Proteolytic effect of matrix metalloproteinase (MMP)-2 on sarcoplasmic reticulum calcium ATPase (SERCA) and morphofunctional vascular alterations in arterial hypertension

Author(s)

Marcela Maria Blascke de Mello

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2024-04-19

Examining board members

Michele Mazzaron de Castro; Fernando Silva Carneiro; Luciana Venturini Rossoni

• Advisor: Michele Mazzaron de Castro

Abstract

Arterial hypertension increases the activity of matrix metalloproteinase (MMP)-2 in the vasculature, which proteolyzes extra- and intracellular proteins and contributes to vascular remodeling and dysfunction. Sarcoplasmic reticulum calcium ATPase (SERCA) activity is often impaired in the arteries of hypertensive animals. MMP-2 proteolyzes SERCA in the heart during ischemia and reperfusion injury, thus impairing cardiac function. We investigated whether hypertension-induced increased MMP-2 activity in aorta contributes to proteolyze SERCA, resulting in vascular remodeling and dysfunction. To test this hypothesis, aortas from Male Sprague-Dawley rats were incubated with angiotensin II (AngII) in the presence or absence of MMP inhibitors, ONO-4817 or doxycycline (Doxy), and used for zymography and co-immunoprecipitation of SERCA with MMP-2. Male rats were submitted to two kidney-one clip (2K-1C) or Sham surgery and treated with Doxy. Systolic blood pressure was assessed by tail-cuff plethysmography. After 7 days, aortas were collected for gelatin and in situ zymography, western blot for SERCA, mass spectrometry, ATPase activity assay and vascular reactivity to phenylephrine and acetylcholine, Ki-67 immunofluorescence and hematoxylin/eosin stain. It was obtained that AngII increased MMP-2 activity in aortas and MMP-2 co-immunoprecipitated with SERCA. Blood pressure was increased in the 2K-1C rats. Although Doxy had no effects on blood pressure, it decreased MMP-2 activity and prevented SERCA proteolysis in aortas. Cross sectional area, media to lumen ratio and KI-67 immunofluorescence were all increased in the aortas of hypertensive rats and Doxy decreased cell proliferation by KI-67. Aortas of hypertensive rats showed increased potency of phenylephrine to cause vascular contraction and decreased potency and maximum relaxation effect in response to acetylcholine, and Doxy improved this endothelial dysfunction. In conclusion, Doxy reduced MMP-2 activity in the aortas of 2K-1C rats and prevented the impairment in ATPase activity and MMP-2-induced SERCA proteolysis, thus preventing increased cellular proliferation and vascular dysfunction of hypertension. (AU)

• FAPESP's process: 20/02619-1 - Potential effects of matrix metalloproteinase (MMP)-2 on the sarcoplasmic reticulum calcium ATPase (SERCA) in Hypertension-induced vascular dysfunction
• Grantee: Marcela Maria Blascke de Mello
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)