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Background: Patients with Alzheimer's disease (AD) frequently present with cerebral amyloid angiopathy (CAA), characterized by the accumulation of beta-amyloid (Aβ) within the cerebral blood vessels, leading to cerebrovascular dysfunction. Pericytes, which wrap around vascular capillaries, are crucial for regulating cerebral blood flow, angiogenesis, and vessel stability. Despite the known impact of vascular dysfunction on the progression of neurodegenerative diseases, the specific role of pericytes in AD pathology remains to be elucidated., Methods: To explore this, we generated pericyte-like cells from human induced pluripotent stem cells (iPSCs) harboring the Swedish mutation in the amyloid precursor protein (APPswe) along with cells from healthy controls. We initially verified the expression of classic pericyte markers in these cells. Subsequent functional assessments, including permeability, tube formation, and contraction assays, were conducted to evaluate the functionality of both the APPswe and control cells. Additionally, bulk RNA sequencing was utilized to compare the transcriptional profiles between the two groups., Results: Our study reveals that iPSC-derived pericyte-like cells (iPLCs) can produce Aβ peptides. Notably, cells with the APPswe mutation secreted Aβ1-42 at levels ten-fold higher than those of control cells. The APPswe iPLCs also demonstrated a reduced ability to support angiogenesis and maintain barrier integrity, exhibited a prolonged contractile response, and produced elevated levels of pro-inflammatory cytokines following inflammatory stimulation. These functional changes in APPswe iPLCs correspond with transcriptional upregulation in genes related to actin cytoskeleton and extracellular matrix organization., Conclusions: Our findings indicate that the APPswe mutation in iPLCs mimics several aspects of CAA pathology in vitro, suggesting that our iPSC-based vascular cell model could serve as an effective platform for drug discovery aimed to ameliorate vascular dysfunction in AD., (© 2024. The Author(s).)

Neurogenin 2 (NGN2), a neuronal transcription factor, can expedite differentiation of stem cells into mature glutamatergic neurons. We have utilized an allelic series of previously published and characterized isogenic Huntington's disease (IsoHD) human embryonic stem cell lines (Ooi et al., 2019), carrying different CAG repeat lengths in the first exon of the huntingtin gene. These IsoHDs were modified using CRISPR/Cas9 to insert NGN2 under the TET-ON doxycycline inducible promoter. The resulting IsoHD-NGN2 cell lines retained pluripotency in the absence of doxycycline (DOX), and via addition of DOX to the culturing media differentiation to neurons was achieved within 14 days., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Abinaya Chandrasekaran reports financial support was provided by Lundbeck Foundation. Sofie Amalie Flintholm Andersen reports financial support was provided by Lundbeck Foundation. Kristine Karla Freude reports a relationship with University of Copenhagen that includes: employment and funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier B.V. All rights reserved.)

Here we present the generation of a human embryonic stem cell line with the potential to escape immune rejection upon transplantation to an alternate species, in this case sus scrofa. For in vivo detection the cells were modified by CRISPR-Cas9 to express human secreted alkaline phosphatase. To avoid immune recognition and subsequent rejection by host, genes encoding hB2M and hCIITA were knocked out and the porcine gene for CD47 was introduced. Upon editing and subsequent culture, cells maintained molecular and phenotypic pluripotent charactaristics and a normal karyotype supporting viability and functionality of the engineered cell line., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Although current stem cell therapies exhibit promising potential, the extended process of employing autologous cells and the necessity for donor-host matching to avert the rejection of transplanted cells significantly limit the widespread applicability of these treatments. It would be highly advantageous to generate a pluripotent universal donor stem cell line that is immune-evasive and, therefore, not restricted by the individual's immune system, enabling unlimited application within cell replacement therapies. Before such immune-evasive stem cells can be moved forward to clinical trials, in vivo testing via transplantation experiments in immune-competent animals would be a favorable approach preceding preclinical testing. By using human stem cells in immune competent animals, results will be more translatable to a clinical setting, as no parts of the immune system have been altered, although in a xenogeneic setting. In this way, immune evasiveness, cell survival, and unwanted proliferative effects can be assessed before clinical trials in humans. The current study presents the generation and characterization of three human embryonic stem cell lines (hESCs) for xenogeneic transplantation in immune-competent mice. The major histocompatibility complexes I- and II-encoding genes, B2M and CIITA, have been deleted from the hESCs using CRISPR-Cas9-targeted gene replacement strategies and knockout. B2M was knocked out by the insertion of murine CD47. Human-secreted embryonic alkaline phosphatase (hSEAP) was inserted in a safe harbor site to track cells in vivo. The edited hESCs maintained their pluripotency, karyotypic normality, and stable expression of murine CD47 and hSEAP in vitro . In vivo transplantation of hESCs into immune-competent BALB/c mice was successfully monitored by measuring hSEAP in blood samples. Nevertheless, transplantation of immune-evasive hESCs resulted in complete rejection within 11 days, with clear immune infiltration of T-cells on day 8. Our results reveal that knockout of B2M and CIITA together with species-specific expression of CD47 are insufficient to prevent rejection in an immune-competent and xenogeneic context., Competing Interests: Authors AG, KV and UD were employed by Novo Nordisk A/S. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Frederiksen, Glantz, Vøls, Skov, Tveden-Nyborg, Freude and Doehn.)

Developmental and epileptic encephalopathies (DEEs) are early-onset conditions that cause intractable seizures and developmental delays. Missense variants in Gamma-aminobutyric acid type A receptor (GABAAR) subunits commonly cause DEEs. Ahring et al. (2022) showed a variant in the gene that encodes the delta subunit (GABRD) is strongly associated with the gain-of-function of extrasynaptic GABAAR. Here, we report the generation of two patient-specific human induced pluripotent stem cells (hiPSC) lines with (i) a de novo variant and (ii) a maternal variant, both for the pathogenic GABRD c.872 C>T, (p.T291I). The variants in the generated cell line were corrected using the CRISPR-Cas9 gene editing technique (respective isogenic control lines)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Today, neurodegenerative disorders like Alzheimer's disease (AD), Parkinson's disease (PD), frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) affect millions of people worldwide, and as the average human lifespan increases, similarly grows the number of patients. For many decades, cognitive and motoric decline has been explained by the very apparent deterioration of neurons in various regions of the brain and spinal cord. However, more recent studies show that disease progression is greatly influenced by the vast population of glial cells. Astrocytes are traditionally considered star-shaped cells on which neurons rely heavily for their optimal homeostasis and survival. Increasing amounts of evidence depict how astrocytes lose their supportive functions while simultaneously gaining toxic properties during neurodegeneration. Many of these changes are similar across various neurodegenerative diseases, and in this review, we highlight these commonalities. We discuss how astrocyte dysfunction drives neuronal demise across a wide range of neurodegenerative diseases, but rather than categorizing based on disease, we aim to provide an overview based on currently known mechanisms. As such, this review delivers a different perspective on the disease causes of neurodegeneration in the hope to encourage further cross-disease studies into shared disease mechanisms, which might ultimately disclose potentially common therapeutic entry points across a wide panel of neurodegenerative diseases.

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.)

This review examines the substantial involvement of Single Nucleotide Polymorphisms (SNPs) and microRNAs (miRNAs) in the etiology and susceptibility to Schizophrenia, with particular emphasis on the dopaminergic, glutamatergic, and GABAergic systems. It elucidates the potential of SNPs to disrupt miRNA-mRNA interactions, leading to alterations in the regulatory mechanisms of Schizophrenia risk genes and subsequently influencing the susceptibility to Schizophrenia. Specific attention is given to the impact of SNPs in DICER, DROSHA , and DGCR8 , as well as the potential for changes in DRD2 gene expression driven by miR-9 and miR-326, heightening the likelihood of Schizophrenia development. Furthermore, the review explores genetic alterations in the glutamatergic system, focusing on modifications linked to GRIN2A and its associated miRNAs, which have been reported to have a notable impact on the occurrence of Schizophrenia. Knowledge of the involvement of SNPs within miRNAs in influencing the expression of essential genes within the GABA system are emerging and described in this review, including their potential consequences for Schizophrenia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Mohamed and Freude.)

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/.)

Alzheimer's disease (AD) represents a major diagnostic challenge, as early detection is crucial for effective intervention. This review examines the diagnostic challenges facing current AD evaluations and explores the emerging field of retinal alterations as early indicators. Recognizing the potential of the retina as a noninvasive window to the brain, we emphasize the importance of identifying retinal biomarkers in the early stages of AD. However, the examination of AD is not without its challenges, as the similarities shared with other retinal diseases introduce complexity in the search for AD-specific markers. In this review, we address the relevance of using the retina for the early diagnosis of AD and the complex challenges associated with the search for AD-specific retinal biomarkers. We provide a comprehensive overview of the current landscape and highlight avenues for progress in AD diagnosis by retinal examination.

Frontotemporal dementia (FTD) is a common cause of early-onset dementia, with no current treatment options. FTD linked to chromosome 3 (FTD3) is a rare sub-form of the disease, caused by a point mutation in the Charged Multivesicular Body Protein 2B (CHMP2B). This mutation causes neuronal phenotypes, such as mitochondrial deficiencies, accompanied by metabolic changes and interrupted endosomal-lysosomal fusion. However, the contribution of glial cells to FTD3 pathogenesis has, until recently, been largely unexplored. Glial cells play an important role in most neurodegenerative disorders as drivers and facilitators of neuroinflammation. Microglia are at the center of current investigations as potential pro-inflammatory drivers. While gliosis has been observed in FTD3 patient brains, it has not yet been systematically analyzed. In the light of this, we investigated the role of microglia in FTD3 by implementing human induced pluripotent stem cells (hiPSC) with either a heterozygous or homozygous CHMP2B mutation, introduced into a healthy control hiPSC line via CRISPR-Cas9 precision gene editing. These hiPSC were differentiated into microglia to evaluate the pro-inflammatory profile and metabolic state. Moreover, hiPSC-derived neurons were cultured with conditioned microglia media to investigate disease specific interactions between the two cell populations. Interestingly, we identified two divergent inflammatory microglial phenotypes resulting from the underlying mutations: a severe pro-inflammatory profile in CHMP2B homozygous FTD3 microglia, and an "unresponsive" CHMP2B heterozygous FTD3 microglial state. These findings correlate with our observations of increased phagocytic activity in CHMP2B homozygous, and impaired protein degradation in CHMP2B heterozygous FTD3 microglia. Metabolic mapping confirmed these differences, revealing a metabolic reprogramming of the CHMP2B FTD3 microglia, displayed as a compensatory up-regulation of glutamine metabolism in the CHMP2B homozygous FTD3 microglia. Intriguingly, conditioned CHMP2B homozygous FTD3 microglia media caused neurotoxic effects, which was not evident for the heterozygous microglia. Strikingly, IFN-γ treatment initiated an immune boost of the CHMP2B heterozygous FTD3 microglia, and conditioned microglia media exposure promoted neural outgrowth. Our findings indicate that the microglial profile, activity, and behavior is highly dependent on the status of the CHMP2B mutation. Our results suggest that the heterozygous state of the mutation in FTD3 patients could potentially be exploited in form of immune-boosting intervention strategies to counteract neurodegeneration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Developmental and epileptic encephalopathies (DEEs) are rare severe neurodevelopmental disorders with a cumulative incidence of 1:6.000 live births. Many epileptic conditions arise from single nucleotide variants in CACNA1A (calcium voltage-gated channel subunit alpha1 A), encoding the CaV2.1 calcium channel subunit. Human induced pluripotent stem cells (hiPSCs) are an optimal choice for modeling DEEs, as they can be differentiated in vitro into diverse neuronal subpopulations. Here, we report the generation of hiPSC lines with two pathogenic CACNA1A variants c.1767C > T, p. (Arg589Cys), referred to as R589C and c. 2139G > A, p.(Ala713Thr), referred to as A713T, previously associated with epilepsy. The variants were introduced into a hiPSC line from a healthy individual via CRISPR-Cas9 gene editing technology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Sex differences are present in brain morphology, sex hormones, aging processes and immune responses. These differences need to be considered for proper modelling of neurological diseases with clear sex differences. This is the case for Alzheimer's disease (AD), a fatal neurodegenerative disorder with two-thirds of cases diagnosed in women. It is becoming clear that there is a complex interplay between the immune system, sex hormones and AD. Microglia are major players in the neuroinflammatory process occurring in AD and have been shown to be directly affected by sex hormones. However, many unanswered questions remain as the importance of including both sexes in research studies has only recently started receiving attention. In this review, we provide a summary of sex differences and their implications in AD, with a focus on microglia action. Furthermore, we discuss current available study models, including emerging complex microfluidic and 3D cellular models and their usefulness for studying hormonal effects in this disease.

Alzheimer's disease (AD) is a progressive and irreversible brain disorder, which can occur either sporadically, due to a complex combination of environmental, genetic, and epigenetic factors, or because of rare genetic variants in specific genes (familial AD, or fAD). A key hallmark of AD is the accumulation of amyloid beta (Aβ) and Tau hyperphosphorylated tangles in the brain, but the underlying pathomechanisms and interdependencies remain poorly understood. Here, we identify and characterise gene expression changes related to two fAD mutations (A79V and L150P) in the Presenilin-1 (PSEN1) gene. We do this by comparing the transcriptomes of glutamatergic forebrain neurons derived from fAD-mutant human induced pluripotent stem cells (hiPSCs) and their individual isogenic controls generated via precision CRISPR/Cas9 genome editing. Our analysis of Poly(A) RNA-seq data detects 1111 differentially expressed coding and non-coding genes significantly altered in fAD. Functional characterisation and pathway analysis of these genes reveal profound expression changes in constituents of the extracellular matrix, important to maintain the morphology, structural integrity, and plasticity of neurons, and in genes involved in calcium homeostasis and mitochondrial oxidative stress. Furthermore, by analysing total RNA-seq data we reveal that 30 out of 31 differentially expressed circular RNA genes are significantly upregulated in the fAD lines, and that these may contribute to the observed protein-coding gene expression changes. The results presented in this study contribute to a better understanding of the cellular mechanisms impacted in AD neurons, ultimately leading to neuronal damage and death., Competing Interests: Declaration of Competing Interest The authors have no conflict of interests to declare., (Copyright © 2022. Published by Elsevier Inc.)

Alzheimer's disease (AD) is the most common cause of dementia, with no current cure. Consequently, alternative approaches focusing on early pathological events in specific neuronal populations, besides targeting the well-studied amyloid beta (Aβ) accumulations and Tau tangles, are needed. In this study, we have investigated disease phenotypes specific to glutamatergic forebrain neurons and mapped the timeline of their occurrence, by implementing familial and sporadic human induced pluripotent stem cell models as well as the 5xFAD mouse model. We recapitulated characteristic late AD phenotypes, such as increased Aβ secretion and Tau hyperphosphorylation, as well as previously well documented mitochondrial and synaptic deficits. Intriguingly, we identified Golgi fragmentation as one of the earliest AD phenotypes, indicating potential impairments in protein processing and post-translational modifications. Computational analysis of RNA sequencing data revealed differentially expressed genes involved in glycosylation and glycan patterns, whilst total glycan profiling revealed minor glycosylation differences. This indicates general robustness of glycosylation besides the observed fragmented morphology. Importantly, we identified that genetic variants in Sortilin-related receptor 1 ( SORL1 ) associated with AD could aggravate the Golgi fragmentation and subsequent glycosylation changes. In summary, we identified Golgi fragmentation as one of the earliest disease phenotypes in AD neurons in various in vivo and in vitro complementary disease models, which can be exacerbated via additional risk variants in SORL1 ., Competing Interests: HW owns stocks and is a consultant for and co-founder of EbuMab ApS, Hemab ApS, and GO- Therapeutics, Inc., all not involved in, or related to, the research performed in this study. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Haukedal, Corsi, Gadekar, Doncheva, Kedia, de Haan, Chandrasekaran, Jensen, Schiønning, Vallin, Marlet, Poon, Pires, Agha, Wandall, Cirera, Simonsen, Nielsen, Nielsen, Hyttel, Muddashetty, Aldana, Gorodkin, Nair, Meyer, Larsen and Freude.)

Background: Astrocytes play a crucial, yet not fully elucidated role in the selective motor neuron pathology in amyotrophic lateral sclerosis (ALS). Among other responsibilities, astrocytes provide important neuronal homeostatic support, however this function is highly compromised in ALS. The establishment of fully human coculture systems can be used to further study the underlying mechanisms of the dysfunctional intercellular interplay, and has the potential to provide a platform for revealing novel therapeutic entry points., Methods: In this study, we characterised human induced pluripotent stem cell (hiPSC)-derived astrocytes from FUS-ALS patients, and incorporated these cells into a human motor unit microfluidics model to investigate the astrocytic effect on hiPSC-derived motor neuron network and functional neuromuscular junctions (NMJs) using immunocytochemistry and live-cell recordings. FUS-ALS cocultures were systematically compared to their CRISPR-Cas9 gene-edited isogenic control systems., Results: We observed a dysregulation of astrocyte homeostasis, which resulted in a FUS-ALS-mediated increase in reactivity and secretion of inflammatory cytokines. Upon coculture with motor neurons and myotubes, we detected a cytotoxic effect on motor neuron-neurite outgrowth, NMJ formation and functionality, which was improved or fully rescued by isogenic control astrocytes. We demonstrate that ALS astrocytes have both a gain-of-toxicity and loss-of-support function involving the WNT/β-catenin pathway, ultimately contributing to the disruption of motor neuron homeostasis, intercellular networks and NMJs., Conclusions: Our findings shine light on a complex, yet highly important role of astrocytes in ALS, and provides further insight in to their pathological mechanisms., (© 2023. The Author(s).)

Aims: Variants in SCN5A encoding Nav1.5 are associated with cardiac arrhythmias. We aimed to determine the mechanism by which c.638G>A in SCNA5 resulting in p.Gly213Asp (G213D) in Nav1.5 altered Na+ channel function and how flecainide corrected the defect in a family with multifocal ectopic Purkinje-related premature contractions (MEPPC)-like syndrome., Methods and Results: Five patients carrying the G213D variant were treated with flecainide. Gating pore currents were evaluated in Xenopus laevis oocytes. The 638G>A SCN5A variant was introduced to human-induced pluripotent stem cell (hiPSC) by CRISPR-Cas9 gene editing and subsequently differentiated to cardiomyocytes (hiPSC-CM). Action potentials and sodium currents were measured in the absence and presence of flecainide. Ca2+ transients were measured by confocal microscopy. The five patients exhibited premature atrial and ventricular contractions which were suppressed by flecainide treatment. G213D induced gating pore current at potentials negative to -50 mV. Voltage-clamp analysis in hiPSC-CM revealed the activation threshold of INa was shifted in the hyperpolarizing direction resulting in a larger INa window current. The G213D hiPSC-CMs had faster beating rates compared with wild-type and frequently showed Ca2+ waves and alternans. Flecainide applied to G213D hiPSC-CMs decreased window current by shifting the steady-state inactivation curve and slowed the beating rate., Conclusion: The G213D variant in Nav1.5 induced gating pore currents and increased window current. The changes in INa resulted in a faster beating rate and Ca2+ transient dysfunction. Flecainide decreased window current and inhibited INa, which is likely responsible for the therapeutic effectiveness of flecainide in MEPPC patients carrying the G213D variant., Competing Interests: Conflict of interest: H.K.J. is supported by grants from the Novo Nordisk Foundation, Denmark (NNF18OC0031258 and NNF20OC0065151), and received lecture fees from Abbott Denmark and Biosense Webster, Europe. The other authors have no relationships that can be construed as a conflict of interest, (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Characterising Alzheimer's disease (AD) as a metabolic disorder of the brain is gaining acceptance based on the pathophysiological commonalities between AD and major metabolic disorders. Therefore, metabolic interventions have been explored as a strategy for brain energetic rescue. Amongst these, medium-chain fatty acid (MCFA) supplementations have been reported to rescue the energetic failure in brain cells as well as the cognitive decline in patients. Short-chain fatty acids (SCFA) have also been implicated in AD pathology. Due to the increasing therapeutic interest in metabolic interventions and brain energetic rescue in neurodegenerative disorders, in this review, we first summarise the role of SCFAs and MCFAs in AD. We provide a comparison of the main findings regarding these lipid species in established AD animal models and recently developed human cell-based models of this devastating disorder.

Purpose: To investigate the effect of polyquaternium-1 (PQ)-preserved and benzalkonium chloride (BAK)-preserved travoprost eye drops on viability of primary human conjunctival goblet cell (GC) cultures and on secretion of mucin and cytokines. Furthermore, to evaluate the physicochemical properties of the branded travoprost eye drop Travatan® and available generics., Methods: The effect of travoprost eye drops was evaluated on GC cultures. Cell viability was assessed through lactate dehydrogenase (LDH) and tetrazolium dye (MTT) colorimetric assays. Mucin secretion was evaluated by immunohistochemical staining. Secretion of interleukin (IL)-6 and IL-8 was measured using BD Cytometric Bead Arrays. pH, viscosity, droplet mass, osmolality and surface tension were measured for all included eye drops., Results: In the LDH assay, BAK travoprost caused significant GC loss after 2 hrs of incubation compared to the control. PQ travoprost caused no GC loss at any time point. Both PQ- and BAK travoprost caused secretion of mucin to the cytoplasma. No difference in IL-6 and IL-8 secretion was identified compared to controls. The pH values for the generics were lower (pH 6.0) than the pH value for Travatan (pH 6.7; p < 0.0001). The viscosity was lowest for Travatan, while the mean droplet mass was higher for Travatan (35 mg) than the generics (28-30 mg; p ≤ 0.0318). The osmolality and surface tension did not differ between the eye drops investigated., Conclusion: BAK travoprost caused GC loss, indicating that PQ preservation may be preferable in treatment of glaucoma. Furthermore, physicochemical properties of branded and generic travoprost eye drops can not be assumed to be identical., (© 2022 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Ras homolog gene family member A (RhoA) is a small GTPase of the Rho family involved in regulating multiple signal transduction pathways that influence a diverse range of cellular functions. RhoA and many of its downstream effector proteins are highly expressed in the nervous system, implying an important role for RhoA signaling in neurons and glial cells. Indeed, emerging evidence points toward a role of aberrant RhoA signaling in neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. In this review, we summarize the current knowledge of RhoA regulation and downstream cellular functions with an emphasis on the role of RhoA signaling in neurodegenerative diseases and the therapeutic potential of RhoA inhibition in neurodegeneration.