The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosp...The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.展开更多
Inspired by the photoelectric effect,a phototube is incorporated into a simple neural circuit,and then the output voltage and dynamics become sensitive to external illumination within a specific frequency band.The fir...Inspired by the photoelectric effect,a phototube is incorporated into a simple neural circuit,and then the output voltage and dynamics become sensitive to external illumination within a specific frequency band.The firing modes are also dependent on the amplitude and frequency band in the illumination.In this paper,the signal outputs from a chaotic circuit are used as external optical signals,which are filtered and encoded by a phototube.Then,the functional neural circuit is excited to present a variety of firing modes and patterns.An exponential function of the filtering wave is proposed to discover the biophysical mechanism for frequency selection in the retina as most of wave bands of the external illumination are absorbed in the cathode material of the phototube while a specific band is effective in inducing a photocurrent for stimulating the visual neurons.Based on our light-sensitive neural circuit and model,external illumination is filtered and firing modes in the neuron are reproduced;furthermore,the mode transition induced by parameter shift is also investigated in detail.This result discovers the signal processing mechanism in the visual neurons and provides helpful guidance for designing artificial sensors for encoding optical signals and for repairing abnormalities in the retina of the visual system.展开更多
Cottons are the most important fiber crops in the world.The cotton genus Gossypium has 52 species,including seven allotetraploid species and 45 diploids.Four species were domesticated and remain as crops under cultiva...Cottons are the most important fiber crops in the world.The cotton genus Gossypium has 52 species,including seven allotetraploid species and 45 diploids.Four species were domesticated and remain as crops under cultivation today:the New World allopolyploid species G.hirsutum and G.barbadense(2n=52),and the Old World diploid species G.arboreum and G.herbaceum(2n=26).The primary cultivated species is Upland cotton(G.hirsutum L.),which accounts for more than 90%of global cotton fiber production.展开更多
文摘The mitogen-activated protein kinase（MAPK） signaling pathway plays an important role in the regulation of cell growth, proliferation, differentiation, transformation and death. Mitogen-activated protein kinase phosphatase 1（MKP1） has an inhibitory effect on the p38 MAPK and JNK pathways, but it is unknown whether it plays a role in Aβ-induced oxidative stress and neuronal inflammation. In this study, PC12 cells were infected with MKP1 sh RNA, MKP1 lentivirus or control lentivirus for 12 hours, and then treated with 0.1, 1, 10 or 100 μM amyloid beta 42（Aβ42）. The cell survival rate was measured using the cell counting kit-8 assay. MKP1, tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） m RNA expression levels were analyzed using quantitative real time-polymerase chain reaction. MKP1 and phospho-c-Jun N-terminal kinase（JNK） expression levels were assessed using western blot assay. Reactive oxygen species（ROS） levels were detected using 2′,7′-dichlorofluorescein diacetate. Mitochondrial membrane potential was measured using flow cytometry. Superoxide dismutase activity and malondialdehyde levels were evaluated using the colorimetric method. Lactate dehydrogenase activity was measured using a microplate reader. Caspase-3 expression levels were assessed by enzyme-linked immunosorbent assay. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase d UTP nick end labeling method. MKP1 overexpression inhibited Aβ-induced JNK phosphorylation and the increase in ROS levels. It also suppressed the Aβ-induced increase in TNF-α and IL-1β levels as well as apoptosis in PC12 cells. In contrast, MKP1 knockdown by RNA interference aggravated Aβ-induced oxidative stress, inflammation and cell damage in PC12 cells. Furthermore, the JNK-specific inhibitor SP600125 abolished this effect of MKP1 knockdown on Aβ-induced neurotoxicity. Collectively, these results show that MKP1 mitigates Aβ-induced apoptosis, oxidative stress and neuroinflammation by inhibiting the JNK signaling pathway, thereby playing a neuroprotective role.
基金Project supported by the National Natural Science Foundation of China(No.12072139)。
文摘Inspired by the photoelectric effect,a phototube is incorporated into a simple neural circuit,and then the output voltage and dynamics become sensitive to external illumination within a specific frequency band.The firing modes are also dependent on the amplitude and frequency band in the illumination.In this paper,the signal outputs from a chaotic circuit are used as external optical signals,which are filtered and encoded by a phototube.Then,the functional neural circuit is excited to present a variety of firing modes and patterns.An exponential function of the filtering wave is proposed to discover the biophysical mechanism for frequency selection in the retina as most of wave bands of the external illumination are absorbed in the cathode material of the phototube while a specific band is effective in inducing a photocurrent for stimulating the visual neurons.Based on our light-sensitive neural circuit and model,external illumination is filtered and firing modes in the neuron are reproduced;furthermore,the mode transition induced by parameter shift is also investigated in detail.This result discovers the signal processing mechanism in the visual neurons and provides helpful guidance for designing artificial sensors for encoding optical signals and for repairing abnormalities in the retina of the visual system.
基金supported by Chinese Academy of Sciences (XDB11030000)Ministry of Science and Technology of China and Ministry of Agriculture of China (2013CB127000, 2016YFA0500800, 2016ZX08009001-009, 2016ZX08005001-001)National Natural Science Foundation of China (31690092)
文摘Cottons are the most important fiber crops in the world.The cotton genus Gossypium has 52 species,including seven allotetraploid species and 45 diploids.Four species were domesticated and remain as crops under cultivation today:the New World allopolyploid species G.hirsutum and G.barbadense(2n=52),and the Old World diploid species G.arboreum and G.herbaceum(2n=26).The primary cultivated species is Upland cotton(G.hirsutum L.),which accounts for more than 90%of global cotton fiber production.
