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The Journal of Neuroscience : the... May 2024Neurons in the caudal nucleus of the solitary tract (cNTS) and intermediate reticular nucleus (IRt) that express the glucagon gene give rise to GLP1-immunopositive...
Populations of hindbrain glucagon-like peptide 1 (GLP1) neurons that innervate the hypothalamic PVH, thalamic PVT, or limbic forebrain BST have axon collaterals that reach all central regions innervated by GLP1 neurons.
Neurons in the caudal nucleus of the solitary tract (cNTS) and intermediate reticular nucleus (IRt) that express the glucagon gene give rise to GLP1-immunopositive axons in the spinal cord and many subcortical brain regions. Central GLP1 receptor signaling contributes to motivated behavior and stress responses in rats and mice, in which hindbrain GLP1 neurons are activated to express cFos in a metabolic state-dependent manner. The present study examined whether GLP1 inputs to distinct brain regions arise from distinct subsets of -expressing neurons, and mapped the collective distribution of axon collaterals arising from projection-defined GLP1 neural populations. Using our Gcg-Cre knock-in rat model, Cre-dependent adeno-associated virus (AAV1) tracing was conducted in adult male and female rats to compare axonal projections of IRt vs. cNTS GLP1 neurons. Overlapping axonal projections were observed in all brain regions that receive GLP1 input, with the caveat that cNTS injections produced Cre-dependent labeling of some IRt neurons, and vice-versa. In additional experiments, specific diencephalic or limbic forebrain nuclei were microinjected with Cre-dependent retrograde AAVs (AAVrg) expressing reporters that fully labeled the axon collaterals of transduced GLP1 neural populations. AAVrg injected into each forebrain site labeled expressing neurons in both the cNTS and IRt. The collective axon collaterals of these labeled neurons entered the spinal cord and every brain region previously reported to contain GLP1-positive axons. These results indicate that axons arising from populations of GLP1 neurons that innervate the thalamic PVT, hypothalamic PVH, and/or limbic forebrain BST collectively innervate all central regions that receive GLP1 axonal input. Our novel anatomical findings indicate that target-defined populations of forebrain-projecting GLP1 neurons collectively project to downstream target regions in a widespread sprinkler-type manner, although collateralized axons arising from individual GLP1 projection neurons remain to be defined. Considered together with results from studies investigating the role of central GLP1 receptor signaling pathways in physiology and behavior, these findings support our emerging view that hindbrain -expressing neurons are positioned to simultaneously modulate synaptic transmission in widespread spinal cord, brainstem, hypothalamic, and limbic forebrain circuits in a metabolic state-dependent manner.
PubMed: 38811166
DOI: 10.1523/JNEUROSCI.2063-23.2024 -
Heliyon May 2024The reserve of glycogen is essential for embryonic development. In oviparous fish, egg is an isolated system after egg laying with all the required energy deposits by...
The reserve of glycogen is essential for embryonic development. In oviparous fish, egg is an isolated system after egg laying with all the required energy deposits by their mothers. However, the key regulated factor mediates the storage of maternal glycogen reserve which support for embryogenesis in the offspring is largely unknown. Glycogen synthase (GYS) is a central enzyme for glycogen synthesis. In our previous study, we generated a knockout zebrafish line, showed an embryonic developmental defect in F generation. In this study, firstly we determined that the was maternal origin by backcrossing the F mutant with wildtype lines. PAS staining and glycogen content measurement showed that glycogen reserve was reduced both in ovaries and embryos in the mutant group compared to wildtypes. Free glucose measurement analysis showed a 50 % of reduction in mutant embryos compared to wildtype embryos at 24 hpf; showed an approximal 50 % of reduction in mutant adults compared to wildtypes. Microinjection of 2-NBDG in embryos and comparison of fluorescent signal demonstrated that glucose uptake ability was decreased in the mutant embryos, indicating an impaired glucose metabolism. Untargeted metabolomics analysis then was employed and revealed that key modified metabolites enriched into vitamin B pathway, carbohydrate and unsaturated fatty acid pathways. These results demonstrated that played a role on glycogen metabolism, involved into the maternal glycogen reserve which essentially contribute to embryonic development.
PubMed: 38803914
DOI: 10.1016/j.heliyon.2024.e31149 -
Advanced Drug Delivery Reviews Jul 2024Microneedles (MNs) offer minimally-invasive access to interstitial fluid (ISF) - a potent alternative to blood in terms of monitoring physiological analytes. This... (Review)
Review
Microneedles (MNs) offer minimally-invasive access to interstitial fluid (ISF) - a potent alternative to blood in terms of monitoring physiological analytes. This property is particularly advantageous for the painless detection and monitoring of drugs and biomolecules. However, the complexity of the skin environment, coupled with the inherent nature of the analytes being detected and the inherent physical properties of MNs, pose challenges when conducting physiological monitoring using this fluid. In this review, we discuss different sensing mechanisms and highlight advancements in monitoring different targets, with a particular focus on drug monitoring. We further list the current challenges facing the field and conclude by discussing aspects of MN design which serve to enhance their performance when monitoring different classes of analytes.
Topics: Humans; Needles; Microinjections; Animals; Extracellular Fluid; Drug Monitoring; Skin; Biosensing Techniques
PubMed: 38797317
DOI: 10.1016/j.addr.2024.115341 -
Neuroscience Letters Jun 2024Stattic, a commercial inhibitor of STAT3, can drive the development of neuropathic pain. Exploring the connection between Stattic and JAK1/STAT3 signaling may facilitate...
Stattic, a commercial inhibitor of STAT3, can drive the development of neuropathic pain. Exploring the connection between Stattic and JAK1/STAT3 signaling may facilitate the understanding of neuropathic pain caused by postherpetic neuralgia (PHN). In the current study, as crucial regulators of inflammation, STAT3 and its associated JAK1/STAT3 pathway were found to be upregulated and activated in the L4-L6 dorsal root ganglion (DRG) of mice in response to resiniferatoxin (RTX)-induced PHN, while subcutaneous administration of Stattic was found to downregulate STAT3 expression and phosphorylation in a PHN model. Stattic administration further attenuated hypersensitivity to mechanical and thermal stimuli in PHN mice, and alleviated inflammation and cell death in the L4-L6 DRG of mice. Overexpression of STAT3 via microinjection of a lentiviral-STAT3 overexpression vector reversed the abnormal decrease of STAT3 at both the mRNA and protein levels in the L4-6 DRGs of PHN mice and significantly promoted hypersensitivity to mechanical stimuli in the mice. Collectively, we found that subcutaneous static administration alleviated RTX-induced neuropathic pain by deactivating JAK1/STAT3 in mice.
Topics: Animals; Neuralgia, Postherpetic; Mice; STAT3 Transcription Factor; Ganglia, Spinal; Male; Disease Models, Animal; Neuralgia; Inflammation; Janus Kinase 1; Mice, Inbred C57BL; Injections, Subcutaneous; Signal Transduction; Cyclic S-Oxides; Diterpenes
PubMed: 38796093
DOI: 10.1016/j.neulet.2024.137831 -
International Journal of Biological... Jun 2024The rice pest Nilaparvata lugens (the brown planthopper, BPH) has developed different levels of resistance to at least 11 chemical pesticides. RNAi technology has...
The rice pest Nilaparvata lugens (the brown planthopper, BPH) has developed different levels of resistance to at least 11 chemical pesticides. RNAi technology has contributed to the development of environmentally friendly RNA biopesticides designed to reduce chemical use. Consequently, more precise targets need to be identified and characterized, and efficient dsRNA delivery methods are necessary for effective field pest control. In this study, a low off-target risk dsNlUAP fragment (166 bp) was designed in silico to minimize the potential adverse effects on non-target organisms. Knockdown of NlUAP via microinjection significantly decreased the content of UDP-N-acetylglucosamine and chitin, causing chitinous structural disorder and abnormal phenotypes in wing and body wall, reduced fertility, and resulted in pest mortality up to 100 %. Furthermore, dsNlUAP was loaded with ROPE@C, a chitosan-modified nanomaterial for spray application, which significantly downregulated the expression of NlUAP, led to 48.9 % pest mortality, and was confirmed to have no adverse effects on Cyrtorhinus lividipennis, an important natural enemy of BPH. These findings will contribute to the development of safer biopesticides for the control of N. lugens.
Topics: Animals; Hemiptera; RNA, Double-Stranded; Chitosan; RNA Interference; Chitin; Oryza; Nucleotidyltransferases
PubMed: 38795878
DOI: 10.1016/j.ijbiomac.2024.132455 -
Biochemical and Biophysical Research... Aug 2024Itch, a common somatic sensation, serves as a crucial protective system. Recent studies have unraveled the neural mechanisms of itch at peripheral, spinal cord as well...
Itch, a common somatic sensation, serves as a crucial protective system. Recent studies have unraveled the neural mechanisms of itch at peripheral, spinal cord as well as cerebral levels. However, a comprehensive understanding of the central mechanism governing itch transmission and regulation remains elusive. Here, we report the role of the medial septum (MS), an integral component of the basal forebrain, in modulating the acute itch processing. The increases in c-Fos neurons and calcium signals within the MS during acute itch processing were observed. Pharmacogenetic activation manipulation of global MS neurons suppressed the scratching behaviors induced by chloroquine or compound 48/80. Microinjection of GABA into the MS or pharmacogenetic inhibition of non-GABAergic neurons markedly suppressed chloroquine-induced scratching behaviors. Pharmacogenetic activation of the MS-ACC GABAergic pathway attenuated chloroquine-induced acute itch. Hence, our findings reveal that MS has a regulatory role in the chloroquine-induced acute itch through local increased GABA to inhibit non-GABAergic neurons and the activation of MS-ACC GABAergic pathway.
Topics: Chloroquine; Animals; Pruritus; Male; gamma-Aminobutyric Acid; Gyrus Cinguli; GABAergic Neurons; Mice, Inbred C57BL; Mice; Septal Nuclei
PubMed: 38795633
DOI: 10.1016/j.bbrc.2024.150145 -
STAR Protocols Jun 2024During development, the zebrafish embryo relies on its yolk sac as a nutrient source. Here, we present a protocol for modifying the free fatty acid (FFA) and...
During development, the zebrafish embryo relies on its yolk sac as a nutrient source. Here, we present a protocol for modifying the free fatty acid (FFA) and triacylglycerol (TAG) content of the zebrafish yolk sac by microinjection. We describe steps for needle and injection mold preparation, FFA and TAG solution preparation, and microinjection. This protocol can elucidate how excesses of FFA and TAG affect development and modify the transcriptome of zebrafish embryos. For complete details on the use and execution of this protocol, please refer to Konadu et al. .
Topics: Animals; Zebrafish; Microinjections; Triglycerides; Fatty Acids, Nonesterified; Embryo, Nonmammalian; Yolk Sac
PubMed: 38795351
DOI: 10.1016/j.xpro.2024.103086 -
International Journal of Molecular... May 2024In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes and , a...
In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes and , a pivotal approach for genetic analysis and vector control. Despite RNAi's potential for species-specific gene targeting, our independent efforts to establish oral delivery of RNAi for identifying genes critical for mosquito development and fitness encountered significant challenges, failing to reproduce previously reported potent RNAi effects. We independently evaluated a range of RNAi-inducing molecules (siRNAs, shRNAs, and dsRNAs) and administration methods (oral delivery, immersion, and microinjection) in three different laboratories. We also tested various mosquito strains and utilized microorganisms for RNA delivery. Our results reveal a pronounced inconsistency in RNAi efficacy, characterized by minimal effects on larval survival and gene expression levels in most instances despite strong published effects for the tested targets. One or multiple factors, including RNase activity in the gut, the cellular internalization and processing of RNA molecules, and the systemic dissemination of the RNAi signal, could be involved in this variability, all of which are barely understood in mosquitoes. The challenges identified in this study highlight the necessity for additional research into the underlying mechanisms of mosquito RNAi to develop more robust RNAi-based methodologies. Our findings emphasize the intricacies of RNAi application in mosquitoes, which present a substantial barrier to its utilization in genetic control strategies.
Topics: Animals; Aedes; RNA Interference; RNA, Small Interfering; Mosquito Vectors; Larva; RNA, Double-Stranded; Gene Silencing; Gene Knockdown Techniques
PubMed: 38791257
DOI: 10.3390/ijms25105218 -
Antioxidants (Basel, Switzerland) Apr 2024Research on ozonated sunflower oil (OSO) is mostly restricted to its topical application, whereas the functional and toxicological assessment of oral OSO consumption is...
Oral Supplementation of Ozonated Sunflower Oil Augments Plasma Antioxidant and Anti-Inflammatory Abilities with Enhancement of High-Density Lipoproteins Functionality in Rats.
Research on ozonated sunflower oil (OSO) is mostly restricted to its topical application, whereas the functional and toxicological assessment of oral OSO consumption is yet to be solved. Herein, OSO was orally supplemented in rats to assess the impact on plasma antioxidant status, low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Also, the functionality of HDL from the OSO-supplemented rats (OSO-HDL) was tested against carboxymethyllysine (CML)- induced hyperinflammation in embryo and adult zebrafish. The results revealed that four weeks of OSO supplementation (3 g/kg BW/day) had no adverse effect on rats' hematological and blood biochemical profiles. Nonetheless, decreased interleukin (IL)-6, and LDL-C levels, along with enhanced ferric ion reduction ability (FRA) and sulfhydryl content, were observed in the plasma of OSO-supplemented rats compared to the control and sunflower oil (SO) supplemented group. In addition, OSO supplementation stabilized apoA-I/HDL and augmented HDL-allied paraoxonase (PON)-1 activity. The microinjection of OSO-HDL (10 nL, 2 mg/mL) efficiently prevented the CML (500 ng)-induced zebrafish embryo mortality and developmental deformities. Similarly, OSO-HDL thwarted CML-posed neurotoxicity and demonstrated a significant hepatoprotective effect against CML-induced fatty liver changes, hepatic inflammation, oxidative stress, and apoptosis, as well as exhibiting a noticeable influence to revert CML-induced dyslipidemia. Conclusively, OSO supplementation demonstrated no toxic effects on rats, ameliorated plasma antioxidant status, and positively influenced HDL stability and functionality, leading to a protective effect against CML-induced toxicity in zebrafish.
PubMed: 38790634
DOI: 10.3390/antiox13050529 -
Cells May 2024Intestinal homeostasis results from the proper interplay among epithelial cells, the enteric nervous system (ENS), interstitial cells of Cajal (ICCs), smooth muscle...
Intestinal homeostasis results from the proper interplay among epithelial cells, the enteric nervous system (ENS), interstitial cells of Cajal (ICCs), smooth muscle cells, the immune system, and the microbiota. The disruption of this balance underpins the onset of gastrointestinal-related diseases. The scarcity of models replicating the intricate interplay between the ENS and the intestinal epithelium highlights the imperative for developing novel methods. We have pioneered a sophisticated tridimensional in vitro technique, coculturing small intestinal organoids with myenteric and submucosal neurons. Notably, we have made significant advances in (1) refining the isolation technique for culturing the myenteric plexus, (2) enhancing the isolation of the submucosal plexus-both yielding mixed cultures of enteric neurons and glial cells from both plexuses, and (3) subsequently co-culturing myenteric and submucosal neurons with small intestinal organoids. This co-culture system establishes neural innervations with intestinal organoids, allowing for the investigation of regulatory interactions in the context of gastrointestinal diseases. Furthermore, we have developed a method for microinjecting the luminal space of small intestinal organoids with fluorescently labeled compounds. This technique possesses broad applicability such as the assessment of intestinal permeability, transcytosis, and immunocytochemical and immunofluorescence applications. This microinjection method could be extended to alternative experimental setups, incorporating bacterial species, or applying treatments to study ENS-small intestinal epithelium interactions. Therefore, this technique serves as a valuable tool for evaluating the intricate interplay between neuronal and intestinal epithelial cells (IECs) and shows great potential for drug screening, gene editing, the development of novel therapies, the modeling of infectious diseases, and significant advances in regenerative medicine. The co-culture establishment process spans twelve days, making it a powerful asset for comprehensive research in this critical field.
Topics: Animals; Mice; Coculture Techniques; Gastrointestinal Tract; Intestine, Small; Myenteric Plexus; Neurons; Organoids; Submucous Plexus
PubMed: 38786037
DOI: 10.3390/cells13100815