Examining the endogenous antioxidant response through immunofluorescent analysis of Nrf2 in tissue

Synergistic Effects of Vitamin D and Exercise on Diabetes-induced Gonadotoxicity in Male Wistar Rats: Role of Xanthine Oxidase/Uric Acid and Nrf2/NfkB Signaling

Type 2 Diabetes mellitus (T2DM) is one of the oldest known chronic diseases, characterized by elevated fasting blood sugar (FBS). T2DM is a metabolic disorder that can distort the activities of multiple physiological systems, including the reproductive system. Although different drugs have been designed for managing this disorder, these drugs have been reported to have negative side effects. Hence, this study was designed to explore the possible synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction. Thirty-six male Wistar rats were randomized into six (6) groups: control, diabetes untreated, diabetes treated with 1000 IU/kg of vitamin D, diabetes treated with 5 min/day of physical exercise, diabetes treated with vitamin D and exercise, diabetes treated with 180 mg/kg of metformin. T2DM induction led to a significant increase in FBS, lactate, and lactate dehydrogenase, and was reversed by vitamin D supplementation and exercise. Also, vitamin D and exercise synergistically blunted T2DM-induced oxido-inflammatory response evidenced by a significant decrease in testicular malondialdehyde, interleukin 1β, interleukin 6, and tumor necrosis factor alpha, and an increase in superoxide dismutase, catalase, glutathione peroxidase, and interleukin 10. These events were associated with a decrease in T2DM-induced increase in XO, UA, and Nf-κb and an increase in T2DM-induced decrease in Nrf2. Also, vitamin D and EX reversed the observed impairment in sperm quality and testicular histology following T2DM-induction. This study revealed the synergistic effect of vitamin D and exercise on T2DM-induced testicular dysfunction.

Zinc abates sodium benzoate -induced testicular dysfunction via upregulation of Nrf2/ HO-1/ Nf-κB signaling and androgen receptor gene

BACKGROUND

Sodium Benzoate (SB) is used in daily products such as drinks, juices, sauces, oils, ketchup, toothpaste, mouthwashes, cosmetics, dentifrices, and pharmaceutical products. However, SB has been implicated in gonadotoxicity even at a dosage within the safe limit. Zinc (Zn), on the other hand, has been shown to improve various fertility indices. Hence, this study was designed to explore the possible ameliorative effect of Zn on SB-induced testicular toxicity.

METHODS

Animals were randomly divided into control, SB, Zn, and SB+Zn. All treatment lasted for 28 days.

RESULTS

SB treatment caused a derangement in reproductive hormone levels, sperm function, and kinematics and a down-regulation of the Androgen receptor (ANDR). Also, a decrease in testicular levels of SOD, CAT, GSH, Nrf2, and HO- 1 activity and an increase in IL-1β, TNF-α, Nf-κB, and Caspase 3 were observed. These SB-induced distortions were ameliorated in SB-treated rats exposed to Zn.

CONCLUSION

Our study suggests that zinc abates SB-induced testicular toxicity by modulating Nrf2/HO-1/ Nf-κB signaling and ANDR upregulation.

Carob (Ceratonia siliqua L.) fruit hydro-alcoholic extract alleviates reproductive toxicity of lead in male mice: Evidence on sperm parameters, sex hormones, oxidative stress biomarkers and expression of Nrf2 and iNOS

OBJECTIVE

Carob (Ceratonia siliqua L.) is an evergreen tree with fruits that have potent antioxidant activity. The aim of this study was to investigate alleviative effects of carob fruit hydro-alcoholic extract (CFHAE) against reproductive toxicity induced by lead (Pb) in male mice.

MATERIALS AND METHODS

Forty-two NMRI adult male mice were randomly categorized into 7 groups (N=6). Group I was the control group and received no treatment. Group II was the sham group and received 0.2 ml distilled water per day. Group III (Pb group) received Pb acetate 1000 ppm/kg/day. Groups IV and V received CFHAE 500 and 1000 mg/kg/day, respectively. Groups VI and VII received both Pb 1000 ppm/kg/day and CFHAE at doses of 500 and 1000 mg/kg/day, respectively at the same time. The groups were treated by gavage. After 35 days, sperm parameters (count, motility, morphology, viability, DNA damage, and teratozoospermia index), total antioxidant capacity (TAC), reduced glutathione content (GSH), antioxidant enzymes (SOD, CAT, and GPx) activity, MDA levels, and sex hormones (FSH, LH, and testosterone) concentrations in serum, testicular expression of Nrf2 and iNOS genes and histopathological alterations were evaluated.

RESULTS

Our findings revealed that co-administration of CFHAE with Pb significantly (p<0.05 to p<0.01) improved sperm parameters, elevated sex hormones, TAC, GSH content, and antioxidant enzymes activity of serum, decreased serum MDA levels, and down-regulated testicular expression of Nrf2 and iNOS genes compared with Pb group. Also, CFHAE ameliorated histopathological alterations in testis tissue caused by Pb.

CONCLUSION

CFHAE can alleviate reproductive toxicity following Pb exposure in male mice.

Seabuckthorn Paste Protects Lipopolysaccharide-Induced Acute Lung Injury in Mice through Attenuation of Oxidative Stress

Oxidative stress is one of the major mechanisms implicated in endotoxin-induced acute lung injury. Seabuckthorn paste (SP), a traditional Tibetan medicine with high content of polyphenols and remarkable antioxidant activity, is commonly used in treating pulmonary diseases. In the present study, the protective effects and possible underlying mechanisms of SP on lipopolysaccharide- (LPS-) induced acute lung injury in mice were investigated. It was found that body weight loss, lung tissue microstructure lesions, transvascular leakage increase, malondialdehyde augmentation, and the reduction of superoxide dismutase and glutathione peroxidase levels caused by LPS challenge were all consistently relieved by SP treatment in a dose-dependent manner. Moreover, accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) in lung nuclei caused by SP treatment was observed. Our study demonstrated that SP can provide significant protection against LPS-induced acute lung injury through maintaining redox homeostasis, and its mechanism involves Nrf2 nuclear translocation and activation.

Abrogation of Nrf2 impairs antioxidant signaling and promotes atrial hypertrophy in response to high-intensity exercise stress

BACKGROUND

Anomalies in myocardial structure involving myocyte growth, hypertrophy, differentiation, apoptosis, necrosis etc. affects its function and render cardiac tissue more vulnerable to the development of heart failure. Although oxidative stress has a well-established role in cardiac remodeling and dysfunction, the mechanisms linking redox state to atrial cardiomyocyte hypertrophic changes are poorly understood. Here, we investigated the role of nuclear erythroid-2 like factor-2 (Nrf2), a central transcriptional mediator, in redox signaling under high intensity exercise stress (HIES) in atria.

METHODS

Age and sex-matched wild-type (WT) and Nrf2(-/-) mice at >20 months of age were subjected to HIES for 6 weeks. Gene markers of hypertrophy and antioxidant enzymes were determined in the atria of WT and Nrf2(-/-) mice by real-time qPCR analyses. Detection and quantification of antioxidants, 4-hydroxy-nonenal (4-HNE), poly-ubiquitination and autophagy proteins in WT and Nrf2(-/-) mice were performed by immunofluorescence analysis. The level of oxidative stress was measured by microscopical examination of di-hydro-ethidium (DHE) fluorescence.

RESULTS

Under the sedentary state, Nrf2 abrogation resulted in a moderate down regulation of some of the atrial antioxidant gene expression (Gsr, Gclc, Gstα and Gstµ) despite having a normal redox state. In response to HIES, enlarged atrial myocytes along with significantly increased gene expression of cardiomyocyte hypertrophy markers (Anf, Bnf and β-Mhc) were observed in Nrf2(-/-) when compared to WT mice. Further, the transcript levels of Gclc, Gsr and Gstµ and protein levels of NQO1, catalase, GPX1 were profoundly downregulated along with GSH depletion and increased oxidative stress in Nrf2(-/-) mice when compared to its WT counterparts after HIES. Impaired antioxidant state and profound oxidative stress were associated with enhanced atrial expression of LC3 and ATG7 along with increased ubiquitination of ATG7 in Nrf2(-/-) mice subjected to HIES.

CONCLUSIONS

Loss of Nrf2 describes an altered biochemical phenotype associated with dysregulation in genes related to redox state, ubiquitination and autophagy in HIES that result in atrial hypertrophy. Therefore, our findings direct that preserving Nrf2-related antioxidant function would be one of the effective strategies to safeguard atrial health.

The chronic effects of low lead level on the expressions of Nrf2 and Mrp1 of the testes in the rats

Lead is linked to many reproductive problems. This study was to explore the chronic effects of low lead level on expressions of Nrf2 and Mrp1 in rats' testes. Maternal SD rats were administered lead acetate from 10 days before gestation to weaning at three doses respectively after randomization. From each group, 15 male offsprings were then chosen and administrated lead acetate from weaning to six months old at the doses of 0, 0.3 and 0.9g/L respectively. The dose administrations were through drinking water freely. The methods of RT-PCR, Western blotting and immunohistochemistry were used for Mrp1 and Nrf2 of the testes. Compared with control group, significant increases were observed in the expressions of Mrp1 and Nrf2 in two lead groups (P<0.05); nucleus translocation of Nrf2 was observed; both GST and GSH was decreased with increasing the lead dose. In conclusion, Mrp1 might play important roles in lead detoxification by Nrf2.

Cystamine protects from 3-nitropropionic acid lesioning via induction of nf-e2 related factor 2 mediated transcription

Systemic administration of cystamine is known to protect from both chemical and genetic models of neurotoxicity. Despite positive effects in laboratory models, cystamine has not been successfully translated to clinical application for neurodegenerative disease. Furthermore, the long held assumption that cystamine protects through tissue transglutaminase inhibition has recently been challenged. The studies described here examine other potential mechanisms of cystamine-mediated protection in an attempt to reveal molecular targets for neurodegenerative therapy. Based on previously described effects of cystamine, we examined the potential for activation of NF-E2 related factor 2 (Nrf2) mediated signaling through the antioxidant response element (ARE). We found that cystamine activates Nrf2/ARE both in cell culture and in brain tissue and then probed the mechanism of activation in cell culture. In live animals, we show that neuroprotection from 3-nitropropionic acid (3NP) toxicity is Nrf2-dependent. Therefore, these findings provide strong evidence that Nrf2 signaling may be an effective target for prevention of neurodegeneration.

The drug monosodium luminol (GVT) preserves crypt-villus epithelial organization and allows survival of intestinal T cells in mice infected with the ts1 retrovirus

Of the cytopathic retroviruses that affect mammals, including HIV-1, many selectively infect CD4+ T cells and cause immunosuppressive syndromes. These diseases destroy both the thymus and the small and large intestines, after infecting and killing T-lineage cells in both tissues. A mutant of the murine leukemia retrovirus MoMuLV-TB, called ts1, causes this syndrome in susceptible strains of mice. In FVB/N strain mice that are infected at birth, thymic atrophy, CD4+ T cell loss, intestinal collapse, body wasting, and death occur by approximately 30-40 days postinfection (dpi). Apoptosis of ts1-infected T-lineage cells, in the thymus, peripheral lymphoid system and intestines is caused by accumulation of the ts1 mutant viral envelope preprotein gPr80(env), which is inefficiently cleaved into the mature viral proteins gp70 and PrP15E. We show here that ts1 infection in the small intestine is followed by loss of intestinal epithelial cell (IEC) thyroid-stimulating hormone (TSH) and cell cycling gradients (along the crypt-villus axes), accumulation of gPr80(env) in intestinal cells, apoptosis of developing T cells in the lamina propria (LP), and intestinal collapse by approximately 30 dpi. In infected mice treated with the antioxidant drug monosodium luminol (GVT), however, normal intestinal epithelial cell gradients are still in place at 30 dpi, and IECs covering both the crypts and villi contain large amounts of the antioxidant transcription factor Nrf2. In addition, no apoptotic cells are present, and accumulated gpr80(env) is absent from the tissue at this time. We conclude that GVT treatment can make ts1 a noncytopathic virus for intestinal lymphoid cells, as it does for thymocytes [25]. As in the thymus, GVT may protect the intestine by reducing oxidant stress in infected intestinal T cells, perhaps by prevention of gPr80(env) accumulation via Nrf2 upregulation in the IECs. These results identify GVT as a potential therapy for intestinal diseases or inflammatory conditions, including HIV-AIDS, in which oxidative stress is a triggering or exacerbating factor.