Decoys provide a scalable platform for the identification of plant E3 ubiquitin ligases that regulate circadian function.

The circadian clock relies on regulated degradation of clock proteins to maintain rhythmicity. Despite this, we know few components that mediate protein degradation. This is due to high levels of functional redundancy within plant E3 ubiquitin ligase families. In order to overcome this issue and discover E3 ubiquitin ligases that control circadian function, we generated a library of transgenic Arabidopsis plants expressing dominant-negative 'decoy' E3 ubiquitin ligases. We determined their effects on the circadian clock and identified dozens of new potential regulators of circadian function. To demonstrate the potency of the decoy screening methodology to overcome redundancy and identify bona fide clock regulators, we performed follow-up studies on MAC3A (PUB59) and MAC3B (PUB60). We show that they redundantly control circadian period by regulating splicing. This work demonstrates the viability of ubiquitin ligase decoys as a screening platform to overcome genetic challenges and discover E3 ubiquitin ligases that regulate plant development.

Glucose metabolism dysregulation at the onset of mental illness is not limited to first episode psychosis: A systematic review and meta-analysis.

AIM: To compare the differences of glucose metabolism outcomes between treatment-naïve, patients with first episode psychosis (FEP) and mood disorders. METHODS: We conducted a systematic review and meta-analysis of glucose intolerance in treatment-naïve, first episode patients with severe mental illnesses (SMIs). RESULTS: We identified 31 eligible studies. Compared to healthy controls, FEP group have higher insulin and insulin resistance levels, and both groups have higher glucose tolerance test results. No significant differences were found in glucose metabolism outcomes between FEP and mood disorder groups. CONCLUSIONS: Our results highlight impaired glucose metabolism at the onset of SMIs, suggesting both patients with psychosis and mood disorders are high-risk groups for diabetes development.

How accurate are self-reported height and weight in the seriously mentally ill?

AIMS: (1) Determine the accuracy of self-reported height, weight, and body mass index (BMI) calculated from those values in a population suffering from both serious mental illness (SMI) and overweight/obesity; (2) identify any associations that may predict error in self-reported measurements. Data were collected from screening appointments for two clinical trials for adult patients with SMI and overweight/obesity (BMI > 28) who gained weight while on antipsychotic medications. Both studies were conducted at the same urban community mental health center. Differences in self-reported and measured height, weight, and BMI were calculated. Analysis included age, sex, race, psychiatric diagnosis, and level of education. BMI calculated from self-reported height and weight were significantly lower (-0.47kg/m2) than measured values. Height was significantly overestimated (1.04cm), while weight was underestimated (0.055kg). Men underestimated BMI more than women (0.55 vs. 0.41kg/m2). Increasing age correlated with lower accuracy of self-reported height and BMI. No differences due to psychiatric diagnosis, race, or education were found. BMI calculated from self-reported height and weight from patients with SMI and overweight/obesity is as accurate as the self-reported measurements collected from the general population and, while measurement is best, self-reports can be used as a tool for screening for obesity.

Biological impact of xeno-free chemically defined cryopreservation medium on amniotic epithelial cells.

BACKGROUND: Amnion-derived stem cells have been proposed for cell replacement therapy and tissue regeneration. An easily accessible cell source, the placenta, allows us to potentially establish a bio-bank of cells for immunotype matched clinical applications. Several xeno-free (XF) cryopreservation media are currently available for pluripotent stem cells, however, these media have not yet been evaluated for the cryopreservation of amnion-derived stem cells. METHODS: Human amniotic epithelial cells were collected using standard protocols, and stored at -160 °C in one of five commercially available media. Cells frozen in standard media containing fetal bovine serum served as controls. Cells were then thawed, and evaluated for viability, mitochondrial membrane stability, and senescence status. Quantitative real time PCR was utilized to assess for expression of stem cell genes, and flow cytometry was used to identify the stem cell surface markers. RESULTS: Cell recovery and repopulation assays indicated no significant difference between XF media versus standard cryopreservation medium. In addition, no impact was observed on the senescence status, the cytostructural or mitochondrial morphology between the tested cryopreservation media. Differences were observed on the expression of stem cell marker genes (OCT4, SOX2, and NANOG) and a cell surface marker (TRA1-60) following cryopreservation in different chemically defined XF media, however, these were not statistically significant. CONCLUSIONS: Xeno-free cryopreservation of human amnion-derived stem cells is feasible and can be standardized to establish a bio-bank with human amnion-derived stem cells for future clinical application. Optimization of this media may allow for improved preservation of stem cell-like characteristics.

GABAergic regulation of spontaneous spike patterns in the developing rabbit retina.

Spontaneous retinal waves play a critical role in the establishment of precise neuronal connections in the developing visual system. Retinal waves in mammals progress through three distinct developmental stages prior to eye opening. Using multielectrode array (MEA) recording from the rabbit retina, this study found characteristic changes in the spontaneous spike pattern in the ganglion cell layer during the transition from stage II to stage III retinal waves. These changes led to an increased diversity in the spatiotemporal pattern of the spontaneous activity, consistent with a potential role of stage III retinal waves in the establishment of diverse, cell type-specific neuronal connectivity during visual system development. The study also showed that GABAergic inhibition, predominantly mediated by GABAA receptors, was critical in breaking down large waves of ganglion cell spiking into spatially restricted and temporally diverse spike patterns at stage III, suggesting an important role of amacrine cells in shaping the diverse spontaneous activity patterns of developing ganglion cells.