@article {2472, title = {FMRP protects the lung from xenobiotic stress by facilitating the Integrated Stress Response.}, journal = {J Cell Sci}, year = {2022}, month = {2022 Mar 23}, abstract = {

Stress response pathways protect the lung from the damaging effects of environmental toxicants. Here we investigate the role of the Fragile X Mental Retardation Protein (FMRP), a multifunctional protein implicated in stress responses, in the lung. We report that FMRP is expressed in murine and human lungs, in the airways and more broadly. Analysis of airway stress responses in mice and in a murine cell line ex vivo, using the well-established Naphthalene (Nap) injury model, reveals that FMRP-deficient cells exhibit increased expression of markers of oxidative and genotoxic stress and increased cell death. Further inquiry shows that FMRP-deficient cells fail to actuate the Integrated Stress Response Pathway (ISR) and upregulate the transcription factor ATF4. Knockdown of ATF4 expression phenocopies the loss of FMRP. We extend our analysis of the role of FMRP to human bronchial BEAS-2B cells, using a 9, 10-Phenanthrenequinone air pollutant model, to find FMRP-deficient BEAS-2B also fail to actuate the ISR and exhibit greater susceptibility. Taken together, our data suggest that FMRP has a conserved role in protecting the airways by facilitating the ISR.

}, issn = {1477-9137}, doi = {10.1242/jcs.258652}, author = {Basu, Deblina Sain and Bhavsar, Rital and Gulami, Imtiyaz and Chavda, Saraswati and Lingamallu, Sai Manoz and Muddashetty, Ravi and Veeranna, Chandrakanth and Chattarji, Sumantra and Thimmulappa, Rajesh and Bhattacharya, Aditi and Guha, Arjun} } @article {2401, title = {Pharmacological intervention in young adolescents rescues synaptic physiology and behavioural deficits in Syngap1 mice.}, journal = {Exp Brain Res}, year = {2021}, month = {2021 Nov 05}, abstract = {

Haploinsufficiency in SYNGAP1 is implicated in intellectual disability (ID) and autism spectrum disorder (ASD) and affects the maturation of dendritic spines. The abnormal spine development has been suggested to cause a disbalance of excitatory and inhibitory (E/I) neurotransmission at distinct developmental periods. In addition, E/I imbalances in Syngap1 mice might be due to abnormalities in K-Cl co-transporter function (NKCC1, KCC2), in a maner similar to the murine models of Fragile-X and Rett syndromes. To study whether an altered intracellular chloride ion concentration represents an underlying mechanism of modified function of GABAergic synapses in Dentate Gyrus Granule Cells of Syngap1 recordings were performed at different developmental stages of the mice. We observed depolarised neurons at P14-15 as illustrated by decreased Cl reversal potential in Syngap1 mice. The KCC2 expression was decreased compared to Wild-type (WT) mice at P14-15. The GSK-3β inhibitor, 6-bromoindirubin-3{\textquoteright}-oxime (6BIO) that crosses the blood-brain barrier, was tested to restore the function of GABAergic synapses. We discovered that the intraperitoneal administration of 6BIO during the critical period or young adolescents [P30 to P80 (4-week to 10-week)] normalised an altered E/I balance, the deficits of synaptic plasticity, and behavioural performance like social novelty, anxiety, and memory of the Syngap1 mice. In summary, altered GABAergic function in Syngap1 mice is due to reduced KCC2 expression leading to an increase in the intracellular chloride concentration that can be counteracted by the 6BIO, which restored cognitive, emotional, and social symptoms by pharmacological intervention, particularly in adulthood.

}, issn = {1432-1106}, doi = {10.1007/s00221-021-06254-x}, author = {Verma, Vijaya and Kumar, M J Vijay and Sharma, Kavita and Rajaram, Sridhar and Muddashetty, Ravi and Manjithaya, Ravi and Behnisch, Thomas and Clement, James P} } @article {1602, title = {Generation of a set of isogenic, gene-edited iPSC lines homozygous for all main APOE variants and an APOE knock-out line.}, journal = {Stem Cell Res}, volume = {34}, year = {2019}, month = {2019 Jan}, pages = {101349}, abstract = {

Alzheimer{\textquoteright}s disease (AD) is the most frequent neurodegenerative disease amongst the elderly. The SNPs rs429358 and rs7412 in the APOE gene are the most common risk factor for sporadic AD, and there are three different alleles commonly referred to as APOE-ε2, APOE-ε3 and APOE-ε4. Induced pluripotent stem cells (iPSCs) hold great promise to model AD as such cells can be differentiated in vitro to the required cell type. Here we report the use of CRISPR/Cas9 technology employed on iPSCs from a healthy individual with an APOE-ε3/ε4 genotype to obtain isogenic APOE-ε2/ε2, APOE-ε3/ε3, APOE-ε4/ε4 lines as well as an APOE-knock-out line.

}, issn = {1876-7753}, doi = {10.1016/j.scr.2018.11.010}, author = {Schmid, Benjamin and Prehn, Kennie R and Nimsanor, Natakarn and Garcia, Blanca Irene Aldana and Poulsen, Ulla and J{\o}rring, Ida and Rasmussen, Mikkel A and Clausen, Christian and Mau-Holzmann, Ulrike A and Ramakrishna, Sarayu and Muddashetty, Ravi and Steeg, Rachel and Bruce, Kevin and Mackintosh, Peter and Ebneth, Andreas and Holst, Bj{\o}rn and Cabrera-Socorro, Alfredo} } @article {1609, title = {Generation of two iPSC lines with either a heterozygous V717I or a heterozygous KM670/671NL mutation in the APP gene.}, journal = {Stem Cell Res}, volume = {34}, year = {2019}, month = {2019 Jan}, pages = {101368}, abstract = {

Alzheimer{\textquoteright}s disease (AD) is the most common form of dementia, affecting millions of people worldwide. Mutations in the genes PSEN1, PSEN2 or APP are known to cause familial forms of AD with an early age of onset. In this study, specific pathogenic mutations in the APP gene were introduced into an iPSC line from a healthy individual by the use of CRISPR-Cas9. The study resulted in the generation of two new cell lines, one carrying the V717I APP mutation and one with the KM670/671NL APP mutation.

}, issn = {1876-7753}, doi = {10.1016/j.scr.2018.101368}, author = {Frederiksen, Henriette R and Holst, Bj{\o}rn and Ramakrishna, Sarayu and Muddashetty, Ravi and Schmid, Benjamin and Freude, Kristine} }