


![]()
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Parkison
Disease
Arthritis
2007/4/19/6
Comment in: ATP release guides neutrophil
chemotaxis via P2Y2 and A3 receptors. · Chen Y, Corriden R, Inoue Y, Yip L, Hashiguchi N, Zinkernagel A, Nizet V, Insel PA, Junger WG. Department of Surgery, Cells must amplify external
signals to orient and migrate in chemotactic
gradient fields. We find that human neutrophils
release adenosine triphosphate (ATP) from the
leading edge of the cell surface to amplify chemotactic
signals and direct cell orientation by feedback through P2Y2 nucleotide
receptors. Neutrophils rapidly hydrolyze released
ATP to adenosine that then acts via A3-type adenosine receptors, which are
recruited to the leading edge, to promote cell migration. Thus, ATP release
and autocrine feedback through P2Y2 and A3
receptors provide signal amplification, controlling gradient sensing and
migration of neutrophils. PMID: 17170310 [PubMed
- indexed for MEDLINE] J Rheumatol. 2007 Jan;34(1):20-6. Overexpression of A3 adenosine receptor in peripheral
blood mononuclear cells in rheumatoid arthritis: involvement of nuclear
factor-kappaB in mediating receptor level. · Madi L, Cohen S, Ochayin A, Bar-Yehuda S, Barer F, Fishman P. Can-Fite BioPharma Ltd., Kiryat-Matalon,
OBJECTIVE: A3 adenosine receptor
(A3AR) upregulation has been found in cells of synovial tissue and in peripheral blood mononuclear
cells (PBMC) of rats with adjuvant-induced arthritis. We investigated A3AR
levels in PBMC of patients with rheumatoid arthritis (RA) and in mitogen-activated PBMC from healthy subjects. We
examined the role of nuclear factor-kappaB
(NF-kappaB), a transcription factor present in the A3AR promoter, in
mediating receptor upregulation. METHODS: A3AR
and NF-kappaB protein levels were evaluated in
PBMC of RA patients (n = 23) and healthy subjects by Western blot. A3AR and
NF-kappaB levels were also analyzed in phytohemagglutinin (PHA) and lipopolysaccharide
(LPS)-stimulated PBMC in the presence and absence of antibodies against
interleukin 2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha). Reverse
transcription-polymerase chain reaction was performed in PHA-stimulated
PBMC of healthy subjects to determine A3AR expression. RESULTS: A3AR was overexpressed in PBMC of RA patients compared to
healthy subjects and was directly correlated to an increase in NF-kappaB. Similar findings were observed in PHA and
LPS-stimulated PBMC from healthy subjects. Antibodies against IL-2 or
TNF-alpha prevented the increase in A3AR and NF-kappaB
expression. CONCLUSION: Overexpression of A3AR
was found in PBMC of RA patients. Receptor upregulation
was induced by inflammatory cytokines controlling the expression of the
A3AR transcription factor NF-kappaB. PMID: 17216675 [PubMed
- in process
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