uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
EVOLUTION OF HEMATOPOIESIS: AN ASTAKINE INDUCED NOVEL HEMATOPOIETIC FACTOR
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology.
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

We report here the cloning and initial characterization of a novel invertebrate hematopoietic factor. This factor was identified from the SSH library with the aim to find the downstream genes of an invertebrate cytokine, astakine 1 in the freshwater crayfish Pacifastacus leniusculus. This Pacifastacus Hematopoietic Factor (PHF) was found to be induced in the primary cell culture of crayfish Hpt cells (precursor of crayfish blood cells) by treatment with astakine 1. Silencing PHF did not affect the renewal of Hpt cells in vitro, but induced the apoptosis rate of Hpt cells. PHF is dominantly present in the blood lineage of crayfish (Hpt cells and blood cells), and in vivo RNAi experiment shows that knockdown of this gene results in severe loss of blood cells in the animal. Our data suggest that crayfish PHF is critical for the survival of not only hemocytes but also the Hpt cells by preventing their apoptosis, thus it plays an important role in the hematopoiesis in crayfish. PHF is a small cysteine rich protein (ca. 9 kDa) with high similarity with the N-terminal region of vertebrate CRIM1 and both of them contains an IGFBP variant motif with unknown function. Our study of PHF may also shed light on the function of this untypical IGFBP motif located in the N-terminal of vertebrate CRIM1.

Keyword [en]
astakine, hematopoiesis, apoptosis, cytokine, invertebrate, CRIM1
National Category
Immunology
Research subject
Biology with specialization in Comparative Physiology
Identifiers
URN: urn:nbn:se:uu:diva-120999OAI: oai:DiVA.org:uu-120999DiVA: diva2:304540
Available from: 2010-03-18 Created: 2010-03-17 Last updated: 2010-03-19
In thesis
1. Hematopoiesis in a Crustacean
Open this publication in new window or tab >>Hematopoiesis in a Crustacean
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Hemocytes (blood cells) play an important role in the immune response in invertebrates, and thus the regulation of hemocyte homeostasis (hematopoiesis) is essential for the host survival against pathogens. Astakine 1, a homologue to vertebrate prokineticins, was first identified in the freshwater crayfish Pacifastacus leniusculus as a cytokine, and was found to be necessary for new hemocyte synthesis and release in vivo, and also to induce spreading and proliferation of Hematopoietic tissue cells (Hpt cells, precursor of hemocytes) in vitro. The work of this thesis is aimed to further our understanding of the molecular mechanisms involved in astakine 1 induced hematopoiesis.

Crayfish transglutaminase (Tgase) has been identified in the hemocytes, and is essential for the coagulation reaction. Interestingly this enzyme is exceedingly abundant in the Hpt cells, and the spreading of Hpt cells induced by astakine 1 was accompanied by sequential loss of TGase activity from the surface of these cells. This loss of TGase activity may be an important effect of astakine 1, resulting in recruiting new hemocytes into the circulatory system. Although astakine 1 contain a prokineticin domain, it lacks the conserved N-terminal AVIT motif present in its vertebrate homologues. This motif is important for vertebrate prokineticins to interact with their receptors, indicating a different receptor interaction for crayfish astakine 1. Astakine 1 was indeed found to interact with a completely different receptor, the β-subunit of ATP synthase, on a portion of Hpt cells, and subsequently block its extracellular ATP formation. Surface ATP synthase has been reported on numerous mammalian cells, but now for the first time in an invertebrate. The activity of ATP synthase on the Hpt cells may be important for the survival and proliferation of Hpt cells, but the underlying mechanisms remain further study. With the finding of a second type of astakine in crayfish, invertebrate astakines can be divided into two groups: astakine 1 and astakine 2. The properties of astakine 2 are different from those of astakine 1 both in structure and function. In primary cell culture of Hpt cells, only astakine 1 can promote proliferation as well as differentiation into semigranular cells, whereas astakine 2 may play a potential role in the maturation of granular cells. Moreover, a novel cysteine rich protein, Pacifastacus hematopoiesis factor (PHF), was found to be one target gene of astakine 1 in Hpt cells. Down regulation of PHF results in increased apoptosis in Hpt cells in vitro, and in vivo silencing PHF leads to a severe loss of hemocytes in the animal. Therefore astakine 1 acquires the anti-apoptosis ability by inducing its downstream gene PHF in the Hpt cells. With its ability to promote the survival, proliferation and differentiation of Hpt cells, astakine 1 is proven to be an important hematopoietic growth factor.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2010. 46 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 723
Keyword
astakine, cytokine, hematopoiesis, prokineticin, transglutaminase, ATP synthase, innate immunity, apoptosis
National Category
Immunology
Research subject
Biology with specialization in Comparative Physiology
Identifiers
urn:nbn:se:uu:diva-121000 (URN)978-91-554-7755-4 (ISBN)
Public defence
2010-05-05, Lindahlsalen, Evolutionary Biology Centre, Norbyvägen 18A, Uppsala, 13:00 (English)
Opponent
Supervisors
Available from: 2010-04-13 Created: 2010-03-17 Last updated: 2013-10-29

Open Access in DiVA

No full text

Authority records BETA

Lin, Xionghui

Search in DiVA

By author/editor
Lin, Xionghui
By organisation
Comparative Physiology
Immunology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 554 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf