Explore the vast range of titles available.

Background Induced pluripotent stem cell-derived microglia (iMGL) represent an excellent tool in studying microglial function in health and disease. Yet, since differentiation and survival of iMGL are highly reliant on colony-stimulating factor 1 receptor (CSF1R) signaling, it is difficult to use iMGL to study microglial dysfunction associated with pathogenic defects in CSF1R. Methods Serial modifications to an existing iMGL protocol were made, including but not limited to changes in growth factor combination to drive microglial differentiation, until successful derivation of microglia-like cells from an adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) patient carrying a c.2350G > A (p.V784M) CSF1R variant. Using healthy control lines, the quality of the new iMGL protocol was validated through cell yield assessment, measurement of microglia marker expression, transcriptomic comparison to primary microglia, and evaluation of inflammatory and phagocytic activities. Similarly, molecular and functional characterization of the ALSP patient-derived iMGL was carried out in comparison to healthy control iMGL. Results The newly devised protocol allowed the generation of iMGL with enhanced transcriptomic similarity to cultured primary human microglia and with higher scavenging and inflammatory competence at ~ threefold greater yield compared to the original protocol. Using this protocol, decreased CSF1R autophosphorylation and cell surface expression was observed in iMGL derived from the ALSP patient compared to those derived from healthy controls. Additionally, ALSP patient-derived iMGL presented a migratory defect accompanying a temporal reduction in purinergic receptor P2Y12 ( P2RY12 ) expression, a heightened capacity to internalize myelin, as well as heightened inflammatory response to Pam 3 CSK 4 . Poor P2RY12 expression was confirmed to be a consequence of CSF1R haploinsufficiency, as this feature was also observed following CSF1R knockdown or inhibition in mature control iMGL, and in CSF1R WT/KO and CSF1R WT/E633K iMGL compared to their respective isogenic controls. Conclusions We optimized a pre-existing iMGL protocol, generating a powerful tool to study microglial involvement in human neurological diseases. Using the optimized protocol, we have generated for the first time iMGL from an ALSP patient carrying a pathogenic CSF1R variant, with preliminary characterization pointing toward functional alterations in migratory, phagocytic and inflammatory activities. Graphical Abstract

Chronic obstructive pulmonary disease (COPD) is an incurable and prevalent respiratory disorder that is characterized by chronic inflammation and emphysema. COPD is primarily caused by cigarette smoke (CS). CS alters numerous cellular processes, including the post-transcriptional regulation of mRNAs. The identification of RNA-binding proteins (RBPs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) as main factors engaged in the regulation of RNA biology opens the door to understanding their role in coordinating physiological cellular processes. Dysregulation of post-transcriptional regulation by foreign particles in CS may lead to the development of diseases such as COPD. Here we review current knowledge about post-transcriptional events that may be involved in the pathogenesis of COPD.

The aryl hydrocarbon receptor (AhR) is a cytosolic transcription factor that can be activated by endogenous (e.g., 6-formylindolo(3,2-b) carbazole (FICZ)) or xenobiotic (e.g., dioxin and benzo[a]pyrene (B[a]P)) ligands. Once the AhR is activated, it translocates into the nucleus, dimerizes with the AhR nuclear translator (ARNT), and binds to specific DNA sequences called xenobiotic response elements (XRE) to promote the target gene transcription, including cytochrome P450 (CYP1A1). The AhR not only mediates the toxic effects of dioxin, but also has physiological functions such as suppressing inflammation, oxidative stress, and apoptosis. We have previously shown that AhR-dependent regulation of endogenous miR-196a expression suppressed cigarette smoke (CS)-induced apoptosis. However, the exact mechanism of how AhR regulates apoptosis through miR-196a is still poorly understood. We think that part of the mechanism of action for the AhR is through regulation of long non-coding RNA (lncRNAs) expression. LncRNAs may play important roles in the response to xenobiotics. LncRNAs are defined as transcript more than 200 nucleotides in length that do not encode a protein but are implicated in many physiological processes such as cell differentiation, cell proliferation, and apoptosis. A few studies revealed that the AhR affects the expression of lncRNA. Therefore, we hypothesize that AhR activation regulates the expression of lncRNA in response to B[a]P in the human alveolar epithelial cell line (A549). The aims of this study are: (1) investigate the effect of B[a]P on lncRNAs expression and (2) determine whether B[a]P regulates lncRNAs expression is in an AhR-dependent manner. First, to confirm whether B[a]P regulates the well-characterized lncRNAs (NEAT1, HOTTIP, SOX2OT, MALAT1, H19, and Linc00673) is in AhR-dependent manner, A549WT and AhR knock-out (A549-AhRKO) cells were treated with B[a]P (8M) for 6 and 24h. The expression of well-characterized mRNA and lncRNAs was measured by RT-qPCR. Despite AhR activation, as indicated by induction of CYP1A1 and CYP1B1 mRNA, we found that neither treatment nor AhR expression affected the expression of NEAT1, HOTTIP, SOX2OT, MALAT1, H19, and Linc00673. Next, to evaluate transcriptome profiles of B[a]P in A549 cells, RNA sequencing was performed. We found that 704 and 811 lncRNAs (e.g., SATB1-AS1, MIR4290HG, AC008969.1, LINC01533, VIPR1-AS1) and protein-coding RNAs (e.g., CYP1A1, BX005266.2, AQP3, BTG2, DCX, and AhRR), respectively, were differentially-expressed in A549 cells treated with B[a]P (8M) after 6 and 24h. GO analyses indicated that DE protein-coding RNAs are associated with distinct molecular functions, whereas KEGG analyses showed the hsa01100 pathway was associated with differently-expressed lncRNAs. In summary, our research revealed that B[a]P affects lncRNAs expression; however, further investigations are required to reveal the role of these lncRNA in modulating AhR function. This study profiles the lncRNAs expression in A549 cells exposed to B[a]P, which could assist in establishing the basis for the physiological functions of AhR