Abstract

Purpose of the Study: To investigate the role of paraoxonase 1 (PON1) and vitamin E in the pathogenesis of some autoimmune diseases, and to correlate their levels with the disease activity. Procedures: This randomized case control study was performed on 60 subjects: 45 patients [suffering from psoriasis, vitiligo and alopecia areata (AA) 15 patients each group] and 15 healthy controls. Venous blood and tissue biopsy were collected from each subject to estimate the levels of vitamin E and PON1. Results: All patients showed significantly lower levels of both PON1 and vitamin E in tissue and serum than the controls (p < 0.001). Conclusion: An association between oxidative stress and pathogenesis of these autoimmune diseases is identified. Attenuation of oxidative stress might be a relevant therapeutic approach and it would be useful to recommend additional drugs with antioxidant effects in the treatment of these conditions.

Abstract

Microvascular injury and increased vascular leak are prominent features of radiation-induced lung injury (RILI) andoften follow cancer-associated thoracic irradiation.Our previous studies demonstrated that polymorphisms in the gene (MIF)encoding macrophage migratory inhibition factor (MIF), a multi-functional pleiotropic cytokine, confer susceptibility to acute inflammatory lung injury and increased vascular permeability. In this study, we exposed wildtype (WT) and genetically engineered mif-/-miceto 20 Gysingle fraction thoracic radiation to investigate the age-related role of MIF in a preclinical model of murine RILI (ages 8 wk, 8 mos, 16 mos). Relative to 8wk old mice,decreased MIF was observed in bronchoalveolar lavage (BAL)fluid and lung tissues of 8-16 mos wildtypemice.Additionally, radiated 8-16 mosmif-/-mice exhibit significantly decreased total antioxidant levelsin BAL with progressive age-related decreasesin nuclear expression of Nrf2, a transcription factor involved in antioxidant gene upregulation in response to reactive oxygen species. This was accompanied by decreasesin both protein levels (NQO1, GCLC, heme oxygenase-1) and mRNA levels (Gpx1, Prdx1,Txn1) of Nrf2-influenced antioxidant gene targets.Additionally, MIF-silenced (siRNA) human lung endothelial cells failed to express Nrf2 following oxidative (H2O2) challenge, an effect reversed byrecombinant MIF administration. However, treatment withan antioxidant (GSH) but not an Nrf2 substrate (NAC), protected aged mif-/-mice from RILI.These findings implicatean important role for MIFin radiation-induced alterations in lung cell antioxidant levels via Nrf2and suggest that MIF may contribute to age-related susceptibility to thoracic radiation.

Abstract

Migrating fish such as salmonids are affected by external environmental factors and salinity changes are particularly important, influencing spawning migration. The aim of this study was to test whether changes in salinity would affect the expression of the hypothalamic-pituitary-gonadal (HPG) axis hormones (gonadotropin-releasing hormones (GnRHs) [salmon GnRH and chicken GnRH-II], GnRH receptors [GnRHR1 and GnRHR5], and mRNA of the gonadotropin hormone [GTH] subunits [GTHα, follicle stimulating hormone β, and luteinizing hormone β]) in chum salmon (Oncorhynchus keta). Fish were progressively transferred from seawater (SW) through 50% SW to freshwater (FW), and the relationship between the osmoregulatory hormone prolactin (PRL) and sexual maturation was determined. The expression and activity of HPG hormones and their receptors, and levels of estradiol-17β and PRL increased after fish were transferred to FW, demonstrating that changes in salinity stimulate the HPG axis and PRL production in migrating chum salmon. These findings reveal details about the role of the endocrine system in maintaining homeostasis and stimulating sexual maturation and reproduction in response to salinity changes in this species.

Abstract

Background and Purpose

Retinal swelling, leading to irreversible visual impairment, is an important early complication in retinal ischemia/reperfusion (I/R) injury. Diosmin, a naturally occurring flavonoid glycoside, has been shown to have antioxidative and anti-inflammatory effects against I/R injury. The present study was performed to evaluate the retinal microvascular protective effect of diosmin in a model of I/R injury.

Methods

Unilateral retinal I/R was induced by increasing intraocular pressure to 110 mm Hg for 60 min followed by reperfusion. Diosmin (100 mg/kg) or vehicle solution was administered intragastrically 30 min before the onset of ischemia and then daily after I/R injury until the animals were sacrificed. Rats were evaluated for retinal functional injury by electroretinogram (ERG) just before sacrifice. Retinas were harvested for HE staining, immunohistochemistry assay, ELISA, and western blotting analysis. Evans blue (EB) extravasation was determined to assess blood–retinal barrier (BRB) disruption and the structure of tight junctions (TJ) was examined by transmission electron microscopy.

Results

Diosmin significantly ameliorated the reduction of b-wave, a-wave, and b/a ratio in ERG, alleviated retinal edema, protected the TJ structure, and reduced EB extravasation. All of these effects of diosmin were associated with increased zonular occluden-1 (ZO-1) and occludin protein expression and decreased VEGF/PEDF ratio.

Conclusions

Maintenance of TJ integrity and reduced permeability of capillaries as well as improvements in retinal edema were observed with diosmin treatment, which may contribute to preservation of retinal function. This protective effect of diosmin may be at least partly attributed to its ability to regulate the VEGF/PEDF ratio.

Abstract

Aortic dissection(AD) is an acute process of large blood vessels characterized by dangerous pathogenic conditions and high disability and high mortality. The pathogenesis of AD remains debated. Matrix metalloproteinase-12 (MMP-12) participates in many pathological processes such as abdominal aortic aneurysm, atherosclerosis, emphysema and cancer. However, this elastase has rarely been assessed in the presence of AD. The aim of the present study was to investigate the expression of MMP-12 in aortic tissue so as to offer a better understanding of the possible mechanisms of AD.

Methods

The protein expression levels of MMP-12 were analyzed and compared in aorta tissue and the blood serum samples by reverse transcription polymerase chain reaction(RT-PCR), Western blotting, immuno-histochemistry, fluorescence resonance energy transfer ( FRET ) activity assay and enzyme-linked immuno sorbent assay ( ELISA ), respectively. Ascending aorta tissue specimens were obtained from 12 patients with an acute Stanford A-dissection at the time of aortic replacement, and from 4 patients with coronary artery disease (CAD) undergoing coronary artery bypass surgery. Meanwhile, serum samples were harvested from 15 patients with an acute Stanford A-dissection and 10 healthy individuals who served as the control group.

Results

MMP-12 activity could be detected in both AD and CAD groups, but the level in the AD group was higher than those in the CAD group (P < 0.05). MMP-12 proteolysis existed in both serum samples of the AD and healthy groups, and the activity level in the AD group was clearly higher than in the healthy group (P < 0.05). For AD patients, MMP-12 activity in serum was higher than in the aorta wall (P < 0.05). MMP-12 activity in the aortic wall tissue can be inhibited by MMP inhibitor v (P < 0.05).

Conclusion

The present study directly demonstrates that MMP-12 proteolytic activity exists within the aorta specimens and blood samples from aortic dissection patients. MMP-12 might be of potential relevance as a clinically diagnostic tool and therapeutic target in vascular injury and repair.