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SUN, J.

Publications and source records attributed to SUN, J..

3 recordsLinked to original sources

Single-type neuron transcriptomics uncovers cell-type-specific regulators of host defense in Caenorhabditis elegans

Understanding how the nervous system regulates immune responses requires insight into how individual neurons respond to infection. In Caenorhabditis elegans, sensory neurons such as ASH play important roles in modulating innate immunity; however, the molecular mechanisms operating within these neurons remain poorly defined. Previous transcriptomic studies have relied on whole-animal RNA sequencing, which lacks the cellular resolution needed to detect neuron-specific signaling programs. Here, we performed single-type neuron transcriptomic profiling to characterize gene expression in ASH neurons from infected and uninfected animals. We found that ASH neurons undergo extensive transcriptional remodeling in response to pathogen exposure, with enrichment of genes associated with G protein-coupled receptor signaling, neuropeptide activity, and sensory transduction. Notably, we identified genes, including zig-3 and F36F2.8, that are strongly induced in ASH neurons but are not detected in whole-animal transcriptomic datasets. Functional analysis using ASH-specific RNA interference demonstrated that knockdown of either gene significantly reduces survival during Pseudomonas aeruginosa infection, whereas whole-animal RNAi produces no detectable phenotype. Together, these findings reveal that cell-type-resolved transcriptomics can uncover functionally important regulators of host defense that are masked in bulk analyses and provide new insight into neuron-intrinsic mechanisms of neuroimmune regulation.

molecular biology↗

Structural circuit plasticity by a neurotrophin with a Toll modifies dopamine-dependent behaviour

Experience shapes the brain, as neural circuits can be modified by neural stimulation or the lack of it. The molecular mechanisms underlying structural circuit plasticity and how plasticity modifies behaviour, are poorly understood. Subjective experience requires dopamine, a neuromodulator that assigns a value to stimuli, and it also controls behaviour, including locomotion, learning and memory. In Drosophila, Toll receptors are ideally placed to translate experience into structural brain change. Toll-6 is expressed in dopaminergic neurons (DANs), raising the intriguing possibility that Toll-6 could regulate structural plasticity in dopaminergic circuits. Drosophila neurotrophin-2 (DNT-2) is the ligand for Toll-6 and Kek-6, but whether it is required for circuit structural plasticity was unknown. Here, we show that DNT-2 expressing neurons connect with DANs, and they modulate each other. Loss of function for DNT-2 or its receptors Toll-6 and kinase-less Trk-like kek-6 caused DAN and synapse loss, impaired dendrite growth and connectivity, decreased synaptic sites and caused locomotion deficits. By contrast, over-expressed DNT-2 increased DAN cell number, dendrite complexity and promoted synaptogenesis. Neuronal activity modified DNT-2, it increased synaptogenesis in DNT-2-positive neurons and DANs, and over-expression of DNT-2 did too. Altering the levels of DNT-2 or Toll-6 also modified dopamine-dependent behaviours, including locomotion and long-term memory. To conclude, a feedback loop involving dopamine and DNT-2 sculpted the circuits engaged, and DNT-2 with Toll-6 and Kek-6 induced structural plasticity in this circuit modifying brain function and behaviour.

neuroscience↗

The effect of dietary ginseng polysaccharide supplementation on the immune responses involved in porcine milk-derived esRNAs

Ginseng and its polysaccharides (GPS) have been well known as an immune modulator. This study was conducted to investigate the effects of dietary supplemental GPS on the immune responses involved in sows milk-derived exosomal shuttle RNAs (esRNAs) using RNA-Seq and miRNA-Seq. Of the 213 identified miRNA types, a total of 26 conserved miRNAs were differently expressed in response to GPS supplementation, including 10 up-regulated and 16 down-regulated miRNAs in GPS feeding group. In addition, exosomal transcriptome analysis identified 14,696 protein-coding genes in sows milk exosomes, and 283 genes with 204 and 79 candidates showing up and down-regulation were significantly responded to GPS supplementation. Integrated analysis of each differently expressed miRNA with significantly expressed genes further revealed the presence of 51 highly conserved miRNA-gene interactions that were annotated to be related to immunoregulatory functions. This work provided an important advance in the functional identification of dietary GPS supplementation and more fundamental information about how GPS promoted the immune response and healthy growth of the infant from mothers at molecular levels.

genomics↗