Restricted accessResearch articleFirst published online 2019-06
Loureirin B Promotes Axon Regeneration by Inhibiting Endoplasmic Reticulum Stress: Induced Mitochondrial Dysfunction and Regulating the Akt/GSK-3β Pathway after Spinal Cord Injury
Axon retraction greatly limits functional recovery after spinal cord injury (SCI) and neuron polarization, which affects processes including axon formation and development, is a promising target for promoting axon regeneration. Increasing microtubule stability has been demonstrated to improve intrinsic axon regeneration processes and is critically related to endoplasmic reticulum (ER)–mitochondria interactions. We used real-time polymerase chain reaction, Western blotting, and immunofluorescence to screen a variety of natural compounds, and found that Loureirin B (LrB) effectively promoted neuron polarization and axon regeneration in vitro and in vivo. LrB significantly inhibited ER stress and thereby promoted mitochondrial functions by regulating mitochondrial fusion. Further, LrB reactivated the Akt/GSK-3β pathway, which plays critical roles in cell survival and microtubule stabilization. Taken together, our results suggest that the effects of LrB on neuron regeneration involve the inhibition of ER stress–induced mitochondrial dysfunction and activation of the Akt/GSK-3β pathway, which further promotes microtubule stabilization. LrB may therefore be a promising candidate for facilitating recovery following SCI.
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References
1.
AhujaC.S., MartinA.R., and FehlingsM. (2016). Recent advances in managing a spinal cord injury secondary to trauma. F1000Res. 5. pii, F1000 Faculty Rev-1017.
2.
RaspaA., PuglieseR., MalekiM., and GelainF. (2016). Recent therapeutic approaches for spinal cord injury. Biotechnol. Bioeng. 113, 253–259.
3.
HiltonB.J. and BradkeF. (2017). Can injured adult CNS axons regenerate by recapitulating development?. Development, 144, 3417–3429.
4.
ChenH., JiH., ZhangM., LiuZ., LaoL., DengC., ChenJ., and ZhongG. (2017). An agonist of the protective factor SIRT1 improves functional recovery and promotes neuronal survival by attenuating inflammation after spinal cord injury. J. Neurosci. 37, 2916–2930.
5.
WrobelM.R. and SundararaghavanH.G. (2017). Positive and negative cues for modulating neurite dynamics and receptor expression. Biomed. Mater. 12, 025016.
6.
Dell'AnnoM.T. and StrittmatterS.M. (2017). Rewiring the spinal cord: Direct and indirect strategies. Neurosci. Lett. 652, 25–34.
7.
HeZ. and JinY. (2016). Intrinsic Control of Axon Regeneration. Neuron, 90, 437–451.
8.
RamerL.M., RamerM.S., and BradburyE.J. (2014). Restoring function after spinal cord injury: towards clinical translation of experimental strategies. Lancet Neurol. 13, 1241–1256.
9.
CondeC. and CáceresA. (2009). Microtubule assembly, organization and dynamics in axons and dendrites. Nat. Rev. Neurosci. 10, 319.
10.
KahnO.I. and BaasP.W. (2016). Microtubules and growth cones: motors drive the turn. Trends Neurosci. 39, 433–440.
11.
BaasP.W. and AhmadF.J. (2013). Beyond taxol: microtubule-based treatment of disease and injury of the nervous system. Brain, 136, 2937–2951.
12.
ErtürkA., HellalF., EnesJ.. and BradkeF. (2007). Disorganized microtubules underlie the formation of retraction bulbs and the failure of axonal regeneration. J. Neurosci. 27, 9169–9180.
13.
StiessM. and BradkeF. (2011). Neuronal polarization: the cytoskeleton leads the way. Dev. Neurobiol. 71, 430–444.
14.
PopovichP.G., TovarC.A., LemeshowS., YinQ., and JakemanL.B. (2014). Independent evaluation of the anatomical and behavioral effects of Taxol in rat models of spinal cord injury. Exp. Neurol. 261, 97–108.
15.
LiH. and WuW. (2017). Microtubule stabilization promoted axonal regeneration and functional recovery after spinal root avulsion. Eur. J. Neurosci. 46, 1650–1662.
16.
ChenH., ChomynA., and ChanD.C. (2005). Disruption of fusion results in mitochondrial heterogeneity and dysfunction. J. Biol. Chem. 280, 26185–26192.
17.
YangL., LongQ., LiuJ., TangH., LiY., BaoF., QinD., PeiD., and LiuX. (2015). Mitochondrial fusion provides an ‘initial metabolic complementation'controlled by mtDNA. Cell. Mol. Life Sci. 72, 2585–2598.
18.
PernasL. and ScorranoL. (2016). Mito-morphosis: mitochondrial fusion, fission, and cristae remodeling as key mediators of cellular function. Ann. Rev. Physiol. 78, 505–531.
19.
van SpronsenM., MikhaylovaM., LipkaJ., SchlagerM.A., van den HeuvelD.J., KuijpersM., WulfP.S., KeijzerN., DemmersJ., and KapiteinL.C. (2013). TRAK/Milton motor-adaptor proteins steer mitochondrial trafficking to axons and dendrites. Neuron, 77, 485–502.
20.
BertholetA., DelerueT., MilletA., MoulisM., DavidC., DaloyauM., Arnaune-PelloquinL., DavezacN., MilsV., and MiquelM. (2016). Mitochondrial fusion/fission dynamics in neurodegeneration and neuronal plasticity. Neurobiol. Dis. 90, 3–19.
21.
GriffinE.E., GraumannJ., and ChanD.C. (2005). The WD40 protein Caf4p is a component of the mitochondrial fission machinery and recruits Dnm1p to mitochondria. J. Cell Biol. 170, 237–248.
22.
KorobovaF., RamabhadranV., and HiggsH.N. (2013). An actin-dependent step in mitochondrial fission mediated by the ER-associated formin INF2. Science, 339, 464–467.
23.
BravoR., VicencioJ.M., ParraV., TroncosoR., MunozJ.P., BuiM., QuirogaC., RodriguezA.E., VerdejoH.E., and FerreiraJ. (2011). Increased ER–mitochondrial coupling promotes mitochondrial respiration and bioenergetics during early phases of ER stress. J. Cell. Sci. 124, 2143–2152.
24.
DarlingN.J., BalmannoK., and CookS.J. (2017). ERK1/2 signalling protects against apoptosis following endoplasmic reticulum stress but cannot provide long-term protection against BAX/BAK-independent cell death. PloS One, 12, e0184907.
25.
WangZ., WangY., YeJ., LuX., ChengY., XiangL., ChenL., FengW., ShiH., and YuX. (2015). bFGF attenuates endoplasmic reticulum stress and mitochondrial injury on myocardial ischaemia/reperfusion via activation of PI3K/Akt/ERK1/2 pathway. J. Cell. Mol. Med. 19, 595–607.
26.
GuoX., SniderW.D., and ChenB. (2016). GSK3β regulates AKT-induced central nervous system axon regeneration via an eIF2Bɛ-dependent, mTORC1-independent pathway. Elife. 5.
27.
JuD.T., KuoW.W., HoT.J., PaulC.R., KuoC.H., ViswanadhaV.P., LinC.C., ChenY.S., ChangY.M., and HuangC.Y. (2015). Protocatechuic acid from alpinia oxyphylla induces schwann cell migration via ERK1/2, JNK and p38 activation. Am. J. Chin. Med. 43, 653–665.
28.
BaiX., HeT., LiuJ., WangY., FanL., TaoK., ShiJ., TangC., SuL., and HuD. (2015). Loureirin B inhibits fibroblast proliferation and extracellular matrix deposition in hypertrophic scar via TGF‐β/Smad pathway. Exp. Dermatol. 24, 355–360.
29.
HeT., BaiX., YangL., FanL., LiY., SuL., GaoJ., HanS., and HuD. (2015). Loureirin B inhibits hypertrophic scar formation via inhibition of the TGF-β1-ERK/JNK pathway. Cell. Physiol. Biochem. 37, 666–676.
30.
WangC., ChenS., and LiuX.M. (2007). Loureirin B inhibits capsaicin-induced currents in rat dorsal root ganglion neurons. Chin. Pharmacol. Bull. 23, 211.
31.
LiJ., WangQ., WangH., WuY., YinJ., ChenJ., ZhengZ., JiangT., XieL., WuF., ZhangH., LiX., XuH., and XiaoJ. (2018). Lentivirus mediating FGF13 enhances axon regeneration after spinal cord injury by stabilizing microtubule and improving mitochondrial function. J. Neurotrauma, 35, 548–559.
32.
ZhouK.L., ZhouY.F., WuK., TianN.F., WuY.S., WangY.L., ChenD.H., ZhouB., WangX.Y., XuH.Z., and ZhangX.L. (2015). Stimulation of autophagy promotes functional recovery in diabetic rats with spinal cord injury. Sci. Rep. 5, 17130.
33.
YeL.B., YuX.C., XiaQ.H., YangY., ChenD.Q., WuF., WeiX.J., ZhangX., ZhengB.B., and FuX.B. (2016). Regulation of caveolin-1 and junction proteins by bFGF contributes to the integrity of blood–spinal cord barrier and functional recovery. Neurotherapeutics, 13, 844–858.
DuttaR., McDonoughJ., YinX., PetersonJ., ChangA., TorresT., GudzT., MacklinW.B., LewisD.A., and FoxR.J. (2006). Mitochondrial dysfunction as a cause of axonal degeneration in multiple sclerosis patients. Ann. Neurol. 59, 478–489.
36.
WuQ.F., YangL., LiS., WangQ., YuanX.B., GaoX., BaoL., and ZhangX. (2012). Fibroblast growth factor 13 is a microtubule-stabilizing protein regulating neuronal polarization and migration. Cell, 149, 1549–1564.
37.
WitteH., NeukirchenD., and BradkeF. (2008). Microtubule stabilization specifies initial neuronal polarization. J. Cell. Biol. 180, 619–632.
38.
JangE.H., SimA., ImS.K., and HurE.M. (2016). Effects of microtubule stabilization by epothilone B depend on the type and age of neurons. Neural Plast. 2016, 5056418.
39.
BrizuelaM., BlizzardC.A., ChuckowreeJ.A., DawkinsE., GasperiniR.J., YoungK.M., and DicksonT.C. (2015). The microtubule-stabilizing drug Epothilone D increases axonal sprouting following transection injury in vitro. Mol. Cell. Neurosci. 66, 129–140.
40.
RuschelJ. and BradkeF. (2017). Systemic administration of epothilone D improves functional recovery of walking after rat spinal cord contusion injury. Exp Neurol. 306, 243–249.
41.
Rodríguez-MartínT., PoolerA.M., LauD.H., MórotzG.M., De VosK.J., GilleyJ., ColemanM.P., and HangerD.P. (2016). Reduced number of axonal mitochondria and tau hypophosphorylation in mouse P301L tau knockin neurons. Neurobiol. Dis. 85, 1–10.
42.
CaoY., LvG., WangY.S., FanZ.K., BiY.L., ZhaoL., and GuoZ.P. (2013). Mitochondrial fusion and fission after spinal cord injury in rats. Brain Res. 1522, 59–66.
43.
CsordásG., WeaverD., and HajnóczkyG. (2018). Endoplasmic reticular–mitochondrial contactology: structure and signaling functions. Trends Cell. Biol. 1522, 59–66.
44.
MiskoA., JiangS., WegorzewskaI., MilbrandtJ., and BalohR.H. (2010). Mitofusin 2 is necessary for transport of axonal mitochondria and interacts with the Miro/Milton complex. J. Neurosci. 30, 4232–4240.
45.
PsilodimitrakopoulosS., PetegniefV., de VeraN., HernandezO., ArtigasD., PlanasA.M., and Loza-AlvarezP. (2013). Quantitative imaging of microtubule alteration as an early marker of axonal degeneration after ischemia in neurons. Biophys. J. 104, 968–975.
46.
BurtéF., CarelliV., ChinneryP.F., and Yu-Wai-ManP. (2015). Disturbed mitochondrial dynamics and neurodegenerative disorders. Nat. Rev. Neurol. 11, 11.
47.
LamA.K. and GalioneA. (2013). The endoplasmic reticulum and junctional membrane communication during calcium signaling. Biochim. Biophys. Acta, 1833, 2542–2559.
48.
McEwenM.L., SullivanP.G., RabchevskyA.G., and SpringerJ.E. (2011). Targeting mitochondrial function for the treatment of acute spinal cord injury. Neurotherapeutics, 8, 168–179.
49.
ZhangH., WuF., KongX., YangJ., ChenH., DengL., ChengY., YeL., ZhuS., and ZhangX. (2014). Nerve growth factor improves functional recovery by inhibiting endoplasmic reticulum stress-induced neuronal apoptosis in rats with spinal cord injury. J. Transl. Med. 12, 130.
50.
ZhangZ., TongN., GongY., QiuQ., YinL., LvX., and WuX. (2011). Valproate protects the retina from endoplasmic reticulum stress-induced apoptosis after ischemia–reperfusion injury. Neurosci. Lett. 504, 88–92.
51.
OhriS.S., HetmanM., and WhittemoreS.R. (2013). Restoring endoplasmic reticulum homeostasis improves functional recovery after spinal cord injury. Neurobiol. Dis. 58, 29–37.
52.
AhnJ.Y., RongR., LiuX., and YeK. (2004). PIKE/nuclear PI 3‐kinase signaling mediates the antiapoptotic actions of NGF in the nucleus. EMBO J. 23, 3995–4006.
53.
ZhuH., ZhangY., ShiZ., LuD., LiT., DingY., RuanY., and XuA. (2016). The neuroprotection of liraglutide against ischaemia-induced apoptosis through the activation of the PI3K/AKT and MAPK pathways. Sci. Rep. 6, 26859.
54.
ItohY., HiguchiM., OishiK., KishiY., OkazakiT., SakaiH., MiyataT., NakajimaK., and GotohY. (2016). PDK1–Akt pathway regulates radial neuronal migration and microtubules in the developing mouse neocortex. Proc. Natl. Acad. Sci. 113, E2955–E2964.
55.
KathC., Goni-OliverP., MüllerR., SchultzC., HauckeV., EickholtB., and SchmoranzerJ. (2018). PTEN suppresses axon outgrowth by down-regulating the level of detyrosinated microtubules. PloS One, 13, e0193257.
56.
ZhangW., CuiY., GaoJ., LiR., JiangX., TianY., WangK., and CuiJ. (2018). Recombinant osteopontin improves neurological functional recovery and protects against apoptosis via PI3K/Akt/GSK-3β Pathway Following Intracerebral Hemorrhage. Med. Sci. Monit. 24, 1588.
57.
FilousA.R. and SilverJ. (2016). Targeting astrocytes in CNS injury and disease: a translational research approach. Prog. Neurobiol. 144, 173–187.
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