The decrease of expression of ryanodine receptor sub-type 2 is reversed by gentamycin sulphate in vascular myocytes...

Area of Science:

• Cardiovascular Research
• Muscle Physiology
• Molecular Biology

Background:

• Duchenne muscular dystrophy (DMD) mouse models exhibit impaired muscle contractility.
• Vascular smooth muscle dysfunction is implicated in DMD pathology.
• Ryanodine receptors (RYRs) are critical for calcium release in muscle cells.

Purpose of the Study:

• To investigate alterations in RYR subtypes in the vascular smooth muscle of mdx mice.
• To determine the role of RYRs in vascular calcium signaling.
• To explore the therapeutic potential of gentamicin in restoring vascular function in mdx mice.

Main Methods:

• Quantitative analysis of RYR1, RYR2, and RYR3 mRNA and protein levels in mdx and wild-type mouse portal vein myocytes.
• Utilized antisense oligonucleotides to assess the functional contribution of RYR subtypes.
• Measured caffeine-induced calcium responses and calcium spark frequency.
• Administered gentamicin treatment to mdx mice and evaluated its effects on RYR2 expression and vascular function.

Main Results:

• RYR2 expression was significantly decreased in mdx myocytes, while RYR1 and RYR3 remained unchanged.
• RYR2 and RYR1 were essential for caffeine-induced calcium responses and calcium spark frequency.
• Caffeine-induced calcium responses and spark frequency were diminished in mdx mice.
• Gentamicin treatment normalized RYR2 expression and improved calcium signaling in mdx mice.

Conclusions:

• Reduced RYR2 expression contributes to impaired vascular calcium signaling in mdx mice.
• RYR1 and RYR2 are crucial for normal vascular smooth muscle calcium homeostasis.
• Gentamicin shows therapeutic potential for restoring vascular function in DMD by upregulating RYR2 and dystrophin expression.