Role of ENPP1 Gene Variants in the Susceptibility to Diabetic Nephropathy in Patients with type 2 Diabetes Mellitus.

Genetic factors are known to play a significant role in the susceptibility of diabetic patients to severe complications such as diabetic nephropathy (DN). This study aimed to evaluate the association between polymorphism of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) variants (rs997509, K121Q, rs1799774, and rs7754561) and DN in patients with type 2 diabetes mellitus (T2DM). A total number of 492 patients with T2DM with and without DN were categorized into case and control groups. The extracted DNA samples were genotyped using TaqMan allelic discrimination assay amplified by polymerase chain reaction (PCR). The haplotype analysis among the case and control groups was performed using an expectation-maximization algorithm by the maximum-likelihood method. The analysis of laboratory findings demonstrated significant differences in fasting blood sugar (FBS) and hemoglobin A1c (HbA1c) between the case and control groups (P < 0.05). The results showed that K121Q was significantly related to DN under a recessive model of inheritance (P = 0.006); however, rs1799774 and rs7754561 both were protective for DN under a dominant model of inheritance (P = 0.034 and P = 0.010, respectively) among four studied variants. Two haplotypes, including C-C-delT-G with a frequency < 0.02 and T-A-delT-G with a frequency < 0.01, were associated with the increased risk of DN (P < 0.05). The present study demonstrated that K121Q was associated with the susceptibility of DN; however, rs1799774 and rs7754561 were protecrtive variants for DN in patients with T2DM.

CD33 mRNA Has Elevated Expression Levels in the Leukocytes of Peripheral Blood in Patients with Late-Onset Alzheimer's Disease.

BACKGROUND/AIMS: In despite of conflicting results among different ethnic groups, the rs3865444 of CD33 gene has previously been identified as a risk factor for late-onset Alzheimer's disease (LOAD).This study was aimed to evaluate the association between rs3865444 SNP with LOAD occurrence, and to investigate whether CD33 mRNA expression will change in the leukocytes of peripheral blood in LOAD patients. METHODS: The rs3865444 polymorphism was genotyped in 233 LOAD and 238 control subjects using the Tetra-ARMS-PCR method. CD33 mRNAs expression in leukocytes were assessed and analyzed using the real-time qPCR method. We used in silico approach to analyze potential effects imparted by rs3865444 polymorphism in LOAD pathogenesis. RESULTS: Our results show a significant increase in CD33 mRNA expression levels in white blood cells of LOAD patients, however, the association between CD33 rs3865444 polymorphism and LOAD was found to be not significant. We also noticed that LOAD patients with the C/A genotype had higher CD33 mRNA levels in their peripheral blood than those of the control group. CONCLUSIONS: rs3865444, located upstream of the 5'CD33 coding region, might positively influence CD33 mRNAs expression in leukocytes of LOAD versus healthy people. This is likely to happen through interfering rs3865444 (C) with the functional activity of several other transcription factors given that rs3865444 is in linkage disequilibrium with other functional polymorphisms in this coding region according to an in silico study. We propose that CD33 mRNAs elevation in peripheral immune cells - as a potential biomarker in LOAD - is related to peripheral immune system impairment.

Association of OPRK1 gene polymorphisms with opioid dependence in addicted men undergoing methadone treatment in an Iranian population.

Previous studies have shown significant associations between OPRK1 and susceptibility to opioid dependence and the relationships between libido dysfunction and insomnia among opium addicts who underwent methadone maintenance treatment. The authors investigated the single locus and haplotype association of rs997917, rs6985606, and rs6473797 with susceptibility to opioid addiction. Samples were selected among 202 healthy individuals and 202 opium addicts undergoing methadone maintenance treatment. Genomic DNA was extracted from the whole blood samples of all subjects through a salting out procedure. All three variants were genotyped in the studied subjects using Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR). The whole analysis process was performed using SNPAlyze and SPSS ver.20 software packages. According to the single locus analyses, rs997917 and rs6985606 represented significant associations with opium addiction under recessive (p = 0.0128) and co-dominant (p = 0.0001) inheritance models, respectively. The haplotypes C-T-C (Permutation p = 0.014) and C-T-T (Permutation p = 0.0002) were significantly associated with opioid dependence. Among methadone maintenance treatment individuals, rs997917 was significantly associated with insomnia in both allelic and genotypic levels (p = 0.0001 and p = 0.038, respectively). Furthermore, rs6985606 had the only significant association with the co-incidence of insomnia and libido dysfunction in the methadone maintenance treatment group (p = 0.038). The OPRK1 gene variants showed significant association with susceptibility to opioid dependence among Iranians.

Association of OPRD1 Gene Variants with Opioid Dependence in Addicted Male Individuals Undergoing Methadone Treatment in the North of Iran.

Genetic association of rs678849 along with neuroimaging and biomarker phenotypes, parallel with the known involvements of the OPRD1 in drug abuse, provided additional support for targeting these receptors as potential therapeutic targets in both neurodegenerative diseases and neuropsychiactric disorders such as Alzheimer's disease. Samples were selected among 202 opium-addicted participants undergoing methadone treatment and 202 healthy controls. Genomic DNA of all subjects was extracted from whole blood samples through a Salting Out procedure. Four variants (rs678849, 2236857, 2236855, and 760589) were genotyped in the studied subjects using ARMS-PCR. The analysis was performed using SNPalyze and SPSS ver.20 software. According to single locus analysis, rs678849 under dominant model (p < 0.001), rs2236857 under recessive model (p = 0.006), and the two variants, rs2236855 and rs760589 under co-dominant model, showed significant contributions between groups (p = 0.001 and p = 0.009, respectively). rs2236855 was associated with the development of libido dysfunction in opium-addicted patients undergoing methadone treatment (p = 0.011). Through haplotype analyses, five haplotypes with frequency of more than 5% displayed significant association with opioid dependence in study participants. In conclusion, the four studied OPRD1 gene variants and their haplotypes can play important roles in susceptibility to opioid dependence.

Selective regulation of class I and class II histone deacetylases expression by inhibitors of histone deacetylases in cultured mouse neural cells.

The expression of 10 histone deacetylases (HDAC1-10) mRNAs in mouse neuroblastoma Neuro-2a and microglia N9 cell cultures after treatment by inhibitors of HDACs, sodium butyrate and trichostatin A was studied to elucidate whether HDAC inhibitors affect the gene expression of HDACs themselves. Northern blot analysis demonstrated two- to four-fold elevated levels of mRNAs for HDAC1, -3, -5, and -6 after drug treatment in comparison with untreated cells, while mRNA levels for HDAC2 and -7 did not change significantly. In both Neuro-2a and N9 cells the highest increase was observed for HDAC5 and -6 mRNA, whereas, HDAC4 had a prominent increase in mRNA levels after drug treatment only in N9 microglia cell line but not in Neuro-2a. Immunocytochemical examination confirmed that changes in protein levels of HDACs were similar to changes in their mRNA levels. There exists an auto-regulatory feedback loop to the expression levels of several HDACs after inhibition of their biochemical activity, adding several HDAC genes to the list of genes regulated by HDAC inhibitors.

Upregulation of class II histone deacetylases mRNA during neural differentiation of cultured rat hippocampal progenitor cells.

We studied the expression of histone deacetylases (HDACs 1-10) mRNAs during early differentiation of cultured rat hippocampal progenitor cells using Northern blot analysis. Embryonic rat hippocampal progenitors were kept proliferating and undifferentiated (neurospheres) in the presence of mitogens and induced to stop proliferation and to differentiate into neurons and astrocytes by mitogen removal. We found two- to four-fold elevated levels of mRNAs for HDAC 5, 6, 7 and 9 in early differentiation times in comparison with proliferating neurospheres while mRNA levels for HDAC 1, 2 and 3 did not change significantly. Interestingly, the upregulated HDACs all belong to class II of histone deacetylases. mRNAs for HDAC 4, 8 and 10 were not detectable by Northern analysis. We suggest that the changes in HDAC mRNA expression levels might be connected with chromatin rearrangement during neural differentiation.

Overexpression of a truncated TrkB isoform increases the proliferation of neural progenitors.

The truncated isoform of TrkB, TrkB.T1, has been shown to be expressed in the neurogenic region of rodent brain. TrkB.T1 lacks tyrosine kinase activity and it may modify the action of the full-length TrkB. We show here that the full-length TrkB and TrkB.T1 are expressed at the same relative expression levels in mouse neural progenitor cell cultures. The number of neurosphere-forming progenitors was reduced and apoptosis increased in neurospheres generated from mice overexpressing TrkB.T1 when compared with wild-type neurospheres. The proliferation of the transgenic neural progenitors was increased, as indicated by the larger average diameter of spheres (140% of control), the increased cell growth in an MTT assay (137% of control) and the faster rate of 3H-thymidine incorporation (128% of control) in the transgenic cell cultures than in controls. The proliferation of neural progenitors was also increased after lentivirus-mediated TrkB.T1 overexpression. A significant increase in 3H-thymidine incorporation (119% of control) and the average diameter of spheres (112% of control) in the TrkB.T1-transduced neurospheres compared with neurospheres transduced with the control vectors confirmed the role of TrkB.T1 in proliferation of neural progenitor. When induced to differentiate, progenitors overexpressing TrkB.T1 generated two to three times more neurons than did wild-type cells. The increase in the number of neurons correlated with an increase in the number of apoptotic cells (two-fold) at these time points. The data indicate that changes in the relative expression levels of different TrkB isoforms influence the replicative capacity of neural progenitors.