Altered expression of the plasminogen activation pathway in peripheral blood mononuclear cells in multiple sclerosis: possible pathomechanism of matrix metalloproteinase activation

[Effect of different groups of first line DMT on endothelial damage in multiple sclerosis]

INTRODUCTION

Vascular changes, including destabilization of the blood-brain barrier, are common pathological signs in multiple sclerosis (MS). There are prerequisites, which indicate the direct effects of disease modifying therapy (DMT) on the state of the vascular wall and reduce the damage to the endothelium in MS.

AIM OF THIS STUDY

Was to identify and evaluate the relationship of endothelial dysfunction in patients with multiple sclerosis with used DMT.

MATERIALS AND METHODS

The study included 85 patients with a reliable diagnosis of MS according to the McDonald criteria of 2010 (56 women, 29 men) aged from 17 to 62 years (average age 36.3±1.2 years). All patients underwent a comprehensive clinical and neurological examination, laboratory tests (blood serum analysis for the content of adhesion molecules sICAM-1, sPECAM-1, sE-selectin, sP-selectin, for the content of homocysteine and matrix metalloproteinase 9 (MMR-9) by ELISA; blood plasma analysis for Von Willebrand factor antigen (vWf) by ELISA).

The results of the study indicate a decrease of endothelial damage in MS during interferon therapy. Its also allow the use of indicators such as von Willebrand factor antigen, sPECAM-1, sE-selectin levels as potential markers of the effectiveness of DMT.

Molecular imaging of the urokinase plasminogen activator receptor: opportunities beyond cancer

The urokinase plasminogen activator receptor (uPAR) plays a multifaceted role in almost any process where migration of cells and tissue-remodeling is involved such as inflammation, but also in diseases as arthritis and cancer. Normally, uPAR is absent in healthy tissues. By its carefully orchestrated interaction with the protease urokinase plasminogen activator and its inhibitor (plasminogen activator inhibitor-1), uPAR localizes a cascade of proteolytic activities, enabling (patho)physiologic cell migration. Moreover, via the interaction with a broad range of cell membrane proteins, like vitronectin and various integrins, uPAR plays a significant, but not yet completely understood, role in differentiation and proliferation of cells, affecting also disease progression. The implications of these processes, either for diagnostics or therapeutics, have received much attention in oncology, but only limited beyond. Nonetheless, the role of uPAR in different diseases provides ample opportunity to exploit new applications for targeting. Especially in the fields of oncology, cardiology, rheumatology, neurology, and infectious diseases, uPAR-targeted molecular imaging could offer insights for new directions in diagnosis, surveillance, or treatment options.

Genome-Wide Multiple Sclerosis Association Data and Coagulation

The emerging concept of a crosstalk between hemostasis, inflammation, and immune system prompt recent works on coagulation cascade in multiple sclerosis (MS). Studies on MS pathology identified several coagulation factors since the beginning of the disease pathophysiology: fibrin deposition with breakdown of blood brain barrier, and coagulation factors within active plaques may exert pathogenic role, especially through the innate immune system. Studies on circulating coagulation factors showed complex imbalance involving several components of hemostasis cascade (thrombin, factor X, factor XII). To analyze the role of the coagulation process in connection with other pathogenic pathways, we implemented a systematic matching of genome-wide association studies (GWAS) data with an informative and unbiased network of coagulation pathways. Using MetaCore (version 6.35 build 69300, 2018) we analyzed the connectivity (i.e., direct and indirect interactions among two networks) between the network of the coagulation process and the network resulting from feeding into MetaCore the MS GWAS data. The two networks presented a remarkable over-connectivity: 958 connections vs. 561 expected by chance; z-score = 17.39; p-value < 0.00001. Moreover, genes coding for cluster of differentiation 40 (CD40) and plasminogen activator, urokinase (PLAU) shared both networks, pointed to an integral interplay between coagulation cascade and main pathogenic immune effectors. In fact, CD40 pathways is especially operative in B cells, that are currently a major therapeutic target in MS field. The potential interaction of PLAU with a signal of paramount importance for B cell pathogenicity, such as CD40, suggest new lines of research and pave the way to implement new therapeutic targets.

MATRIX METALLOPROTEINASE-9 AND INFLAMMATION IN DIFFERENT TYPES OF MULTIPLE SCLEROSIS

Different clinical courses of multiple sclerosis, heterogeneity of its clinical implications, different effect of immunomodulatory therapy for the same clinical forms implies various pathogenetic mechanisms of central nervous system damage at this disease. Applicability of immunological and biochemical markers for the estimation of immunocorrecting and anti-inflammatory therapy efficacy is important. This research aims at improvement of pathological process stages diagnostics at multiple sclerosis and further therapy optimization depending on the activity of the inflammatory process. In the article matrix metalloproteinase-9 rate was assessed in 135 patients with multiple sclerosis of different course types and at different activity stages of the pathological process. The highest matrix metalloproteinase-9 rates were in patients with relapsing-remitting type at the stage of exacerbation, with the lowest rate being in patients with primary-progressive multiple sclerosis. Determination of matrix metalloproteinase-9 rate allows to assess the degree of inflammatory process expression and to monitor the efficacy of multiple sclerosis treatment.

Common genetic variants in the plasminogen activation pathway are not associated with multiple sclerosis

Matrix metalloproteinase 9 (MMP9) is involved in multiple sclerosis (MS) aetiology. Previously, we identified differential gene expression of plasminogen activation cascade genes in MS patients. Based on our gene expression results, we wanted to identify whether polymorphisms in the genes associated with the plasminogen pathway could predict MS risk. We genotyped 1153 trio families, 727 MS cases and 604 healthy controls for 17 polymorphisms in MMP9, plasminogen activator urokinase (PLAU), PLAU receptor (PLAUR) and serpin peptidase inhibitor/clade 2/member B2 (SERPINB2) genes. No associations were found between the 17 polymorphisms and MS. Also, gene expression levels were analysed according to genotype: no associations were observed. In conclusion despite the consistent evidence for the role of MMP9 and the plasminogen activation cascade in MS, we found no associations between genotype nor gene expression. This suggested there are other potentially modifiable factors influencing gene expression in MS.

Blood RNA profiling in a large cohort of multiple sclerosis patients and healthy controls

Multiple sclerosis (MS) is the most common autoimmune disease of the central nervous system (CNS). It is characterized by the infiltration of autoreactive immune cells into the CNS, which target the myelin sheath, leading to the loss of neuronal function. Although it is accepted that MS is a multifactorial disorder with both genetic and environmental factors influencing its development and course, the molecular pathogenesis of MS has not yet been fully elucidated. Here, we studied the longitudinal gene expression profiles of whole-blood RNA from a cohort of 195 MS patients and 66 healthy controls. We analyzed these transcriptomes at both the individual transcript and the biological pathway level. We found 62 transcripts to be significantly up-regulated in MS patients; the expression of 11 of these genes was counter-regulated by interferon treatment, suggesting partial restoration of a 'healthy' gene expression profile. Global pathway analyses linked the proteasome and Wnt signaling to MS disease processes. Since genotypes from a subset of individuals were available, we were able to identify expression quantitative trait loci (eQTL), a number of which involved two genes of the MS gene signature. However, all these eQTL were also present in healthy controls. This study highlights the challenge posed by analyzing transcripts from whole blood and how these can be mitigated by using large, well-characterized cohorts of patients with longitudinal follow-up and multi-modality measurements.