Mice with Mutation in Dynein Heavy Chain 1 Do Not Share the Same Tau Expression Pattern with Mice with SOD1-Related Motor Neuron Disease

Due to controversy about the involvement of Dync1h1 mutation in pathogenesis of motor neuron disease, we investigated expression of tau protein in transgenic hybrid mice with Dync1h1 (so-called Cra1/+), SOD1G93A (SOD1/+), double (Cra1/SOD1) mutations and wild-type controls. Total tau-mRNA and isoforms 0, 1 and 2 N expression was studied in frontal cortex, hippocampus, spinal cord and cerebellum of presymptomatic and symptomatic animals (age 70, 140 and 365 days). The most significant differences were found in brain cortex and cerebellum, but not in hippocampus and spinal cord. There were less changes in Cra1/SOD1 double heterozygotes compared to mice harboring single mutations. The differences in total tau expression and in profile of its isoforms between Cra1/+ and SOD1/+ transgenics indicate a distinct pathogenic entity of these two conditions

Differences in glutathione S-transferase pi expression in transgenic mice with symptoms of neurodegeneration

Glutathione S-transferase pi (GST pi) is an enzyme involved in cell protection against toxic electrophiles and products of oxidative stress. GST pi expression was studied in transgenic mice hybrids (B6-C3H) with symptoms of neurodegeneration harboring SOD1G93A (SOD1/+), Dync1h1 (Cra1/+) and double (Cra1/SOD1) mutations, at presymptomatic and symptomatic stages (age 70, 140, 365 days) using RT-PCR and Western blotting. The main changes in GST pi expression were observed in mice with the SODG93A mutation. In SOD1/+ and Cra1/SOD1 transgenics, with the exception of cerebellum, the changes in GST pi-mRNA accompanied those in GST pi protein. In brain cortex of both groups the expression was unchanged at the presymptomatic (age 70 days) but was lower at the symptomatic stage (age 140 days) and at both stages in hippocampus and spinal cord of SOD1/+ but not of Cra1/SOD1 mice compared to age-matched wild-type controls. In cerebellum of the presymptomatic and the symptomatic SOD1/+ mice and presymptomatic Cra1/SOD1 mice, the GST pi-mRNA was drastically elevated but the protein level remained unchanged. In Cra1/+ transgenics there were no changes in GST pi expression in any CNS region both on the mRNA and on the protein level. It can be concluded that the SOD1G93A but not the Dync1h1 mutation significantly decreases detoxification efficiency of GST pi in CNS, however the Dync1h1 mutation reduces the effects caused by the SOD1G93A mutation. Despite similarities in neurological symptoms, the differences in GST pi expression between SOD1/+ and Cra1/+ transgenics indicate a distinct pathogenic entity of these two conditions

Changes in kinesin expression in the CNS of mice with dynein heavy chain 1 mutation

Dysfunction of fast axonal transport, vital for motor neurons, may lead to neurodegeneration. Anterograde transport is mediated by N-kinesins (KIFs), while retrograde transport by dynein 1 and, to a minor extent, by C-kinesins. In our earlier studies we observed changes in expression of N- and C-kinesins (KIF5A, 5C, C2) in G93ASOD1-linked mouse model of motor neuron degeneration. In the present work we analyze the profile of expression of the same kinesins in mice with a dynein 1 heavy chain mutation (Dync1h1, called Cra1), presenting similar clinical symptoms, and in Cra1/SOD1 mice with milder disease progression than SOD1 transgenics. We found significantly higher levels of mRNA for KIF5A and KIF5C but not the KIFC2 in the frontal cortex of symptomatic Cra1/+ mice (aged 365 days) compared to the wild-type controls. No changes in kinesin expression were found in the spinal cord of any age group and only mild changes in the hippocampus. The expression of kinesins in the cerebellum of the presymptomatic and symptomatic mice (aged 140 and 365 days, respectively) was much lower than in age-matched controls. In Cra1/SOD1 mice the changes in KIFs expression were similar or more severe than in the Cra1/+ groups, and they also appeared in the spinal cord. Thus, in mice with the Dync1h1 mutation, which impairs dynein 1-dependent retrograde transport, expression of kinesin mRNA is affected in various structures of the CNS and the changes are similar or milder than in mice with double Dync1h1/hSOD1G93A mutations

Ct values for candidate internal control genes (ICGs).

<p>The expression was studied as described in Material and Method section and expressed as medians (25th-75th percentile).</p

Validation of qPCR reference genes in lymphocytes from patients with amyotrophic lateral sclerosis

<div><p>Quantitative polymerase chain reaction (qPCR) is the most specific and reliable method for determination of mRNA gene expression. Crucial point for its accurate normalization is the choice of appropriate internal control genes (ICGs). In the present work we determined and compare the expression of eight commonly used ICGs in lymphocytes from 26 patients with amyotrophic lateral sclerosis (ALS) and 30 control subjects. Peripheral blood mononuclear cells (PBMCs) before and after immortalization by EBV transfection (lymphoblast cell lines—LCLs) were used for qPCR analysis. LCLs were studied before and after liquid nitrogen cryopreservation and culturing (groups LCL1 and LCL2, respectively). qPCR data of 8 ICGs expression was analyzed by BestKeeper, NormFinder and geNorm methods. All studied genes (<i>18SRNA</i>, <i>ACTB</i>, <i>B2M</i>, <i>GUSB</i>,<i>GAPDH</i>, <i>HPRT1</i>, <i>MT-ATP6</i> and <i>RPS17</i>) were expressed in PBMCs, whereas only first four in LCLs. LCLs cryopreservation had no effect on ICGs expression. Comprehensive ranking indicated <i>RPS17</i> with <i>MT-ATP6</i> as the best ICGs for qPCR in PBMCs of control and ALS subjects, and <i>RPS17</i> with <i>18RNA</i> or <i>MT-ATP6</i> in LCLs from ALS. In PBMCs <i>18RNA</i> shouldn’t be used as ICG.</p></div

Validation of internal control genes in PBMCs from ALS patients.

<p>Validation of internal control genes in PBMCs from ALS patients.</p

Internal control assays on TaqMan® Array Plate.

<p>Internal control assays on TaqMan® Array Plate.</p