Two Potential Biomarkers Identified in Mesenchymal Stem Cells and Leukocytes of Patients with Sporadic Amyotrophic lateral Sclerosis

Abstract

Abstract. Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder caused by degeneration of motor neurons.The cause for most cases of ALS is multi-factorial,this enhances the need to characterize and isolate specific biomarkers found in biological samples from ALS patients. To this end we use human mesenchymal stem cells (hMSC) derived from the bone marrow of six ALS patients (ALS hMSC) and identified two genes, Cytoplasmic FMR Interacting Protein 2 (CyFIP2) and Retinoblastoma (Rb) Binding Protein 9 (RbBP9) with a significant decrease in post transcriptional A to I RNA editing compared to hMSC of healthy individuals. At the transcriptional level we show abnormal expression of these two genes in ALS hMSC by quantitative real time-PCR (qRT-PCR) and Western blot suggesting a problem in the regulation of these genes in ALS. To strengthen this view we tested by qRT-PCR the expression of these genes in peripheral blood leukocytes (PBL) isolated from blood samples of 17 ALS patients and found that CyFIP2 and RbBP9 levels of expression were significantly different compared to the levels of expression of these two genes in 19 normal PBL samples. Altogether we found two novel ALS potential biomarkers in non-neural tissues from ALS patients that may have direct diagnostic and therapeutic implications to the disease.Keywords: ALS biomarkers, CyFIP2, RbBP9, human mesenchymal stem cells, leukocytes BackgroundALS is a fatal and incurable neurodegenerative disorder characterized by progressive loss of motor neurons in the spinal cord, brainstem and motor cortex, resulting in generalized weakness and muscle atrophy. ALS is the most common motor neuron disorder, with a prevalence of 6 per 100,000 at any given time [1]. Approximately 90% of the cases are sporadic, and the remaining 10% are familial [2]. Over 100 distinct mu- [6]. Moreover, previous study in our laboratory reveals that these stem cells bearthe rare biological capacity to survive for prolonged time under serum free culture conditions due to the production of their own survival factors, like bone morphogenetic protein [7].RNA editing is a post-transcriptional mechanism for expanding the proteomic repertoire. Adenosineto-inosine (A to I) RNA editing by enzymes named ADARs (adenosine deaminases acting on RNAs) is essential for normal life and development of both invertebrates and vertebrates [8][9][10]. When functioning improperly, this essential process, can lead to pathological conditions ranging from epilepsy to malignant gliomas [11][12][13]. So far, only abnormal RNA editing at the Q/R (glutamine/arginine) site of the GluR-2 gene of the AMPA (Amino-3-hydroxy-5-methyl-4-isoxazolepropionate) receptor has been identified to be implicated in ALS [14][15][16][17]. It is unknown whether the RNA editing deficiency in the GluR-2 gene is part of a more global RNA problem related with ADARs activity in ALS [18].Here we show that ALS hMSC have abnormal pattern of RNA editing in two novel genes, CyFIP2 and RbBP9, which also expressed significantly differen...

Further development of biomarkers in amyotrophic lateral sclerosis

“…Potentially more sensitive thematic transcriptomic approaches focused on pathophysiological mechanisms can also be used. Several RNA expressed in non-neural tissues, such as Smad RNA in muscle, have been proposed as potential ALS biomarkers [55][56]. Studies on the expression of miRNAs found in biological fluids that are considered to be stable, such as CSF, blood and urine could also provide biomarkers in ALS [57][58] through global method i.e.…”

Potential Therapeutic Drugs and Methods for the Treatment of Amyotrophic Lateral Sclerosis

“…Coupled with NfH levels, other potential biomarkers have been identified, such as Cytoplasmic FMR Interacting Protein (CyFIP2) and/or Retinoblastoma Binding Protein 9 (RbBP9) in ALS patients [27]. It was found that mesenchymal stem cells (MSCs) of ALS patients exhibited a change in the expression levels and RNA editing of CyFIP2 and RbBP9 genes compared to non-ALS patients [27].…”

“…It was found that mesenchymal stem cells (MSCs) of ALS patients exhibited a change in the expression levels and RNA editing of CyFIP2 and RbBP9 genes compared to non-ALS patients [27]. …”

A differential autophagy dependent response to DNA-double strand brakes in bone marrow mesenchymal stem cells from sporadic ALS patients

“…Supporting this view is the finding that astrocytes derived from fALS and sALS patients were toxic to MNs (Haidet-Phillips et al, 2011), together with evidence showing that thymic involution leading to immunodeficiency contributes to ALS pathology (Seksenyan et al, 2010). Since degenerating MNs cannot be harvested from ALS patients for research, there are great benefits to using non-neural cell types like human mesenchymal stem cells (hMSCs) (Nachmany et al, 2012; Lilo et al, 2013; Kassis et al, 2013), which are readily isolated from tissues by less-invasive procedures and can be harvested in culture in large quantities without the need for re-sampling, for experimental purposes. The importance of such human ALS patient cell sample models for research is that they keep both the genetic background and their intrinsic epigenetic makeup that may have contributed to the development of ALS in the patient.…”

“…Together with this, recent advances in producing MNs from somatic cells of ALS patients by induced pluripotent stem cells methodologies (Devlin et al, 2015; Dimos et al, 2008) may help to investigate relevant cellular neurodegenerative mechanisms in respect to the genetic makeup of the patient. Our previous work in human mesenchymal stem cells (hMSCs) isolated from the bone marrow of several sALS patients (ALS-hMSCs) identified four ALS biomarkers, CyFIP2, RbBP9, TDP-43 (also known as TARDBP) and SLPI, that showed abnormal mRNA expression levels (Nachmany et al, 2012; Lilo et al, 2013). Moreover, these genes also show differential expression in brain, spinal cord and muscle in the SOD1 G93A ALS mouse model supporting, on one hand, the pathophysiological relevance of the ALS biomarkers discovered in non-neuronal samples of sALS patients and, on the other, the potential of ALS-hMSCs to be a useful model to study the intrinsic cell molecular mechanism of the disease.…”