Autoimmune regulator, Aire, is a novel regulator of chondrocyte differentiation

Chondrocyte differentiation is controlled by various regulators, such as Sox9 and Runx2, but the process is complex. To further understand the precise underlying molecular mechanisms of chondrocyte differentiation, we aimed to identify a novel regulatory factor of chondrocyte differentiation using gene expression profiles of micromass-cultured chondrocytes at different differentiation stages. From the results of microarray analysis, the autoimmune regulator, Aire, was identified as a novel regulator. Aire stable knockdown cells, and primary cultured chondrocytes obtained from Aire^−/− mice, showed reduced mRNA expression levels of chondrocyte-related genes. Over-expression of Aire induced the early stages of chondrocyte differentiation by facilitating expression of Bmp2. A ChIP assay revealed that Aire was recruited on an Airebinding site (T box) in the Bmp2 promoter region in the early stages of chondrocyte differentiation and histone methylation was modified. These results suggest that Aire can facilitate early chondrocyte differentiation by expression of Bmp2 through altering the histone modification status of the promoter region of Bmp2.     

Algicidal effects on Heterosigma akashiwo and Chattonella marina (Raphidophyceae), and toxic effects on natural plankton assemblages by a thiazolidinedione derivative TD49 in a microcosm

The algicidal effects of the thiazolidinedione derivative TD49 on Heterosigma akashiwo and Chattonella marina (Raphidophyceae) were assessed, and the response of the planktonic community and environment to the algicide was evaluated in a microcosm, quantifying 12 L. The abundance of over 80 % of H. akashiwo and C. marina declined in a day significantly in microcosms to which TD49 was added (final concentration 2 μM), and this was correlated with an abrupt decline in the culture pH. The number of protists (i.e., ciliates) other than H. akashiwo and C. marina gradually increased with time in the TD49 treatments, implying that the decline in numbers of H. akashiwo and C. marina cells resulting from TD49 treatment was a major factor in the growth of the other organisms. However, TD49 may be toxic to aquatic zooplankton communities, even though it is a highly selective algicide for harmful algae bloom species. The study indicates that TD49 is an effective agent for the control for H. akashiwo and C. marina blooms in enclosed and eutrophic water bodies.     

Newly discovered insect RNA viruses in China

Insects are a group of arthropods and the largest group of animals on Earth,with over one million species described to date.Like other life forms,insects suffer from viruses that cause disease and death.Viruses that are pathogenic to beneficial insects cause dramatic economic losses on agriculture.In contrast,viruses that are pathogenic to insect pests can be exploited as attractive biological control agents.All of these factors have led to an explosion in the amount of research into insect viruses in recent years,generating impressive quantities of information on the molecular and cellular biology of these viruses.Due to the wide variety of insect viruses,a better understanding of these viruses will expand our overall knowledge of their virology.Here,we review studies of several newly discovered RNA insect viruses in China.     

Aging Dogs Manifest Myopia as Measured by Autorefractor

Objective

Dogs, like humans, experience eye changes with aging: hardening and clouding of the lens and accumulated oxidative damage from UV sunlight. It has been debated whether such changes could be affecting the visual function of dogs. The objective of this study was to determine if autorefractometry could be used to measure visual function in dogs.

Animals and Methods

Nine Beagle dogs (ages 1 to 14 years) were examined by a veterinary ophthalmologist and their eyes determined to be free of cataracts. Spherical equivalent refractive error was measured by handheld autorefractor (Welch Allyn SureSight) under both indirect and direct lighting conditions with five measurements per condition, per eye. Measures were repeated on three different days for each dog within six weeks. Nonparametric statistics were used to detect differences among lighting conditions and test days, and between eyes. Spearmen correlation assessed the visual measurement outcomes’ association with age.

Results

There was no difference for day-to-day or between-eye measurements. Significantly, the Beagles showed a myopic shift with aging (average spherical equivalent ranged from plano to -3.00 diopters), suggesting that dogs become more near-sighted as they age (r = -0.48 and -0.73 under direct and indirect lights; p<0.05 both). Younger dogs were able to make larger accommodation changes from indirect light to direct light conditions, indicating a more flexible lens (r = -0.50, p<0.05).

Conclusions

Although designed for humans, the hand-held autorefractor technique is applicable to dogs and sensitive to light conditions. The age-associated myopic shift could be expected to compromise dogs’ visual functions.     

Monocyte Trafficking,Engraftment, and Delivery of Nanoparticles and an Exogenous Gene into the Acutely Inflamed Brain Tissue – Evaluations on Monocyte-Based Delivery System for the Central Nervous System

The ability of monocytes and monocyte-derived macrophages (MDM) to travel towards chemotactic gradient, traverse tissue barriers, and accumulate precisely at diseased sites makes them attractive candidates as drug carriers and therapeutic gene delivery vehicles targeting the brain, where treatments are often hampered by the blockade of the blood brain barrier (BBB). This study was designed to fully establish an optimized cell-based delivery system using monocytes and MDM, by evaluating their homing efficiency, engraftment potential, as well as carriage and delivery ability to transport nano-scaled particles and exogenous genes into the brain, following the non-invasive intravenous (IV) cell adoptive transfer in an acute neuroinflammation mouse model induced by intracranial injection of Escherichia coli lipopolysaccharides. We demonstrated that freshly isolated monocytes had superior inflamed-brain homing ability over MDM cultured in the presence of macrophage colony stimulating factor. In addition, brain trafficking of IV infused monocytes was positively correlated with the number of adoptive transferred cells, and could be further enhanced by transient disruption of the BBB with IV administration of Mannitol, Bradykinin or Serotonin right before cell infusion. A small portion of transmigrated cells was detected to differentiate into IBA-1 positive cells with microglia morphology in the brain. Finally, with the use of superparamagnetic iron oxide nanoparticles SHP30, the ability of nanoscale agent-carriage monocytes to enter the inflamed brain region was validated. In addition, lentiviral vector DHIV-101 was used to introduce green fluorescent protein (GFP) gene into monocytes, and the exogenous GFP gene was detected in the brain at 48 hours following IV infusion of the transduced monocytes. All together, our study has set up the optimized conditions for the more-in-depth tests and development of monocyte-mediated delivery, and our data supported the notion to use monocytes as a non-invasive cell-based delivery system for the brain.     

Combined Single-Cell Profiling of lncRNAs and Functional Screening Reveals that H19 Is Pivotal for Embryonic Hematopoietic Stem Cell Development

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Different responses of avian feeding guilds to spatial and environmental factors across an elevation gradient in the central Himalaya

Although elevational patterns of species richness have been well documented, how the drivers of richness gradients vary across ecological guilds has rarely been reported. Here, we examined the effects of spatial factors (area and mid‐domain effect; MDE) and environmental factors, including metrics of climate, productivity, and plant species richness on the richness of breeding birds across different ecological guilds defined by diet and foraging strategy. We surveyed 12 elevation bands at intervals of 300 m between 1,800 and 5,400 m a.s.l using line‐transect methods throughout the wet season in the central Himalaya, China. Multiple regression models and hierarchical partitioning were used to assess the relative importance of spatial and environmental factors on overall bird richness and guild richness (i.e., the richness of species within each guild). Our results showed that richness for all birds and most guilds displayed hump‐shaped elevational trends, which peaked at an elevation of 3,300–3,600 m, although richness of ground‐feeding birds peaked at a higher elevation band (4,200–4,500 m). The Normalized Difference Vegetation Index (NDVI)—an index of primary productivity—and habitat heterogeneity were important factors in explaining overall bird richness as well as that of insectivores and omnivores, with geometric constraints (i.e., the MDE) of secondary importance. Granivore richness was not related to primary production but rather to open habitats (granivores were negatively influenced by habitat heterogeneity), where seeds might be abundant. Our findings provide direct evidence that the richness–environment relationship is often guild‐specific. Taken together, our study highlights the importance of considering how the effects of environmental and spatial factors on patterns of species richness may differ across ecological guilds, potentially leading to a deeper understanding of elevational diversity gradients and their implications for biodiversity conservation.     

dXNP, a Drosophila homolog of XNP/ATRX, induces apoptosis via Jun-N-terminal kinase activation

XNP/ATRX, a causative gene of X-linked alpha-thalassemia/mental retardation syndrome, encodes an SNF2 family ATPase/helicase protein. To better understand the role of XNP/ATRX in development, we isolated and characterized a Drosophila XNP/ATRX homolog, dXNP, which contains highly conserved SNF2 and helicase domains. Ectopically expressed dXNP induced strong apoptosis in the developing eye and wing, but did not affect cell cycle progression or the expression of wingless and engrailed, essential regulators of development. The dXNP-induced apoptosis was strongly suppressed by DJNKK/hemipterous mutation, and dXNP increased JNK activity. Taken together, these results suggest that dXNP regulates apoptosis via JNK activation.