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Table of Contents

    Topic review

    Sex-Specific Differences to Ischemic Stroke

    Subjects: Cell Biology
    View times: 9
    Submitted by: Louise McCullough

    Definition

    Macroautophagy (called autophagy thereafter) is a self-catabolic process where subcellular proteins, macromolecules, and organelles are sequestered within membrane-enclosed vesicles (autophagosomes) and are degraded by fusion with lysosomes (autolysosomes). Autophagy plays a role in cellular homeostasis by degrading damaged cellular contents and redistributing the constituents for other cellular processes. During times of cell stress, such as ischemia, autophagy may become dysregulated and increase injury, or conversely may increase the ability of the cell to survive under conditions with low energy substrates. There is increasing evidence that autophagy is a sex-dependent process.

    1. Overview

    Ischemic stroke triggers a series of complex pathophysiological processes including autophagy. Differential activation of autophagy occurs in neurons derived from males versus females after stressors such as nutrient deprivation. Whether autophagy displays sexual dimorphism after ischemic stroke is unknown. We used a cerebral ischemia mouse model (middle cerebral artery occlusion, MCAO) to evaluate the effects of inhibiting autophagy in ischemic brain pathology. We observed that inhibiting autophagy reduced infarct volume in males and ovariectomized females. However, autophagy inhibition enhanced infarct size in females and in ovariectomized females supplemented with estrogen compared to control mice. We also observed that males had increased levels of Beclin1 and LC3 and decreased levels of pULK1 and p62 at 24 h, while females had decreased levels of Beclin1 and increased levels of ATG7. Furthermore, the levels of autophagy markers were increased under basal conditions and after oxygen and glucose deprivation in male neurons compared with female neurons in vitro. E2 supplementation significantly inhibited autophagy only in male neurons, and was beneficial for cell survival only in female neurons. This study shows that autophagy in the ischemic brain differs between the sexes, and that autophagy regulators have different effects in a sex-dependent manner in neurons.

    2. Macroautophagy

    Epidemiologic and clinical evidence have demonstrated the importance of sex differences in the incidence and response to ischemic brain injury [1][2][3]. Women have lower stroke incidence relative to men until well after menopause; however, rates climb dramatically in elderly women who also have greater disability, morbidity and mortality after stroke than men [2][4]. Previous studies have suggested that sex-dependent pathways are activated in response to stroke, including caspase-dependent apoptosis and poly (ADP-ribose) polymerase-mediated DNA repair [5][6][7][8]. With the cost of stroke care in the USA projected to exceed 180 billion dollars by 2030, understanding sex differences and optimizing neuroprotective agents is critical to the development of efficacious therapies [9][10][11].
    Macroautophagy (called autophagy thereafter) is a self-catabolic process where subcellular proteins, macromolecules, and organelles are sequestered within membrane-enclosed vesicles (autophagosomes) and are degraded by fusion with lysosomes (autolysosomes) [12][13][14][15]. Autophagy plays a role in cellular homeostasis by degrading damaged cellular contents and redistributing the constituents for other cellular processes [14]. During times of cell stress, such as ischemia, autophagy may become dysregulated and increase injury, or conversely may increase the ability of the cell to survive under conditions with low energy substrates. There is increasing evidence that autophagy is a sex-dependent process [13][16][17][18].
    Recent reports have revealed increased levels of autophagy in experimental models of both hemorrhagic and ischemic stroke [19][20][21][22][23]. Pharmacological inhibition of autophagy in male animals during or up to several hours after experimental stroke reduced tissue death [19][20][24][25][26][27]. Studies in neonates show that females have higher basal levels of autophagy and caspase activation following hypoxic-ischemic injury [28]. We hypothesized that sex differences are present in autophagy in the ischemic brain, and that down regulating autophagy after experimental ischemic stroke in mice would have differential efficacy in males and females.

    3. Conclusions

    It is well established that neuronal tissue is rapidly lost as stroke progresses. Autophagy plays a major role in the response to cellular stress, and has been implicated in the response to tissue ischemia [29]. Evidence suggests that survival of the ischemic penumbra depends strongly on the interaction between regulators of autophagy and apoptosis [30]. This study provides the first evidence that sex differences in autophagy previously noted in vitro are present in vivo following stroke in adult mice. Five key autophagy proteins, p62, LC3, ATG7, Beclin1, and pULK1, show differential expression in response to cerebral ischemia in males and females. Furthermore, post-stroke treatment with 3MA reduced tissue death in males but had no benefit in females, and exacerbated injury. This has important implications for the development of autophagy modulators as neuroprotective agents.
    Down regulation of autophagy by 3MA occurs through interaction with a complex consisting of Vps34, p150, and Beclin1 [31]. A recent systematic review analyzed the effects of 3MA on animal models of cerebral infarction [32]. Unfortunately, there is no consensus about the beneficial effects of 3MA on cell viability in the brain: some studies found that inhibiting autophagy with 3MA prevents cell death after ischemic stroke [27][33]; however, other studies propose that 3MA may promote neuronal death [34][35]. However, none of these examined sex-specific effects or were performed only with male animals. Our study provides evidence about sex differences in brain damage and autophagy after ischemic stroke in mice. We found that at 6 h, there were higher levels of Beclin1 in males when compared to females; however, there was no effect of stroke. At 24 h, stroke males had a significant increase in Beclin1 compared to male shams, whereas stroke females had a significant decrease in Beclin1 compared to female shams. The increase in Beclin1 and LC3-II seen in males suggests that males rapidly induce autophagy after ischemia and could explain the selective effectiveness of 3MA treatment in males after stroke. Coinciding with an increase in Beclin1 and LC3-II levels, male mice subjected to stroke had a decrease in levels of p62, suggesting that the autophagy cargo p62 is degraded and autophagy is stimulated. Further, this suggestion is supported by reduced phosphorylation of ULK1 at SER 757, which is phosphorylated by mTOR and is an indicator of enhanced autophagy [36][37]. The number of studies on sex differences in autophagy in animal models of ischemic stroke is limited. To our knowledge, only one study examined sex differences in autophagy, which examined the autophagy regulator, HIF-1α, which was upregulated in male rats 24 h after ischemic stroke compared with females [38]. Thus, our study provides novel data and highlights the importance of studying the mechanisms that govern sex differences in autophagy in the brain after stroke.
     

    The entry is from 10.3390/cells10071825

    References

    1. Seshadri, S.; Beiser, A.; Kelly-Hayes, M.; Kase, C.S.; Au, R.; Kannel, W.B.; Wolf, P.A. The lifetime risk of stroke: Estimates from the Framingham Study. Stroke 2006, 37, 345–350.
    2. Petrea, R.E.; Beiser, A.S.; Seshadri, S.; Kelly-Hayes, M.; Kase, C.S.; Wolf, P.A. Gender differences in stroke incidence and poststroke disability in the Framingham heart study. Stroke 2009, 40, 1032–1037.
    3. Roger, V.L.; Go, A.S.; Lloyd-Jones, D.M.; Benjamin, E.J.; Berry, J.D.; Borden, W.B.; Bravata, D.M.; Dai, S.; Ford, E.S.; Fox, C.S.; et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee Heart disease and stroke statistics—2012 update: A report from the American Heart Association. Circulation 2012, 125, e2–e220.
    4. Lofmark, U.; Hammarstrom, A. Evidence for age-dependent education-related differences in men and women with first-ever stroke. Results from a community-based incidence study in northern Sweden. Neuroepidemiology 2007, 28, 135–141.
    5. Renolleau, S.; Fau, S.; Goyenvalle, C.; Joly, L.M.; Chauvier, D.; Jacotot, E.; Mariani, J.; Charriaut-Marlangue, C. Specific caspase inhibitor Q-VD-OPh prevents neonatal stroke in P7 rat: A role for gender. J. Neurochem. 2007, 100, 1062–1071.
    6. Siegel, C.; Li, J.; Liu, F.; Benashski, S.E.; McCullough, L.D. miR-23a regulation of X-linked inhibitor of apoptosis (XIAP) contributes to sex differences in the response to cerebral ischemia. Proc. Natl. Acad. Sci. USA 2011, 108, 11662–11667.
    7. Hagberg, H.; Wilson, M.A.; Matsushita, H.; Zhu, C.; Lange, M.; Gustavsson, M.; Poitras, M.F.; Dawson, T.M.; Dawson, V.L.; Northington, F.; et al. PARP-1 gene disruption in mice preferentially protects males from perinatal brain injury. J. Neurochem. 2004, 90, 1068–1075.
    8. Liu, F.; Lang, J.; Li, J.; Benashski, S.E.; Siegel, M.; Xu, Y.; McCullough, L.D. Sex differences in the response to poly(ADP-ribose) polymerase-1 deletion and caspase inhibition after stroke. Stroke 2011, 42, 1090–1096.
    9. Brown, D.L.; Boden-Albala, B.; Langa, K.M.; Lisabeth, L.D.; Fair, M.; Smith, M.A.; Sacco, R.L.; Morgenstern, L.B. Projected costs of ischemic stroke in the United States. Neurology 2006, 67, 1390–1395.
    10. Ovbiagele, B.; Goldstein, L.B.; Higashida, R.T.; Howard, V.J.; Johnston, S.C.; Khavjou, O.A.; Lackland, D.T.; Lichtman, J.H.; Mohl, S.; Sacco, R.L.; et al. American Heart Association Advocacy Coordinating Committee and Stroke Council Forecasting the future of stroke in the United States: A policy statement from the American Heart Association and American Stroke Association. Stroke 2013, 44, 2361–2375.
    11. Norrving, B.; Kissela, B. The global burden of stroke and need for a continuum of care. Neurology 2013, 80, S5–S12.
    12. Kroemer, G.; Levine, B. Autophagic cell death: The story of a misnomer. Nat. Rev. Mol. Cell Biol. 2008, 9, 1004–1010.
    13. Kroemer, G.; Marino, G.; Levine, B. Autophagy and the integrated stress response. Mol. Cell 2010, 40, 280–293.
    14. Yang, Z.; Klionsky, D.J. Eaten alive: A history of macroautophagy. Nat. Cell Biol. 2010, 12, 814–822.
    15. Levine, B.; Mizushima, N.; Virgin, H.W. Autophagy in immunity and inflammation. Nature 2011, 469, 323–335.
    16. Mizushima, N.; Levine, B.; Cuervo, A.M.; Klionsky, D.J. Autophagy fights disease through cellular self-digestion. Nature 2008, 451, 1069–1075.
    17. Beau, I.; Mehrpour, M.; Codogno, P. Autophagosomes and human diseases. Int. J. Biochem. Cell Biol. 2011, 43, 460–464.
    18. Lista, P.; Straface, E.; Brunelleschi, S.; Franconi, F.; Malorni, W. On the role of autophagy in human diseases: A gender perspective. J. Cell Mol. Med. 2011, 15, 1443–1457.
    19. Wen, Y.D.; Sheng, R.; Zhang, L.S.; Han, R.; Zhang, X.; Zhang, X.D.; Han, F.; Fukunaga, K.; Qin, Z.H. Neuronal injury in rat model of permanent focal cerebral ischemia is associated with activation of autophagic and lysosomal pathways. Autophagy 2008, 4, 762–769.
    20. Puyal, J.; Vaslin, A.; Mottier, V.; Clarke, P.G. Postischemic treatment of neonatal cerebral ischemia should target autophagy. Ann. Neurol. 2009, 66, 378–389.
    21. Sheng, R.; Zhang, L.S.; Han, R.; Liu, X.Q.; Gao, B.; Qin, Z.H. Autophagy activation is associated with neuroprotection in a rat model of focal cerebral ischemic preconditioning. Autophagy 2010, 6, 482–494.
    22. Yan, W.; Zhang, H.; Bai, X.; Lu, Y.; Dong, H.; Xiong, L. Autophagy activation is involved in neuroprotection induced by hyperbaric oxygen preconditioning against focal cerebral ischemia in rats. Brain Res. 2011, 1402, 109–121.
    23. Wang, Z.; Shi, X.Y.; Yin, J.; Zuo, G.; Zhang, J.; Chen, G. Role of autophagy in early brain injury after experimental subarachnoid hemorrhage. J. Mol. Neurosci. 2012, 46, 192–202.
    24. Noh, H.S.; Shin, I.W.; Ha, J.H.; Hah, Y.S.; Baek, S.M.; Kim, D.R. Propofol protects the autophagic cell death induced by the ischemia/reperfusion injury in rats. Mol. Cells 2010, 30, 455–460.
    25. Wang, J.Y.; Xia, Q.; Chu, K.T.; Pan, J.; Sun, L.N.; Zeng, B.; Zhu, Y.J.; Wang, Q.; Wang, K.; Luo, B.Y. Severe global cerebral ischemia-induced programmed necrosis of hippocampal CA1 neurons in rat is prevented by 3-methyladenine: A widely used inhibitor of autophagy. J. Neuropathol. Exp. Neurol. 2011, 70, 314–322.
    26. Jiang, Y.; Zhu, J.; Wu, L.; Xu, G.; Dai, J.; Liu, X. Tetracycline inhibits local inflammation induced by cerebral ischemia via modulating autophagy. PLoS ONE 2012, 7, e48672.
    27. Cui, D.R.; Wang, L.; Jiang, W.; Qi, A.H.; Zhou, Q.H.; Zhang, X.L. Propofol prevents cerebral ischemia-triggered autophagy activation and cell death in the rat hippocampus through the NF-kappaB/p53 signaling pathway. Neuroscience 2013, 246, 117–132.
    28. Weis, S.N.; Toniazzo, A.P.; Ander, B.P.; Zhan, X.; Careaga, M.; Ashwood, P.; Wyse, A.T.; Netto, C.A.; Sharp, F.R. Autophagy in the brain of neonates following hypoxia-ischemia shows sex- and region-specific effects. Neuroscience 2014, 256, 201–209.
    29. Saver, J.L. Time is brain—Quantified. Stroke 2006, 37, 263–266.
    30. Rami, A.; Kogel, D. Apoptosis meets autophagy-like cell death in the ischemic penumbra: Two sides of the same coin? Autophagy 2008, 4, 422–426.
    31. Wirth, M.; Joachim, J.; Tooze, S.A. Autophagosome formation--the role of ULK1 and Beclin1-PI3KC3 complexes in setting the stage. Semin. Cancer Biol. 2013, 23, 301–309.
    32. Zhang, A.; Song, Y.; Zhang, Z.; Jiang, S.; Chang, S.; Cai, Z.; Liu, F.; Zhang, X.; Ni, G. Effects of autophagy inhibitor 3-Methyladenine on ischemic stroke: A protocol for systematic review and meta-analysis. Medicine 2021, 100, e23873.
    33. Wang, M.; Liang, X.; Cheng, M.; Yang, L.; Liu, H.; Wang, X.; Sai, N.; Zhang, X. Homocysteine enhances neural stem cell autophagy in in vivo and in vitro model of ischemic stroke. Cell Death Dis. 2019, 10.
    34. Shi, R.; Weng, J.; Zhao, L.; Li, X.M.; Gao, T.M.; Kong, J. Excessive autophagy contributes to neuron death in cerebral ischemia. CNS Neurosci. Ther. 2012, 18, 250–260.
    35. Sun, Y.; Zhang, T.; Zhang, Y.; Li, J.; Jin, L.; Sun, Y.; Shi, N.; Liu, K.; Sun, X. Ischemic Postconditioning Alleviates Cerebral Ischemia-Reperfusion Injury Through Activating Autophagy During Early Reperfusion in Rats. Neurochem. Res. 2018, 43, 1826–1840.
    36. Kim, J.; Kundu, M.; Viollet, B.; Guan, K.L. AMPK and mTOR regulate autophagy through direct phosphorylation of Ulk1. Nat. Cell Biol. 2011, 13, 132–141.
    37. Shang, L.; Chen, S.; Du, F.; Li, S.; Zhao, L.; Wang, X. Nutrient starvation elicits an acute autophagic response mediated by Ulk1 dephosphorylation and its subsequent dissociation from AMPK. Proc. Natl. Acad. Sci. USA 2011, 108, 4788–4793.
    38. Acaz-Fonseca, E.; Castelló-Ruiz, M.; Burguete, M.C.; Aliena-Valero, A.; Salom, J.B.; Torregrosa, G.; García-Segura, L.M. Insight into the molecular sex dimorphism of ischaemic stroke in rat cerebral cortex: Focus on neuroglobin, sex steroids and autophagy. Eur. J. Neurosci. 2020, 52, 2756–2770.
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