Title:3-Methyladenine Inhibits Procollagen-1 and Fibronectin Expression in Dermal Fibroblasts Independent of Autophagy
Volume: 20
Issue: 9
Author(s): Ji-yong Jung, Hyunjung Choi, Eui-Dong Son and Hyoung-june Kim*
Affiliation:
- Basic Research & Innovation Division, Amorepacific Corporation R&D Center, Yongin-si, Gyeonggi-do, 17074,Korea
Keywords:
3-methyladenine, autophagy, CREB, dermal extracellular matrix, normal human dermal fibroblasts, Smad3–p300 binding.
Abstract:
Background: Autophagy is deeply associated with aging, but little is known
about its association with the extracellular matrix (ECM). 3-methyladenine (3-MA) is a
commonly used autophagy inhibitor.
Objective: We used this compound to investigate the role of autophagy in dermal ECM
protein synthesis.
Methods: Normal human dermal fibroblasts (NHDFs) were treated with 3-MA for 24 h,
and mRNA encoding several ECM proteins was analyzed in addition to the protein
expression of procollagen-1 and fibronectin. Several phosphoinositide 3-kinase (PI3K)
inhibitors, an additional autophagy inhibitor, and small interfering RNA (siRNA) targeting
autophagy-related genes were additionally used to confirm the role of autophagy in ECM
synthesis.
Results: Only 3-MA, but not other chemical compounds or autophagy-related genetargeting
siRNA, inhibited the transcription of procollagen-1 and fibronectin-encoding
genes. Further, 3-MA did not affect the activation of regulatory Smads, but inhibited the
interaction between Smad3 with p300. Moreover, 3-MA treatment increased the
phosphorylation of cAMP response element-binding protein (CREB); however, CREB
knock-down did not recover 3-MA-induced procollagen-1 and fibronectin
downregulation.
Conclusion: We revealed that 3-MA might inhibit procollagen-1 and fibronectin
synthesis in an autophagy-independent manner by interfering with the binding between
Smad3 and p300. Therefore, 3-MA could be a candidate for the treatment of diseases
associated with the accumulation of ECM proteins.
