment using western blot technique. These results revealed that aqueous extract of raw garlic may have antioxidant and antiapoptotic activity that could be used in treatment of diabetes mellitus

Evaluation of oxidative stress and apoptosis in breast cancer

Reactive oxygen species are important in the pathogenesis of many diseases, including breast cancers. In this study, we aimed to evaluate oxidative stress in patients with breast cancer and to investigate its relationship with apoptosis. Our results showed that, the median levels and positivity rates of Malondialdehyde [MDA], Nitric Oxide [NO], Total Antioxidant [TAO], caspase-3,%DNA fragmentation and MDA/TAO ratio measured in breast cancer tissues by colorimetric methods were higher in the malignant group as compared to benign control group. Moreover, MDA, NO and%DNA fragmentations were over produced in advanced grade and stage P<0.05. Furthermore, a significant positive correlation was found between MDA/TAO ratio and positive lymph node metastasis. Also, there were significant positive correlations of caspase-3 and%DNA fragmentation with positive estrogen receptor and NO. Moreover, the total antioxidants were positively correlated with positive progesterone receptor. In Conclusion; oxidative stress, NO and apoptosis are highly detected in breast cancer tissues especially with advanced grade and stage

possible renoprotective effect of some drugs inducing heat shock proteins in renal ischemic reperfusion injury in rats

Renal ischemia reperfusion [RIRI] injury is a clinically important problem. The aim of this study was to assess the possible renoprotective effect of inducing heat shock proteins by hydrocortisone and acetylsalicylic acid [ASA] in RIRI in rats. The present study was conducted on 56 male albino rats that were divided into four groups. Group I included normal Sham-operated rats that served as control for group II, Group II was subdivided into Group IIa in which renal ischemia reperfusion injury [RIRI] was induced and group IIb [in which RIRI was induced and received quercetin [HSP70 inhibitor] 24 hours and again 1 hour prior to the induction of RIRI. Groups III and IV consisted of rats with RIRI that received hydrocortisone without [Group IIIa] or with [Group IIIb] quercetin, and that received ASA without [Group IVa] or with [Group IVb] quercetin, respectively, intramuscularly 24 and 12 hours before and after the induction of RIRI. Thirty hours after induction of RIRI, serum urea concentration and creatinine clearance were assessed. Moreover; renal heat shock protein-70 [HSP70] level and renal caspase-3 activity [as an index of apoptosis] were assessed. A significant increase in serum urea concentration and in renal HSP70 level, and caspase-3 activity together with a significant decrease in creatinine clearance, has been observed in non-treated rats [group II] killed 30 hrs after RIRI compared to Sham-operated rats. Administration of hydrocortisone or ASA resulted in a significant decrease in serum urea concentration and in renal caspase-3 activity as well as a significant increase in creatinine clearance and a significant increase in renal HSP70 in rats killed 30 hrs following RIRI [group III and IV] compared to non-treated rats with RIRI. Induction of HSP70 mediated the renoprotective role of both drugs evidenced by a significant decrease in renoprotective effect of either drug in the groups that received quercetin [IIIb and IVb] compared to those that didn't receive quercetin [IIIa and IVa]. This study demonstrates a role for HSP70 in protection against RIRI. Pharmacological strategies to increase stress protein expression have potential merit to prevent ischemic injury to the kidney and other organs. The ability of hydrocortisone and ASA to induce ischemic tolerance suggests that there are advantages in their application in RIRI. First, either is a safe drug in clinical practice. Second, the induction time of ischemic tolerance is relatively rapid after administration of either. Third, there is no additional or special equipment required for the induction of tolerance. Clinical studies will be necessary to evaluate the therapeutic properties of either drug in preventing I/R injury not only in kidneys but also in other solid organs

Targeting apoptosis in the heart of streptozotocin-induced diabetic rats

To address the issue of cardiomyocyte apoptosis as a possible cause of diabetic cardiomyopathy and whether it would be possible to suppress this apoptosis by the use of PPAR gamma agonists [glitazones] and PPAR alpha agonists [fibrates], versus insulin. forty male rats were made diabetic by intraperitoneal [i.p.] streptozotocin [STZ] injection and were divided into four groups: group II [STZ-injected rats], groups III, IV and V [STZ-injected rats treated with insulin, PPAR gamma agonist [rosiglitazone] and PPAR alpha agonist [bezafirate] respectively, for twelve weeks starting one week following STZ injection]. Additionally, ten rats were injected i.p. by a single dose of saline and served as a control for group II. At the end of the experimental period, plasma glucose was measured. Left ventricular [LV] papillary muscles isometric force [developed tension [DT]] was determined. Oxidative stress as assessed by cardiac malondialdehyde [MDA] and reduced glutathione [GSH] concentrations as well as caspase-3 activity as an index of apoptosis were determined. STZ-injection induced diabetes, evidenced by significant higher mean value in plasma glucose concentration in group II compared to that of the control group I. Significant cardiomyopathy could be observed, in the form of significantly decreased DT of LV papillary muscles in group II compared to the control group I. STZ-injection resulted in oxidative stress evidenced by significant higher mean value in cardiac MDA concentration and significant lower mean value in cardiac GSH concentration in group II compared to the control group I. STZ-injection resulted in cardiac apoptosis evidenced by significant higher mean value in cardiac caspase-3 activity in group II compared to the control group I. The use of insulin, rosiglitazone as well as bezafibrate caused a significant decrease in plasma glucose concentration as well as a significant increase in body weight compared to group II. The use of insulin as well as rosiglitazone, but not bezafibrate, decreased cardiac caspase-3 activity and improved oxidative stress parameters evidenced by significant lower mean value in cardiac MDA concentration and significant higher mean value in cardiac GSH concentration compared to group II. Rosigitazone but neither insulin nor bezafibrate resulted in significant improvement of LV papillary muscle DT compared to group II. The results of the present study support the hypothesis that apoptosis plays a key role in the pathophysiology of diabetic cardiomyopathy and demonstrate that the use of PPAR gamma agonists might have a protective role against diabetic cardiomyopathy. We recommend further human studies to evaluate the role of the addition of PPAR gamma agonists to the treatment regimen of diabetes, from the onset of the disease, in protection against diabetic cardiomyopathy. Although the use of PPAR-alpha agonists seems counterintuitive in light of the current findings, the benefit of reduced delivery of fatty acids to the myocardium may outweigh the effects of activating the cardiac PPARalpha pathway in the diabetic patient

study of possible pro-oxidant and apoptotic effects of hyperhomocysteinemia on rat kidney and the influence of folic acid supplementation

Although kidney dysfunction is an important risk factor causing hyperhomocysteinemia [HHcy], recent evidence documents direct role of HHcy in glomerular and interstitial damage. However, the mechanism mediating these pathogenic renal effects of HHcy is poorly understood. In the present study, we hypothesized that if HHcy induced DNA damage and apoptosis that was dependent on oxidative stress, folic acid supplementation would have a major preventive effect. The study was carried out on [20] albino rats classified into 2 groups each including ten animals. Folate-free group [FF] that were fed folatedeficient diet and folate-supplemented group [FS] that were supplemented with folic acid [8 mg / Kg diet] . The feeding of animals continued for 4 weeks after which, blood samples were collected for estimation of folate, homocysteine [Hcy], urea and creatinine. Then, the animals were scarified and kidneys were removed. Kidney homogenates were used for measurement of renal oxidative stress markers including renal malondialdehyde [MDA] and reduced glutathione [GSH]; in addition to renal caspase-3 activity as an apoptotic marker. The results showed that HHcy was confirmed in FF group, with higher MDA and lower GSH levels in renal tissues as compared with FS group. Also, renal Caspase 3 activity was significantly elevated in FF group compared with FS group. Significant correlations were detected between plasma Hcy, plasma folic acid, renal oxidative stress markers and renal caspase 3 activity. It was concluded that dietary folate deprivation either directly or secondary to elevated plasma Hcy concentrations increased susceptibility of renal tissue to lipid peroxidation associated with enhanced apoptotic activity. Thus, Folate supplementation is warranted as it could have a protective effect on kidney either directly or via ameliorating HHcy