Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Leandro Castaneyra-Ruiz
 -- 1293 2022-09-13 20:19:11 |
2 layout
Camila Xu
 Meta information modification 1293 2022-09-14 02:28:23 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Castañeyra-Ruiz, L.;  González-Marrero, I.;  Hernández-Abad, L.G.;  Lee, S.;  Castañeyra-Perdomo, A.;  Muhonen, M. AQP4 and Astrogenesis. Encyclopedia. Available online: https://encyclopedia.pub/entry/27145 (accessed on 16 May 2024).
Castañeyra-Ruiz L,  González-Marrero I,  Hernández-Abad LG,  Lee S,  Castañeyra-Perdomo A,  Muhonen M. AQP4 and Astrogenesis. Encyclopedia. Available at: https://encyclopedia.pub/entry/27145. Accessed May 16, 2024.
Castañeyra-Ruiz, Leandro, Ibrahim González-Marrero, Luis G. Hernández-Abad, Seunghyun Lee, Agustín Castañeyra-Perdomo, Michael Muhonen. "AQP4 and Astrogenesis" Encyclopedia, https://encyclopedia.pub/entry/27145 (accessed May 16, 2024).
Castañeyra-Ruiz, L.,  González-Marrero, I.,  Hernández-Abad, L.G.,  Lee, S.,  Castañeyra-Perdomo, A., & Muhonen, M. (2022, September 13). AQP4 and Astrogenesis. In Encyclopedia. https://encyclopedia.pub/entry/27145
Castañeyra-Ruiz, Leandro, et al. "AQP4 and Astrogenesis." Encyclopedia. Web. 13 September, 2022.
AQP4 and Astrogenesis
Edit
This entry is adapted from the peer-reviewed paper 10.3390/ijms231810438

Aquaporin 4 (AQP4) is a cerebral glial marker that labels ependymal cells and astrocytes’ endfeet and is the main water channel responsible for the parenchymal fluid balance. Even though specific markers do not exist for the different stages of astrogenesis, it has been suggested that astrogenesis progresses trough at least four cellular stages: a radial glial cell (RGC), an intermediate progenitor cell, a maturing postnatal astrocyte, and an adult astrocyte.

AQP4 astrogenesis pediatric hydrocephalus

1. Introduction

Although 90% of brain tissue is composed of glial cells, most cellular brain studies have focused on neuronal physiology; consequently, the glial cells have been relegated to a supportive position. Astrocytes are the most common glial cells in the CNS, accounting for 20 to 40% of total brain cells [1] and play a fundamental role in neural development, neural circuit function, neurotransmission, blood–brain barrier creation, and neural metabolic support. Astrocytes support the neurovascular systems by connecting neurons and endothelial cells, maintaining brain homeostasis, controlling water, amino acid, and neurotransmitter intake, and monitoring the local activity of synaptic circuits [2][3][4][5].
Since Ramon y Cajal proposed the neuron theory in the early 20th century [6], hundreds of neuron types and functions have been identified [7][8]. However, astrocytes are still considered a homogeneous population, only classified as protoplasmic or fibrous [9]. Astrocytes’ morphological and functional diversity, including their critical role in governing neuronal activity, is well-accepted. Therefore, defining astrogliogenesis to identify astrocytes’ functional and anatomical heterogeneity is crucial to understanding brain physiology [5][10].
Astrogenesis characterization is impeded by a lack of precursor and intermediate stages markers. Furthermore, astrocytes’ plasticity allows proliferative capabilities after being differentiated, complicating their identification [5][10]. 

2. AQP4: A Possible Astrogenesis Marker

Even though specific markers do not exist for the different stages of astrogenesis, it has been suggested that astrogenesis progresses trough at least four cellular stages: a radial glial cell (RGC), an intermediate progenitor cell, a maturing postnatal astrocyte, and an adult astrocyte. RGCs are fundamental in early brain development, serving as a scaffold for intermediate progenitors and neuro-glial precursors. After the cessation of neurogenesis, the RGCs become gliogenic (gliogenic switch) and the intermediate progenitors and astrocyte precursors migrate away from the germinal areas to differentiate into astrocytes [5][10][11].
AQP4 is a water channel linked to a glial lineage in the brain since it is expressed in astrocytes (mainly in the endfeet) and the ependymal cells [12][13][14]. AQP4 is expressed in neural stem cells (NSC) and their glial progeny [15] and modulates the proliferation, survival, migration, and neuronal differentiation of adult NSCs [16][17][18]. Interestingly, in adult lesser hedgehog tenrec (Echinops telfairi), immature radial glial cells persist through adulthood without expressing AQP4 [19]. In zebrafish, another form of astroglial cells continues through adulthood as RGCs expressing AQP4 [20]. In primates, cortical interlaminar astrocytes seem to have an RGC origin since they express typical RGC markers and adult astrocytes markers such as AQP4 [21]. All the animal findings support that AQP4 is associated with an astroglial lineage that may remain undifferentiated as RGCs in adulthood. In utero, AQP4 labels RGCs committed to the astrocyte lineage in humans [22][23] and mice [24]. It has been proposed that unpolarized AQP4-positive cells in the brain show proliferative and regenerative properties as neural stem cells [25]. In mice, the unpolarized expression of AQP4 in RGCs is not detected at the end of in utero life (E16), and the expression of AQP4 is restricted to the astroglial endfeet postnatally (polarized), at P1–3 [24] However, in humans, the AQP4-positive RGCs are present at the beginning of the second trimester of the pregnancy (13–14 postconceptional weeks, PCW), and the polarized expression of AQP4 forming the neurovascular unit is detected at the beginning of the third trimester (25 PCW) [22][23]. Therefore, the maturation of the expression of AQP4 seems to be delayed in mice compared to humans. 
Interestingly, GSCs follow a temporospatial expression pattern that may indicate the end of neurogenesis and the beginning of gliogenesis [22][23]. GSCs’ first detection is in the glioepithelium of the fimbria of the archicortex and progresses toward fibrous tracts, such as the corpus callosum (CC), the fornix, and the internal capsule in medial areas of the brain. From 25 PCW onward, AQP4 is expressed throughout the neocortex, mainly in the intermediate zone or subplate, giving rise to the cerebral cortex’s white matter. AQP4 is expressed primarily on the main fibrous tracts of the isocortex, possibly to provide homeostasis to facilitate neural impulse transmission to incipient fiber tracts. In general terms, AQP4-positive GSC expression progresses from medial to lateral, starting in the dorsal and ventral hippocampus archicortex, followed by the CC and the ganglionic eminences (transitory structures that contribute to the development of first neurogenic, later gliogenic, and ultimately degenerate), and finally, terminating in the intermediate zone of the resting brain. AQP4-dependent maturity progresses from medial to polar, initially in the perisylvian regions and finally in the occipital and prefrontal zones [22][23][26] (see Figure 1). This correlates with CC maturation. According to classic neuroanatomic studies and recent human embryology neuroimaging, the colossal connections begin centrally in the hippocampal primordium and progress bidirectionally both anteriorly and posteriorly [27][28][29][30][31], with more prominent anterior growth [32][33]. The expression pattern of AQP4-dependent GSCs could define a developmental pathway for cortical neuron functionality, with the archicortex (primitive cortex) acquiring functionality in early gestation, while the frontal and occipital poles acquire functionality at the end of gestation. Therefore, there is an ontogenic logic in which occipital and prefrontal areas achieve functionality and maturity late in brain development since they are responsible for the vision and complex behaviors such as the expression of personality, respectively.
Figure 1. Schematic representation of the expression of AQP4 in brain development (obtained from castaneyra et al., 2022[34]). In the telencephalon, AQP4 expression starts in GSCs and GBs and progresses from the para hippocampal VZ toward the glioepithelium of the fimbria of the dorsal hippocampus at 12–13 PCW. At 21 PCW, AQP4 has advanced medial to lateral in the coronal view, and medial to polar in the sagittal view. At this point, AQP4 is expressed in the ventricular zone adjacent to the medial portion of the CC, where the GSCs project their cellular process toward CC fibers. GSCs are also found in the LGE and the lenticular nucleus projecting toward the internal capsule. At 25 PCW, the AQP4 is patent cortically, and GSC processes are found projecting from the SVZ to the IZ. Polarized AQP4 expression is located in the astrocyte’s endfeet as a part of the neurovascular unit at the IZ, indicating maturity and functionality. LV, lateral ventricle; MZ, marginal zone; CP, cortical plate; SCP, subcortical plate; IZ, intermediate zone; SVZ, subventricular zone; VZ, ventricular zone; CC, corpus callosum; IC, internal capsule; DHip, dorsal hippocampus; Tha, thalamus; GE ganglionic eminence; LGE, lateral ganglionic eminence; MGE, medial ganglionic eminence; Ca, caudate; LN, lenticular nucleus; GP, glial progenitor; A, astrocyte; BV, blood vessel; AQP4, aquaporin 4.
In summary, unpolarized expression of AQP4 is found in proliferative cells with different morphologies: GSCs (with a long projection that is used for other cells to migrate and populate the white matter tracks), and intermediate progenitor cells (without a long projection and oval shape). Researchers hypothesize that the expression of AQP4 in these progenitor cells indicates a gliogenic switch that represents the early stages of astrogenesis. Finally, when AQP4 expression is polarized (astrocytes’ endfeet), this indicates astrocyte maturity as a final step of the astrogenesis. Currently, three specific markers are accepted to identify astrocyte precursors: GLAST, FABP7/BLBP/, and FGFR3 [35][36][37][38]. GLAST is a glutamate transporter active in astrocytes, and its expression initiates with the gliogenic switch indicating specifically astrogenesis precursors. However, FABP7/BLBP/and FGFR3 are also expressed during neurogenic stages, making them unspecific markers [11]. In humans, AQP4 initiates its expression at the gliogenic switch, labeling different astrocyte precursors [22][23]. Thus, this water channel shows a similar expression pattern to GLAST and could be a relevant marker of astrogenesis. Further studies in experimental models should be conducted to confirm this.

References

  1. Herculano-Houzel, S. The glia/neuron ratio: How it varies uniformly across brain structures and species and what that means for brain physiology and evolution. Glia 2014, 62, 1377–1391.
  2. Morel, L.; Chiang, M.S.R.; Higashimori, H.; Shoneye, T.; Iyer, L.K.; Yelick, J.; Tai, A.; Yang, Y. Molecular and Functional Properties of Regional Astrocytes in the Adult Brain. J. Neurosci. 2017, 37, 8706–8717.
  3. Chai, H.; Diaz-Castro, B.; Shigetomi, E.; Monte, E.; Octeau, J.C.; Yu, X.; Cohn, W.; Rajendran, P.S.; Vondriska, T.M.; Whitelegge, J.P.; et al. Neural Circuit-Specialized Astrocytes: Transcriptomic, Proteomic, Morphological, and Functional Evidence. Neuron 2017, 95, 531–549.e9.
  4. John Lin, C.-C.; Yu, K.; Hatcher, A.; Huang, T.-W.; Lee, H.K.; Carlson, J.; Weston, M.C.; Chen, F.; Zhang, Y.; Zhu, W.; et al. Identification of diverse astrocyte populations and their malignant analogs. Nat. Neurosci. 2017, 20, 396–405.
  5. Akdemir, E.S.; Huang, A.Y.-S.; Deneen, B. Astrocytogenesis: Where, when, and how. F1000Research 2020, 9, 233.
  6. López-Muñoz, F.; Boya, J.; Alamo, C. Neuron theory, the cornerstone of neuroscience, on the centenary of the Nobel Prize award to Santiago Ramón y Cajal. Brain Res. Bull. 2006, 70, 391–405.
  7. Zeisel, A.; Hochgerner, H.; Lönnerberg, P.; Johnsson, A.; Memic, F.; van der Zwan, J.; Häring, M.; Braun, E.; Borm, L.E.; La Manno, G.; et al. Molecular Architecture of the Mouse Nervous System. Cell 2018, 174, 999–1014.e22.
  8. Saunders, A.; Macosko, E.Z.; Wysoker, A.; Goldman, M.; Krienen, F.M.; de Rivera, H.; Bien, E.; Baum, M.; Bortolin, L.; Wang, S.; et al. Molecular Diversity and Specializations among the Cells of the Adult Mouse Brain. Cell 2018, 174, 1015–1030.e16.
  9. Batiuk, M.Y.; Martirosyan, A.; Wahis, J.; de Vin, F.; Marneffe, C.; Kusserow, C.; Koeppen, J.; Viana, J.F.; Oliveira, J.F.; Voet, T.; et al. Identification of region-specific astrocyte subtypes at single cell resolution. Nat. Commun. 2020, 11, 1220.
  10. Molofsky, A.V.; Krenick, R.; Ullian, E.; Tsai, H.-H.; Deneen, B.; Richardson, W.D.; Barres, B.A.; Rowitch, D.H. Astrocytes and disease: A neurodevelopmental perspective. Genes Dev. 2012, 26, 891–907.
  11. Molofsky, A.V.; Deneen, B. Astrocyte development: A Guide for the Perplexed. Glia 2015, 63, 1320–1329.
  12. Nielsen, S.; King, L.S.; Christensen, B.M.; Agre, P. Aquaporins in complex tissues. II. Subcellular distribution in respiratory and glandular tissues of rat. Am. J. Physiol. 1997, 273, C1549–C1561.
  13. Rash, J.E.; Yasumura, T.; Hudson, C.S.; Agre, P.; Nielsen, S. Direct immunogold labeling of aquaporin-4 in square arrays of astrocyte and ependymocyte plasma membranes in rat brain and spinal cord. Proc. Natl. Acad. Sci. USA 1998, 95, 11981–11986.
  14. Leandro Castañeyra-Ruiz; Ibrahim González-Marrero; Juan M González-Toledo; Agustin Castañeyra-Ruiz; Héctor de Paz-Carmona; Agustín Castañeyra-Perdomo; Emilia M Carmona-Calero; Aquaporin-4 expression in the cerebrospinal fluid in congenital human hydrocephalus. Fluids and Barriers of the CNS 2013, 10, 18-5, 10.1186/2045-8118-10-18.
  15. Cavazzin, C.; Ferrari, D.; Facchetti, F.; Russignan, A.; Vescovi, A.L.; La Porta, C.A.; Gritti, A. Unique expression and localization of aquaporin- 4 and aquaporin-9 in murine and human neural stem cells and in their glial progeny. Glia 2006, 53, 167–181.
  16. Kong, H.; Fan, Y.; Xie, J.; Ding, J.; Sha, L.; Shi, X.; Sun, X.; Hu, G. AQP4 knockout impairs proliferation, migration and neuronal differentiation of adult neural stem cells. J. Cell Sci. 2008, 121, 4029–4036.
  17. La Porta, C.A.; Gena, P.; Gritti, A.; Fascio, U.; Svelto, M.; Calamita, G. Adult murine CNS stem cells express aquaporin channels. Biol. Cell 2006, 98, 89–94.
  18. Liang, R.; Yong, S.; Huang, X.; Kong, H.; Hu, G.; Fan, Y. Aquaporin-4 Mediates the Suppressive Effect of Lipopolysaccharide on Hippocampal Neurogenesis. Neuroimmunomodulation 2016, 23, 309–317.
  19. Mack, A.F.; Künzle, H.; Lange, M.; Mages, B.; Reichenbach, A.; Härtig, W. Radial glial elements in the cerebral cortex of the lesser hedgehog tenrec. Brain Struct. Funct. 2018, 223, 3909–3917.
  20. Gleiser, C.; Wagner, A.; Fallier-Becker, P.; Wolburg, H.; Hirt, B.; Mack, A.F. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs—A Comparative Perspective. Int. J. Mol. Sci. 2016, 17, 1411.
  21. Falcone, C.; Penna, E.; Hong, T.; Tarantal, A.F.; Hof, P.R.; Hopkins, W.D.; Sherwood, C.C.; Noctor, S.C.; Martínez-Cerdeño, V. Cortical Interlaminar Astrocytes Are Generated Prenatally, Mature Postnatally, and Express Unique Markers in Human and Nonhuman Primates. Cereb. Cortex 2021, 31, 379–395.
  22. Holst, C.B.; Brøchner, C.B.; Vitting-Seerup, K.; Møllgård, K. Astrogliogenesis in human fetal brain: Complex spatiotemporal immunoreactivity patterns of GFAP, S100, AQP 4 and YKL -40. J. Anat. 2019, 235, 590–615.
  23. Castañeyra-Ruiz, L.; González-Marrero, I.; Hernández-Abad, L.G.; Carmona-Calero, E.M.; Pardo, M.R.; Baz-Davila, R.; Lee, S.; Muhonen, M.; Borges, R.; Castañeyra-Perdomo, A. AQP4 labels a subpopulation of white matter-dependent glial radial cells affected by pediatric hydrocephalus, and its expression increased in glial microvesicles released to the cerebrospinal fluid in obstructive hydrocephalus. Acta Neuropathol. Commun. 2022, 10, 41.
  24. Fallier-Becker, P.; Vollmer, J.P.; Bauer, H.; Noell, S.; Wolburg, H.; Mack, A.F. Onset of aquaporin-4 expression in the developing mouse brain. Int. J. Dev. Neurosci. 2014, 36, 81–89.
  25. Mack, A.F.; Wolburg, H. A Novel Look at Astrocytes: Aquaporins, ionic homeostasis, and the role of the microenvironment for regeneration in the CNS. Neuroscientist 2013, 19, 195–207.
  26. Gömöri, E.; Pál, J.; Ábrahám, H.; Vajda, Z.; Sulyok, E.; Seress, L.; Dóczi, T. Fetal development of membrane water channel proteins aquaporin-1 and aquaporin-4 in the human brain. Int. J. Dev. Neurosci. 2006, 24, 295–305.
  27. Deoni, S.C.L.; Mercure, E.; Blasi, A.; Gasston, D.; Thomson, A.; Johnson, M.; Williams, S.; Murphy, D. Mapping Infant Brain Myelination with Magnetic Resonance Imaging. J. Neurosci. 2011, 31, 784–791.
  28. Kier, E.L.; Truwit, C.L. The normal and abnormal genu of the corpus callosum: An evolutionary, embryologic, anatomic, and MR analysis. AJNR Am. J. Neuroradiol. 1996, 17, 1631–1641.
  29. Huang, H.; Xue, R.; Zhang, J.; Ren, T.; Richards, L.J.; Yarowsky, P.; Miller, M.I.; Mori, S. Anatomical Characterization of Human Fetal Brain Development with Diffusion Tensor Magnetic Resonance Imaging. J. Neurosci. 2009, 29, 4263–4273.
  30. Barkovich, A.J.; Lyon, G.; Evrard, P. Formation, maturation, and disorders of white matter. AJNR Am. J. Neuroradiol. 1992, 13, 447–461.
  31. Paul, L.K. Developmental malformation of the corpus callosum: A review of typical callosal development and examples of developmental disorders with callosal involvement. J. Neurodev. Disord. 2011, 3, 3–27.
  32. Rakic, P.; Yakovlev, P.I. Development of the corpus callosum and cavum septi in man. J. Comp. Neurol. 1968, 132, 45–72.
  33. Luders, E.; Thompson, P.; Toga, A.W. The Development of the Corpus Callosum in the Healthy Human Brain. J. Neurosci. 2010, 30, 10985–10990.
  34. Leandro Castañeyra-Ruiz; Ibrahim González-Marrero; Luis G. Hernández-Abad; Seunghyun Lee; Agustín Castañeyra-Perdomo; Michael Muhonen; AQP4, Astrogenesis, and Hydrocephalus: A New Neurological Perspective. International Journal of Molecular Sciences 2022, 23, 10438, 10.3390/ijms231810438.
  35. Anthony, T.E.; Klein, C.; Fishell, G.; Heintz, N. Radial Glia Serve as Neuronal Progenitors in All Regions of the Central Nervous System. Neuron 2004, 41, 881–890.
  36. Owada, Y.; Yoshimoto, T.; Kondo, H. Spatio-temporally differential expression of genes for three members of fatty acid binding proteins in developing and mature rat brains. J. Chem. Neuroanat. 1996, 12, 113–122.
  37. Pringle, N.P.; Yu, W.-P.; Howell, M.; Colvin, J.S.; Ornitz, D.M.; Richardson, W.D. Fgfr3 expression by astrocytes and their precursors: Evidence that astrocytes and oligodendrocytes originate in distinct neuroepithelial domains. Development 2003, 130, 93–102.
  38. Shibata, T.; Yamada, K.; Watanabe, M.; Ikenaka, K.; Wada, K.; Tanaka, K.; Inoue, Y. Glutamate Transporter GLAST Is Expressed in the Radial Glia–Astrocyte Lineage of Developing Mouse Spinal Cord. J. Neurosci. 1997, 17, 9212–9219.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Developmental Biology
Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Leandro Castañeyra-Ruiz
,
Ibrahim González-Marrero
,
Luis G. Hernández-Abad
,
Seunghyun Lee
,
Agustín Castañeyra-Perdomo
,
Michael Muhonen
View Times: 395
Revisions: 2 times (View History)
Update Date: 14 Sep 2022
Table of Contents
    1000/1000
    Hot Most Recent
    Feedback