Spyros P. Batzios

Developing treatment options for metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) represents a devastating lysosomal storage disease characterized by intralysosomal accumulation of the sphingolipid sulfatide in various tissues. Three types of the disease are currently distinguished: the late-infantile, which is the most commonly observed, the juvenile and the adult type. Demyelination represents the main histopathological feature of the disorder, leading to neurological impairment with no curative treatment currently available. Nevertheless, the increased scientific interest on the disease has led to the experimental use of innovative therapeutic approaches in animal models, aiming to provide an effective therapeutic regimen for human patients, as well. This paper provides an overview of developing treatment options among patients with MLD. Apart from hematopoietic stem cell transplantation, already in use for decades, other recent data discussed includes umbilical cord blood and stem cell transplantation, enzyme replacement therapy, gene therapy and autologous hematopoietic transplantation of genetically modified stem cells. Gene therapy with oligodedroglial, neural progenitor, embryonic and microencapsulated recombinant cells represents add-on treatment options still on experimental level.

Acute exacerbations of COPD are associated with significant activation of matrix metalloproteinase 9 irrespectively of airway obstruction, emphysema and infection

BackgroundAcute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. In this study, we investigated if AE-COPD are associated with differential expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in bronchoalveolar lavage (BAL).MethodsCOPD patients undergoing diagnostic bronchoscopy, with either stable disease (n = 53) or AE-COPD (n = 44), matched for their demographics and lung function parameters were included in this study. Protein levels of MMP-2,–9,–12 and of TIMP-1 and -2 in BAL were measured by ELISA. Enzymatic activity of MMP-2 and -9 was assessed by gelatin zymography.ResultsWe observed that MMP-9, TIMP-1 and TIMP-2 were significantly increased in BAL during AE-COPD. Furthermore, there was a significant negative correlation of MMP-9, TIMP-1 and TIMP-2 with FEV1% predicted and a significant positive correlation of TIMP-1 and TIMP-2 with RV% predicted in AE-COPD. None of MMPs and TIMPs correlated with DLCO% predicted, indicating that they are associated with airway remodeling leading to obstruction rather than emphysema. In AE-COPD the gelatinolytic activity of MMP-2 was increased and furthermore, MMP-9 activation was significantly up-regulated irrespective of lung function, bacterial or viral infections and smoking.ConclusionsThe results of this study indicate that during AE-COPD increased expression of TIMP-1, TIMP-2, and MMP-9 and activation of MMP-9 may be persistent aggravating factors associated with airway remodeling and obstruction, suggesting a pathway connecting frequent exacerbations to lung function decline.

Alterations in serum MMP and TIMP concentrations following chronic heroin abuse

Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce. Objective: In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users. Materials and methods: Twenty-six heroin-dependent male volunteers and an equal number of healthy individuals participated in this study. ELISA was used to assess the serum levels of MMP-2, MMP-9, TIMP-1 and TIMP-2. Heroin users were assessed both upon admission and upon completion of a 21-d detoxification program. Results: Serum TIMP-1 concentrations were significantly lower and the ratios MMP-2/TIMP-1, MMP-9/TIMP-1 and MMP-2/TIMP-2 were significantly higher in heroin users compared to healthy individuals. Heroin users who were seropositive had lower MMP concentrations, as well as lower MMP/TIMP ratios, compared to those who were seronegative. Discussion: Our results showed that in heroin-addicted individuals, and especially those who are positive for anti-HCV antibodies, the balance between MMPs and TIMPs in serum is disrupted and this disruption cannot be restored within 21 d of abstinence. Conclusion: Chronic heroin abuse disrupts the balance between MMPs and TIMPs in serum and this effect is not reversible within 21 d of abstinence.

Extracellular matrix components: An intricate network of possible biomarkers for lysosomal storage disorders?

Biomarkers are extremely important in the case of multisystemic diseases, such as lysosomal storage disorders (LSDs), which are often difficult to assess in clinical practice. Several studies demonstrated significant alterations in the expression of extracellular matrix (ECM) components in LSD patients, raising important questions in relation to their possible involvement in disease pathogenesis and providing evidence for their possible utility as disease biomarkers. This article provides an overview of the possible pathogenic correlations between LSDs and ECM. Data regarding the expression of these molecules are discussed. Finally, the possible implication of ECM components as therapeutic targets in this group of diseases along with the impact of the differential expression of these components in current LSD treatment will be critically addressed.

Moyamoya syndrome and neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is the most prevalent autosomal dominant genetic disorder among humans. NF1 vasculopathy is a significant but underrecognized complication of the disease, affecting both arterial and venous blood vessels of all sizes. Moyamoya syndrome is a cerebral vasculopathy that is only rarely observed in association with NF1, particularly in the pediatric age range. Herein, we report of a 5-year-old female with NF1 and moyamoya syndrome and we briefly review the existing literature.

Differential expression of matrix metalloproteinases and proteoglycans in Juvenile Hyaline Fibromatosis

BACKGROUND Juvenile Hyaline Fibromatosis (JHF) is a rare autosomal recessive disorder, histologically characterized by the production and deposition of an unidentified hyaline material in the skin and other organs. Extracellular matrix molecules are implicated in the development of skin lesion which is debilitating and recurrent and, so far, no treatment is satisfactory. OBJECTIVE To investigate the expression of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs) and proteoglycans in lesional as compared to site-matched lesion-free skin tissue specimens of a JHF patient, aiming to elucidate the aetiopathological mechanisms involved in the development of JHF skin lesions. METHODS Gelatinase activity of MMP-2 and MMP-9 was investigated by gelatine zymography. Protein levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in skin tissue extracts were measured by ELISA. Gene expression of MMPs, TIMPs and proteoglycans was examined by quantitative RT-PCR. RESULTS JHF lesions exhibited significantly higher activity as well as elevated protein and gene expression of MMP-2 and MMP-9, as compared to lesion-free skin tissue specimens. Decorin was downregulated and aggrecan was upregulated in lesional skin, as compared to normal skin. CONCLUSION The results presented in this study indicate that MMPs and proteoglycans may be involved in the pathogenesis of JHF and therefore these molecules may offer alternative targets for pharmacological intervention to achieve more radical and effective treatment.

MYH9-related disorders: Report on a patient of greek origin presenting with macroscopic hematuria and presenile cataract, caused by an R1165C mutation

Myosin heavy chain-9 (MYH9)-related disorders represent a heterogenous group of hereditary diseases caused by mutations in the gene encoding the heavy chain of nonmuscle myosin IIA. May-Hegglin anomaly and Fechtner, Sebastian, and Epstein syndromes are the four phenotypes of the disease, characterized by congenital macrothrombocytopenia and distinguished by different combinations of clinical signs that may include glomerulonephritis, sensorineural hearing loss, and presenile cataract. The spectrum of mutations responsible for the disease is wide and the existence of genotype-phenotype correlation remains a critical issue. We report the first case of an MYH9-RD in a patient of Greek origin presenting with macroscopic hematuria and presenile cataract caused by a p.R1165C mutation. The same mutation was present in the patient’s father, who exhibited no extrahematological features of the disease. The p.R1165C mutation is one of the MYH9 alterations whose prognostic significance is still poorly defined. Thus, the patients described add to the limited existing data on the MYH9 mutations and their resultant phenotypes.

Differential Expression of Matrix Metalloproteinases in the Serum of Patients with Mucopolysaccharidoses

Mucopolysaccharidoses (MPS) represent a heterogeneous group of hereditary disorders, characterized by accumulation of glycosaminoglycans within the lysosomes. The objective of this study was to elucidate the expression and activity of matrix metalloproteinases (MMPs) in the serum of pediatric patients with MPS. Serum gelatinase activity was assessed by gelatin zymography and the concentration of circulating MMP-2, MMP-9, and of tissue inhibitors of MMPs (TIMP)-1 and TIMP-2 was measured by ELISA in the serum of seven patients with MPS (five with MPS III, 1 with MPS II and 1 with MPS VI), and healthy age- and sex-matched participants. Serum activity and protein levels of MMP-9 were significantly reduced whereas of MMP-2 were significantly increased in patients with MPS III, as compared to controls. There were no significant alterations in serum protein levels of TIMP-1 and TIMP-2 in patients with MPS III, as compared to controls. In MPS II, proMMP-2 activity and protein levels of MMP-2 were significantly increased, as compared to control. In MPS VI, enzyme replacement therapy reduced the activity and protein levels of MMP-9 up to 4 months after the initiation of treatment. The reported alterations in the expression of MMPs in the serum of patients with MPS suggest that these molecules may be used as potential biomarkers for the diagnosis, follow-up and response to therapy in patients with MPS.

Nephrocalcinosis and Renal Failure in Lesch-Nyhan Syndrome: Report of Two Familial Cases and Review of the Literature

Lesch-Nyhan syndrome is an X-linked recessive inborn error of purine metabolism, due to deficiency of the enzyme HPRT (hypoxanthine-guanine phosphoribosyl transferase) and underlying HPRT gene mutations (over 300 mutations identified up to date). It is characterized by a wide range of neurological symptoms and signs (mainly a combination of spastic diplegia with choreoathetosis and an overall psychomotor redardation). Herein, we report of two cousins with Lesch-Nyhan syndrome and a confirmed novel HPRT gene mutation: c.65T>C, who both developed nephrocalcinosis and renal failure, findings not been previously published in children with HPRT deficiency.

PP03.13 – 2568: Two further Greek cases of Krabbe disease and a new mutation in the GALC gene

Objective Krabbe disease is an autosomal recessive neurodegenerative disorder due to a defect of the lysosomal enzyme galactocerebrosidase (GALC) and is classified into infantile and late-onset form, depending on the age of onset. Methods and results We report two Greek patients with Krabbe disease with the infantile and late-infantile forms, respectively. The first patient was admitted at the age of 3.5 months, due to generalized hypertonia and developmental delay. A brain MRI demonstrated signs of leukodystrophy, while nerve conduction velocities (NCVs) were significantly decreased. A severe reduction in â-galactocerebrosidase activity (0.003 nmol/mg protein/hr, normal range 0.1–0.97 units), indicated the diagnosis of Krabbe disease, which was confirmed by molecular genetic testing (an homozygous c.411_413delTAA [K139del] mutation in the GALC gene). The second patient manifested with psychomotor regression at the age of 6 months, while the brain MRI was normal. At the age of 18 months, a repeated brain MRI demonstrated leukodystrophic changes, whereas NCVs were significantly delayed, too. A total lack of â-galactoserebrosidase activity (0.00 nmol/mg protein/hr, normal range 0.1–0.97 units) led to further molecular genetic testing, which revealed a homozygous c.749T>C [p.I250T] mutation in the GALC gene. At their last follow-up visit at the age of 4 and 10 years, respectively, both patients were bed-ridden and demonstrated the clinical picture of spastic tetraplegia suffering from frequent infections of the respiratory tract and fed through a gastrostomy catheter. Conclusion The c.411_413delTAA [K139del] mutation is the first reported in the literature, while there are another two reports of patients bearing the c.749T>C [p.I250T] mutation. Interestingly, both these patients were of Greek ancestry, a fact that could be indicative of a founder effect. Genotyping of patients of Krabbe disease is important, in order to contribute to a European mutation database and to further study possible genotype-phenotype correlations.