Decorin, a small leucine-rich proteoglycan, regulates extracellular matrix organization, growth factor-mediated signaling and cell growth. As decorin may directly modulate immune responses, we investigated its role in a mouse model of contact allergy (oxazolone-mediated delayed-type hypersensitivity, DTH) in decorin-deficient (Dcn−/−) and wild-type mice. Dcn−/− mice showed a reduced ear swelling 24 hours after oxazolone treatment with a concurrent attenuation of leukocyte infiltration. These findings were corroborated by reduced glucose metabolism as determined by 18FDG uptake in positron emission tomography scans. Unexpectedly, polymorphonuclear leukocyte numbers in Dcn−/− blood vessels were significantly increased, accompanied by large numbers of flattened leukocytes adherent to the endothelium. Intravital microscopy, flow chamber and static adhesion assays confirmed increased adhesion and reduced transmigration of Dcn−/− leukocytes. Circulating blood neutrophil numbers were significantly increased in Dcn−/− mice 24 hours after DTH elicitation, but only moderately increased in wild-type mice. Expression of the pro-inflammatory cytokine TNF-α was reduced, while syndecan-1 and ICAM-1 were overexpressed in inflamed ears of Dcn−/− mice, indicating that these adhesion molecules could be responsible for increased leukocyte adhesion. Decorin treatment of endothelial cells increased tyrosine phosphorylation and reduced syndecan-1 expression. Notably, absence of syndecan-1 in a genetic background lacking decorin rescued the attenuated DTH phenotype of Dcn−/− mice. Collectively, these results implicate a role for decorin in mediating DTH responses by influencing polymorphonuclear leukocyte attachment to the endothelium. This occurs via two non-mutually exclusive mechanisms that involve a direct anti-adhesive effect on polymorphonuclear leukocytes and a negative regulation of ICAM-1 and syndecan-1 expression.

Background: The message delivered to the public regarding vitamin D is unclear, and contradictory; particularly regarding sun exposure; previous studies in Jordan have revealed high prevalence of low vitamin D among university students. The aim of this study was to investigate university students’ knowledge, attitudes and practice regarding vitamin D.Method: A web-based cross-sectional survey completed by students at a Jordanian university in 2019. Binary logistic regression analysis was used to predict supplement use.Results: 496 students completed the questionnaire. The mean knowledge score was 31.3 (± 11.3) out of 100. Women had significantly higher beliefs that vitamin D deficiency is an escalating health issue (p<0.01). Negative practices regarding sun exposure was significantly higher in women than men (p<0.01). The majority of participants recognized that insufficient sun exposure was a cause of vitamin D deficiency, but 50.7 % avoid sun exposure, and 67.6% expose only their face and hands. The consumption of fortified foods (OR 3.59-;p<0.001) was the only studied variable associated with vitamin D consumption.Conclusion: There is a gap between knowledge, attitude, and practice regarding vitamin D which can be bridged by promoting Vitamin D related awareness.

Background: Exposure to vanadium exhibits deleterious neurotoxicity. Doxycycline is a potential antioxidant that prevents the progression of disease through inhibition of lipid peroxidation. Objectives: This research investigates the neuroprotective effects of doxycycline, in different rat brain areas in an animal model intoxicated with vanadium. Materials and Methods: Male Sprague-Dawley rats were equally divided into the following four groups: control group, doxycycline-treated group, vanadium-treated group, and concomitant doses of doxycycline plus vanadium-treated group, all given orally for 10 consecutive days. The animals were watched daily for any signs of neurological defects. They were sacrificed by decapitation 24 h after the last dose. Brain was removed rapidly and dissected into cerebral cortex, cerebellum, and brain stem. Biochemical studies including the concentrations of phospholipids, cholesterol, cerebrosides, glutathione (GSH), acetylcholinesterase (AChE) activity, gangliosides, ascorbic acid, calcium, and lipid peroxidation levels were determined. Results: The results revealed that vanadium produced significant reduction in body and absolute brain weight, with neurological function deficits. Vanadium significantly decreased the concentrations of phospholipids, cholesterol, cerebrosides, and GSH and inhibited AChE activity together with significant increase in gangliosides, ascorbic acid, calcium, and lipid peroxidation levels compared to saline controls. Animals which were given the combined treatment of vanadium and doxycycline regained weight and became normal. Moreover, doxycycline reversed the effect of vanadium on the metabolic variables and inhibited lipid peroxidation nearing to normal levels to that of saline controls. Conclusion: These findings demonstrated the antioxidant or chelating action of doxycycline against vanadium neurotoxicity and its therapeutic potential to avert neurodegenerative changes in different rat brain areas.

Background The liver is target following exposure to pentavalent vanadium (V5+). Doxycycline is an antioxidant that prevents the progression of disease through inhibition of lipid peroxidation. Aim The present study was designed to evaluate the protective effects of doxycycline against vanadium-induced hepatoxicity. Methods Sixty two male Sprague-Dawley rats (250–300 g) were equally divided into the following four groups: control group (received 0.2 mL of physiological saline), doxycycline control group (received 4 mg/kg body weight on day 1 and 2 mg/kg body weight daily thereafter), vanadium group (received elemental vanadium 1.5 mg/kg-body weight in distilled water), and concomitantly treated group (doxycycline + vanadium) received (doxycycline 4 mg/kg body weight on day 1 and 2 mg/kg body weight thereafter + vanadium 1.5 mg/kg body weight), all given orally for 10 consecutive days. The rats were sacrificed by decapitation 24 hours after the last dose. The liver was removed rapidly and processed for the evaluation of metabolic variables: phospholipids, cholesterol, cerebrosides, gangliosides, reduced glutathione (GSH), vitamin C, calcium, acetylcholinesterase enzyme, and lipid peroxidation. Results Vanadium administration significantly reduced (−60 g) the body weight and significantly increased (+28%) the relative liver weight compared with controls. The rats exhibited neurological function deficits. Vanadium administration decreased the concentrations of metabolic variables compared with controls, cerebrosides (−50%), cholesterol (−39%), phospholipids (−18%), GSH (−45%), and inhibited acetylcholinesterase enzyme (–48%). Gangliosides (+ 38%), vitamin C (+ 20%), and calcium (+ 80%) were increased together with an enhancement (+64%) in lipid peroxidation. The combined treatment (vanadium and doxycycline) significantly increased (+25 g) the body weight and relative liver weight of rat was significantly reduced (+5%) compared with vanadium administered group. The levels of metabolic variables were significantly reversed in this group in the following order: cholesterol (+17%), phospholipids (+7%), vitamin C (−14%), acetylcholinesterase enzyme activity (−27%) together with inhibition (−16%) of lipid peroxidation. All levels were (p < 0.05). Doxycycline presented no effect on the levels of GSH, cerebrosides, and gangliosides. Conclusion Results of this study suggested vanadium-induced oxidation of lipids and sphingolipids in hepatocytes and much of GSH was consumed against high production of reactive oxygen species. Doxycycline protected against vanadium-induced oxidative damage that could be attributed to its free radical scavenging effects on membrane-bound lipids and acetylcholinesterase enzyme.

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