Sequence-Specific Extracellular MicroRNAs Activate TLR7

Toll-like receptors (TLRs) play an important role in the innate immune system. Emerging evidence shows that TLRs, especially endosomal TLRs, can participate in CNS diseases by increasing the production of proinflammatory cytokines via recognition of microRNAs (miRNAs), however which of the miRNAs are able to activate signaling and whether specific sequence motifs are involved remains incompletely defined. Here we found that numerous miRNAs induced TNF-a production across multiple myeloid cell types, including microglia, and that this effect was abolished in cells deficient of TLR7. In particular, miR-20a-5p and miR-148b-3p preferentially stimulate cytokine secretion compared to miR-20b-5p and miR-148a-3p, respectively, despite sharing similar sequences. Further examination of closely related miRNAs that differed in their ability to activate TLR7 resulting in the identification of a motif (UGCUUAU) as well as specific nucleotides (all of the uridines but surprisingly including the cytosine as well), that were vital for secretion of cytokines through TLR7 stimulation. A minimal 10-nucleotide sequence including this motif was found to be the shortest ssRNA that was identified to signal through TLR7. A miRNA containing this motif induced multiple pro-inflammatory molecules, which required the PI3K, MAPK and NF-kB signaling pathways. Wild-type mice that were administered miR-20a-5p (containing this motif) demonstrated increased leukocyte migration. This effect was significantly ameliorated in TLR7 knockout mice, and mice injected with miR-20b-5p (in which the motif is mutated) failed to exert this effect. Our results provide a detailed analysis of miRNAs that activate endosomal TLR7, and identify key nucleotide features of sequence motif recognized by TLR7

Neobaicalein prevents isoflurane anesthesia-induced cognitive impairment in neonatal mice via regulating CREB1

Objectives: Isoflurane (ISO) is widely used in the clinic and research. The authors aimed to explore whether Neobaicalein (Neob) could protect neonatal mice from ISO-induced cognitive damage. Method: The open field test, Morris water maze test, and tail suspension test was performed to assess the cognitive function in mice. Enzyme-linked immunosorbent assay was used to evaluate inflammatory-related protein concentrations. Immunohistochemistry was used to assess Ionized calcium-Binding Adapter molecule-1 (IBA-1) expression. Hippocampal neuron viability was detected using the Cell Counting Kit-8 assay. Double immunofluorescence staining was employed to confirm the interaction between proteins. Western blotting was used to assess protein expression levels. Results: Neob notably improved cognitive function and exhibited anti-inflammatory effects; moreover, under iso-treatment, it exhibited neuroprotective effects. Furthermore, Neob suppressed interleukin-1β, tumor necrosis factor-α, and interleukin-6 levels and upregulated interleukin-10 levels in ISO-treated mice. Neob significantly mitigated iso-induced increases in IBA-1–positive cell numbers of the hippocampus in neonatal mice. Furthermore, it inhibited ISO-induced neuronal apoptosis. Mechanistically, Neob was observed to upregulate cAMP Response Element Binding protein (CREB1) phosphorylation and protected hippocampal neurons from ISO-mediated apoptosis. Moreover, it rescued ISO-induced abnormalities of synaptic protein. Conclusions: Neob prevented ISO anesthesia-induced cognitive impairment by suppressing apoptosis and inflammation through upregulating CREB1

A Comprehensive Study to Delineate the Role of an Extracellular Vesicle-Associated MicroRNA-29a in Chronic Methamphetamine Use Disorder

Extracellular vesicles (EVs), which express a repertoire of cargo molecules (cf. proteins, microRNA, lipids, etc.), have been garnering a prominent role in the modulation of several cellular processes. Here, using both non-human primate and rodent model systems, we provide evidence that brain-derived EV (BDE) miRNA, miR-29a-3p (mir-29a), is significantly increased during chronic methamphetamine (MA) exposure. Further, miR-29a levels show significant increase both with drug-seeking and reinstatement in a rat MA self-administration model. We also show that EV-associated miR-29a is enriched in EV pool comprising of small EVs and exomeres and further plays a critical role in MA-induced inflammation and synaptodendritic damage. Furthermore, treatment with the anti-inflammatory drug ibudilast (AV411), which is known to reduce MA relapse, decreased the expression of miR-29a and subsequently attenuated inflammation and rescued synaptodendritic injury. Finally, using plasma from MUD subjects, we provide translational evidence that EV-miR29a could potentially serve as a biomarker to detect neuronal damage in humans diagnosed with MA use disorder (MUD). In summary, our work suggests that EV-associated miR-29a-3p plays a crucial role in MUD and might be used as a potential blood-based biomarker for detecting chronic inflammation and synaptic damage

A comprehensive study to delineate the role of an extracellular vesicle-associated microRNA-29a in chronic methamphetamine use disorder

Extracellular vesicles (EVs), which express a repertoire of cargo molecules (cf. proteins, microRNA, lipids, etc.), have been garnering a prominent role in the modulation of several cellular processes. Here, using both non-human primate and rodent model systems, we provide evidence that brain-derived EV (BDE) miRNA, miR- 29a-3p (mir-29a), is significantly increased during chronic methamphetamine (MA) exposure. Further, miR-29a levels show significant increase both with drug-seeking and reinstatement in a rat MA self-administration model. We also show that EVassociated miR-29a is enriched in EV pool comprising of small EVs and exomeres and further plays a critical role in MA-induced inflammation and synaptodendritic damage. Furthermore, treatment with the anti-inflammatory drug ibudilast (AV411), which is known to reduce MA relapse, decreased the expression of miR-29a and subsequently attenuated inflammation and rescued synaptodendritic injury. Finally, using plasma fromMUDsubjects, we provide translational evidence that EV-miR29a could potentially serve as a biomarker to detect neuronal damage in humans diagnosed with MA use disorder (MUD). In summary, our work suggests that EVassociated miR-29a-3p plays a crucial role in MUD and might be used as a potential blood-based biomarker for detecting chronic inflammation and synaptic damage