* Delivering progranulin to neuronal lysosomes protects against excitotoxicity.
- Loss-of-function mutations in progranulin (GRN) are a major genetic cause of frontotemporal dementia (FTD), possibly due to loss of progranulin's neurotrophic and anti-inflammatory effects. Progranulin promotes neuronal growth and protects against excitotoxicity and other forms of injury. It is unclear if these neurotrophic effects are mediated through cellular signaling or through promotion of lysosomal function. Progranulin is a secreted proprotein that may activate neurotrophic signaling through cell-surface receptors. However, progranulin is efficiently trafficked to lysosomes and is necessary for maintaining lysosomal function. To determine which of these mechanisms mediates progranulin's protection against excitotoxicity, we generated lentiviral vectors expressing progranulin (PGRN) or lysosome-targeted progranulin (L-PGRN). L-PGRN was generated by fusing the LAMP-1 transmembrane and cytosolic domains to the C-terminus of progranulin. L-PGRN exhibited no detectable secretion, but was delivered to lysosomes and processed into granulins. PGRN and L-PGRN protected against NMDA excitotoxicity in rat primary cortical neurons, but L-PGRN had more consistent protective effects than PGRN. L-PGRN's protective effects were likely mediated through the autophagy-lysosomal pathway. In control neurons, an excitotoxic dose of NMDA stimulated autophagy, and inhibiting autophagy with 3-methyladenine reduced excitotoxic cell death. L-PGRN blunted the autophagic response to NMDA and occluded the protective effect of 3-methyladenine. This was not due to a general impairment of autophagy, as L-PGRN increased basal autophagy and did not alter autophagy after nutrient starvation. These data show that progranulin's protection against excitotoxicity does not require extracellular progranulin, but is mediated through lysosomes, providing a mechanistic link between progranulin's lysosomal and neurotrophic effects.
=>趣旨, 結果, 影響, 効力, 活動, 印象, 効果, 成し遂げる
Overview of noun effect
The noun effect has 6 senses (first 5 from tagged texts)
1. (101) consequence, effect, outcome, result, event, issue, upshot -- (a phenomenon that follows
and is caused by some previous phenomenon; "the magnetic effect was greater when the rod was
lengthwise"; "his decision had depressing consequences for business"; "he acted very wise after the
event")
2. (11) impression, effect -- (an outward appearance; "he made a good impression"; "I wanted to
create an impression of success"; "she retained that bold effect in her reproductions of the
original painting")
3. (9) effect -- (an impression (especially one that is artificial or contrived); "he just did it
for effect")
4. (2) effect, essence, burden, core, gist -- (the central meaning or theme of a speech or literary
work)
5. (1) effect, force -- ((of a law) having legal validity; "the law is still in effect")
6. effect -- (a symptom caused by an illness or a drug; "the effects of sleep loss"; "the effect of
the anesthetic")
Overview of verb effect
The verb effect has 2 senses (first 2 from tagged texts)
1. (17) effect, effectuate, set up -- (produce; "The scientists set up a shock wave")
2. (3) effect -- (act so as to bring into existence; "effect a change")
--- WordNet end ---