Mouse model of nitric oxide deficiency, induced by prolonged treatment with NG‐nitro‐L‐arginine methyl ester (L‐NAME) was used for infrared spectroscopy (FTIR) analysis of plasma. L‐NAME leads to increased peripheral resistance and systemic hypertension. Classification of spectral response was by principal component analysis (PCA) and linear discriminant analysis (LDA). PCA allowed to separate each animal group showing that FTIR spectra are sensitive to development of NO‐deficiency on contrary to blood pressure values indicating hypertension. Globally, the most pronounced spectral alternations were observed in the second and third week of L‐NAME treatment indicating that infrared signature of blood plasma can serve as indicator of early and late stages of the disease. The PLS‐DA method provided >95% classification accuracy. Spectral features characteristic for L‐NAME treatment were mainly associated with an elevated level of proteins accompanied by a decrease of a tyrosine content and changes in lipids/phospholipid concentration. In our work we discuss these changes for which statistically significant differences (p < 0.05 – 0.005) were observed between spectra collected for each time‐point of the L‐NAME treatment versus control subjects. We demonstrated for the first time that NO‐deficiency and hypertension resulted in changes in biochemical profile of plasma that was detected by FTIR spectroscopy.
BACKGROUND: To test whether the differentiating embryo is susceptible to the teratogenic effects of the nitric oxide (NO) synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME). METHODS: ICR-(CD-1) mice received a single intraperitoneal injection of L-NAME at 90, 150, or 300 mg/kg on Gestation Day (GD) 8 or 9. Controls were treated with vehicle on GD 8 and 9. Teratological assessments were carried out near term (GD 18). RESULTS: Maternal treatment with a single dose of L-NAME at 150 or 300 mg/kg on either GD 8 or 9 produced axial skeletal defects in the ICR (CD-1) mouse fetuses. Other treatment-related effects included increased embryo lethality and fetal growth restriction. CONCLUSIONS: This study provides evidence that in utero exposure to L-NAME can affect organogenesis of the axial skeleton. 相似文献
Mechanism of testicular toxicity induced by dietary cadmium (Cd) has been less investigated than that following acute Cd injection. In the present study we characterized testicular injury in a small rodent, the bank vole, exposed subchronically to dietary Cd in a quantity of 0.9 mol/g, and determined the importance of some factors (Cd accumulation, metallothionein (MT), oxidative stress, and zinc (Zn)) in the injury. Dietary Cd induced moderate histopathological changes (hemorrhage in interstitium, necrosis and apoptosis in seminiferous tubule epithelium) in young (1 month old) bank voles fed, for 6 weeks, Fe-adequate (1.1–1.4 mol/g) and Fe-enriched (4.5–4.8 mol/g) diets. In contrast, adult (5 months old) bank voles appeared to be resistant to the toxic effects of dietary Cd, despite the fact that testicular Cd contents were higher and MT levels lower than those in the young animals. The Cd-induced histopathological changes and apoptosis were accompanied by increased testicular lipid peroxidation, decreased testicular Zn concentration and elevated levels of hepatic and renal MT and Zn. Supplemental dietary Zn (1.7–1.8 mol/g) prevented the Cd-induced testicular Zn depletion and injury. The data indicate that dietary Cd produces testicular lesions indirectly, through decreasing testicular Zn, which seems to be due to the sequestration of this element by the Cd-induced hepatic and renal MT. 相似文献
AbstractAims. Endoplasmic reticulum (ER) stress exerts myocardial oxidative stress, apoptosis, and contractile anomalies, although the precise interplay between ER stress and apoptosis remains elusive. This study was designed to examine the impact of the cysteine-rich free radical scavenger metallothionein on ER stress-induced myocardial contractile defect and underlying mechanisms. Methods and results. Wild-type friendly virus B and transgenic mice with cardiac-specific overexpression of metallothionein were challenged with the ER stress inducer tunicamycin (1 mg/kg, intraperitoneal, 48 h) prior to the assessment of myocardial function, oxidative stress, and apoptosis. Our results revealed that tunicamycin promoted cardiac remodeling (enlarged left ventricular end systolic/diastolic diameters with little changes in left ventricular wall thickness), suppressed fractional shortening and cardiomyocyte contractile function, elevated resting Ca2+, decreased stimulated Ca2+ release, prolonged intracellular Ca2+ clearance, and downregulated sarco(endo)plasmic reticulum Ca2+-ATPase levels, the effects of which were negated by metallothionein. Treatment with tunicamycin caused cardiomyocyte mitochondrial injury, as evidenced by decreased mitochondrial membrane potential (??m, assessed by JC-1 staining), the effect of which was negated by the antioxidant. Moreover, tunicamycin challenge dramatically facilitated myocardial apoptosis as manifested by increased Bax, caspase 9, and caspase 12 protein levels, as well as elevated caspase 3 activity. Interestingly, metallothionein transgene significantly alleviated tunicamycin-induced myocardial apoptosis. Conclusion. Taken together, our data favor a beneficial effect of metallothionein against ER stress-induced cardiac dysfunction possibly associated with attenuation of myocardial apoptosis. 相似文献
Paraquat is a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant 1-methyl-4-phenyl-pyridine and acts as a potential etiologic factor for the development of Parkinson's disease. In this study, we investigated the protective roles of lipocalin-type prostaglandin (PG) D synthase (L-PGDS) against paraquat-mediated apoptosis of human neuronal SH-SY5Y cells. The treatment of SH-SY5Y cells with paraquat decreased the intracellular GSH level, and enhanced the cell death with elevation of the caspase activities. L-PGDS was expressed in SH-SY5Y cells, and its expression was enhanced with the peak at 2?h after the initiation of the treatment with paraquat. Inhibition of PGD? synthesis and exogenously added PGs showed no effects regarding the paraquat-mediated apoptosis. SiRNA-mediated suppression of L-PGDS expression in the paraquat-treated cells increased the cell death and caspase activities. Moreover, over-expression of L-PGDS suppressed the cell death and caspase activities in the paraquat-treated cells. The results of a promoter-luciferase assay demonstrated that paraquat-mediated elevation of L-PGDS gene expression occurred through the NF-κB element in the proximal promoter region of the L-PGDS gene in SH-SY5Y cells. These results indicate that L-PGDS protected against the apoptosis in the paraquat-treated SH-SY5Y cells through the up-regulation of L-PGDS expression via the NF-κB element. Thus, L-PGDS might potentially serve as an agent for prevention of human neurodegenerative diseases caused by oxidative stress and apoptosis. 相似文献
Objective : Determine the biochemical pathways involved in induction of apoptosis by ajoene, an organosulfur compound from garlic. Research Methods and Procedures : Mature 3T3‐L1 adipocytes were incubated with ajoene at concentrations up to 200 μM. Viability and apoptosis were quantified using an MTS‐based cell viability assay and an enzyme‐linked immunosorbent assay for single‐stranded DNA (ssDNA), respectively. Intracellular reactive oxygen species (ROS) production was measured based on production of the fluorescent dye, dichlorofluorescein. Activation of the mitogen‐activated protein kinases extracellular signal‐regulating kinase 1/2 (ERK) and c‐Jun‐N‐terminal kinase (JNK) was shown by Western blot. Western blot was also used to show activation of caspase‐3, translocation of apoptosis‐inducing factor (AIF) from mitochondria to nucleus, and cleavage of 116‐kDa poly(ADP‐ribose) polymerase (PARP)‐1. Results : Ajoene induced apoptosis of 3T3‐L1 adipocytes in a dose‐ and time‐dependent manner. Ajoene treatment resulted in activation of JNK and ERK, translocation of AIF from mitochondria to nucleus, and cleavage of 116‐kDa PARP‐1 in a caspase‐independent manner. Ajoene treatment also induced an increase in intracellular ROS level. Furthermore, the antioxidant N‐acetyl‐l ‐cysteine effectively blocked ajoene‐mediated ROS generation, activation of JNK and ERK, translocation of AIF, and degradation of PARP‐1. Discussion : These results indicate that ajoene‐induced apoptosis in 3T3‐L1 adipocytes is initiated by the generation of hydrogen peroxide, which leads to activation of mitogen‐activated protein kinases, degradation of PARP‐1, translocation of AIF, and fragmentation of DNA. Ajoene can, thus, influence the regulation of fat cell number through the induction of apoptosis and may be a new therapeutic agent for the treatment of obesity. 相似文献
Our previous studies have shown that vanadium, a dietary micronutrient, has an inhibitory effect against experimentally induced rat hepatocarcinogenesis. In this study, we evaluated the role of vanadium on some potential protein expression markers of carcinogenesis, such as metallothionein (MT), an intracellular metal-binding protein linked with cell proliferation and apoptosis, Ki-67 nuclear antigen, and p53 tumor suppressor during 2-acetylaminofluorene (2-AAF)-induced (0.05% in basal diet) rat liver preneoplasia. In a short-term regimen, supplementation of vanadium at a dose of 0.5 ppm effectively suppressed the formation of DNA 'comets' (29.55%; P < 0.02), thereby indicating its nongenotoxicity at this particular dose. Vanadium administration throughout the study reduced relative liver weight (RLW), nodular incidence (57.15%), total number, and multiplicity (48.45%) with restoration of hepatic zinc (Zn), magnesium (Mg), selenium (Se), copper (Cu), iron (Fe), and calcium (Ca) contents when compared to the carcinogen control. Moreover, treatment with vanadium significantly abated the expressions of MT and Ki-67, studied at four sequential time points. An increased immunopositivity of p53 protein (1.03 +/- 0.23%; P < 0.02) was found in vanadium-treated rat liver with an elevated apoptotic-labeling index (AI; P < 0.001) as documented by TUNEL assay. Furthermore, a positive correlation between MT expression and Ki-67 labeling along with a strong negative correlation between MT immunoreactivity and AI (r = -0.9000, P = 0.0004 at week 24) at various time intervals suggest that, vanadium-mediated suppression of MT and Ki-67 expressions may be associated with induction of apoptosis. The results thus provide evidence for the first time in support of the potential role of vanadium on induction of p53 and apoptosis with concurrent suppression of MT and Ki-67 in order to have an understanding, in part, of the chemopreventive mechanism of this trace element in limiting neoplastic transformation in a defined model of experimental rat hepatocarcinogenesis. 相似文献
Up-regulation of insulin-like growth factor 2 receptor (IGF-2R) involved in angiotensin II-induced cell apoptosis in cardiomyoblasts, and correlated with cardiomyocyte apoptosis in hypertensive rat hearts. Here, we detected IGF-2R levels and explored the possible underlying implications in end-stage heart failure (HF) patients before and after heart transplantation. Western blot and immunohistochemistry were used to measure cardiac IGF-2R levels. ELISA was used to detect serum IGF-2R and CD8 levels. Labelling of DNA strand breaks and dihydroethidium detection were used to determine cellular apoptosis and reactive oxygen species, respectively. Cardiac IGF-2R levels increased in end-stage HF patients (n = 11) compared with non-failing control subjects. Leu27-IGF-2, an IGF-2 analogue to activate specially the IGF-2R, could induce apoptosis and reactive oxygen species production in neonatal rat ventricular myocytes. The serum IGF-2R levels were significantly higher in HF patients than those in non-failing control subjects. An unexpected observation is that the serum IGF-2R levels further increased after heart transplantation, peaked at the first month, and gradually reduced close to the levels before heart transplantation at the 6th months after heart transplantation. Serum CD8, a marker of acute rejection, had no change after heart transplantation, but IGF-2R and Granzyme B, as a ligand for the IGF-2R and a marker for CD8 T lymphocyte activation, coexisted in the transplanted hearts. Our preliminary studies suggest that elevation of IGF-2R may participate in pathological process of end-stage HF and involved in the acute cellular rejection after heart transplantation. 相似文献
Although the neurotoxicity of trimethyltin (TMT) is well known, mechanisms are still not clear. Glia have been proposed to mediate the toxic action of TMT on nerve cells. Accordingly, the effects of TMT were tested in primary neuronal cultures from rat cerebellum and compared to effects in astrocytes and mixed cultures. Neuronal damage observed following TMT exposure was less in the presence of astrocytes and astrocytes alone were resistant to TMT. Thus, astrocytes have a protective effect against TMT-induced neurotoxicity. TMT caused an oxidative stress in granule cell cultures involving a variety of oxidative species (O2)*-, H2O2, NO), but astrocytes were less sensitive to TMT-induced oxidative species generation. Antioxidants, glutathione and 7-nitroindazole attenuated neuronal cell death induced by TMT. It appears that oxidative stress mediates a large part of the destructive action of TMT in neuronal cultures. The presence of astrocytes appears to modulate TMT-induced oxidative stress so that TMT causes only a small increase in lipid peroxidation in mouse brain after systemic administration. Thus, TMT induces a pronounced oxidative stress in cultured neurons, but when astrocytes are present, oxidative species play a lesser role in the neurotoxic action of TMT. 相似文献
Ubiquitin carboxyl-terminal hydrolase 1 (UCH-L1) can be detected in mouse testicular germ cells, mainly spermatogonia and somatic Sertoli cells, but its physiological role is unknown. We show that transgenic (Tg) mice overexpressing EF1alpha promoter-driven UCH-L1 in the testis are sterile due to a block during spermatogenesis at an early stage (pachytene) of meiosis. Interestingly, almost all spermatogonia and Sertoli cells expressing excess UCH-L1, but little PCNA (proliferating cell nuclear antigen), showed no morphological signs of apoptosis or TUNEL-positive staining. Rather, germ cell apoptosis was mainly detected in primary spermatocytes having weak or negative UCH-L1 expression but strong PCNA expression. These data suggest that overexpression of UCH-L1 affects spermatogenesis during meiosis and, in particular, induces apoptosis in primary spermatocytes. In addition to results of caspases-3 upregulation and Bcl-2 downregulation, excess UCH-L1 influenced the distribution of PCNA, suggesting a specific role for UCH-L1 in the processes of mitotic proliferation and differentiation of spermatogonial stem cells during spermatogenesis. 相似文献
