Article

Open-label add-on treatment trial of minocycline in fragile X syndrome

BMC Neurology (Impact Factor: 2.49). 10/2010; 10. DOI: 10.1186/1471-2377-10-91
Source: DOAJ

ABSTRACT Abstract Background Fragile X syndrome (FXS) is a disorder characterized by a variety of disabilities, including cognitive deficits, attention-deficit/hyperactivity disorder, autism, and other socio-emotional problems. It is hypothesized that the absence of the fragile X mental retardation protein (FMRP) leads to higher levels of matrix metallo-proteinase-9 activity (MMP-9) in the brain. Minocycline inhibits MMP-9 activity, and alleviates behavioural and synapse abnormalities in fmr1 knockout mice, an established model for FXS. This open-label add-on pilot trial was conducted to evaluate safety and efficacy of minocycline in treating behavioural abnormalities that occur in humans with FXS. Methods Twenty individuals with FXS, ages 13-32, were randomly assigned to receive 100 mg or 200 mg of minocycline daily. Behavioural evaluations were made prior to treatment (baseline) and again 8 weeks after daily minocycline treatment. The primary outcome measure was the Aberrant Behaviour Checklist-Community Edition (ABC-C) Irritability Subscale, and the secondary outcome measures were the other ABC-C subscales, clinical global improvement scale (CGI), and the visual analog scale for behaviour (VAS). Side effects were assessed using an adverse events checklist, a complete blood count (CBC), hepatic and renal function tests, and antinuclear antibody screen (ANA), done at baseline and at 8 weeks. Results The ABC-C Irritability Subscale scores showed significant improvement (p < 0.001), as did the VAS (p = 0.003) and the CGI (p < 0.001). The only significant treatment-related side effects were minor diarrhea (n = 3) and seroconversion to a positive ANA (n = 2). Conclusions Results from this study demonstrate that minocycline provides significant functional benefits to FXS patients and that it is well-tolerated. These findings are consistent with the fmr1 knockout mouse model results, suggesting that minocycline modifies underlying neural defects that account for behavioural abnormalities. A placebo-controlled trial of minocycline in FXS is warranted. Trial registration ClinicalTrials.gov Open-Label Trial NCT00858689.

Download full-text

Full-text

Available from: Iryna M Ethell, Aug 17, 2015
0 Followers
 · 
198 Views
  • Source
    • "High MMP-9 activity levels are also lowered by minocycline in fragile X syndrome patients (Dziembowska et al., 2013). Notably, minocycline has been tested in clinical trials to treat fragile X syndrome and shown to provide significant functional benefits (Paribello et al., 2010; Utari et al., 2010; Leigh et al., 2013). Matrix metalloproteinases have also been implicated in other forms of autism (Abdallah and Miche1, 2013). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic spines are the locus for excitatory synaptic transmission in the brain and thus play a major role in neuronal plasticity. The ability to alter synaptic connections includes volumetric changes in dendritic spines that are driven by scaffolds created by the extracellular matrix (ECM). Here, we review the effects of the proteolytic activity of ECM proteases in physiological and pathological structural plasticity. We use matrix metalloproteinase-9 (MMP-9) as an example of an ECM modifier that has recently emerged as a key molecule in regulating the morphology and dysmorphology of dendritic spines that underlie synaptic plasticity and neurological disorders, respectively. We summarize the influence of MMP-9 on the dynamic remodeling of the ECM via the cleavage of extracellular substrates. We discuss its role in the formation, modification, and maintenance of dendritic spines in learning and memory. Finally, we review research that implicates MMP-9 in aberrant synaptic plasticity and spine dysmorphology in neurological disorders, with a focus on morphological abnormalities of dendritic protrusions that are associated with epilepsy.
    Frontiers in Neuroanatomy 07/2014; 8:68. DOI:10.3389/fnana.2014.00068 · 4.18 Impact Factor
  • Source
    • "№ improved 12 E 99.6 (3.38) p =0.003 p =0.007 p =0.03 Effect size 0.04 Citation Berry-Kravis et al. (2008) Leigh et al. (2013); Paribello et al. (2010) Erickson et al. (2011) Jacquemont et al. (2011) "
    [Show abstract] [Hide abstract]
    ABSTRACT: Advances in understanding the underlying mechanisms of conditions such as fragile X syndrome (FXS) and autism spectrum disorders have revealed heterogeneous populations. Recent trials of novel FXS therapies have highlighted several challenges including subpopulations with possibly differential therapeutic responses, the lack of specific outcome measures capturing the full range of improvements of patients with FXS, and a lack of biomarkers that can track whether a specific mechanism is responsive to a new drug and whether the response correlates with clinical improvement. We review the phenotypic heterogeneity of FXS and the implications for clinical research in FXS and other neurodevelopmental disorders. Residual levels of fragile X mental retardation protein (FMRP) expression explain in part the heterogeneity in the FXS phenotype; studies indicate a correlation with both cognitive and behavioral deficits. However, this does not fully explain the extent of phenotypic variance observed or the variability of drug response. Post hoc analyses of studies involving the selective mGluR5 antagonist mavoglurant and the GABAB agonist arbaclofen have uncovered significant therapeutic responses following patient stratification according to FMR1 promoter methylation patterns or baseline severity of social withdrawal, respectively. Future studies designed to quantify disease modification will need to develop new strategies to track changes effectively over time and in multiple symptom domains. Appropriate selection of patients and outcome measures is central to optimizing future clinical investigations of these complex disorders.
    Psychopharmacology 10/2013; 231(6). DOI:10.1007/s00213-013-3289-0 · 3.99 Impact Factor
  • Source
    • "Marker is shown on the left. in the fmr1 KO mouse establishes it as a potential pharmacotherapy for the treatment of FXS [Bilousova et al., 2009]. Although clinical studies have indicated that patients benefited from minocycline pharmacotherapy in a survey [Utari et al., 2010], open label [Paribello et al., 2010], and controlled trial [Leigh et al., 2013] molecular measures showing a clear biological response to minocycline have not been established. Here we report that MMP-9 activity is elevated in FXS as reported in the animal models [Bilousova et al., 2009; Siller and Broadie, 2011] and that minocycline can substantially lower the level of MMP-9. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Fragile X syndrome (FXS) is a neurodevelopmental disorder characterized by lack of the FMR1 protein, FMRP, a translational repressor. Its absence leads to up-regulation of locally translated proteins involved in synaptic transmission and plasticity, including the matrix metalloproteinase-9 (MMP-9). In the Fmr1 knock-out (KO), a mouse model of FXS, an abnormal elevated expression of MMP-9 in the brain was pharmacologically down-regulated after treatment with the tetracycline derivative minocycline. Moreover, the rescue of immature dendritic spine morphology and a significant improvement of abnormal behavior were associated with down-regulation of MMP-9. Here, we report on high plasma activity of MMP-9 in individuals with FXS. In addition, we investigate MMP-9 changes in patients with FXS who have gone through a minocycline controlled clinical trial and correlate MMP-9 activity to clinical observations. The results of this study suggest that, in humans, activity levels of MMP-9 are lowered by minocycline and that, in some cases, changes in MMP-9 activity are positively associated with improvement based on clinical measures. © 2013 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 08/2013; 161(8). DOI:10.1002/ajmg.a.36023 · 2.05 Impact Factor
Show more