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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Actins, Adolescent, Animals, Cells, Cultured, Child, Collagen Type I, Collagen Type IV, Conjunctiva, Conjunctivitis, Allergic, Down-Regulation, Fibroblasts, Humans, Male, Matrix Metalloproteinase 9, Mice, Muscle, Smooth, Nerve Growth Factor, RNA, Messenger, Receptor, Nerve Growth Factor, Receptor, trkA, Up-Regulation.
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Does nerve growth factor have a modulatory role on human primary fibroblast cultures derived from vernal keratoconjunctivitis-affected conjunctiva? Context: To evaluate the role of nerve growth factor (NGF) in remodeling processes of vernal keratoconjunctivitis (VKC). VKC is a chronic inflammatory disorder of the conjunctiva and is characterized by marked tissue remodeling. NGF, a pleiotrophic factor with documented profibrogenic activities, is produced by inflammatory and structural cells populating the VKC conjunctiva and is increased in the serum and tears of VKC patients. Primary cultures of VKC-derived fibroblasts (VKC-FBs) were exposed to increasing NGF concentrations (1-500 ng/ml) to evaluate and compare the expression of alpha-smooth muscle actin (alphaSMA, a defining myofibroblast marker), collagens (types I and IV), and metalloproteinases and tissue inhibitors (MMP9/TIMP1, MMP2/TIMP2) at the biochemical as well as molecular levels. Endogenous NGF was increased in the VKC-FB supernatant, as compared to healthy-FB supernatant. VKC-FBs expressed alphaSMA and increased types I and IV collagens. VKC-FBs, and in particular all alphaSMA positive cells, expressed both trkA(NGFR) and p75(NTR), while healthy-FBs only expressed trkA(NGFR). Exogenous NGF did not change alphaSMA expression, while alphaSMA expression was enhanced by specific neutralization of p75(NTR). NGF (10 ng/ml) exposure significantly decreased type I collagen expression, without affecting type IV collagen, and increased MMP9mRNA and protein.
assistant
The autocrine modulation of differentiation and response of VKC-FBs to NGF exposure with downregulation of type I collagen and upregulation of MMP9 expression supports a relevant role for NGF in tissue remodeling of VKC. Final Decision: yes