PMID- 10955718
OWN - NLM
STAT- MEDLINE
DCOM- 20010201
LR  - 20190720
IS  - 0302-766X (Print)
IS  - 0302-766X (Linking)
VI  - 301
IP  - 2
DP  - 2000 Aug
TI  - Changes in the expression of the nerve growth factor receptors TrkA and p75LNGR 
      in the rat thymus with ageing and increased nerve growth factor plasma levels.
PG  - 225-34
AB  - The nerve growth factor (NGF) receptors p75LNGR and TrkA are expressed by thymic 
      epithelial cells. Presumably, the NGF-TrkA system is involved in the paracrine 
      communication between thymic epithelial cells and thymocytes, whereas the 
      functional role of p75LNGR is still unknown. The thymus of vertebrates undergoes 
      age-related changes that in part depend on hormonal factors. In order to find out 
      whether thymic epithelial cells are responsive to NGF during the whole lifespan 
      of the rat, we studied NGF receptor expression in the thymus from birth to 2 
      years of age, using immunohistochemistry. Furthermore, to evaluate whether 
      increased plasma levels of NGF affected the ageing process, either NGF or 
      4-methylcatechol (4MC), an inductor of NGF synthesis, was administered. Both TrkA 
      and p75LNGR were expressed by a subpopulation of thymic epithelial cells during 
      the whole age range studied and their expression peaked at around 3 months. TrkA 
      was primarily found in subcortical and medullary epithelial cells, whereas 
      p75LNGR was seen in a subpopulation of medullary cells. Cortical epithelial 
      cells, neural crest-derived cells, other stromal cells and thymocytes were not 
      immunoreactive for NGF receptors. Neither the administration of NGF nor the 
      increased NGF plasma levels obtained after 4MC treatment seemed to affect the 
      ageing of the thymus as assessed by morphological and immunohistochemical 
      criteria, but this increase in NGF levels did produce a shift in the expression 
      of p75LNGR from epithelial cells to ED1-positive macrophages in animals of 6 
      months and older. Present results indicate that the expression of p75LNGR and 
      TrkA in the rat thymus undergoes age-dependent changes that parallel those of 
      epithelial cells. NGF could therefore be important for thymus homeostasis, 
      possibly acting on epithelial cells. Nevertheless, NGF did not seem to be able to 
      prevent the involution of this organ, although it produced a switch in the 
      expression of p75LNGR, the significance of which remains to be established.
FAU - Garcia-Suarez, O
AU  - Garcia-Suarez O
AD  - Departmento de Morfologia y Biologia Celular, Facultad de Medicina, Universidad 
      de Oviedo, Spain.
FAU - Germana, A
AU  - Germana A
FAU - Hannestad, J
AU  - Hannestad J
FAU - Perez-Perez, M
AU  - Perez-Perez M
FAU - Esteban, I
AU  - Esteban I
FAU - Naves, F J
AU  - Naves FJ
FAU - Vega, J A
AU  - Vega JA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Cell Tissue Res
JT  - Cell and tissue research
JID - 0417625
RN  - 0 (Catechols)
RN  - 0 (Receptor, Nerve Growth Factor)
RN  - 12GLI7JGB3 (4-methylcatechol)
RN  - 9061-61-4 (Nerve Growth Factor)
RN  - EC 2.7.10.1 (Receptor, trkA)
SB  - IM
MH  - *Aging
MH  - Animals
MH  - Catechols/pharmacology
MH  - Epithelial Cells/metabolism
MH  - Immunohistochemistry
MH  - Macrophages/metabolism
MH  - Male
MH  - Nerve Growth Factor/*blood/pharmacology
MH  - Rats
MH  - Rats, Wistar
MH  - Receptor, Nerve Growth Factor/immunology/*metabolism
MH  - Receptor, trkA/immunology/*metabolism
MH  - Thymus Gland/cytology/*growth & development/*metabolism
EDAT- 2000/08/24 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/08/24 11:00
PHST- 2000/08/24 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/08/24 11:00 [entrez]
AID - 10.1007/s004419900133 [doi]
PST - ppublish
SO  - Cell Tissue Res. 2000 Aug;301(2):225-34. doi: 10.1007/s004419900133.