Objective:To examine the effect of shikonin against streptozotocin(STZ)-induced diabetic retinopathy in rats and elucidate the underlying mechanisms.Methods:Intraperitoneal administration of STZ(65 mg/kg)was used for ...Objective:To examine the effect of shikonin against streptozotocin(STZ)-induced diabetic retinopathy in rats and elucidate the underlying mechanisms.Methods:Intraperitoneal administration of STZ(65 mg/kg)was used for the induction of diabetic retinopathy in rats.Rats received oral administration of shikonin(10,20,and 30 mg/kg).The blood glucose level,insulin,body weight,and organ weight were estimated.Advanced glycation end products(AGEs)levels in serum and lens as well as protein carbonyl content of the lens were determined.The parameters related to oxidative stress and inflammation,and the levels of nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),intercellular adhesion molecule-1(ICAM-1),and vascular cell adhesion molecule 1(VCAM-1)were also measured.In addition,quantitative RT-PCR was performed to determine the mRNA expressions.Results:Shikonin treatment decreased glucose level and boosted insulin level,along with an increase in body weight and improved organ weight.It also lowered O2•−,ONOO−,serum and lens AGEs,and protein carbonyl content.Furthermore,shikonin treatment significantly alleviated oxidative stress and inflammation,as evidenced by reduced malonaldehyde,nitric oxide,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,cyclooxygenase-2,prostaglandin E2,protein carbonyl content,and nuclear factor kappa-B,and increased superoxide dismutase,glutathione,catalase,and glutathione peroxidase.Markedly decreased levels of ICAM-1 and VCAM-1,as well as heightened levels of Nrf2 and HO-1,were noticed after treatment with shikonin.Furthermore,the mRNA expressions of TNF-α,IL-1β,IL-6,ICAM-1,VCAM-1,RAGE,collagenⅣ,and fibronectin were significantly downregulated.Conclusions:Shikonin exhibits protective effects against STZ-induced diabetic retinopathy in rats via modulating the Nrf2/HO-1 and NF-κB signaling pathways.展开更多
Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity o...Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy.Sprague-Dawley rats were mated with male rats at a 1：1 ratio.Rats were administered 0,5,10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21.The gait scores were examined in pregnant rats in each group to analyze maternal toxicity.Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies.Nissl staining was used to observe histological change in the hippocampus.Immunohistochemistry was conducted to observe the condition of neurites,including dendrites and axons.Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein,growth associated protein 43,and the presynaptic vesicle membrane specific protein,synaptophysin.The gait scores of gravid rats significantly increased,suggesting that acrylamide induced maternal motor dysfunction.The number of neurons,as well as expression of growth associated protein 43 and synaptophysin,was reduced with increasing acrylamide dose in postnatal day 21 weaning rats.These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.展开更多
We theoretically propose a narrowband perfect absorber metasurface(PAMS) based on surface phonon polaritons in the terahertz range. The PAMS has unit cell consisting of a silver biarc on the top, a thin polar-dielectr...We theoretically propose a narrowband perfect absorber metasurface(PAMS) based on surface phonon polaritons in the terahertz range. The PAMS has unit cell consisting of a silver biarc on the top, a thin polar-dielectric in the middle and a silver layer at the bottom. The phonon polaritons are excited at the interface between the silver biarc and the polar dielectric, and enhance the absorption of the PAMS. The absorption peak is at 36.813 μm and the full width half maximum(FWHM) is nearly 36 nm, independent of the polarization and incidence angle. The electric fields are located at the split of the biarc silver layer and the quality factor Q is 1150. The FWHM decreases with the decreasing split width. When the thickness of the bottom layer is larger than 50 nm, the narrow band and high absorption are insensitive to the thickness of those layers. The designed absorber may have useful applications in terahertz spectra such as energy harvesting, thermal emitter, and sensing.展开更多
文摘Objective:To examine the effect of shikonin against streptozotocin(STZ)-induced diabetic retinopathy in rats and elucidate the underlying mechanisms.Methods:Intraperitoneal administration of STZ(65 mg/kg)was used for the induction of diabetic retinopathy in rats.Rats received oral administration of shikonin(10,20,and 30 mg/kg).The blood glucose level,insulin,body weight,and organ weight were estimated.Advanced glycation end products(AGEs)levels in serum and lens as well as protein carbonyl content of the lens were determined.The parameters related to oxidative stress and inflammation,and the levels of nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),intercellular adhesion molecule-1(ICAM-1),and vascular cell adhesion molecule 1(VCAM-1)were also measured.In addition,quantitative RT-PCR was performed to determine the mRNA expressions.Results:Shikonin treatment decreased glucose level and boosted insulin level,along with an increase in body weight and improved organ weight.It also lowered O2•−,ONOO−,serum and lens AGEs,and protein carbonyl content.Furthermore,shikonin treatment significantly alleviated oxidative stress and inflammation,as evidenced by reduced malonaldehyde,nitric oxide,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),IL-6,cyclooxygenase-2,prostaglandin E2,protein carbonyl content,and nuclear factor kappa-B,and increased superoxide dismutase,glutathione,catalase,and glutathione peroxidase.Markedly decreased levels of ICAM-1 and VCAM-1,as well as heightened levels of Nrf2 and HO-1,were noticed after treatment with shikonin.Furthermore,the mRNA expressions of TNF-α,IL-1β,IL-6,ICAM-1,VCAM-1,RAGE,collagenⅣ,and fibronectin were significantly downregulated.Conclusions:Shikonin exhibits protective effects against STZ-induced diabetic retinopathy in rats via modulating the Nrf2/HO-1 and NF-κB signaling pathways.
基金supported by the Guangdong Provincial Department of Science and Technology in China,No.2016A020225007
文摘Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy.Sprague-Dawley rats were mated with male rats at a 1：1 ratio.Rats were administered 0,5,10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21.The gait scores were examined in pregnant rats in each group to analyze maternal toxicity.Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies.Nissl staining was used to observe histological change in the hippocampus.Immunohistochemistry was conducted to observe the condition of neurites,including dendrites and axons.Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein,growth associated protein 43,and the presynaptic vesicle membrane specific protein,synaptophysin.The gait scores of gravid rats significantly increased,suggesting that acrylamide induced maternal motor dysfunction.The number of neurons,as well as expression of growth associated protein 43 and synaptophysin,was reduced with increasing acrylamide dose in postnatal day 21 weaning rats.These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.
基金Project supported by the National Natural Science Foundation of China(Grant No.11204056)Harbin Normal University Master’s Innovation Project(Grant Nos.HSDSSCX2018-77 and HSDSSCX2018-79)+2 种基金Key Laboratory of Engineering Dielectrics and Its Application(Harbin University of Science and Technology)Ministry of Education,China(Grant No.KF20171110)Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2019A028).
文摘We theoretically propose a narrowband perfect absorber metasurface(PAMS) based on surface phonon polaritons in the terahertz range. The PAMS has unit cell consisting of a silver biarc on the top, a thin polar-dielectric in the middle and a silver layer at the bottom. The phonon polaritons are excited at the interface between the silver biarc and the polar dielectric, and enhance the absorption of the PAMS. The absorption peak is at 36.813 μm and the full width half maximum(FWHM) is nearly 36 nm, independent of the polarization and incidence angle. The electric fields are located at the split of the biarc silver layer and the quality factor Q is 1150. The FWHM decreases with the decreasing split width. When the thickness of the bottom layer is larger than 50 nm, the narrow band and high absorption are insensitive to the thickness of those layers. The designed absorber may have useful applications in terahertz spectra such as energy harvesting, thermal emitter, and sensing.
