Interactions between neuroactive steroids and reelin haploinsufficiency in Purkinje cell survival.

We determined total Purkinje cell (PC) numbers in cerebella of wild-type (+/+) and heterozygous (rl/+) reeler mice of either sex during early postnatal development; in parallel, we quantified levels of neuroactive steroids in the cerebellum with mass spectrometry. We also quantified reelin mRNA and protein expression with RT-PCR and Western blotting. PC numbers are selectively reduced at postnatal day 15 (P15) in rl/+ males in comparison to +/+ males, +/+ females, and rl/+ females. Administration of 17beta-estradiol (17beta-E) into the cisterna magna at P5 increases PC numbers in rl/+ males, but not in the other groups; conversely, estrogen antagonists 4-OH-tamoxifen or ICI 182,780 reduce PC numbers in +/+ and rl/+ females, but have no effect in males. Testosterone (T) levels at P5 are much higher in males than in females, reflecting the perinatal testosterone surge in males. In addition, rl/+ male cerebella at P5 show a peculiar hormonal profile in comparison with the other groups, consisting of increased levels of T and 17beta-E, and decreased levels of dihydrotestosterone. RT-PCR analysis indicated that heterozygosity leads to a 50% reduction of reelin mRNA in the cerebellum in both sexes, as expected, and that 17beta-E upregulates reelin mRNA, particularly in rl/+ males; reelin mRNA upregulation is associated with an increase of all major reelin isoforms. These effects may represent a novel model of how reelin deficiency interacts with variable perinatal levels of neuroactive steroids, leading to gender-dependent differences in genetic vulnerability.

Impaired nerve regeneration in reeler mice after peripheral nerve injury.

Reelin, an extracellular matrix protein, plays an important role in the regulation of neuronal migration and cortical lamination in the developing brain. Little is known, however, about the role of this protein in axonal regeneration. We have previously shown that Reelin is secreted by Schwann cells in the peripheral nerve compartment during postnatal development and that it is up-regulated following nerve injury in adult mice. In this work, we generated mice deficient in Reelin (reeler) that express yellow fluorescent protein (YFP) in a subset of neurons and examined the axonal regeneration following nerve crush. We found that axonal regeneration was significantly altered compared with wild-type mice. By contrast, retrograde tracing with Fluorogold dye after sciatic nerve crush was unaffected in these mutants, being comparable with normal axonal transport observed in wild-type. These results indicate that the absence of Reelin impairs axonal regeneration following injury and support a role for this protein in the process of peripheral nerve regeneration.

Oncologist perspectives on chemotherapy-induced nausea and vomiting (CINV) management and outcomes: A quantitative market research-based survey.

BACKGROUND: Chemotherapy-induced nausea and vomiting (CINV) is a distressing side effect that can negatively impact patients' quality of life and could discourage completion of chemotherapy, thereby affecting overall treatment outcomes. Although adherence to antiemetic guidelines can reduce CINV incidence in patients receiving highly or moderately emetogenic chemotherapy, CINV control remains inadequate. AIMS: The objectives of this survey were to determine oncologists' practice patterns in CINV management, identify factors that contribute to antiemetic treatment failure, and determine the outcomes of uncontrolled CINV on health care resource utilisation and on patients' attitude towards chemotherapy. METHODS AND RESULTS: Quantitative market research was performed using an online questionnaire. Responses from 300 European oncologists who prescribe antiemetics and see ≥50 patients/month were analysed. Results showed that the main reasons reported by oncologists for antiemetic treatment failure were underestimating the emetogenic potential of chemotherapy, utilising weaker antiemetic regimens than required, and patient non-adherence because of administration mistakes or missed/delayed doses. Educational initiatives for the oncology multidisciplinary team may help improve guideline-consistent prescribing. Also, the availability of simpler, more convenient antiemetic therapies may improve guideline adherence and patient compliance during home administration. CONCLUSION: Achieving effective CINV control is a crucial goal to improve patients' quality of life, which should optimise chemotherapy outcomes, and would ultimately reduce health care costs.

A 3D model of Reelin subrepeat regions predicts Reelin binding to carbohydrates.

Reelin is a large molecule of the extracellular matrix (ECM) which regulates neuronal positioning during the early stages of cortical development in vertebrate species. The Reelin molecule can be subdivided into a smaller N-terminal domain, showing homology with F-spondin, and a larger C-terminal region containing 8 EGF-like repeats. The localization of Reelin in the ECM, its large dimensions and the modular organization of its primary structure led us to suppose a structure of its modules similar to domains commonly found in ECM proteins such as Agrin, laminins and thrombospondins. We therefore performed a sequence alignment and molecular modeling analysis to study the three-dimensional fold of the Reelin subrepeat regions. Our analysis produces a tentative model of the core region of the Reelin subrepeat sequences and suggests the presence in this 3D model of structural features common to polysaccharide-binding modules which are often found on proteoglycans of the ECM. These findings provide a conceptual framework for further experiments aimed at testing the functions of the EGF-like repeat regions of Reelin.

Reelin expression in human prostate cancer: a marker of tumor aggressiveness based on correlation with grade.

Reelin is a glycoprotein that plays a critical role in the regulation of neuronal migration during brain development and, since reelin has a role in the control of cell migration, it might represents an important factor in cancer pathology. In this study, 66 surgical specimens of prostate cancer were analyzed for reelin expression by immunohistochemical method. The reelin expression was correlated with Gleason score and individual Gleason patterns. Reelin expression was found in 39% prostate cancers. Stromal tissues, normal epithelial cells and prostate intraepithelial neoplasia (PIN) of any grade around and distant from cancer were always negative for reelin. Reelin was found in malignant prostatic epithelial glands of 50% cases Gleason score 10, 52% Gleason score 9, 56% Gleason score 8, 18% Gleason score 7, while no sample of prostate cancers with Gleason score 6 showed reelin expression (P=0,005). As reelin staining is frequently found in high Gleason score prostate cancers, we explored whether reelin expression is influenced by single Gleason patterns. While Gleason 3 pattern did not show reelin immunoreactivity, reelin expression was found in 35% Gleason 4 patterns and 45% Gleason 5 patterns (P<0.001). Our results demonstrated for the first time that reelin is expressed in prostate cancer and not in benign prostate tissue and its expression occurs in higher Gleason score and correlates significantly with increasing of single Gleason patterns. This suggests reelin may behave as a specific histological marker and may represent a useful biomarker to predict aggressive phenotypic behavior of prostatic cancer cells.

Reelin is transiently expressed in the peripheral nerve during development and is upregulated following nerve crush.

Reelin is an extracellular matrix protein which is critical for the positioning of migrating post-mitotic neurons and the laminar organization of several brain structures during development. We investigated the expression and localization of Reelin in the rodent peripheral nerve during postnatal development and following crush injury in the adult stage. As shown with Western blotting, immunocytochemistry and RT-PCR, Schwann cells in the developing peripheral nerve and in primary cultures from neonatal nerves produce and secrete Reelin. While Reelin levels are downregulated in adult stages, they are again induced following sciatic nerve injury. A morphometric analysis of sciatic nerve sections of reeler mice suggests that Reelin is not essential for axonal ensheathment by Schwann cells, however, it influences the caliber of myelinated axons and the absolute number of fibers per unit area. This indicates that Reelin may play a role in peripheral nervous system development and repair by regulating Schwann cell-axon interactions.