17α-Oestradiol-induced neuroprotection in the brain of spontaneously hypertensive rats

17β-oestradiol is a powerful neuroprotective factor for the brain abnormalities of spontaneously hypertensive rats (SHR). 17α-Oestradiol, a nonfeminising isomer showing low affinity for oestrogen receptors, is also endowed with neuroprotective effects in vivo and in vitro. We therefore investigated whether treatment with 17α-oestradiol prevented pathological changes of the hippocampus and hypothalamus of SHR. We used 20-week-old male SHR with a blood pressure of approximately 170 mmHg receiving s.c. a single 800 μg pellet of 17α-oestradiol dissolved in cholesterol or vehicle only for 2 weeks Normotensive Wistar-Kyoto (WKY) rats were used as controls. 17α-Oestradiol did not modify blood pressure, serum prolactin, 17β-oestradiol levels or the weight of the testis and pituitary of SHR. In the brain, we analysed steroid effects on hippocampus Ki67+ proliferating cells, doublecortin (DCX) positive neuroblasts, glial fibrillary acidic protein (GFAP)+ astrocyte density, aromatase immunostaining and brain-derived neurotrophic factor (BDNF) mRNA. In the hypothalamus, we determined arginine vasopressin (AVP) mRNA. Treatment of SHR with 17α-oestradiol enhanced the number of Ki67+ in the subgranular zone and DCX+ cells in the inner granule cell layer of the dentate gyrus, increased BDNF mRNA in the CA1 region and gyrus dentatus, decreased GFAP+ astrogliosis in the CA1 subfield, and decreased hypothalamic AVP mRNA. Aromatase expression was unmodified. By contrast to SHR, normotensive WKY rats were unresponsive to 17α-oestradiol. These data indicate a role for 17α-oestradiol as a protective factor for the treatment of hypertensive encephalopathy. Furthermore, 17α-oestradiol is weakly oestrogenic in the periphery and can be used in males.

Wage -specific assessment of mammography screening in Brazilian women

OBJECTIVE

Mammography is an inexpensive examination that has become a standard screening method thanks to its cost-effectiveness. Due to an enormous cost escalation of cancer treatment over the last years, the assessment of this method, especially in the settings of an emerging country, is a matter of serious concern.

METHODS

A search within the national health database was conducted registering the data with nation- wide coverage. Data collection and analysis was commenced in 2010 with referrence to the year 2008 as the most recently updated period. The obtained information on mammography screening among Brazilian women was evaluated by subdividing the data in four groups according to socioeconomic status of the subjects. The study population was estimated to comprise about 2 million individuals.

RESULTS

More than 45% of Brazilian women older than 40 years of age have never undergone a mammography. The figures correlated with the income level, reaching an astonishing number of 62.2% in a group of patients with the lowest income level.

CONCLUSION

Mammography has proved effective in early detection of breast cancer in women. This study suggests that the lack of compliance in breast cancer screening in Brazil, pronounced especially in low- income families, may contribute to the increasing mortality rates associated with the disease.

The anatomy of a scientific rumor

The announcement of the discovery of a Higgs boson-like particle at CERN will be remembered as one of the milestones of the scientific endeavor of the 21(st) century. In this paper we present a study of information spreading processes on Twitter before, during and after the announcement of the discovery of a new particle with the features of the elusive Higgs boson on 4(th) July 2012. We report evidence for non-trivial spatio-temporal patterns in user activities at individual and global level, such as tweeting, re-tweeting and replying to existing tweets. We provide a possible explanation for the observed time-varying dynamics of user activities during the spreading of this scientific "rumor". We model the information spreading in the corresponding network of individuals who posted a tweet related to the Higgs boson discovery. Finally, we show that we are able to reproduce the global behavior of about 500,000 individuals with remarkable accuracy.

Progesterone attenuates several hippocampal abnormalities of the Wobbler mouse

It is now recognised that progesterone plays a protective role for diseases of the central nervous system. In the Wobbler mouse, a model of motoneurone degeneration, progesterone treatment prevents spinal cord neuropathology and clinical progression of the disease. However, neuropathological and functional abnormalities have also been discovered in the brain of Wobbler mice and patients with amyotrophic lateral sclerosis. The present study examined the hippocampus of control and afflicted Wobbler mice and the changes in response to progesterone treatment. Mice received either a single progesterone implant (20 mg for 18 days). We found that the hippocampal pathology of the untreated Wobblers involved a decreased expression of brain-derived neurotrophic factor (BDNF) mRNA, decreased astrogliosis in the stratum lucidum, stratum radiatum and stratum lacunosum-moleculare, decreased doublecortin (DCX)-positive neuroblasts in the subgranular zone of the dentate gyrus and a decreased density of GABA immunoreactive hippocampal interneurones and granule cells of the dentate gyrus. Although progesterone did not change the normal parameters of control mice, it attenuated several hippocampal abnormalities in Wobblers. Thus, progesterone increased hippocampal BDNF mRNA expression, decreased glial fibrillary acidic protein-positive astrocytes and increased the number of GABAergic interneurones and granule cells. The number of DCX expressing neuroblasts and immature neurones remained impaired in both progesterone-treated and untreated Wobblers. In conclusion, progesterone treatment exerted beneficial effects on some aspects of hippocampal neuropathology, suggesting its neuroprotective role in the brain, in agreement with previous data obtained in the spinal cord of Wobbler mice.

Increased expression of the mineralocorticoid receptor in the brain of spontaneously hypertensive rats

The mineralocorticoid receptor (MR) has been considered as both neuroprotective and damaging to the function of the central nervous system. MR may be also involved in central regulation of blood pressure. In the present study, we compared the expression of MR and the glucocorticoid receptor (GR) in the hippocampus and hypothalamus of 16-week-old spontaneously hypertensive rats (SHR) and normotensive control Wistar Kyoto (WKY) rats. In the hippocampus, MR expression was studied by in situ hybridization (ISH), quantitative polymerase chain reaction (PCR) and immunohistochemistry, whereas GR expression was analysed using the latter two procedures. Hypertensive animals showed an increased expression of MR mRNA in the whole hippocampus according to qPCR data and also in CA3 by ISH. Immunocytochemical staining for MR of the dorsal hippocampus, however, did not reveal differences between SHR and WKY rats. SHR showed elevated hypothalamic MR mRNA by qPCR, as well as an increased number of MR immunopositive cells in the magnocellular paraventricular region, compared to WKY rats. By contrast, expression levels of GR mRNA or protein in the hippocampus and hypothalamus of SHR were similar to those of WKY rats. Furthermore, we investigated the role of MR in the hypertensive rats by i.c.v. injection of the MR antagonist RU-2831. This compound produced a significant drop in blood pressure for SHR. In conclusion, MR expression is increased in the hippocampus and hypothalamus of SHR. We suggest that pathological MR overdrive may take responsibility for up-regulation of blood pressure and the encephalopathy of hypertension.

213 TRANSCRIPTOMIC COMPARISON BETWEEN PORCINE ADIPOSE AND BONE MARROW MESENCHYMAL STEM CELLS DURING IN VITRO OSTEOGENIC AND ADIPOGENIC DIFFERENTIATION

Previous data support the use of adipose-derived stem cells (ASC) as an alternative to bone marrow as a source of adult stem cells for therapeutic purposes. The aims of the present study were to directly compare the transcriptome of ASC and bone marrow-derived mesenchymal stem cells (BMSC) in order to uncover potential functional differences between the two mesenchymal stem cells (MSC), to identify differentially expressed genes (DEG) and related functions that may drive MSC to become bone or adipose and to identify potential markers for adipogenic and osteogenic differentiation. ASC and BMSC, isolated from subcutaneous adipose tissue and femurs of 3 adult pigs were differentiated in vitro along the osteogenic and adipogenic lineage for up to 4 wk. At 0, 2, 7 and 21 days of differentiation, RNA was extracted for microarray analysis. Data were normalized by Lowess and statistical analysis run using ANOVA with Benjamini-Hochberg false discovery rate (FDR) correction. Data mining was carried out using Ingenuity Pathway Analysis and DAVID. Analysis of undifferentiated MSC for genes with the highest expression and DEG between MSC and fully differentiated tissues uncovered MSC being featured by low immunity and high angiogenic capacity. The direct comparison between differentiation lineages indicated that the expression of a limited number of genes has to change in order to determine cell fate. Functional analysis of the DEG between differentiation lineages indicated that osteogenesis is characterised by larger cell proliferation and cytoskeleton organisation with a crucial role of G-proteins compared to adipogenesis. On the other hand, adipogenesis is driven by PPAR signalling, has greater angiogenesis, lipid metabolism, migration and tumorigenesis capacity compared to osteogenesis. The direct comparison between ASC and BMSC during the same differentiation uncovered that ASC is featured by a greater lipid metabolism compared to BMSC, while BMSC has a more pronounced cell growth and proliferation than ASC. In addition, we uncovered 39 specific gene markers for adipogenesis and 65 for osteogenesis. NAD(P)H dehydrogenase quinone 1 (NQO1), aquaporin 3 (AQP3), stearoyl-CoA desaturase (SCD), fatty acid binding protein 3 and 5 (FABP3 and FABP5) and ferritin light polypeptide (FTL) were among the best adipogenic markers. Hemopexin (HPX), collagenase type 3α (COL3A1), annexin A8-like 1 (ANXA8L1), flotillin 2 (FLOT2) and periostin or osteoblast specific factor (POSTN) were among the best osteogenic markers. Overall, the data indicated that the transcriptome of the two MSC are similar across the conditions studied. In addition, despite the limited DEG between the two MSC, the enrichment of several functions/pathways might indicate differences in therapeutic application. This work was support by the Illinois Regenerative Medicine Institute (IDPH # 63080017).

314 ADIPOSE- AND BONE MARROW-DERIVED MESENCHYMAL STEM CELLS PRESENT LARGE SIMILARITIES IN TRANSCRIPTOME PRIOR TO AND DURING ADIPOGENIC AND OSTEOGENIC DIFFERENTIATION

Previous data support adipose-derived stem cells as an alternative to bone marrow as a source of adult stem cells for therapeutic purposes. The aim of the present study was to directly compare the transcriptome of adipose-derived (ADSC) and bone marrow-derived (BMSC) mesenchymal stem cells prior to differentiation and during in vitro osteogenic and adipogenic differentiation. The ADSC and BMSC were harvested from 3 adult pigs and differentiated in vitro into adipocytes and osteocytes for up to 4 weeks. Prior to differentiation and at differentiation day 2, 7, and 21, cells were harvested and RNA extracted for transcriptomics analysis by a 13 263 oligo 70-mers array (Sus scrofa AROS V1.0 with extension; Operon). Data were normalized by Lowess and statistical analysis was run using ANOVA with Benjamini-Hochberg false discovery rate (FDR) correction. Data mining was carried out using Ingenuity Pathway Analysis and David. Using an FDR of <0.05 for overall tissue effect and a post-hoc correction of P < 0.001, we observed 65 differentially expressed genes (DEG) between ADSC and BMSC before starting differentiation (0.66% of unique genes in the array). Functional analysis uncovered significant enrichment of extracellular matrix genes with direct roles in cell adhesion, migration, movement, and morphology. When the interaction cell type × differentiation × time was assessed, we observed >2 000 DEG with an FDR <0.05. This large number was mostly due to time effects. When pair-wise comparisons between cell types for each time point during the same differentiation were performed (post-hoc P < 0.001), we observed a strikingly low number of DEG. The number of DEG was lower between cell types in osteogenic (<100 DEG) compared with adipogenic (<200 DEG) differentiation. We observed significant enrichment (FDR-corrected P-value cut-off <0.05) of functions related to metabolism, antigen presentation, angiogenesis, and cell cycle in both differentiation conditions. We also observed an overall greater induction of the enriched functions in ADSC and a decrease in BMSC during adipogenic differentiation and the opposite during osteogenic differentiation except for metabolism, which appeared to be larger in ADSC in all cases. Among the significant enriched functions of DEG between the 2 differentiations, we observed enrichment of genes involved in metabolism, cell death, cell-to-cell signalling, and antigen presentation in ADSC during adipogenic compared with osteogenic differentiation. In BMSC we observed enrichment of functions related to cell death, antigen presentation, and lipid metabolism in osteogenic v. adipogenic differentiation. Overall data uncovered a high similarity at the transcriptional level between ADSC and BMSC both prior to differentiation and during differentiation. Those data support ADSC being particularly similar to BMSC. This work was support by the Illinois Regenerative Medicine Institute (IDPH # 63080017).

Involvement of brain-derived neurotrophic factor and neurogenesis in oestradiol neuroprotection of the hippocampus of hypertensive rats

The hippocampus of spontaneously hypertensive rats (SHR) and deoxycorticosterone (DOCA)-salt hypertensive rats shows decreased cell proliferation and astrogliosis as well as a reduced number of hilar cells. These defects are corrected after administration of 17β-oestradiol (E(2) ) for 2 weeks. The present work investigated whether E(2) treatment of SHR and of hypertensive DOCA-salt male rats modulated the expression of brain-derived neurotrophic factor (BDNF), a neurotrophin involved in hippocampal neurogenesis. The neurogenic response to E(2) was simultaneously determined by counting the number of doublecortin-immunopositive immature neurones in the subgranular zone of the dentate gyrus. Both hypertensive models showed decreased expression of BDNF mRNA in the granular zone of the dentate gyrus, without changes in CA1 or CA3 pyramidal cell layers, decreased BDNF protein levels in whole hippocampal tissue, low density of doublecortin (DCX)-positive immature neurones in the subgranule zone and decreased length of DCX+ neurites in the dentate gyrus. After s.c. implantation of a single E(2) pellet for 2 weeks, BDNF mRNA in the dentate gyrus, BDNF protein in whole hippocampus, DCX immunopositive cells and the length of DCX+ neurites were significantly raised in both SHR and DOCA-salt-treated rats. These results indicate that: (i) low BDNF expression and deficient neurogenesis distinguished the hippocampus of SHR and DOCA-salt hypertensive rats and (ii) E(2) was able to normalise these biologically important functions in the hippocampus of hypertensive animals.