Platelets and Matrix Metalloproteinases: A Bidirectional Interaction with Multiple Pathophysiologic Implications

Study on diagnostic-sensitive markers of primary immune thrombocytopaenia in children based on plasma proteomics

To use proteomic techniques to identify sensitive diagnostic biomarkers for paediatric immune thrombocytopenia (ITP). We selected children in ITP and control groups, using a four-dimensional data-independent acquisition approach (4D-DIA) to analyse its protein expression. The significantly differentially expressed proteins were selected for enzyme-linked immunosorbent assay (ELISA) validation in a cohort comprising 50 samples (13 healthy controls, 15 secondary thrombocytopenia controls and 22 children with ITP). Receiver operating characteristics (ROC) were generated to diagnose ITP and to assess the diagnostic effectiveness of this approach. Compared with the control group, 55 differentially expressed proteins (43 increased and 12 decreased) were determined in the ITP group. Matrix metalloproteinases-9 (MMP-9) and thrombospondin-1 (THBS1) were significantly expressed and selected for ELISA. The verification outcomes aligned with the findings from the proteomic examinations. In contrast to the control cohort, the ITP subjects exhibited markedly elevated plasma MMP-9 levels and reduced plasma THBS1 concentrations. Additionally, the ROC curves indicated the diagnostic value of these biomarkers. In conclusion, proteomics facilitates identifying the sensitive biomarkers for ITP diagnosis. We have preliminarily selected two differentially expressed proteins, MMP-9 and THBS1, whose potential role as biomarkers for diagnosing ITP requires further research.

Targeting Vascular Impairment, Neuroinflammation, and Oxidative Stress Dynamics with Whole-Body Cryotherapy in Multiple Sclerosis Treatment

Multiple sclerosis (MS), traditionally perceived as a neurodegenerative disease, exhibits significant vascular alternations, including blood-brain barrier (BBB) disruption, which may predispose patients to increased cardiovascular risks. This vascular dysfunction is intricately linked with the infiltration of immune cells into the central nervous system (CNS), which plays a significant role in perpetuating neuroinflammation. Additionally, oxidative stress serves not only as a byproduct of inflammatory processes but also as an active contributor to neural damage. The synthesis of these multifaceted aspects highlights the importance of understanding their cumulative impact on MS progression. This review reveals that the triad of vascular damage, chronic inflammation, and oxidative imbalance may be considered interdependent processes that exacerbate each other, underscoring the need for holistic and multi-targeted therapeutic approaches in MS management. There is a necessity for reevaluating MS treatment strategies to encompass these overlapping pathologies, offering insights for future research and potential therapeutic interventions. Whole-body cryotherapy (WBCT) emerges as one of the potential avenues for holistic MS management approaches which may alleviate the triad of MS progression factors in multiple ways.

Multi-omics approaches to study platelet mechanisms

Platelets are small anucleate cell fragments (2-4 μm in diameter) in the blood, which play an essential role in thrombosis and hemostasis. Genetic or acquired platelet dysfunctions are linked to bleeding, increased risk of thromboembolic events and cardiovascular diseases. Advanced proteomic approaches may pave the way to a better understanding of the roles of platelets in hemostasis, and pathophysiological processes such as inflammation, metastatic spread and thrombosis. Further insights into the molecular biology of platelets are crucial to aid drug development and identify diagnostic markers of platelet activation. Platelet activation is known to be an extremely rapid process and involves multiple post-translational mechanisms at sub second time scale, including proteolysis and phosphorylation. Multi-omics technologies and biochemical approaches can be exploited to precisely probe and define these posttranslational pathways. Notably, the absence of a nucleus in platelets significantly reduces the number of present proteins, simplifying mass spectrometry-based proteomics and metabolomics approaches.

Release of MMP-2 in the circulation of patients with acute coronary syndromes undergoing percutaneous coronary intervention: Role of platelets

INTRODUCTION

Matrix metalloproteinases (MMPs) of atherosclerotic tissue contribute to plaque rupture triggering acute coronary syndromes (ACS). Several MMPs, including MMP-2, are also contained in platelets and released upon activation. An increase in circulating levels of MMP-2 has been reported in patients undergoing percutaneous coronary interventions (PCI), but its time-course and origin remain unclear. Aims of our study were to assess the time-course of MMP-2 release in blood of stable and unstable coronary artery disease patients undergoing PCI and to unravel the possible contribution of platelets to its release.

METHODS

Peripheral blood samples were drawn immediately before, 4 and 24 h after PCI from patients with ACS (NSTEMI or STEMI, n = 21) or with stable angina (SA, n = 21). Platelet-poor plasma and washed platelet lysates were prepared and stored for subsequent assay of MMP-2 and β-thromboglobulin (β-TG), a platelet-specific protein released upon activation.

RESULTS

Plasma MMP-2 and β-TG increased significantly 4 h after PCI and returned to baseline at 24 h in ACS patients, while they did not change in SA patients. Platelet content of MMP-2 and β-TG decreased significantly 4 h after PCI in patients with ACS, compatible with intravascular platelet activation and release, while they did not change in patients with SA.

CONCLUSIONS

PCI triggers the release of MMP-2 in the circulation of ACS patients but not in that of patients with SA. Platelets activated by PCI contribute to the increase of plasma MMP-2 releasing their MMP-2 content. Given that previous mechanicistic studies have shown that MMP-2 may sustain platelet activation and unstabilize downstream-located plaques and in the long term favour restenosis and atherosclerosis progression, these data may encourage the search for therapeutic agents blocking MMP-2 release or activity in ACS.