Pathological Mechanism of Neuronal Autophagy Flow Disturbance Caused by NSF ATPase Inactivation After Cerebral Ischemia / 生物化学与生物物理进展

Cerebral ischemic stroke is an acute cerebrovascular disease caused by cerebral vascular occlusion, and it is associated with high incidence, disability, and mortality rates. Studies have found that excessive or insufficient autophagy can lead to cellular damage. Autophagy consists of autophagosome formation and maturation, autophagosome-lysosome fusion, degradation and clearance of autophagic substrates within autolysosomes, and these processes collectively constitute autophagic flux. Research has revealed that cerebral ischemia can induce impaired fusion between autophagosomes and lysosomes, resulting in autophagic flux impairment. Intracellular membrane fusion is mediated by three core components: N-ethylmaleimide sensitive factor (NSF) ATPase, soluble NSF attachment protein (SNAP), and soluble NSF attachment protein receptors (SNAREs). SNAREs, after mediating fusion between autophagosomes and lysosomes, remain in an inactive complex state on the autolysosomal membrane, requiring NSF reactivation into monomers to perform subsequent rounds of membrane fusion-mediated functions. NSF is the sole ATPase capable of reactivating SNAREs. Recent studies have shown that cerebral ischemia significantly inhibits NSF ATPase activity, reducing its reactivation of SNAREs. This may be a pathological mechanism for impaired fusion between autophagosomes and lysosomes, leading to neuronal autophagic flux impairment. This article discusses the pathological mechanisms of NSF ATPase inactivation, including SNAREs dysregulation, impaired fusion between autophagosomes and lysosomes, and insufficient transport of proteolytic enzymes to lysosomes, and explores approaches to improve neuronal autophagic flux through NSF ATPase reactivation. It provides references for stroke treatment improvement and points out directions for further research.

Rhodojaponin VI indirectly targets Cav2.2 channels via N-ethylmaleimide-sensitive fusion protein to alleviate neuropathic pain

Neuropathic pain is a chronic disease that severely afflicts the life and emotional status of patients, but currently available treatments are often ineffective. Novel therapeutic targets for the alleviation of neuropathic pain are urgently needed. Rhodojaponin VI, a grayanotoxin from Rhododendron molle, showed remarkable antinociceptive efficacy in models of neuropathic pain, but its biotargets and mechanisms are unknown. Given the reversible action of rhodojaponin VI and the narrow range over which its structure can be modified, we perforwmed thermal proteome profiling of the rat dorsal root ganglion to determine the protein target of rhodojaponin VI. N-Ethylmaleimide-sensitive fusion (NSF) was confirmed as the key target of rhodojaponin VI through biological and biophysical experiments. Functional validation showed for the first time that NSF facilitated trafficking of the Cav2.2 channel to induce an increase in Ca2+ current intensity, whereas rhodojaponin VI reversed the effects of NSF. In conclusion, rhodojaponin VI represents a unique class of analgesic natural products targeting Cav2.2 channels via NSF.

From fission to fusion: A perspective on the research that won the Nobel Prize in Physiology or Medicine, 2013.

Secretion is widespread in all eukaryotic cells: all of us experience this in the course of daily life – saliva, mucus, sweat, tears, bile juice, adrenalin, etc. – the list is extremely long. How does a cell manage to repeatedly spit out some stuff without losing the rest? The answer is: through regulated vesicle trafficking within the cell. The Nobel Prize in Physiology or Medicine 2013 was awarded to Drs Randy Schekman, James E Rothman and Thomas C Südhof for their ‘discoveries of machinery regulating vesicle traffic, a major transport system in our cells’. Dr Randy Schekman and his colleagues discovered a number of genes required for vesicle trafficking from the endoplasmic reticulum (ER) and Golgi; the James E Rothman group unravelled the protein machinery that allows vesicles to bud off from the membrane and fuse to their targets; and Dr Thomas C Südhof along with his colleagues revealed how calcium ions could instruct vesicles to fuse and discharge their contents with precision. These enabled the biotechnology industry to produce a variety of pharmaceutical and industrial products like insulin and hepatitis B vaccines, in a cost-efficient manner, using yeast and tissue cultured cells.

Role of astrocyte in the proligeration and differentiation of nerve stem cells by activating PKA signal pathway / 重庆医科大学学报

Objective:To study the effect of astrocyte activating PKA signal pathway on the proligeration and differentiation of nerve stem cells.Methods:Cerebral cortex of 13-day embryo mice was taken and the nerve stem cells were cultured scatteringly. Astrocyte was used to stimulate the nerve stem cells,and H89,PKA recepter antagonist, was used to pretreat the nerve stem cells of the cerebral cortex, then the contents of PKA,nestin,and NSF in the nerve stem cells were determined using western blot. MTT was applied to determine and analyse the effect of horizontal cell on the proliferation and orientational dif- ferentiation of cultured nerve stem cells. Results:In the normal control group the content of NSF in the nerve stem cells was low;after astrocyte stimulation the nestin content decreased rapidly,while the content of NSF increased gradually. H8(915 ?mol/L) could markedly supress the increase of NSF content in the nerve stem cell stimulated by horizontal cells. Conclusion:Astrocyte can promote the proliferation and differentiation of nerve stem cells by activating PKA signal pathway of nerve stem cells.

THE EFFECT OF CORIARIA LECTON-ACTIVITED ASTROCYTE-CONDITIONED MEDIUM AND CNQX ON NSF OF THE CEREBRAL OF NORMAL RATS AND CULTURED NEURONS / 解剖学报

Objective To explore the effects of astrocytes on the N-ethylmaleimide-sensitive fusion protin,(NSF) and AMPA receptor of the neurons as well as their function in epileptogenesis. Methods ACM was injected into lateral ventricle of SD rats and the behaviour changes were observed; Immunohistochemical method was used to assess the changes of the expression of NSF in the cerebral cortex and hippocampus; The cultured neurons were divided into control group, ACM group and CNQX+ACM group at random, immunocytochemistry was used to assess the changes of the expression of NSF, Western blotting was used to assess the changes of the content of NSF of the cultured neurons. Results Seizure was observed in ACM group 30 min after injecting ACM. the immunoreaction of NSF in hippocampus and cerebral cortex of rats were depressed than those of the control group 2h, 4h after injecting ACM (P