TRPV1 Receptor Identification in Bovine and Canine Mitral Valvular Interstitial Cells.

Myxomatous mitral valve degeneration (MMVD) is the most common acquired cardiac disease in canine species, and valvular interstitial cells (VICs) are considered the main responsible for the development of this pathology. The scientific interest is focused on isolating and characterizing these cells. The aims of the present study were to verify a novel VICs mechanical isolation method and to characterize isolated cells using immunocytochemistry and immunofluorescence, with parallel histological and immunohistochemistry assays on bovine and canine healthy and MMVD mitral valves. Antibodies against vimentin (VIM), smooth muscle actin (SMA), von Willebrand (vW) factor, Transforming Growth Factor (TGF) ß1, and Transient Receptor Potential Vanilloid 1 (TRPV1) were used. The isolation method was considered reliable and able to isolate only VICs. The different assays demonstrated a different expression of SMA in healthy and MMVD mitral valves, and TRPV1 was isolated for the first time from bovine and canine VICs and the correspondent mitral valve leaflets. The novelties of the present study are the new isolation method, that may allow correlations between laboratory and clinical conditions, and the identification of TRPV1, which will lead to further investigations to understand its function and possible role in the etiology of MMVD and to the design of new therapeutic strategies.

Cardioprotection of PLGA/gelatine cardiac patches functionalised with adenosine in a large animal model of ischaemia and reperfusion injury: A feasibility study.

The protection from ischaemia-reperfusion-associated myocardial infarction worsening remains a big challenge. We produced a bioartificial 3D cardiac patch with cardioinductive properties on stem cells. Its multilayer structure was functionalised with clinically relevant doses of adenosine. We report here the first study on the potential of these cardiac patches in the controlled delivery of adenosine into the in vivo ischaemic-reperfused pig heart. A Fourier transform infrared chemical imaging approach allowed us to perform a characterisation, complementary to the histological and biochemical analyses on myocardial samples after in vivo patch implantation, increasing the number of investigations and results on the restricted number of pigs (n = 4) employed in this feasibility step. In vitro tests suggested that adenosine was completely released by a functionalised patch, a data that was confirmed in vivo after 24 hr from patch implantation. Moreover, the adenosine-loaded patch enabled a targeted delivery of the drug to the ischaemic-reperfused area of the heart, as highlighted by the activation of the pro-survival signalling reperfusion injury salvage kinases pathway. At 3 months, though limited to one animal, the used methods provided a picture of a tissue in dynamic conditions, associated to the biosynthesis of new collagen and to a non-fibrotic outcome of the healing process underway. The synergistic effect between the functionalised 3D cardiac patch and adenosine cardioprotection might represent a promising innovation in the treatment of reperfusion injury. As this is a feasibility study, the clinical implications of our findings will require further in vivo investigation on larger numbers of ischaemic-reperfused pig hearts.