Refining iPSC-based 3D neural cell models and characterization tools to address brain microenvironment-related diseases

Brain microenvironment plays important roles in neurodevelopment and pathology and can affect therapy efficacy. Neural cell culture typically relies on the use of heterologous matrices that poorly resemble brain extracellular matrix (ECM) or reflect its pathological features. We have shown that perfusion bioreactor-based 3D differentiation of iPSC-derived human neural stem cells (hiPSC-NSC) sustains the concomitant differentiation of the three neural lineages (neurospheroids). If this neurospheroid culture strategy also allows deposition of native neural ECM it would be possible to (i) mimic cellular and microenvironment remodeling during neural differentiation, without the confounding effects of exogenous matrices and (ii) recapitulate pathological phenotypic features of diseases in which homotypic/ heterotypic cell-cell interactions and ECM are relevant. To characterize the neural extracellular space we employed quantitative transcriptomic (NGS) and proteome (SWATH-MS) analysis. Neurogenic developmental pathways were recapitulated in neurospheroids, with significant changes in cell membrane and ECM composition along differentiation; a significant enrichment in structural proteoglycans, typical of brain ECM, a downregulation of basement membrane proteins constituents and a higher expression of synaptic and ion transport machinery were observed. Neurospheroids were generated using hiPSC-NSC derived from Mucopolysaccharidosis type VII (MPS VII) patients. MPS VII is a rare neuronopathic lysosomal storage disease caused by deficient β-glucuronidase (β-gluc) activity, leading to glycosaminoglycan (GAGs) accumulation in the brain. The main MPS VII molecular hallmarks were recapitulated, e.g. accumulation og GAGs. By combining the neurospheroid culture with a 3D neuronal connectivity assay based on calcium imaging analysis we refined a new analytical strategy to characterize neuronal connectivity defects in a more predictive setting. We showed that MPS VII neurospheroids presented reduced neuronal activity and disturbances in network functionality, with alterations in connectivity and synchronization. These data provide insights into the interplay between reduced β-gluc activity, GAGs accumulation, alterations in neuronal network and its impact on MPS VII-associated cognitive defects Applying the characterization tools refined in this work to cope with 3D neurospheroid cultures, namely the neuronal connectivity assay, we provide a new platform to unveil the cellular processes responsible for brain dysfunction in neurological disorders and to test and optimize new therapies. Acknowledgments: iNOVA4Health – UID/Multi/04462/2013, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement, is acknowledged. PD/BD/52473/2014, PD/BD/52481/2014, and PD/BD/128371/2017 PhD fellowships funded by FCT, Portugal. N.R. is supported by the European Research Council Starting Grant 337327. MS data were obtained by UniMS – Mass Spectrometry Unit, ITQB and iBET, Oeiras, Portugal

Climate Change Effect on Water Use Efficiency under Selected Soil and Water Conservation Practices in the Ruzizi Catchment, Eastern D.R. Congo

peer reviewedConcerns have been raised on the effectiveness and sustainability of Soil and Water Conservation (SWC) practices as adaptation options to climate change and high intra– and inter–annual rainfall variabilities in eastern Democratic Republic of Congo (DRC). This study was conducted in the Ruzizi Plain, a dryland area, to assess the performance of maize (Zea mays L.) under two Representative Concentration Pathways (RCP 4.5 and 8.5) and two SWC practices (tied ridges and conventional tillage). The AgMIP’s Regional Integrated Assessment (RIA) approach was used to simulate Water Use Efficiency (WUE) under the Cropping System Model–Crop Environment Resource Synthesis (CSM–CERES–Maize) of the Decision Support System for Agro–technology Transfer (DSSAT). The model was calibrated using experimental data from nine cropping seasons (2011–2018) and 100 farms. The model sensitivity was assessed as a function of temperature, water, and SWC practices for the same environments. Initial conditions of crop management practices were used as input data for CSM–CERES–Maize. Current climate data were extracted from AgMERRA datasets corrected with local data for the period of 1980 to 2021. Future climate projections (2022–2099) were obtained after down−scaling the data from the 29 General Circulation Models (GCMS) of Coupled Model Intercomparison Project 5 (CMIP5) and subsetted to five GCMs based on climate regimes. GCMS results were a strong indicator that climate change in this DRC dryland will result in an increase in average annual temperatures for both RCP 4.5 and 8.5, with the highest increase (3.05 ◦C) under hot/dry conditions for RCP8.5 and the lowest (1.04 ◦C) under cool/dry conditions for RCP 4.5. All the models selected for five climate regimes for 2022–2099 showed no change in the rainfall trends for RCP 4.5 (p > 0.05). The models projected yield declines of 5–25%, with less yield losses under tied ridges as an adaptation practice. The use of efficient SWC practices could therefore be a promising strategy in reducing potential losses from climate change in drylands of eastern DRC

Paediatric trauma at Kenyatta National Hospital, Nairobi Kenya.

Background: Medical Literature identities injuries as the most important preventable cause of death and disability in children beyond the first few months of life. Methods: A descriptive prospective study undertaken between October 2003 and July 2004 at Kenyatta National Hospital on children below the age of 13 years. Results: A total of 187 patients were admitted to KNH with trauma during that period. The age range was liont3 weeks to 12 years 4 months with a mean age of 3.9 years. There were 53.5% males and 46.5% females. Burns accounted for 34.8% falls 25.1%. Foreign bodies 17.6% while 8% were a result of road traffic accidents. Conclusions: Traumatic burns accounted for the highest single cause of trauma at 34.8% (n = 65). 92.3% of those burnt were aged 5 years and below. Most of these burns occurred in homes and were preventable