Phenotypic and genetic variations between Asian and Caucasian polypoidal choroidal vasculopathy

PURPOSE

To compare phenotypic and genetic variations in polypoidal choroidal vasculopathy (PCV) between Caucasian and Asian patients.

METHODS

We analysed phenotypic and genotypic data from two sites, Association for Innovation and Biomedical Research on Light and Image, Portugal and Singapore National Eye Centre, Singapore. Baseline fundus photography, spectral domain-optical coherence tomography, indocyanine green and fluorescein angiography scans were analysed by respective reading centres using a standardised grading protocol. Single nucleotide polymorphisms across 8 PCV loci were compared between cases and controls selected from each population.

RESULTS

One hundred and forty treatment-naïve PCV participants (35 Portuguese and 105 Singaporean) were included. The Portuguese cohort were older (72.33±8.44 vs 68.71±9.40 years, p=0.043) and were comprised of a lower proportion of males (43% vs 71%, p=0.005) compared with the Singaporean cohort. Differences in imaging features include higher prevalence of soft drusen (66% vs 30%, p=0.004), lower prevalence of subretinal haemorrhage (14% vs 67%, p<0.001), smaller polypoidal lesion (PL) area (0.09±0.09 vs 0.76±0.93 mm², p<0.001), lower ratio of PL to branching vascular network area (3% vs 38%, p<0.001) and lower central retinal thickness (346.48±93.74 vs 493.16±212.92 µm, p<0.001) in the Portuguese cohort. CETP rs3764261 (OR 2.467; 95% CI 1.282 to 4.745, p=0.006) in the Portuguese population was significantly associated with PCV and CFH rs800292 (OR 1.719; 95% CI 1.139 to 2.596, p=0.010) in the Singaporean population, respectively.

CONCLUSION

Among Asian and Caucasian patients with PCV, there are significant differences in the expression of phenotype. We also identified different polymorphisms associated with PCV in the two populations.

Why could a woman have three Trisomy 21 pregnancies? - a case report

Mosaicism, an important cause for recurrent T21, should be suspected in families with more than one affected child wishing to receive prenatal counseling. Fluorescence in-situ hybridization analysis in a large number of cells and in different tissue samples is critical for detecting low-level mosaicism and is a key prognostic factor.

Senescent bronchial fibroblasts induced to senescence by Cr(VI) promote epithelial-mesenchymal transition when co-cultured with bronchial epithelial cells in the presence of Cr(VI)

Cellular senescence is a physiological process that serves as a powerful barrier for tumorigenesis. However, senescent cells can be deleterious for the tissue microenvironment. Such is the case of senescent fibroblasts that release several pro-tumorigenic factors that promote malignant transformation in the nearby epithelial cells. Occupational exposure to hexavalent chromium [Cr(VI)] compounds is a cause of respiratory cancers. Although Cr(VI) is known to induce senescence in human foreskin fibroblasts, the role of senescent fibroblasts in the Cr(VI)-induced malignant transformation of human bronchial epithelial cells was never assessed. Thus, to study the evolutionary dynamics generated by the interaction between human bronchial epithelial cells and senescent bronchial fibroblasts, the non-tumorigenic human bronchial epithelial BEAS-2B cells were co-cultured with Cr(VI)-induced senescent human bronchial fibroblasts for 4 weeks. Under the pressure of 0.5 µM Cr(VI), senescent fibroblasts promoted the acquisition of mesenchymal features on BEAS-2B cells, e.g. the fusiform shape and increased Vimentin expression, consistent with the occurrence of an epithelial-mesenchymal transition-like process. Features of transformed cells including larger nuclei, as well as nuclei with heterogeneous size, were also observed. Altogether the results obtained demonstrate that besides acting over the epithelium, Cr(VI) also affects bronchial fibroblasts driving them senescent. As a consequence, a paracrine communication loop is established with the above-placed epithelium prompting the epithelial cells for malignant transformation and thus facilitating the initial steps of tumorigenesis.

Genomic characterization of three urinary bladder cancer cell lines: understanding genomic types of urinary bladder cancer

Several genomic regions are frequently altered and associated with the type, stage and progression of urinary bladder cancer (UBC). We present the characterization of 5637, T24 and HT1376 UBC cell lines by karyotyping, fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH) and multiplex ligation-dependent probe amplification (MLPA) analysis. Some cytogenetic anomalies present in UBC were found in the three cell lines, such as chromosome 20 aneuploidy and the loss of 9p21. Some gene loci losses (e.g. CDKN2A) and gains (e.g. HRAS, BCL2L1 and PTPN1) were coincident across all cell lines. Although some significant heterogeneity and complexity were detected between them, their genomic profiles exhibited a similar pattern to UBC. We suggest that 5637 and HT1376 represent the E2F3/RB1 pathway due to amplification of 6p22.3, concomitant with loss of one copy of RB1 and mutation of the remaining copy. The HT1376 presented a 10q deletion involving PTEN region and no alteration of PIK3CA region which, in combination with the inactivation of TP53, bears more invasive and metastatic properties than 5637. The T24 belongs to the alternative pathway of FGFR3/CCND1 by presenting mutated HRAS and over-represented CCND1. These cell lines cover the more frequent subtypes of UBC and are reliable models that can be used, as a group, in preclinical studies.

Identification of a 0.4 Kb deletion region in 10q26 associated with endometrial carcinoma

We have identified an allelic deletion common region in the q26 region of chromosome 10 in endometrial carcinomas, which has been reported previously as a potential target of genetic alterations related to this neoplasia. An allelotyping analysis of 19 pairs of tumoral and non-tumoral samples was accomplished using seven microsatellite polymorphic markers mapping in the 10q26 chromosomal region. Loss of heterozygosity for one or more loci was detected in 29% of the endometrial carcinoma samples. The observed pattern of loss enabled the identification of a 3.5 Mb common deleted region located between the D10S587 and D10S186 markers. An additional result from an endometrial sample with evidence of a RER phenotype may suggest a more centromeric region of loss within the above-mentioned interval. This 401.84 Kb interval flanked by the D10S587 and D10S216 markers may be a plausible location for a putative suppressor gene involved in early stage endometrial carcinogenesis.

Human bronchial epithelial cells malignantly transformed by hexavalent chromium exhibit an aneuploid phenotype but no microsatellite instability

Hexavalent chromium [Cr(VI)] is a well-recognized human lung carcinogen. In order to gain further insight into Cr(VI)-induced carcinogenesis, we have established an adequate in vitro cellular model for the study of this process. To this end, BEAS-2B cells were used. Chronic exposure of cells to 1 microM Cr(VI) induced changes in the cells' ploidy and a decrease in cloning efficiency, although cultures continued to progress to confluence. After prolonged exposure (12 passages), the culture became heterogeneous, exhibiting areas where apparently normal epithelial cells and morphologically altered cells coexisted. Subsequent culture at a very low density strongly accentuated the Cr(VI)-induced changes in morphology and pattern of growth. Three individual colonies were then ring-cloned and expanded into three subclonal aneuploid cell lines. These subclonal cell lines showed changes in growth pattern and morphology, as well as a karyotype drift concomitant with the overexpression of genes commonly involved in malignant transformation (c-MYC, EGFR, HIF-1alpha and LDH-A). Moreover, when one of these cell lines (RenG2) was injected into nude mice, it showed the ability to induce tumors. This cell line revealed no microsatellite instability (MSI), which points to the expression of a functional MLH1 protein and an active mismatch repair (MMR) system. Therefore, the progression to malignancy of the BEAS-2B cells involved Cr(VI)-induced transformants that retained the ability to repair DNA damage, suggesting that genotoxicity underlies the ongoing carcinogenic process.

Serotonin transporter is differentially localized in subpopulations of lymphocytes of major depression patients. Effect of fluoxetine on proliferation

Modifications of lymphocyte serotonergic system have been described in major depression. The aim of this study was to determine new possible changes of this system in depression. Twenty eight patients, free of drugs, diagnosed with major depression disorder by Structured Clinical Interview for Disorders of Axis I, without medical illnesses, written consent, approved by Ethical Committees were included. Controls were 30 healthy subjects without family history of psychiatric disease. Blood monocytes were isolated with Ficoll/Hypaque, and lymphocytes by differential adhesion to plastic. Serotonin and 5-hydroxyindoleacetic acid determined by HPLC. Monocytes had higher serotonin concentrations than lymphocytes, and serotonin/5-hydroxyindoleacetic acid was lower in patients. Basal proliferation was elevated in depressed and not increased by Concanavalin A. Fluoxetine reduced basal proliferation more efficiently in patients, indicating activation of lymphocytes in depression. The number of cells expressing serotonin transporter was reduced in depressed. There were no differences in CD4+ (approximately 50%) or CD8+ (approximately 25%) lymphocytes between the groups, although CD8+ were lower in depressed, and greater number of them co-localized serotonin transporter than CD4+, which could be crucial for function in relation to serotonin and its receptors in immune cells. Lymphocytes were activated in this group of patients and fluoxetine reduced proliferation, probably being relevant for the psychopharmacological treatment of depression.

Cytogenetically invisible microdeletions involving PITX2 in Rieger syndrome

Axenfeld-Rieger syndrome (ARS) is a genetically heterogeneous autosomal dominant disorder mainly characterized by developmental defects of the anterior segment and extraocular anomalies. ARS shows great clinical variability and encompasses several conditions with overlapping phenotypes, including Rieger syndrome (RS). RS is characterized by developmental defects of the eyes, teeth and umbilicus, and the main causative gene is PITX2 (paired-like homeodomain transcription factor 2, or RIEG1) at 4q25. PITX2 mutations show great variety, from point mutations to microscopic or submicroscopic deletions, and apparently balanced translocations in few cases. We identified cytogenetically undetectable submicroscopic deletions at 4q25 in two unrelated patients diagnosed with RS. One patient had a t(4;17)(q25;q22)dn translocation with a deletion at the 4q breakpoint, and the other patient had an interstitial deletion of 4q25. Both deletions included only the PITX2 and ENPEP (glutamyl aminopeptidase) genes.

Null mutations and lethal congenital form of glycogen storage disease type IV

Glycogen branching enzyme deficiency (glycogen storage disease type IV, GSD-IV) is a rare autosomal recessive disorder of the glycogen synthesis with high mortality. Two female newborns showed severe hypotonia at birth and both died of cardiorespiratory failure, at 4 and 12 weeks, respectively. In both patients, muscle biopsies showed deposits of PAS-positive diastase-resistant material and biochemical analysis in cultured fibroblasts showed markedly reduced glycogen branching enzyme activity. Direct sequencing of GBE1 gene revealed that patient 1 was homozygous for a novel c.691+5 g>c in intron 5 (IVS5+5 g>c). RT-PCR analysis of GBE1 transcripts from fibroblasts cDNA showed that this mutation produce aberrant splicing. Patient 2 was homozygous for a novel c.1643G>A mutation leading to a stop at codon 548 in exon 13 (p.W548X). These data underscore that in GSD-IV a severe phenotype correlates with null mutations, and indicate that RNA analysis is necessary to characterize functional consequences of intronic mutations.

Effect of mirtazapine treatment on serotonin transporter in blood peripheral lymphocytes of major depression patients

Lymphocytes from human peripheral blood exhibit a series of markers of neurotransmitters, such as specific receptors and transporters. A reduction of serotonin transporters and an increase of them has been reported after treatment with fluoxetine in depressed patients. The aim of this study was to determine if the administration of an antidepressant with a different mechanism of action, such as mirtazapine, could produce a similar effect. Twenty eight patients (age 41.40+/-2.45) were diagnosed following the criteria for major depression by the Structured Clinical Interview for Disorders of Axis I of the American Psychiatric Association. Severity was measured by Hamilton Scale and by Beck Inventory for Depression, scores of 30.88+/-7.48 and 30.24+/-10.88, respectively, prior to treatment. Samples from control subjects were obtained alternating with patients before and after the administration of the antidepressant: twenty eight and twenty four, respectively (age 38.80+/-2.95). Mirtazapine was given in a dose of 30 mg/day for 6 weeks. Blood lymphocytes were isolated by density gradient from patients and controls before and after treatment. There was a partial response according to clinical evaluation and scores of the Scale and the Inventory. Serotonin transporters were labeled with [3H] paroxetine. Number of sites (B(max)) were 10.86+/-2.60 and 12.58+/-2.71 fmol/10(6) cells for both groups of controls. The depressed patients had a significant reduction of serotonin transporters in their lymphocytes before treatment and an increase after it, with B(max) values of 6.52+/-0.49 and 15.61+/-0.49 fmol/10(6) cells, respectively. There were no significant differences in the affinity for the ligand. Concentrations of serotonin or noradrenaline in lymphocytes were not modified before the treatment, although there was a significant decrease after taking 30 mg/day of the antidepressant for 6 weeks. Mirtazapine, not being a serotonin reuptake inhibitor, did increase the number of transporters in lymphocytes of major depression patients, indicating a complex mechanism, not only directly related to the transporter, but involved in the therapeutic response.

Differential cAMP levels and serotonin effects in blood peripheral mononuclear cells and lymphocytes from major depression patients

cAMP regulates immune responses, and modifications in cAMP signaling are involved in the pathophysiology and treatment of depression. In the present report, basal and forskolin-stimulated levels of cAMP were determined in mononuclear cells and lymphocytes from control individuals and major depression patients. Twenty-eight patients between 24 and 59 years old were diagnosed for a major depression episode according to the criteria of the Structural Clinical Interview for Disorders of Axis I of the American Psychiatric Association. These patients presented a score of 25 for severity as measured by Hamilton Rating Scale of Depression (HAM-D), and 23 for Beck Inventory of Depression (BID). Control and patient mononuclear cells were isolated by Ficoll/Hypaque gradients and their lymphocytes were separated from the total mononuclear population by differential adhesion to plastic surface. The basal concentration of cAMP was 50% lower in mononuclear cells and lymphocytes from the depressed patients compared with the control subjects. The response to forskolin was significantly smaller in lymphocytes of major depression patients than in the controls, but no difference was evident in the mononuclear cell preparations. There was a significant increase in cAMP produced by 5HT in mononuclear cells from the control group, but not in their lymphocytes. This effect on mononuclear cells was reduced by the antagonist of 5HT1A receptors, WAY-100,135. However, the simultaneous addition of a specific agonist of 5HT1A receptors, 8-hydroxy-(dipropylamino)tetralin (DPAT) and WAY-100,135 resulted in higher levels of cAMP than with the agonist alone. This effect probably indicates the blockade of 5HT1A receptors and action of 5HT1A agonist on the other subtypes of serotonin receptors expressed on human lymphocytes. This response was not observed in the patient's lymphocytes. In lymphocytes from major depression patients, serotonin and 8-hydroxy-(dipropylamino)tetralin significantly increased cAmp levels, which was slightly reduced by WAY-100,135. The present report indicates: (1) differential responses of immune cells from control individuals and depressed patients, with lower apparent adenylate cyclase activity in patient's cells; (2) variation in the population of cells, with responses to serotonergic agonists being lower in mononuclear cells and higher in lymphocytes from major depression patients; (3) increases of cAMP levels by serotonin and 5HT1A agonist in the patient's cells; and (4) evidence of impairment in serotonergic transduction systems in immune cells during depression.

Mitochondrial DNA variants in a portuguese population of patients with Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder associated with dementia in late adulthood. Mitochondrial respiratory chain impairment has been detected in the brain, muscle, fibroblasts and platelets of AD patients, indicating a possible involvement of mitochondrial DNA (mtDNA) in the etiology of the disease. Several reports have identified mtDNA mutations in AD patients, but there is no consensual opinion regarding the cause of the impairment. We have studied mtDNA NADH dehydrogenase subunit 1 nucleotides 3337-3340, searching for mutations. Our study group included 129 AD patients and 125 healthy age-matched controls. We have found alterations in two AD patients: one had two already known mtDNA modifications (3197 T-C and 3338 T-C) and the other a novel transition (3199 T-C) which, to our knowledge, has not been described before.

Taurine concentration in human blood peripheral lymphocytes: major depression and treatment with the antidepressant mirtazapine

Major depression is a serious disease with various systemic effects, including dysfunction of the immune response. Taurine has been known to be related to certain modifications of the immune system. The aim of this study was to determine the taurine concentration in lymphocytes of patients with major depression and to evaluate the influence of the antidepressant treatment with mirtazapine for six weeks on the levels of taurine. Gamma-aminobutyric acid, aspartate, glutamate and glutamine were also determined. Taurine, aspartate and glutamine levels were increased in the lymphocytes of depressed patients before mirtazapine treatment compared to the control group, and were normalized after treatment. Gamma-aminobutyric acid and glutamate did not differ between patients and controls. There was a significant and positive correlation between the severity of the disorder, measured by the Hamilton Rating Scale, and the concentration of taurine in the lymphocytes of depressed patients before treatment. This correlation was not observed after treatment and neither was there a correlation observed for the other amino acids. The present observations could be an indication of the relevance of taurine as a protective agent in the lymphocytes of patients with severe depression, and could be the result of modifications of taurine transport or efflux processes.

Serotonin, serotonin 5-HT(1A) receptors and dopamine in blood peripheral lymphocytes of major depression patients

There are increasing evidences of cell markers present in the immune and the nervous systems. These include neurotransmitter receptors and transporters. Serotonin receptor subtypes are related to depression and also have been shown to be present in certain cells of the immune system. In the present report, we determined the presence of 5-HT(1A) receptors by the binding of the selective agonist 8-hydroxy-2-(di-n-propyl-amino)tetralin in lymphocytes of peripheral blood isolated by Ficoll/Hypaque gradients from controls and depressed patients. The capacity of these receptors was around 24 fmol/10(6) cells in both groups of subjects, without significant difference among them. The affinity was in the nM range and either differ between controls and patients. Serotonin, 5-hydroxyindoleacetic acid, dopamine and 3,4-dihydroxyphenylacetic acid were determined by HPLC with electrochemical detector. There were no significant differences between controls and major depression patients in the values obtained for rich and poor platelet plasma or in the isolated cells. However, there was a reduction in serotonin turnover rate indicated by an increase in the ratio serotonin/5-hydroxyindoleacetic acid, but not in that of dopamine, in lymphocytes of major depression patients. Thus, there is a serotonergic dysfunction in immune circulating cells of major depression patients, without changes in the number of 5-HT(1A) receptors, although the coupling of these receptors to transduction mechanisms could be affected and may be related to the alteration of 5-HT turnover rate.

Partial tetrasomy of chromosome 3q and mosaicism in a child with autism

In this report we describe the case of an 11-year-old male with autism and mental retardation, presenting a tetrasomy of chromosome 3q. Cytogenetic analysis showed a mosaic for an unbalanced karyotype consisting of mos46,XY,add(12)(p13.3)(56)/46,XY(45). FISH using WCP and subtelomeric probes identified the extra material on 12p to be an inverted duplication of the distal segment of chromosome 3q. Anomalies in chromosome 3q have not been previously described in association with autism, although association with psychomotor delays and behavior problems has been frequently reported and are here further discussed. This chromosomal 3q segment is therefore likely to include genes involved in specific neurodevelopment pathways, and further analysis of the region is warranted for the identification of the molecular alterations that lead to the autistic features described.

Serotonin, 5-hydroxyindoleacetic acid and serotonin transporter in blood peripheral lymphocytes of patients with generalized anxiety disorder

Several immune system modifications have been reported in pathological anxiety, such as generalized anxiety, panic and obsessive-compulsive disorders. Since serotonin transporter is a marker of peripheral blood lymphocytes and it is modified in major depression, the aim of the present work was to evaluate this transporter by the binding of [3H]paroxetine to membrane preparations of blood peripheral lymphocytes from control subjects and patients with generalized anxiety disorder. The number of transporters and the affinity for the ligand did not differ among the two groups. Serotonin and 5-hydroxyindoleacetic acid (5HIAA) were determined in platelet-rich and -poor plasma, and in lymphocytes. Nonsignificant changes were found in the patients as compared to controls. However, there was a significant positive correlation between serotonin concentration in platelet-poor plasma and in lymphocytes in the patients, but not in the controls. This finding might be an indication of a poor regulation of the transporter function by which serotonin plasma concentration might influence lymphocyte serotonin concentration. Previous results indicate that serotonin transporter is reduced in these cells in major depression disorder; however, in generalized anxiety disorder, the number of transporters was not modified, although the functional efficiency of serotonin transporter might be altered.

[3H]Paroxetine binding to human peripheral lymphocyte membranes of patients with major depression before and after treatment with fluoxetine

Serotonin has been involved in major depression and is also related to central and peripheral mechanisms of neuroimmunomodulation. Recently, the uptake of [3H]serotonin into human peripheral blood lymphocytes has been reported. We determined the density of serotonin uptake sites by the binding of [3H]paroxetine to blood peripheral lymphocyte membrane preparations of controls and of patients with major depression before and after treatment with fluoxetine for six weeks. The severity of depression was assessed by the use of Hamilton Rating Scale for Depression and of Beck Depression Inventory. There was a reduction in the number of sites for [3H]paroxetine in patients before administration of the antidepressant respecting controls, and a recovery after the treatment. Affinity was unchanged. No correlation was obtained between the severity of symptoms determined by Hamilton Rating Scale for Depression or by Beck Depression Inventory, and the number of binding sites for [3H]paroxetine. The levels of the plasma serotonin metabolite, 5-hydroxyindoleacetic acid, did not differ between the three groups of subjects, but serotonin was lower in patients after treatment respecting controls and in patients before treatment. The significant correlation between specific binding of [3H]paroxetine and plasma serotonin levels in controls was not present in the patients. Lymphocyte serotonin transporter is decreased in major depressed patients and is modulated by antidepressant treatment. In addition of counting with a peripheral marker in depression, the study of serotonin system in lymphocytes might contribute to understand the bi-directional interaction between the nervous and the immune systems.