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This document is an editorial from the journal Biomedicines that focuses on animal and cellular models of Alzheimer's disease (AD). The editorial highlights the importance of these models in understanding the pathogenic mechanisms of AD and developing clinical applications and therapies. The document discusses key pathological processes in AD, including vascular damage, myelinization, sex differences, and metabolic alterations. It also presents several studies that investigate the role of brain vasculature, astrocytes, microglia, sex differences, and lipid composition in AD. The editorial concludes that these studies contribute to a better understanding of AD pathology and may guide the development of effective therapies. [Extracted from the article]

Glutamate recycling between neurons and astrocytes is essential to maintain neurotransmitter homeostasis. Disturbances in glutamate homeostasis, resulting in excitotoxicity and neuronal death, have been described as a potential mechanism in Alzheimer's disease (AD) pathophysiology. However, glutamate neurotransmitter metabolism in different human brain cells, particularly astrocytes, has been poorly investigated at the early stages of AD. We sought to investigate glucose and glutamate metabolism in AD by employing human induced pluripotent stem cell (hiPSC)-derived astrocytes and neurons carrying mutations in the amyloid precursor protein (APP) or presenilin-1 (PSEN-1) gene as found in familial types of AD (fAD). Methods such as livecell bioenergetics and metabolic mapping using [13C]-enriched substrates were used to examine metabolism in the early stages of AD. Our results revealed greater glycolysis and glucose oxidative metabolism in astrocytes and neurons with APP or PSEN-1 mutations, accompanied by an elevated glutamate synthesis compared to control WT cells. Astrocytes with APP or PSEN-1 mutations exhibited reduced expression of the excitatory amino acid transporter 2 (EAAT2), and glutamine uptake increased in mutated neurons, with enhanced glutamate release specifically in neurons with a PSEN-1 mutation. These results demonstrate a hypermetabolic phenotype in astrocytes with fAD mutations possibly linked to toxic glutamate accumulation. Our findings further identify metabolic imbalances that may occur in the early phases of AD pathophysiology. [ABSTRACT FROM AUTHOR]

Astrocytes are increasingly recognized for their important role in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). In ALS, astrocytes shift from their primary function of providing neuronal homeostatic support towards a reactive and toxic role, which overall contributes to neuronal toxicity and cell death. Currently, our knowledge on these processes is incomplete, and time-efficient and reproducible model systems in a human context are therefore required to understand and therapeutically modulate the toxic astrocytic response for future treatment options. Here, we present an efficient and straightforward protocol to generate human induced pluripotent stem cell (hiPSC)-derived astrocytes implementing a differentiation scheme based on small molecules. Through an initial 25 days, hiPSCs are differentiated into astrocytes, which are matured for 4+ weeks. The hiPSC-derived astrocytes can be cryopreserved at every passage during differentiation and maturation. This provides convenient pauses in the protocol as well as cell banking opportunities, thereby limiting the need to continuously start from hiPSCs. The protocol has already proven valuable in ALS research but can be adapted to any desired research field where astrocytes are of interest. Key features • This protocol requires preexisting experience in hiPSC culturing for a successful outcome. • The protocol relies on a small molecule differentiation scheme and an easy-to-follow methodology, which can be paused at several time points. • The protocol generates >50 × 10 6 astrocytes per differentiation, which can be cryopreserved at every passage, ensuring a large-scale experimental output., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (©Copyright : © 2024 The Authors; This is an open access article under the CC BY license.)

Intraarticular treatment of osteoarthritis with mesenchymal stem cells (MSCs) has shown promising results and is being increasingly implemented in the clinic. Autologous MSCs are the primary source of therapy but issues related to cell expansion, patient age, and acute therapies have opened a need for allogenic MSCs. Problematic immunological reactions such as pain, joint swelling, urticarial, and MSC destruction are, however, reported when using allogenic MSCs at the first to second treatment. Multiple factors need to be considered when deciding on autologous or allogenic MSC treatment, as argued in this review., (Published under Open Access CC-BY-NC-BD 4.0. https://creativecommons.org/licenses/by-nc-nd/4.0/.)