Over-expression of microRNA-145 Elevating Autophagy Activities via Downregulating FRS2 Expression

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Osteoarthritis (OA) is a prevalent degenerative joint disease causing cartilage breakdown and chondrocyte death.
• MicroRNA-145 (miR-145) is known to modulate autophagy in various cell types, but its role in OA chondrocytes remains unexplored.

Purpose of the Study:

• To investigate the role of miR-145 in regulating chondrocyte autophagy during osteoarthritis development.
• To determine if miR-145 expression levels correlate with OA progression and chondrocyte viability.

Main Methods:

• Analysis of miR-145 expression in human OA joint samples.
• Dual luciferase assay to confirm the targeting relationship between miR-145 and FRS2.
• Assessment of chondrocyte autophagy and viability following manipulation of miR-145 and FRS2 levels.

Main Results:

• miR-145 expression and autophagy markers (LC3-II/LC3-I ratio) were decreased, while SQSTM1 expression was increased in OA patients.
• Overexpression of miR-145 in chondrocytes enhanced autophagy, increased cell viability under oxidative stress, and reduced SQSTM1 levels.
• FRS2 was identified as a direct target of miR-145, mediating its suppressive effect on autophagy via the PI3K/Akt/mTOR pathway.

Conclusions:

• miR-145 functions as a protective factor in chondrocytes by regulating the miR-145/FRS2/autophagy axis.
• Decreased miR-145 in synovial fluid could serve as an early diagnostic marker for OA.
• Modulating miR-145 presents a potential therapeutic strategy for osteoarthritis.