Blocking mouse MMP-9 production in tumor cells and mouse cornea by short hairpin (sh) RNA encoding plasmids

Area of Science:

• Molecular Biology
• Ophthalmology
• Virology

Background:

• Matrix metalloprotein-9 (MMP-9) plays a role in various physiological and pathological processes, including inflammation and tissue remodeling.
• Herpetic simplex keratitis (HSK) is a viral infection of the cornea that can lead to significant vision impairment.
• Angiogenesis, the formation of new blood vessels, is implicated in the pathogenesis of HSK.

Purpose of the Study:

• To evaluate the efficacy of short hairpin RNA (shRNA) targeting matrix metalloprotein-9 (MMP-9) for gene silencing.
• To investigate the in vitro and in vivo effects of MMP-9 knockdown on herpes simplex virus (HSV) infection in the cornea.
• To assess the potential of MMP-9 inhibition in treating herpetic keratitis and associated angiogenesis.

Main Methods:

• Generation of two distinct plasmids encoding shRNA targeting MMP-9 (pshMMP-9).
• In vitro transfection of cells to assess MMP-9 expression inhibition.
• In vivo transfection of mouse corneas to evaluate MMP-9 knockdown efficacy.
• Assessment of angiogenesis and herpetic keratitis severity following pshMMP-9 delivery.

Main Results:

• Transfection with pshMMP-9 specifically inhibited MMP-9 expression both in vitro and in vivo.
• In vivo delivery of pshMMP-9 effectively reduced MMP-9 protein levels in the mouse cornea.
• pshMMP-9 treatment halted angiogenesis and decreased the severity of herpetic keratitis.
• Induced interferon-alpha (IFN-alpha) and interferon-beta (IFN-beta) may also contribute to the observed therapeutic effects.

Conclusions:

• Specific knockdown of MMP-9 using shRNA is a viable strategy for inhibiting its expression.
• MMP-9 inhibition demonstrates therapeutic potential in managing herpetic keratitis by reducing angiogenesis and disease severity.
• The antiviral and anti-angiogenic effects may be partly mediated by induced interferons.