A Call to Standardize Teratoma Assays Used to Define Human Pluripotent Cell Lines

SummaryThe teratoma assay is the gold standard for documenting pluripotency of human stem cells. However, reports of new human ESC and iPSC lines vary widely in both methods and analysis of teratoma data. We call for consensus standards to be established to make this assay worthy of its “golden” status

Recovery of graphite and cathode active materials from spent lithium-ion batteries by applying two pretreatment methods and flotation combined with a rapid analysis technique

This work investigates the comprehensive recycling of graphite and cathode active materials (LiNi0.6Mn0.2Co0.2O2, abbreviated as NMC) from spent lithium-ion batteries via pretreatment and flotation. Specific analytical methods (SPME-GC-MS and Py-GC-MS) were utilized to identify and trace the relevant influencing factors. Two different pretreatment methods, which are Fenton oxidation and roasting, were investigated with respect to their influence on the flotation effectiveness. As a result, for NMC cathode active materials, a recovery of 90% and a maximum grade of 83% were obtained by the optimized roasting and flotation. Meanwhile, a graphite grade of 77% in the froth product was achieved, with a graphite recovery of 75%. By using SPME-GC-MS and Py-GC-MS analyses, it could be shown that, in an optimized process, an effective destruction/removal of the electrolyte and binder residues can be reached. The applied analytical tools could be integrated into the workflow, which enabled process control in terms of the pretreatment sufficiency and achievable separation in the subsequent flotation

Challenges and approaches in data management of LTE trials in tropical field sites: Experiences from two trials in India and Bolivia

Quality data is the key commodity of research projects. But with the size of a research project, number of parties involved and range of data collected, the complexity of data management increases significantly. In long-term experiments (LTE), continuity and comparability of collected data throughout the study duration is important but being challenged by personnel changes and development in infrastructure and technology, as well as changes to the trial itself. Managing a longterm trial remotely at field sites in the tropics adds another layer of challenges, including timely transfer of new data, time consuming pre-processing and validation of data between field and scientific staff, data literacy of local field staff and language barriers due to varying levels of English and local languages within the project team. We share our challenges in data management and the strategies and tools used in the context of two LTE trials with field sites in India and Bolivia, managed by local partner organizations and coordinated by the Research Institute of Organic Agriculture in Switzerland, highlighting the technical infrastructure in use, definition of responsibilities and workflows. Our main considerations are a) finding a balance between data security, easy and timely sharing of data in both directions and minimising number of different data repositories and file versions, b) the use of simple, well-known tools that are flexible enough to consider (evolving) needs of different involved parties including field staff, and c) the importance of quick data availability for analysis to serve as a basis for decision making in trial management

What is the contribution of organic agriculture to sustainable development? A synthesis of twelve years (2007-2019) of the “long-term farming systems comparisons in the tropics (SysCom)”

The SysCom Program compares different agricultural production systems (primarily organic and conventional) in three tropical countries (Kenya, India, and Bolivia). This report aims to provide a synthesis of the findings of 12 years of research in the three countries in a way that is easily comprehensible by specialists and non-specialist alike. It focuses on productivity, profitability, soil fertility, and other aspects of system performance such as product quality, biodiversity, resource use efficiency, and agroecosystem resilience. The report is divided into eight main sections: The first section, conclusions, addresses the findings with regards to the question, “What is the contribution of organic agriculture to sustainable development?”. This section is dedicated to the readers who are only interested in a short comprehensive overview of the results. The second section, the introduction, explains the program’s background and objectives. The following sections present the main findings on productivity, profitability, soil fertility, and other aspects of system performance. These sections start with a summary of the key findings, which are then explained in more detail on the concrete research results. They are designed for readers interested in an in-depth understanding of the facts behind inferences as well as the methodology. At the end of each subsection, references to the relevant scientific publications are provided for further reading. Technical jargon has been kept to a minimum and wherever possible explanations are provided in footnotes. The seventh section includes policy recommendations and offers sound advice for policy development. Finally, the annexes provide more information about the SysCom program, including the programs’ phases, a detailed description of the different sites and the local contexts, as well as SysCom’s capacity building and dissemination efforts

Early Microglia Activation Precedes Photoreceptor Degeneration in a Mouse Model of CNGB1-Linked Retinitis Pigmentosa

Retinitis pigmentosa (RP) denotes a family of inherited blinding eye diseases characterized by progressive degeneration of rod and cone photoreceptors in the retina. In most cases, a rod-specific genetic defect results in early functional loss and degeneration of rods, which is followed by degeneration of cones and loss of daylight vision at later stages. Microglial cells, the immune cells of the central nervous system, are activated in retinas of RP patients and in several RP mouse models. However, it is still a matter of debate whether activated microglial cells may be responsible for the amplification of the typical degenerative processes. Here, we used Cngb1(-/-) mice, which represent a slow degenerative mouse model of RP, to investigate the extent of microglia activation in retinal degeneration. With a combination of FACS analysis, immunohistochemistry and gene expression analysis we established that microglia in the Cngb1(-/-) retina were already activated in an early, predegenerative stage of the disease. The evidence available so far suggests that early retinal microglia activation represents a first step in RP, which might initiate or accelerate photoreceptor degeneration

A molecular atlas of cell types and zonation in the brain vasculature

Cerebrovascular disease is the third most common cause of death in developed countries, but our understanding of the cells that compose the cerebral vasculature is limited. Here, using vascular single-cell transcriptomics, we provide molecular definitions for the principal types of blood vascular and vessel-associated cells in the adult mouse brain. We uncover the transcriptional basis of the gradual phenotypic change (zonation) along the arteriovenous axis and reveal unexpected cell type differences: a seamless continuum for endothelial cells versus a punctuated continuum for mural cells. We also provide insight into pericyte organotypicity and define a population of perivascular fibroblast-like cells that are present on all vessel types except capillaries. Our work illustrates the power of single-cell transcriptomics to decode the higher organizational principles of a tissue and may provide the initial chapter in a molecular encyclopaedia of the mammalian vasculature.Peer reviewe

Recurrent somatic mutations in POLR2A define a distinct subset of meningiomas

RNA polymerase II mediates the transcription of all protein-coding genes in eukaryotic cells, a process that is fundamental to life. Genomic mutations altering this enzyme have not previously been linked to any pathology in humans, which is a testament to its indispensable role in cell biology. On the basis of a combination of next-generation genomic analyses of 775 meningiomas, we report that recurrent somatic p.Gln403Lys or p.Leu438_His439del mutations in POLR2A, which encodes the catalytic subunit of RNA polymerase II (ref. 1), hijack this essential enzyme and drive neoplasia. POLR2A mutant tumors show dysregulation of key meningeal identity genes including WNT6 and ZIC1/ZIC4. In addition to mutations in POLR2A, NF2, SMARCB1, TRAF7, KLF4, AKT1, PIK3CA, and SMO4 we also report somatic mutations in AKT3, PIK3R1, PRKAR1A, and SUFU in meningiomas. Our results identify a role for essential transcriptional machinery in driving tumorigenesis and define mutually exclusive meningioma subgroups with distinct clinical and pathological features

JIP2 haploinsufficiency contributes to neurodevelopmental abnormalities in human pluripotent stem cell–derived neural progenitors and cortical neurons

Phelan–McDermid syndrome (also known as 22q13.3 deletion syndrome) is a syndromic form of autism spectrum disorder and currently thought to be caused by heterozygous loss of SHANK3. However, patients most frequently present with large chromosomal deletions affecting several additional genes. We used human pluripotent stem cell technology and genome editing to further dissect molecular and cellular mechanisms. We found that loss of JIP2 (MAPK8IP2) may contribute to a distinct neurodevelopmental phenotype in neural progenitor cells (NPCs) affecting neuronal maturation. This is most likely due to a simultaneous down-regulation of c-Jun N-terminal kinase (JNK) proteins, leading to impaired generation of mature neurons. Furthermore, semaphorin signaling appears to be impaired in patient NPCs and neurons. Pharmacological activation of neuropilin receptor 1 (NRP1) rescued impaired semaphorin pathway activity and JNK expression in patient neurons. Our results suggest a novel disease-specific mechanism involving the JIP/JNK complex and identify NRP1 as a potential new therapeutic target.National Institutes of Health (Grant 1R01NS088538-01)National Institutes of Health (Grant HD045022)National Institutes of Health (Grant 2R01MH104610-15