TY - JOUR
T1 - Fibroblast growth in vitro suppressed by LPS-activated macrophages. Reversal of suppression by hydrocortisone
AU - Metzger, Zvi
AU - Berg, Doron
AU - Dotan, Miri
N1 - Funding Information:
This work was supported by a grant from the Shreiber Fund, Faculty of Medicine at Tel Aviv University and was carried out in the Alpha Omega Research Laboratories, School of Dental Medicine.
PY - 1997
Y1 - 1997
N2 - Activated macrophages are among the major constituents of the periapical granuloma. Their state of activation may persist for long periods after the local irritant is removed and may delay resolution and repair of the lesion. The effect of activated macrophages on fibroblast growth was studied in vitro. Circular fibroblast colonies were formed using a drop containing 7.5 × 105 murine dermal fibroblasts and allowed to grow for 7 days. When peritoneal exudate macrophages were added (0.5-3.0 × 106 cells/dish) and activated in vitro by LPS (1 μg/ml), the fibroblast colony's growth was suppressed. LPS alone, at the concentration used, had no effect on the fibroblast growth. Hydrocortisone (≥10-7 M) totally reversed the suppression, when added either simultaneously with or 6, 24, or 48 h after the LPS. The efficacy of late hydrocortisone treatment suggests that its effect was through prevention of the expression of the LPS activation of the macrophages. These findings may provide a possible clue to a pharmacological modulation of the healing processes that occur in the periapical lesion once its infective source had been eliminated.
AB - Activated macrophages are among the major constituents of the periapical granuloma. Their state of activation may persist for long periods after the local irritant is removed and may delay resolution and repair of the lesion. The effect of activated macrophages on fibroblast growth was studied in vitro. Circular fibroblast colonies were formed using a drop containing 7.5 × 105 murine dermal fibroblasts and allowed to grow for 7 days. When peritoneal exudate macrophages were added (0.5-3.0 × 106 cells/dish) and activated in vitro by LPS (1 μg/ml), the fibroblast colony's growth was suppressed. LPS alone, at the concentration used, had no effect on the fibroblast growth. Hydrocortisone (≥10-7 M) totally reversed the suppression, when added either simultaneously with or 6, 24, or 48 h after the LPS. The efficacy of late hydrocortisone treatment suggests that its effect was through prevention of the expression of the LPS activation of the macrophages. These findings may provide a possible clue to a pharmacological modulation of the healing processes that occur in the periapical lesion once its infective source had been eliminated.
UR - http://www.scopus.com/inward/record.url?scp=0031197155&partnerID=8YFLogxK
U2 - 10.1016/S0099-2399(97)80313-5
DO - 10.1016/S0099-2399(97)80313-5
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AN - SCOPUS:0031197155
VL - 23
SP - 517
EP - 521
JO - Journal of Endodontics
JF - Journal of Endodontics
SN - 0099-2399
IS - 8
ER -