Dyslipidemia in patients with amyotrophic lateral sclerosis - a case control retrospective study.

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disorder leading to quadriplegia and aphagia. While swallowing difficulties and increased energy demand lead to malnutrition, increased lipid concentration may correlate with survival and respiratory functions. Objective: To analyze the frequency and type of dyslipidemias in a large population of clinically characterized ALS patients (PALS). Methods: The retrospective study included clinical and laboratory data of 650 consecutive PALS fulfilling the El Escorial criteria and 365 age- and gender-matched hospital controls. Results: 65% of PALS suffered from dyslipidemia independently of concomitant metabolic diseases. The most frequent lipid disorder was hypercholesterolemia (35% PALS, 25% controls), followed by mixed dyslipidemia (24.6%, 14%), with rare cases of hypertriglyceridemia and atherogenic dyslipidemia. Triacylglycerols (TAG) and LDL/HDL correlated with BMI, while LDL/HDL and total cholesterol (TCh) with disease duration. Among PALS with concomitant metabolic diseases, TCh correlated with disease duration and ALSFRS-R, while TAG with respiratory functions (FVC) in patients without metabolic diseases. The highest median concentration of TCh, LDL and LDL/HDL was found in classic ALS and PMA and the lowest in PBP. Conclusion: Dyslipidemia occurs more frequently in PALS compared to controls and independently of concomitant metabolic diseases. Similar to the general population, the most frequent lipid disturbance is hypercholesterolemia, followed by mixed dyslipidemia. Although particular lipid parameters correlate with BMI and disease duration, they do not show strong correlations with disease progression rate. There is a need of randomized control trials assessing the risk and benefits of the use of lipid lowering agents in ALS.

ERCC1-deficient cells and mice are hypersensitive to lipid peroxidation.

Lipid peroxidation (LPO) products are relatively stable and abundant metabolites, which accumulate in tissues of mammals with aging, being able to modify all cellular nucleophiles, creating protein and DNA adducts including crosslinks. Here, we used cells and mice deficient in the ERCC1-XPF endonuclease required for nucleotide excision repair and the repair of DNA interstrand crosslinks to ask if specifically LPO-induced DNA damage contributes to loss of cell and tissue homeostasis. Ercc1-/- mouse embryonic fibroblasts were more sensitive than wild-type (WT) cells to the LPO products: 4-hydroxy-2-nonenal (HNE), crotonaldehyde and malondialdehyde. ERCC1-XPF hypomorphic mice were hypersensitive to CCl4 and a diet rich in polyunsaturated fatty acids, two potent inducers of endogenous LPO. To gain insight into the mechanism of how LPO influences DNA repair-deficient cells, we measured the impact of the major endogenous LPO product, HNE, on WT and Ercc1-/- cells. HNE inhibited proliferation, stimulated ROS and LPO formation, induced DNA base damage, strand breaks, error-prone translesion DNA synthesis and cellular senescence much more potently in Ercc1-/- cells than in DNA repair-competent control cells. HNE also deregulated base excision repair and energy production pathways. Our observations that ERCC1-deficient cells and mice are hypersensitive to LPO implicates LPO-induced DNA damage in contributing to cellular demise and tissue degeneration, notably even when the source of LPO is dietary polyunsaturated fats.

[Effect of antioxidants on human primary and metastatic colon cancer cells at hypoxia and normoxia].

THE AIM: Evaluation of some antioxidants on human colon cancer cells viability and proliferation at various oxygen levels. MATERIAL AND METHODS: Human primary (SW480) and metastatic (SW620) colon cancer cells were cultured at hypoxia (1% oxygen), tissues (10% oxygen) and atmospheric (21% oxygen) normoxia with quercetin, epigallocatechin gallate, lipoic acid, hydroxycitric acid, their mixture, and without studied compounds (control). Antioxidants were used at physiological concentrations. The cell viability was determined by trypan blue dye exclusion and proliferation by MTT assay. RESULTS: The viability of each line ranged from 80% to 97%, and it was independent on the compound and oxygen availability. At hypoxia the cell count of both lines was lower than for the controls in the presence of each studied compound. At tissue normoxia the cell count of primary cancer cells was decreased only with epigallocatechin gallate, whereas metastatic cells were sensitive for each antioxidant. CONCLUSIONS: Our results indicated, that the studied antioxidants were not cytotoxic at physiological levels for both pirmary and metastatic colon cancer. Their cytostatic effect depend on the type of cell, oxygen availability and antioxidant concentration.

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

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 (18SRNA, ACTB, B2M, GUSB,GAPDH, HPRT1, MT-ATP6 and RPS17) were expressed in PBMCs, whereas only first four in LCLs. LCLs cryopreservation had no effect on ICGs expression. Comprehensive ranking indicated RPS17 with MT-ATP6 as the best ICGs for qPCR in PBMCs of control and ALS subjects, and RPS17 with 18RNA or MT-ATP6 in LCLs from ALS. In PBMCs 18RNA shouldn't be used as ICG.

Lactate Formation in Primary and Metastatic Colon Cancer Cells at Hypoxia and Normoxia.

High glucose consumption and lactate synthesis in aerobic glycolysis are a hallmark of cancer cells. They can form lactate also in glutaminolysis, but it is not clear how oxygen availability affects this process. We studied lactate synthesis at various oxygen levels in human primary (SW480) and metastatic (SW620) colon cancer cells cultured with L-Ser and/or L-Asp. Glucose and lactate levels were determined colorimetrically, amino acids by HPLC, expression of AST1-mRNA and AST2-mRNA by RT-PCR. In both lines glucose consumption and lactate synthesis were higher at 10% than at 1% oxygen, and lactate/glucose ratio was increased above 2.0 by L-Asp. AST1-mRNA expression was independent on oxygen and cell line, but AST2-mRNA was lower at hypoxia in SW480. We conclude that, in both cell lines at 1% hypoxia, lactate is formed mainly from glucose but at 10% normoxia also from L-Asp. At 10% normoxia, lactate synthesis is more pronounced in primary than metastatic colon cancer cells.

Alteration of Motor Protein Expression Involved in Bidirectional Transport in Peripheral Blood Mononuclear Cells of Patients with Amyotrophic Lateral Sclerosis.

BACKGROUND: Sporadic amyotrophic lateral sclerosis (SALS) is a fatal motor neuron degenerative disease of unclear pathogenesis. Disturbances of intracellular transport are possible causes of the disease. OBJECTIVE: We evaluated the expression of motor proteins involved in the anterograde (kinesins KIF1B, KIF5C) and retrograde (KIFC3, dynactin subunits DCTN1 and DCTN3) intracellular transport in peripheral blood mononuclear cells (PBMCs). MATERIALS AND METHODS: PBMCs were obtained from 74 SALS patients with different clinical phenotypes, 65 blood donors (healthy control I), and 29 cases with other neurological diseases (disease control II) divided into subgroups IIA (atypical parkinsonism) and IIB (ALS-mimicking disorders). mRNA expression was studied by real-time qPCR, and protein level by Western blotting. RESULTS: In SALS, KIF5C and KIFC3 expression was significantly lower and DCTN1 higher than in control I, and dependent of age. KIF1B expression was significantly higher in SALS than in subgroup IIB, whereas DCTN1 and DCTN3 were higher in SALS than in subgroup IIA. All changes in the studied proteins were statistically significant in classic ALS but not in progressive muscular atrophy. CONCLUSION: In SALS, and especially in classic ALS, the changes in motor protein expression may alter bidirectional intracellular transport in PBMCs. More studies are needed to find out whether the levels of KIF5C and DCTN1 may be useful in ALS diagnosis, and whether KIF1B expression may discriminate ALS from ALS-mimicking disorders.

Targeting the expression of glutathione- and sulfate-dependent detoxification enzymes in HepG2 cells by oxygen in minimal and amino acid enriched medium.

Cancer cells exhibit specific metabolism allowing them to survive and proliferate in various oxygen conditions and nutrients' availability. Hepatocytes are highly active metabolically and thus very sensitive to hypoxia. The purpose of the study was to investigate the effect of oxygen on the expression of phase II detoxification enzymes in hepatocellular carcinoma cells (HepG2) cultured in minimal and rich media (with nonessential amino acids and GSH). The cells were cultured at 1% hypoxia, 10% tissue normoxia, and 21% atmospheric normoxia. The total cell count was determined by trypan blue exclusion dye and the expression on mRNA level by RT-PCR. The result indicated that the expression of glutathione-dependent enzymes (GSTA, M, P, and GPX2) was sensitive to oxygen and medium type. At 1% hypoxia the enzyme expression (with the exception of GSTA) was higher in minimal compared to rich medium, whereas at 10% normoxia it was higher in the rich medium. The expression was oxygen-dependent in both types of medium. Among phenol sulfotransferase SULT1A1 was not sensitive to studied factors, whereas the expression of SULT1A3 was depended on oxygen only in minimal medium. It can be concluded that in HepG2 cells, the detoxification by conjugation with glutathione and, to a lower extent with sulfate, may be affected by hypoxia and/or limited nutrients' availability. Besides, because the data obtained at 10% oxygen significantly differ from those at 21%, the comparative studies on hypoxia should be performed in relation to 10% but not 21% oxygen.

GSTP1 Polymorphisms and their Association with Glutathione Transferase and Peroxidase Activities in Patients with Motor Neuron Disease.

Glutathione S-transferase pi (GSTP1) is a crucial enzyme in detoxification of electrophilic compounds and organic peroxides. Together with Se-dependent glutathione peroxidase (Se-GSHPx) it protects cells against oxidative stress which may be a primary factor implicated in motor neuron disease (MND) pathogenesis. We investigated GSTP1 polymorphisms and their relationship with GST and Se-GSTPx activities in a cohort of Polish patients with MND. Results were correlated with clinical phenotypes. The frequency of genetic variants for GSTP1 exon 5 (I105V) and exon 6 (A114V) was studied in 104 patients and 100 healthy controls using real-time polymerase chain reaction. GST transferase activity was determined in serum with 1-chloro-2,4-dinitrobenzene, its peroxidase activity with cumene hydroperoxide, and Se-GSHPx activity with hydrogen peroxide. There were no differences in the prevalence of GSTP1 polymorphism I105V and A114V between MND and controls, however the occurrence of CT variant in codon 114 was associated with a higher risk for MND. GSTP1 polymorphisms were less frequent in classic ALS than in progressive bulbar palsy. In classic ALS C* (heterozygous I /V and A /V) all studied activities were significantly lower than in classic ALS A* (homozygous I /I and A/A). GST peroxidase activity and Se-GSHPx activity were lower in classic ALS C* than in control C*, but in classic ALS A* Se-GSHPx activity was significantly higher than in control A*. It can be concluded that the presence of GSTP1 A114V but not I105V variant increases the risk of MND, and combined GSTP1 polymorphisms in codon 105 and 114 may result in lower protection of MND patients against the toxicity of electrophilic compounds, organic and inorganic hydroperoxides.

Changes in Serum Amino Acids in Migraine Patients without and with Aura and their Possible Usefulness in the Study of Migraine Pathogenesis.

BACKGROUND: Results of several studies suggest that serum amino acids monitoring in migraine might be useful as an objective measurement of the disease status. OBJECTIVE: The aim of the present work was to analyze the profile of aliphatic and aromatic amino acids in blood serum of migraine patients without and with aura between attacks. METHODS: A total number of 37 migraine patients (26 with migraine without aura and 11 with migraine with aura), mean age 39±12 years, and 40 age-matched healthy subjects as the control group, mean age 38±14 years, were included into the study. The levels of glutamic acid, glutamine, histidine (His), valine (Val), isoleucine, leucine (Leu), phenyloalanine, lysine were evaluated. RESULTS: The level of His was significantly higher in both groups of migraine patients (without and with aura) compared to the control group (F(2,74)=10.17, p=0.00). The levels of Val and Leu were significantly different in migraine without but not with aura, when compared with the control group (F(2,74)=4.70, p=0.01 and F(2,74)=4.39, p=0.02, respectively). CONCLUSION: We found higher level of His in migraine patients without and with aura and lower level of Val and Leu in patients with migraine without aura.

Plasma profiling reveals three proteins associated to amyotrophic lateral sclerosis.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is the most common adult motor neuron disease leading to muscular paralysis and death within 3-5 years from onset. Currently, there are no reliable and sensitive markers able to substantially shorten the diagnosis delay. The objective of the study was to analyze a large number of proteins in plasma from patients with various clinical phenotypes of ALS in search for novel proteins or protein profiles that could serve as potential indicators of disease. METHODS: Affinity proteomics in the form of antibody suspension bead arrays were applied to profile plasma samples from 367 ALS patients and 101 controls. The plasma protein content was directly labeled and protein profiles obtained using 352 antibodies from the Human Protein Atlas targeting 278 proteins. A focused bead array was then built to further profile eight selected protein targets in all available samples. RESULTS: Disease-associated significant differences were observed and replicated for profiles from antibodies targeting the proteins: neurofilament medium polypeptide (NEFM), solute carrier family 25 (SLC25A20), and regulator of G-protein signaling 18 (RGS18). INTERPRETATION: Upon further validation in several independent cohorts with inclusion of a broad range of other neurological disorders as controls, the alterations of these three protein profiles in plasma could potentially provide new molecular markers of disease that contribute to the quest of understanding ALS pathology.

Altered L-arginine metabolism in children with controlled asthma.

Decreased level of L-arginine may lead to airway hyperresponsiveness, inflammation, and airway remodeling. Changes in L-arginine metabolism were observed earlier in adult asthmatic patients. Studies on L-arginine metabolism in children with bronchial asthma are limited. Because biosynthesis of L-arginine is insufficient in growing children, its potential metabolic alterations may have important clinical implications. This study was designed to evaluate L-arginine metabolism in children with well-controlled asthma. The studies were conducted on blood serum of 30 asthmatic and 20 healthy children (control group). Levels of L-arginine and its metabolic products, L-citrulline and L-ornithine, were measured by HPLC. Arginase activity was determined spectrophotometrically. Disease severity was evaluated by the asthma control test (ACT) and the level of nitric oxide (NO) in exhaled air. In asthmatic children L-arginine concentration was significantly lowered, whereas arginase activity was unchanged when compared with the healthy group. However, L-ornithine and L-citrulline levels were significantly increased. There was no correlation between arginase activity, amino acids levels, ACT scores, and exhaled NO. In children with chronic, well-controlled asthma L-arginine metabolism is altered. Given that L-arginine is absolutely essential for children, our findings may be of particular importance for the management of children with non-exacerbated asthma. They may also help to develop new therapeutic strategies targeted at L-arginine metabolism in the future.

Significance of arginase determination in body fluids of patients with hepatocellular carcinoma and liver cirrhosis before and after surgical treatment.

OBJECTIVE: To assess the utility of arginase activity and expression in diagnosis of liver diseases. DESIGN AND METHODS: Arginase activity, sensitivity and specificity were determined in serum of 140 patients including 50 with HCC, 60 with LC, 30 with choledocholithiasis (CDL) and 90 healthy controls. In HCC and LC arginase activity in serum was studied before and after tumor resection or liver transplantation. Arginase sensitivity in HCC was compared to that of alpha-fetoprotein (AFP) and aminotransferases (AST, ALT). In LC the activity was determined also in bile before and after transplantation. The expression of arginase isoenzymes in serum was studied by Western blotting. RESULTS: In HCC and LC the preoperative arginase activity was significantly higher compared to controls, and it decreased after surgery. The sensitivity of arginase in HCC was much higher than that of AFP, AST and ALT (96, 40, 20 and 18%, respectively). In HCC it was higher than in LC (93%) and CDL (33%). The specificity of arginase was above 80%. In bile of cirrhotic patients the highest activity was immediately after liver transplantation. It decreased with time but increased dramatically at the time of the graft rejection. Arginase AII was present in serum of HCC and LC but not the control cases. CONCLUSIONS: The increase of arginase activity in serum accompanied by the presence of isoenzyme AII can be useful in HCC and LC diagnosis. The determination of arginase activity in bile may be helpful in monitoring liver graft recipients.

Dynactin Deficiency in the CNS of Humans with Sporadic ALS and Mice with Genetically Determined Motor Neuron Degeneration.

Dynactin is a complex motor protein involved in the retrograde axonal transport disturbances of which may lead to amyotrophic lateral sclerosis (ALS). Mice with hSOD1G93A mutation develop ALS-like symptoms and are used as a model for the disease studies. Similar symptoms demonstrate Cra1 mice, with Dync1h1 mutation. Dynactin heavy (DCTN1) and light (DCTN3) subunits were studied in the CNS of humans with sporadic ALS (SALS), mice with hSOD1G93A (SOD1/+), Dync1h1 (Cra1/+), and double (Cra1/SOD1) mutation at presymptomatic and symptomatic stages. In SALS subjects, in contrast to control cases, expression of DCTN1-mRNA but not DCTN3-mRNA in the motor cortex was higher than in the sensory cortex. However, the mean levels of DCTN1-mRNA and protein were lower in both SALS cortexes and in the spinal cord than in control structures. DCTN3 was unchanged in brain cortexes but decreased in the spinal cord on both mRNA and protein levels. In all SALS tissues immunohistochemical analyses revealed degeneration and loss of neuronal cells, and poor expression of dynactin subunits. In SOD1/+ mice both subunits expression was significantly lower in the frontal cortex, spinal cord and hippocampus than in wild-type controls, especially at presymptomatic stage. Fewer changes occurred in Cra1/SOD1 and Cra1/+ mice.It can be concluded that in sporadic and SOD1-related ALS the impairment of axonal retrograde transport may be due to dynactin subunits deficiency and subsequent disturbances of the whole dynein/dynactin complex structure and function. The Dync1h1 mutation itself has slight negative effect on dynactin expression and it alleviates the changes caused by SOD1G93A mutation.

Analysis of PITX3 gene in patients with multisystem atrophy, progressive supranuclear palsy and corticobasal degeneration.

Interactions of transcriptions factors Nurr1, Pitx3, and EN1 are involved in the maturation and survival of adult midbrain dopaminergic neurons during a lifetime. The aim of the study was to evaluate the presence of mutations and single nucleotide polymorphisms in PITX3 gene in clinically diagnosed multisystem atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). In the group of 77 patients with MSA, 44 with PSP, and 6 with CBD, no pathogenic mutations were identified.

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.

Kinesin expression in the central nervous system of humans and transgenic hSOD1G93A mice with amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis is a fatal motor neuron degenerative disease. Most cases are sporadic (SALS), and approximately 10% are familial (FALS) among which over 20% are linked to the SOD1 mutation. Both SALS and FALS have been associated with retrograde axonal transport defects. Kinesins (KIFs) are motor proteins involved mainly in anterograde transport; however, some also participate in retrograde transport. OBJECTIVE: The purpose of the study was to investigate and compare the expression of kinesins involved in anterograde (KIF5A, 5C) and retrograde (KIFC3/C2) axonal transport in SALS in humans and FALS in mice with the hSOD1G93A mutation. METHODS: The studies were conducted on various parts of the CNS from autopsy specimens of SALS patients, and transgenic mice at presymptomatic and symptomatic stages using real-time quantitative PCR and reverse-transcription PCR. RESULTS: All KIF expression in the motor cortex of individual SALS subjects was higher than in the adjacent sensory cortex, in contrast to the expression in control brains. It was also significantly higher in the frontal cortex of symptomatic but not presymptomatic mice compared to wild-type controls. However, the mean KIF expression in the SALS motor and sensory cortexes was lower than in control cortexes. To a lesser extent the decrease in KIF mean expression also occurred in human but not in mouse ALS spinal cords and in both human and mouse cerebella. CONCLUSION: Disturbances in kinesin expression in the CNS may dysregulate both anterograde and retrograde axonal transports leading to motor neuron degeneration.

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.

[Intracellular transport proteins: classification, structure and function of kinesins]. / Bialka transportu wewnatrzkomórkowego: klasyfikacja, budowa i funkcje kinezyn.

Correct cell functioning, division and morphogenesis rely on efficient intracellular transport. Apart from dyneins and myosins, kinesins are the main proteins responsible for intracellular movement. Kinesins are a large, diverse group of motor proteins, which based on phylogenetic similarity were classified into fourteen families. Among these families, due to the location of their motor domains, three groups have been characterized: N-, C- and M-kinesin. As molecular motors, kinesins transport various molecules and vesicles mainly towards the microtubule plus end (from the cell body) participating in anterograde transport, although there are also kinesins involved in retrograde transport (C-kinesins). Kinesins are also involved in spindle formation, chromosome segregation, and spermatogenesis. Because of their great importance for the correct functioning of cells, mutations in kinesin coding genes may lead to such neurodegenerative diseases as dominant hereditary spastic paraplegia or Charcot-Marie-Tooth disease.

[Evaluation of beta2-microglobuline expression level in gastrointestinal tract tumors due to usefulness as a reference gene in PCR method]. / Ocena poziomu ekspresji beta2-mikroglobuliny w nowotworach przewodu pokarmowego pod wzgledem przydatnosci jako genu referencyjnego w metodzie PCR.

UNLABELLED: Quantitative and semi-quantitative determination of gene expression by PCR plays an important role in studying of tumors initiation and progression mechanisms. Selection of appropriate reference gene is a critical factor influencing the results of gene expression analysis. One of the most commonly used reference genes in PCR is beta2-microglobuline (beta2-M). Recent studies showed however that expression of some common reference genes might be unstable, therefore it is necessary to verify again their usefulness. The aim of the study was to determine the level of beta2-M mRNA in normal and tumor tissues of gastrointestinal tract due to adequate selection of reference gene in gene expression studies. MATERIAL AND METHODS: Samples were taken from 253 patients operated on for gastrointestinal tract tumors: 22 with oral cavity cancer, 12 with benign and 50 with malignant liver tumors, 86 with colorectal cancer, and 83 with metachronous metastases to liver. Also 56 patients with liver cirrhosis were studied, which was treated as pre-tumor state. Together 309 patients were studied. RNA was isolated from tissues by Chomczynski method. The expression level of 12-M was determined by reverse transcriptase PCR (RT-PCR) and given in terms of optical density values. RESULTS: Expression of beta2-M was observed in all studied tissues. There were no differences between normal and tumor tissue. The level of expression of beta2-M was different due to type of studied tissue (oral cavity, liver, colon). CONCLUSIONS: The lack of significant differences in beta2-M expression level in normal and tumor tissues indicated that beta2-M can be used as reference gene in studies of gene expression in gastrointestinal tract tumors. On the other hand differences of beta2-M expression level in different types of tissues point to its tissue specificity and suggest application in PCR of more than one reference gene.

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.