Mouse model of mevalonate kinase deficiency: comparison of cytokine and chemokine profile with that of human patients

Abstract

Background: Mevalonate kinase deficiency (MKD) is a rare genetic autoinflammatory disease caused by blocking of the enzyme mevalonate kinase in the pathway of cholesterol and isoprenoids. The pathogenic mechanism originating an immune response in MKD patients has not been clearly understood. Methods:We investigated the dysregulation of expression of selected cytokines and chemokines in the serum of MKD patients. The results have been compared with those observed in an MKD mouse model obtained by treating the mice with aminobisphosphonate, a molecule that is able to inhibit the cholesterol pathway, mimicking the genetic block characteristic of the disease. results: Interleukin (IL)-1β, IL-5, IL-6, IL-9, IL-17, granulocyte colony-stimulating factor, monocyte chemotactic protein-1, tumor necrosis factor-α, and IL-4 expression were dysregulated in sera from MKD patients and mice. Moreover, geraniol, an exogenous isoprenoid, when administered to MKD mice, restored cytokines and chemokines levels with values similar to those of untreated mice. conclusion: Our findings, which were obtained in patients and a mouse model mimicking the human disease, suggest that these cytokines and chemokines could be MKD specific and that isoprenoids could be considered as potential therapeutic molecules. The mouse model, even if with some limitations, was robust and suitable for routine testing of potential MKD drugs. Mevalonate kinase deficiency (MKD; OMIM no. 251170), is a rare autoinflammatory disease caused by mutations within the second enzyme of the mevalonate pathway (mevalonate kinase (MK), encoded by MVK) (1). MK is an essential enzyme in isoprenoid biosynthesis; this pathway produces cholesterol and nonsterol intermediate compounds (farnesyl pyrophosphate and geranyl-geranyl pyrophosphate), which are known to be involved in the control of several cell functions through protein prenylation (farnesylation and geranyl-geranylation, respectively) (2) (Figure 1). The shortage of geranyl-geranyl pyrophosphate, and the consequent decreased rate of protein geranyl-geranylation, leads to increased interleukin (IL)-1β secretion (3-6); this observation gives new insights into MKD pathogenesis, such as the causal link between the cholesterol pathway dysfunction and the patient's phenotype.Although in the past decade the knowledge of MKD pathogenesis has increased, an etiologic therapy for this orphan drug disease is still unavailable.Different treatments, including steroids, statins, anti-tumor necrosis factor-α (TNF-α), and anti-IL-1 therapy, have been used with variable success to prevent and cure MKD inflammatory symptoms (7,8), whereas only supportive therapies are available for mevalonic aciduria, the more severe form of MKD.The search for new drugs and therapies for MKD could take advantage of an animal model mimicking the characteristics of the human disease. For this reason, we developed a mouse model of MKD (9), showing that the chemical inhibition of the mevalonate pathway through the use of an aminobisphosphonate (alendronate ...

Block of the Mevalonate Pathway Triggers Oxidative and Inflammatory Molecular Mechanisms Modulated by Exogenous Isoprenoid Compounds

“…These findings are sustained by several studies in literature that report the involvement of IL-1α, IL-1β, IL-6 and IL-12 (p40) in the inflammatory processes of MKD [6,22,23]. Moreover, even if less marked, we also observed the involvement of IL-12 (p40) and GM-CSF, which also exert a pro-inflammatory activity and are able to coordinate the subsequent immune response [24,25].…”

“…Furthermore, while the symptoms subside between fever attacks, increased levels of acute-phase reactants and pro-inflammatory cytokines are detected in the serum of patients during the acute episodes [5]. In detail, as demonstrated by ex vivo studies, peripheral blood mononuclear cells from MKD patients produce large amounts of pro-inflammatory cytokines, such as IL-1β, IL-6, TNF-α, in response to lipopolysaccharide (LPS) [6]. It is commonly assumed that caspase-1-dependent IL-1β, derived from the activation of the NALP3-inflammasome (NALP: nucleotide-binding oligomerization-domain protein-like receptors), represents the major cytokine responsible for the systemic inflammatory events observed in MKD patients [7,8].…”

Lack of Prenylated Proteins, Autophagy Impairment and Apoptosis in SH-SY5Y Neuronal Cell Model of Mevalonate Kinase Deficiency

“…This coefficient (see materials and methods) was obtained using FiJi, software for image analysis [17, 18]. We used as a baseline the coefficient obtained using cells transfected only with GFP-RhoA or -RhoAF, hypothesising that this would represent the “normal” distribution of these sensors.…”

“…Considering that the sole available findings on MKD pathogenesis used biochemical model [18] and no genetic model mimicking the effects of MVK mutations in vitro has been proposed at present time, we established a transient expression model in neuroblastoma cell line (SH-SY5Y) using MVK coding plasmid carrying two different mutations: I268T (HGMD CM990888) and N301T (HGMD CM920489). A number of different mutations have been associated either with HIDS or MA, but we decided to focus our attention on these two mutations since both localized in the in silico predicted hot spot region for MA [12].…”

Anti-inflammatory and cytoprotective effects of a squalene synthase inhibitor, TAK-475 active metabolite-I, in immune cells simulating mevalonate kinase deficiency (MKD)-like condition

“…Consequently, MDI levels in MKD patients are reported to be decreased (Hubner et al 1993). MDIs play a crucial role in the regulation and production of a range of cytokines, and decreased MDI levels are implicated in increases in pro-inflammatory mediators, including interleukin-1β (IL-1β), interleukin-6, C-reactive protein (CRP), and monocyte chemotactic protein-1 (Kostjukovits et al 2015; Mandey et al 2006; Marcuzzi et al 2013). Moreover, an increased production of inflammatory cytokines by peripheral blood mononuclear cells (PBMCs), including monocytes, has been suggested as a central mechanism in the inflammatory phenotype of MKD.…”