Ovarian hormones modulate 'compulsive' lever-pressing in female rats

Life events related to the female hormonal cycle may trigger the onset of obsessive-compulsive disorder (OCD) or exacerbate symptoms in women already suffering from it. These observations suggest a possible role for ovarian hormones in the course of this disorder. Yet, the mechanisms that may subserve the modulatory effect of ovarian hormones are currently unknown. The aim of the present study was therefore to test the role of ovarian hormones in the signal attenuation rat model of OCD. Experiment 1 compared the behavior of pre-pubertal and adult male and female rats in the model, and found no age and sex differences in compulsive responding. Experiment 2 found that compulsive responding fluctuates along the estrous cycle, being highest during late diestrous and lowest during estrous. Acute administration of estradiol to pre-pubertal female rats was found to attenuate compulsive behavior (Experiment 3), and withdrawal from chronic administration of estradiol was shown to increase this behavior (Experiment 4). These findings extend the use of the signal attenuation model of OCD to female rats, and by demonstrating that the model is sensitive to the levels of ovarian hormones, provide the basis for using the model to study the role of ovarian hormones in OCD. In addition, the present findings support the hypothesis that the increased risk of onset and exacerbation of OCD in women post-partum may be a result of the decrease in the level of estradiol, which was elevated during pregnancy.     

SOBP is mutated in syndromic and nonsyndromic intellectual disability and is highly expressed in the brain limbic system

Intellectual disability (ID) affects 1%-3% of the general population. We recently reported on a family with autosomal-recessive mental retardation with anterior maxillary protrusion and strabismus (MRAMS) syndrome. One of the reported patients with ID did not have dysmorphic features but did have temporal lobe epilepsy and psychosis. We report on the identification of a truncating mutation in the SOBP that is responsible for causing both syndromic and nonsyndromic ID in the same family. The protein encoded by the SOBP, sine oculis binding protein ortholog, is a nuclear zinc finger protein. In mice, Sobp (also known as Jxc1) is critical for patterning of the organ of Corti; one of our patients has a subclinical cochlear hearing loss but no gross cochlear abnormalities. In situ RNA expression studies in postnatal mouse brain showed strong expression in the limbic system at the time interval of active synaptogenesis. The limbic system regulates learning, memory, and affective behavior, but limbic circuitry expression of other genes mutated in ID is unusual. By comparing the protein content of the +/jc to jc/jc mice brains with the use of proteomics, we detected 24 proteins with greater than 1.5-fold differences in expression, including two interacting proteins, dynamin and pacsin1. This study shows mutated SOBP involvement in syndromic and nonsyndromic ID with psychosis in humans.     

Permanent Occlusion of Feeding Arteries and Draining Veins in Solid Mouse Tumors by Vascular Targeted Photodynamic Therapy (VTP) with Tookad

Background

Antiangiogenic and anti-vascular therapies present intriguing alternatives to cancer therapy. However, despite promising preclinical results and significant delays in tumor progression, none have demonstrated long-term curative features to date. Here, we show that a single treatment session of Tookad-based vascular targeted photodynamic therapy (VTP) promotes permanent arrest of tumor blood supply by rapid occlusion of the tumor feeding arteries (FA) and draining veins (DV), leading to tumor necrosis and eradication within 24–48 h.

Methodology/Principal Findings

A mouse earlobe MADB106 tumor model was subjected to Tookad-VTP and monitored by three complementary, non-invasive online imaging techniques: Fluorescent intravital microscopy, Dynamic Light Scattering Imaging and photosensitized MRI. Tookad-VTP led to prompt tumor FA vasodilatation (a mean volume increase of 70%) with a transient increase (60%) in blood-flow rate. Rapid vasoconstriction, simultaneous blood clotting, vessel permeabilization and a sharp decline in the flow rates then followed, culminating in FA occlusion at 63.2 sec±1.5SEM. This blockage was deemed irreversible after 10 minutes of VTP treatment. A decrease in DV blood flow was demonstrated, with a slight lag from FA response, accompanied by frequent changes in flow direction before reaching a complete standstill. In contrast, neighboring, healthy tissue vessels of similar sizes remained intact and functional after Tookad-VTP.

Conclusion/Significance

Tookad-VTP selectively targets the tumor feeding and draining vessels. To the best of our knowledge, this is the first mono-therapeutic modality that primarily aims at the larger tumor vessels and leads to high cure rates, both in the preclinical and clinical arenas.     

PREDICT modeling and in-silico screening for G-protein coupled receptors

G-protein coupled receptors (GPCRs) are a major group of drug targets for which only one x-ray structure is known (the nondrugable rhodopsin), limiting the application of structure-based drug discovery to GPCRs. In this paper we present the details of PREDICT, a new algorithmic approach for modeling the 3D structure of GPCRs without relying on homology to rhodopsin. PREDICT, which focuses on the transmembrane domain of GPCRs, starts from the primary sequence of the receptor, simultaneously optimizing multiple 'decoy' conformations of the protein in order to find its most stable structure, culminating in a virtual receptor-ligand complex. In this paper we present a comprehensive analysis of three PREDICT models for the dopamine D2, neurokinin NK1, and neuropeptide Y Y1 receptors. A shorter discussion of the CCR3 receptor model is also included. All models were found to be in good agreement with a large body of experimental data. The quality of the PREDICT models, at least for drug discovery purposes, was evaluated by their successful utilization in in-silico screening. Virtual screening using all three PREDICT models yielded enrichment factors 9-fold to 44-fold better than random screening. Namely, the PREDICT models can be used to identify active small-molecule ligands embedded in large compound libraries with an efficiency comparable to that obtained using crystal structures for non-GPCR targets.     

Ultrastructural evidences of HCV infection in hepatocytes of chronically HCV-infected patients

In this study, 13 samples of liver biopsies from patients with chronic hepatitis C were studied by transmission electron microscopy (EM) and immunoelectron microscopy (IEM). The 13 biopsies showed ultrastructural cell damage typical of acute viral hepatitis. In four of the 13 liver biopsies enveloped virus-like particles (VLPs) inside cytoplasmic vesicles and in the cytoplasm of hepatocytes were observed. We also detected the presence of unenveloped VLPs mainly in the cytoplasm and in the endoplasmic reticulum. IEM using anti-core, E1 and E2 monoclonal antibodies (mAbs) confirmed the specific localization of these proteins, in vivo, inside cytoplasm and endoplasmic reticulum. Thus, this work provided evidence for hepatocellular injury related to HCV infection. It also suggested the presence of HCV-related replicating structures in the cytoplasm of hepatocytes and raised the possibility of hepatitis C virion morphogenesis in intracellular vesicles.     

Transgenic mice engineered to target Cre/loxP-mediated DNA recombination into catecholaminergic neurons

To introduce restricted DNA recombination events into catecholaminergic neurons using the Cre/loxP technology, we generated transgenic mice carrying the Cre recombinase gene driven by a 9 kb rat tyrosine hydroxylase (TH) promoter. Immunohistochemistry performed on transgenic mouse brain sections revealed a high number of cells expressing Cre in areas where TH is normally expressed, including the olfactory bulb, hypothalamic and midbrain dopaminergic neurons, and the locus coeruleus. Double immunohistochemistry and immunofluorescence indicated that colocalization of TH and Cre is greater than 80%. Cre expression was also found in TH-positive amacrine neurons of the retina, chromaffin cells of the adrenal medulla, and sympathetic ganglia. We crossbred TH-Cre mice with the floxed reporter strain Z/AP and observed efficient Cre-mediated recombination in all areas expressing TH, indicating that transgenic Cre is functional. Therefore, we have generated a valuable transgenic mouse strain to induce specific mutations of "floxed" genes in catecholaminergic neurons.     

Nodule initiation involves the creation of a new symplasmic field in specific root cells of medicago species

The organogenesis of nitrogen-fixing nodules in legume plants is initiated in specific root cortical cells and regulated by long-distance signaling and carbon allocation. Here, we explore cell-to-cell communication processes that occur during nodule initiation in Medicago species and their functional relevance using a combination of fluorescent tracers, electron microscopy, and transgenic plants. Nodule initiation induced symplasmic continuity between the phloem and nodule initials. Macromolecules such as green fluorescent protein could traffic across short or long distances from the phloem into these primordial cells. The created symplasmic field was regulated throughout nodule development. Furthermore, Medicago truncatula transgenic plants expressing a viral movement protein showed increased nodulation. Hence, the establishment of this symplasmic field may be a critical element for the control of nodule organogenesis.     

A missense mutation in the LIM2 gene is associated with autosomal recessive presenile cataract in an inbred Iraqi Jewish family

In an inbred Iraqi Jewish family, we have studied three siblings with presenile cataract first noticed between the ages of 20 and 51 years and segregating in an autosomal recessive mode. Using microsatellite repeat markers in close proximity to 25 genes and loci previously associated with congenital cataracts in humans and mice, we identified five markers on chromosome 19q that cosegregated with the disease. Sequencing of LIM2, one of two candidate genes in this region, revealed a homozygous T-->G change resulting in a phenylalanine-to-valine substitution at position 105 of the protein. To our knowledge, this constitutes the first report, in humans, of cataract formation associated with a mutation in LIM2. Studies of late-onset single-gene cataracts may provide insight into the pathogenesis of the more common age-related cataracts.