Calcific aortic valve disease (CAVD)—the most common valvular heart disease—is accelerated in diabetes and has no pharmacotherapy. Although it is known that early CAVD is associated with inflammation and osteogenesis, the molecular mechanisms involved in diabetes‐associated CAVD still need to be uncovered. In this context, we have developed a 3D construct based on gelatin populated with human valvular endothelial cells (VEC) and valvular interstitial cells (VIC) and evaluated the effect of high glucose (HG) concentration on osteogenic molecules expression and on calcification mechanisms. First, we characterized the 3D model and assessed VIC remodelling properties at different time‐points. Then, we exposed it to normal glucose (NG) or high glucose (HG) for 7, 14 and 21 days after which the cells were isolated, separated and investigated individually. Our results showed that encapsulated VIC actively remodel the hydrogel, as demonstrated by an increased expression of extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs). Moreover, exposure of the construct to HG triggered bone morphogenetic protein (BMP) and TGF‐β signalling pathways, up‐regulating expression of osteogenic molecules—BMP‐2/‐4, osteocalcin, osteopontin, SMADs and Runt‐related transcription factor (Runx‐2)—and increased calcium deposits in an osteogenic environment. These findings underline the potential of the developed 3D model as a suitable system to investigate the mechanisms of human CAVD and may help to better understand the calcification mechanisms in CAVD associated to diabetes.

Calcific aortic valve disease (CAVD), a degenerative disease characterized by inflammation, fibrosis and calcification, is accelerated in diabetes. Hyperglycemia contributes to this process by mechanisms that still need to be uncovered. We have recently developed a 3D model of the human aortic valve based on gelatin methacrylate and revealed that high glucose (HG) induced osteogenic molecules and increased calcium deposits in a pro-osteogenic environment. To further understand the events leading to calcification in diabetic conditions in CAVD, we analyzed here the inflammatory and remodeling mechanisms induced by HG in our 3D model. We exposed valvular endothelial cells (VEC) and interstitial cells (VIC) to normal glucose (NG) or HG for 7 and 14 days, then we isolated and separated the cells by anti-CD31 immunomagnetic beads. The changes induced by HG in the 3D model were investigated by real-time polymerase chain reaction (RT-PCR), Western blot, enzyme-linked immunosorbent assay (ELISA) and immunofluorescence. Our results showed that HG induced expression of different cytokines, cell adhesion molecules and matrix metalloproteinases in VEC and VIC. In addition, protein kinase C was increased in VEC and VIC, indicating molecular mechanisms associated with HG induced inflammation and remodeling in both valvular cells. These findings may indicate new biomarkers and targets for therapy in diabetes associated with CAVD.

Patients with diabetes mellitus have an increased risk of myocardial infarction and coronary artery disease‐related death, exhibiting highly vulnerable plaques. Many studies have highlighted the major role of macrophages (MAC) and smooth muscle cells (SMC) and the essential part of metalloproteases (MMPs) in atherosclerotic plaque vulnerability. We hypothesize that in diabetes, the interplay between MAC and SMC in high glucose conditions may modify the expression of MMPs involved in plaque vulnerability. The SMC‐MAC cross‐talk was achieved using trans‐well chambers, where human SMC were grown at the bottom and human MAC in the upper chamber in normal (NG) or high (HG) glucose concentration. After cross‐talk, the conditioned media and cells were isolated and investigated for the expression of MMPs, MCP‐1 and signalling molecules. We found that upon cross‐talk with MAC in HG, SMC exhibit: (i) augmented expression of MMP‐1 and MMP‐9; (ii) significant increase in the enzymatic activity of MMP‐9; (iii) higher levels of soluble MCP‐1 chemokine which is functionally active and involved in MMPs up‐regulation; (iv) activated PKCα signalling pathway which, together with NF‐kB are responsible for MMP‐1 and MMP‐9 up‐regulation, and (v) impaired function of collagen assembly. Taken together, our data indicate that MCP‐1 released by cell cross‐talk in diabetic conditions binds to CCR2 and triggers MMP‐1 and MMP‐9 over‐expression and activity, features that could explain the high vulnerability of atherosclerotic plaque found at diabetic patients.

Parathyroid hormone (PTH) is a key regulator of calcium, phosphate and vitamin D metabolism. Although it has been reported that aortic valve calcification was positively associated with PTH, the pathophysiological mechanisms and the direct effects of PTH on human valvular cells remain unclear. Here we investigated if PTH induces human valvular endothelial cells (VEC) dysfunction that in turn could impact the switch of valvular interstitial cells (VIC) to an osteoblastic phenotype. Human VEC exposed to PTH were analyzed by qPCR, western blot, Seahorse, ELISA and immunofluorescence. Our results showed that exposure of VEC to PTH affects VEC metabolism and functions, modifications that were accompanied by the activation of p38MAPK and ERK1/2 signaling pathways and by an increased expression of osteogenic molecules (BMP-2, BSP, osteocalcin and Runx2). The impact of dysfunctional VEC on VIC was investigated by exposure of VIC to VEC secretome, and the results showed that VIC upregulate molecules associated with osteogenesis (BMP-2/4, osteocalcin and TGF-β1) and downregulate collagen I and III. In summary, our data show that PTH induces VEC dysfunction, which further stimulates VIC to differentiate into a pro-osteogenic pathological phenotype related to the calcification process. These findings shed light on the mechanisms by which PTH participates in valve calcification pathology and suggests that PTH and the treatment of hyperparathyroidism represent a therapeutic strategy to reduce valvular calcification.

Acute myocardial infarction (MI) is a major cardiovascular event and a leading cause of mortality worldwide. Beyond the initial ischemic injury, the inflammatory and immune responses play pivotal roles in both tissue damage and subsequent healing. While the anti-inflammatory strategies targeting neutrophil-driven injury have demonstrated potential in limiting early cardiac damage, growing evidence highlights the critical role of innate immune cells beyond the acute phase. Neutrophils, traditionally associated with tissue injury, also contribute to the resolution of inflammation and initiate key repair processes. Monocytes and macrophages follow a dynamic trajectory, transitioning from pro-inflammatory to reparative states, and play essential roles in debris clearance, angiogenesis, and scar formation. In the early inflammatory phase of acute MI, immune cells such as neutrophils and monocytes are rapidly recruited and activated. While they initially amplify inflammation through the release of pro-inflammatory mediators, their subsequent transition toward anti-inflammatory and reparative phenotypes helps limit tissue damage by clearing necrotic debris from the infarcted area and contributes to the resolution of inflammation. Accumulating evidence reveals a complex crosstalk between neutrophils and macrophages post-MI, with resident macrophages being involved in neutrophil recruitment, and neutrophil-derived signals participating in monocyte recruitment and macrophage polarization, thereby coordinating the spatial and temporal phases of cardiac repair. Understanding how neutrophil-derived mediators influence macrophage responses and whether macrophage-secreted factors reciprocally modulate neutrophil behavior opens promising pathways for developing targeted therapies to limit adverse remodeling following MI. Therefore, this review aims to (i) provide an overview of the roles of neutrophils and monocytes/macrophages in the pathophysiology of myocardial infarction, (ii) explore the mechanisms of communication, particularly via neutrophil-derived secreted factors, that influence monocyte/macrophage function and impact post-MI inflammation, repair, and remodeling, and (iii) highlight the potential therapies interfering with inflammation and neutrophil/macrophage cross-talk.