Postnatal gelişim sürecindeki sıçanların akciğerinde Toll-like reseptörlerinin (TLR-2, TLR- 4, TLR-5 ve TLR-9) lokalizasyonları ve ekspresyonları


LİMAN N., ALAN E.

XIII. Ulusal Histoloji ve Embriyoloji Kongresi (Uluslararası Katılımlı), İzmir, Turkey, 30 April - 03 May 2016, vol.5, pp.193-195

  • Publication Type: Conference Paper / Full Text
  • Volume: 5
  • City: İzmir
  • Country: Turkey
  • Page Numbers: pp.193-195
  • Erciyes University Affiliated: Yes

Abstract

OBJECTIVE: Toll-like receptors (TLRs) are the transmembrane proteins, which recognize highly conserved structural motifs known as pathogen-associated microbial patterns (PAMPs), which are exclusively expressed by bacterial, fungal and viral pathogens. TLRs play key role in both in initiating the innate immune response and in the regulation of adaptive immune response against infections. It is known that TLRs are expressed by lung of humans and many other animals and play pivotal role in the pulmonary immune response in the pulmonary disorders. However, there are no studies describing the TLR expression during the neonatal lung development process. This study was conducted to demonstrate the possible changes in expression andlocalization of Toll-like reseptors -2, -4, -5, and -9 belonging to pathogen recognition receptors family in rat lung during the neonatal stage of postnatal development period.
MATERIALS-METHODS: In this study, 30 neonatal rat at 1st,3rd, 5th, 10th and 15th days of postnatal period were used for immunohistochemical and western blot analysis. After birth, the 1st and 3rd days of neonatal stage are defined as saccular stage, whereas the 5th, 10th and 15th days are defined as alveolar stage.
RESULTS: In rat lungs during the saccular and alveolar periods, it was determined that TLR-2, TLR-5 and TLR-9 immunoreactivity exhibited membranous, cytoplasmic and nuclear localization, whereas TLR-4 immunoreactivity showed membranous localization. In the rat lungs of saccular and alveolar stages, the nuclei and membranes of saccular/alveolar epithelium, bronchiolar epithelium and interstitial connective tissue cells as well as vascular endothelium and smooth muscle cells and the endothelial cells of the alveolar capillaries exhibited positive reactions for TLR-2, TLR-5 and TLR-9. Whereas, TLR-4 immunoreactivity was found in the membranes of saccular and alveolar
epithelial cells, vascular endothelial cells and in the basal cytoplasm and apical surfaces of bronchiolar epithelial cells. Following the first day to 15th days after birth, it was determined that TLR-2, TLR-4, TLR-5 and TLR-9 proteins were expressed in the lung tissue from the saccular stage of development to the alveolar stage and their protein levels did not change significantly with postnatal development.
CONCLUSION: These findings indicate that for normal postnatal adaptation to extrauterine life, the rat lung was equipped by TLRs during the prenatal period.