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Frontiers in Cellular Neuroscience 2024Insulin-like growth factor-1 (IGF-1) is a polypeptide hormone with a ubiquitous distribution in numerous tissues and with various functions in both neuronal and...
Insulin-like growth factor-1 (IGF-1) is a polypeptide hormone with a ubiquitous distribution in numerous tissues and with various functions in both neuronal and non-neuronal cells. IGF-1 provides trophic support for many neurons of both the central and peripheral nervous systems. In the central nervous system (CNS), IGF-1R signaling regulates brain development, increases neuronal firing and modulates synaptic transmission. IGF-1 and IGF-IR are not only expressed in CNS neurons but also in sensory dorsal root ganglion (DRG) nociceptive neurons that convey pain signals. DRG nociceptive neurons express a variety of receptors and ion channels that are essential players of neuronal excitability, notably the ligand-gated cation channel TRPV1 and the voltage-gated M-type K channel, which, respectively, triggers and dampens sensory neuron excitability. Although many lines of evidence suggest that IGF-IR signaling contributes to pain sensitivity, its possible modulation of TRPV1 and M-type K channel remains largely unexplored. In this study, we examined the impact of IGF-1R signaling on DRG neuron excitability and its modulation of TRPV1 and M-type K channel activities in cultured rat DRG neurons. Acute application of IGF-1 to DRG neurons triggered hyper-excitability by inducing spontaneous firing or by increasing the frequency of spikes evoked by depolarizing current injection. These effects were prevented by the IGF-1R antagonist NVP-AEW541 and by the PI3Kinase blocker wortmannin. Surprisingly, acute exposure to IGF-1 profoundly inhibited both the TRPV1 current and the spike burst evoked by capsaicin. The Src kinase inhibitor PP2 potently depressed the capsaicin-evoked spike burst but did not alter the IGF-1 inhibition of the hyperexcitability triggered by capsaicin. Chronic IGF-1 treatment (24 h) reduced the spike firing evoked by depolarizing current injection and upregulated the M-current density. In contrast, chronic IGF-1 markedly increased the spike burst evoked by capsaicin. In all, our data suggest that IGF-1 exerts complex effects on DRG neuron excitability as revealed by its dual and opposite actions upon acute and chronic exposures.
PubMed: 38919332
DOI: 10.3389/fncel.2024.1391858 -
Frontiers in Pharmacology 2024Ion channels are critical drug targets for a range of pathologies, such as epilepsy, pain, itch, autoimmunity, and cardiac arrhythmias. To develop effective and safe...
Ion channels are critical drug targets for a range of pathologies, such as epilepsy, pain, itch, autoimmunity, and cardiac arrhythmias. To develop effective and safe therapeutics, it is necessary to design small molecules with high potency and selectivity for specific ion channel subtypes. There has been increasing implementation of structure-guided drug design for the development of small molecules targeting ion channels. We evaluated the performance of two RosettaLigand docking methods, RosettaLigand and GALigandDock, on the structures of known ligand-cation channel complexes. Ligands were docked to voltage-gated sodium (Na), voltage-gated calcium (Ca), and transient receptor potential vanilloid (TRPV) channel families. For each test case, RosettaLigand and GALigandDock methods frequently sampled a ligand-binding pose within a root mean square deviation (RMSD) of 1-2 Å relative to the experimental ligand coordinates. However, RosettaLigand and GALigandDock scoring functions cannot consistently identify experimental ligand coordinates as top-scoring models. Our study reveals that the proper scoring criteria for RosettaLigand and GALigandDock modeling of ligand-ion channel complexes should be assessed on a case-by-case basis using sufficient ligand and receptor interface sampling, knowledge about state-specific interactions of the ion channel, and inherent receptor site flexibility that could influence ligand binding.
PubMed: 38919257
DOI: 10.3389/fphar.2024.1411428 -
Acta Dermatovenerologica Alpina,... Jun 2024This study explores the immunogenetic associations of human leukocyte antigens (HLA) and the calcium release-activated calcium modulator 1 (ORAI1) and stromal...
INTRODUCTION
This study explores the immunogenetic associations of human leukocyte antigens (HLA) and the calcium release-activated calcium modulator 1 (ORAI1) and stromal interaction molecule 1 (STIM1) genes in HIV-1‒positive patients with HIV-related skin disorders.
METHODS
This study assessed the distribution of variants of HLA class II alleles and expression levels of ORAI1 and STIM1 genes in the blood between HIV-1‒positive patients with HIV-related skin disorders and the control group with no HIV within the Latvian population.
RESULTS
The research group comprised 115 HIV-1‒positive patients with HIV-related skin disorders, and the control group included 80 healthy individuals. Risk alleles (HLA- DQB1*02:01-0301 and HLA-DQA1*01:01-0501) and protective alleles (HLA-DRB1*07-13, DRB1*01-13, DRB1*04-11, and HLA-DQA1*05:01-0501) showed statistical significance in the groups. In 38 out of 115 patients, higher expression levels of ORAI1 and STIM1 genes were detected in the blood at the beginning of treatment. A significantly higher level of the microribonucleic acid (mRNA) ORAI1 gene was also found in the control group.
CONCLUSIONS
The results demonstrate that HLA class II alleles are associated with a trend toward risk/protection concerning HIV-related skin disorders in HIV-1‒positive patients. It was also shown that a low level of ORAI1 mRNA and the risk allele HLA-DQB1*0201-0301 were simultaneously present in the research group.
Topics: Humans; ORAI1 Protein; Male; Latvia; Female; Stromal Interaction Molecule 1; Adult; HIV Infections; Middle Aged; Polymorphism, Genetic; Skin Diseases; Case-Control Studies; Neoplasm Proteins; Genetic Predisposition to Disease
PubMed: 38918943
DOI: No ID Found -
Cell & Bioscience Jun 2024Polyamines (PA) are polycations with pleiotropic functions in cellular physiology and pathology. In particular, PA have been involved in the regulation of cell... (Review)
Review
Polyamines (PA) are polycations with pleiotropic functions in cellular physiology and pathology. In particular, PA have been involved in the regulation of cell homeostasis and proliferation participating in the control of fundamental processes like DNA transcription, RNA translation, protein hypusination, autophagy and modulation of ion channels. Indeed, their dysregulation has been associated to inflammation, oxidative stress, neurodegeneration and cancer progression. Accordingly, PA intracellular levels, derived from the balance between uptake, biosynthesis, and catabolism, need to be tightly regulated. Among the mechanisms that fine-tune PA metabolic enzymes, emerging findings highlight the importance of noncoding RNAs (ncRNAs). Among the ncRNAs, microRNA, long noncoding RNA and circRNA are the most studied as regulators of gene expression and mRNA metabolism and their alteration have been frequently reported in pathological conditions, such as cancer progression and brain diseases. In this review, we will discuss the role of ncRNAs in the regulation of PA genes, with a particular emphasis on the changes of this modulation observed in health disorders.
PubMed: 38918813
DOI: 10.1186/s13578-024-01235-3 -
Cell Death & Disease Jun 2024Multiple sevoflurane exposures may damage the developing brain. The neuroprotective function of dexmedetomidine has been widely confirmed in animal experiments and human...
Multiple sevoflurane exposures may damage the developing brain. The neuroprotective function of dexmedetomidine has been widely confirmed in animal experiments and human studies. However, the effect of dexmedetomidine on the glymphatic system has not been clearly studied. We hypothesized that dexmedetomidine could alleviate sevoflurane-induced circulatory dysfunction of the glymphatic system in young mice. Six-day-old C57BL/6 mice were exposed to 3% sevoflurane for 2 h daily, continuously for 3 days. Intraperitoneal injection of either normal saline or dexmedetomidine was administered before every anaesthesia. Meanwhile the circulatory function of glymphatic system was detected by tracer injection at P8 and P32. On P30-P32, behavior tests including open field test, novel object recognition test, and Y-maze test were conducted. Primary astrocyte cultures were established and treated with the PI3K activator 740Y-P, dexmedetomidine, and small interfering RNA (siRNA) to silence ΔFosB. We propose for the first time that multiple exposure to sevoflurane induces circulatory dysfunction of the glymphatic system in young mice. Dexmedetomidine improves the circulatory capacity of the glymphatic system in young mice following repeated exposure to sevoflurane through the PI3K/AKT/ΔFosB/AQP4 signaling pathway, and enhances their long-term learning and working memory abilities.
Topics: Animals; Dexmedetomidine; Sevoflurane; Glymphatic System; Proto-Oncogene Proteins c-akt; Mice; Mice, Inbred C57BL; Phosphatidylinositol 3-Kinases; Aquaporin 4; Signal Transduction; Astrocytes; Male
PubMed: 38918408
DOI: 10.1038/s41419-024-06845-w -
PloS One 2024Gulf War Illness (GWI) is a chronic condition characterized by multisystem symptoms that still affect up to one-third of veterans who engaged in combat in the Gulf War...
Gulf War Illness (GWI) is a chronic condition characterized by multisystem symptoms that still affect up to one-third of veterans who engaged in combat in the Gulf War three decades ago. The aetiology of GWI is mainly explained by exposure to multiple toxic agents, vaccines, and medications. As there is a significant overlap in symptoms between GWI and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), the objective of this study was to investigate a biomarker widely reported in Natural Killer (NK) cells from ME/CFS patients, the Transient Receptor Potential Melastatin 3 (TRPM3) ion channel. NK cells from 6 healthy controls (HC) and 6 GWI participants were isolated, and TRPM3 function was assessed through whole-cell patch-clamp. As demonstrated by prior studies, NK cells from HC expressed typical TRPM3 function after pharmacomodulation. In contrast, this pilot investigation demonstrates a dysfunctional TRPM3 in NK cells from GWI participants through application of a TRPM3 agonist and confirmed by a TRPM3 antagonist. There was a significant reduction in TRPM3 function from GWI than results measured in HC. This study provides an unprecedented research field to investigate the involvement of TRP ion channels in the pathomechanism and potential medical interventions to improve GWI quality of life.
Topics: Humans; TRPM Cation Channels; Persian Gulf Syndrome; Killer Cells, Natural; Male; Middle Aged; Adult; Female; Case-Control Studies; Patch-Clamp Techniques
PubMed: 38917121
DOI: 10.1371/journal.pone.0305704 -
Proceedings of the National Academy of... Jul 2024HCN1-4 channels are the molecular determinants of the I/I current that crucially regulates cardiac and neuronal cell excitability. HCN dysfunctions lead to sinoatrial...
HCN1-4 channels are the molecular determinants of the I/I current that crucially regulates cardiac and neuronal cell excitability. HCN dysfunctions lead to sinoatrial block (HCN4), epilepsy (HCN1), and chronic pain (HCN2), widespread medical conditions awaiting subtype-specific treatments. Here, we address the problem by solving the cryo-EM structure of HCN4 in complex with ivabradine, to date the only HCN-specific drug on the market. Our data show ivabradine bound inside the open pore at 3 Å resolution. The structure unambiguously proves that Y507 and I511 on S6 are the molecular determinants of ivabradine binding to the inner cavity, while F510, pointing outside the pore, indirectly contributes to the block by controlling Y507. Cysteine 479, unique to the HCN selectivity filter (SF), accelerates the kinetics of block. Molecular dynamics simulations further reveal that ivabradine blocks the permeating ion inside the SF by electrostatic repulsion, a mechanism previously proposed for quaternary ammonium ions.
Topics: Ivabradine; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; Molecular Dynamics Simulation; Humans; Cryoelectron Microscopy; Animals; Potassium Channels; Muscle Proteins
PubMed: 38917012
DOI: 10.1073/pnas.2402259121 -
Proceedings of the National Academy of... Jul 2024S100A1, a small homodimeric EF-hand Ca-binding protein (~21 kDa), plays an important regulatory role in Ca signaling pathways involved in various biological functions...
S100A1, a small homodimeric EF-hand Ca-binding protein (~21 kDa), plays an important regulatory role in Ca signaling pathways involved in various biological functions including Ca cycling and contractile performance in skeletal and cardiac myocytes. One key target of the S100A1 interactome is the ryanodine receptor (RyR), a huge homotetrameric Ca release channel (~2.3 MDa) of the sarcoplasmic reticulum. Here, we report cryoelectron microscopy structures of S100A1 bound to RyR1, the skeletal muscle isoform, in absence and presence of Ca. Ca-free apo-S100A1 binds beneath the bridging solenoid (BSol) and forms contacts with the junctional solenoid and the shell-core linker of RyR1. Upon Ca-binding, S100A1 undergoes a conformational change resulting in the exposure of the hydrophobic pocket known to serve as a major interaction site of S100A1. Through interactions of the hydrophobic pocket with RyR1, Ca-bound S100A1 intrudes deeper into the RyR1 structure beneath BSol than the apo-form and induces sideways motions of the C-terminal BSol region toward the adjacent RyR1 protomer resulting in tighter interprotomer contacts. Interestingly, the second hydrophobic pocket of the S100A1-dimer is largely exposed at the hydrophilic surface making it prone to interactions with the local environment, suggesting that S100A1 could be involved in forming larger heterocomplexes of RyRs with other protein partners. Since S100A1 interactions stabilizing BSol are implicated in the regulation of RyR-mediated Ca release, the characterization of the S100A1 binding site conserved between RyR isoforms may provide the structural basis for the development of therapeutic strategies regarding treatments of RyR-related disorders.
Topics: Ryanodine Receptor Calcium Release Channel; S100 Proteins; Calcium; Cryoelectron Microscopy; Animals; Protein Binding; Binding Sites; Models, Molecular; Protein Conformation; Humans
PubMed: 38917010
DOI: 10.1073/pnas.2400497121 -
Proceedings of the National Academy of... Jul 2024Spinal cord dorsal horn inhibition is critical to the processing of sensory inputs, and its impairment leads to mechanical allodynia. How this decreased inhibition...
Spinal cord dorsal horn inhibition is critical to the processing of sensory inputs, and its impairment leads to mechanical allodynia. How this decreased inhibition occurs and whether its restoration alleviates allodynic pain are poorly understood. Here, we show that a critical step in the loss of inhibitory tone is the change in the firing pattern of inhibitory parvalbumin (PV)-expressing neurons (PVNs). Our results show that PV, a calcium-binding protein, controls the firing activity of PVNs by enabling them to sustain high-frequency tonic firing patterns. Upon nerve injury, PVNs transition to adaptive firing and decrease their PV expression. Interestingly, decreased PV is necessary and sufficient for the development of mechanical allodynia and the transition of PVNs to adaptive firing. This transition of the firing pattern is due to the recruitment of calcium-activated potassium (SK) channels, and blocking them during chronic pain restores normal tonic firing and alleviates chronic pain. Our findings indicate that PV is essential for controlling the firing pattern of PVNs and for preventing allodynia. Developing approaches to manipulate these mechanisms may lead to different strategies for chronic pain relief.
Topics: Parvalbumins; Animals; Chronic Pain; Mice; Neurons; Hyperalgesia; Male; Action Potentials; Small-Conductance Calcium-Activated Potassium Channels
PubMed: 38916998
DOI: 10.1073/pnas.2403777121 -
Drug Design, Development and Therapy 2024This study probed the mechanism of action of Xinfeng Capsule (XFC) in myocardial injury in rats with adjuvant arthritis (AA) via the growth arrest-specific transcript 5...
PURPOSE
This study probed the mechanism of action of Xinfeng Capsule (XFC) in myocardial injury in rats with adjuvant arthritis (AA) via the growth arrest-specific transcript 5 (GAS5)/microRNA-21 (miR-21)/Toll-like receptor 4 (TLR4) axis.
METHODS
Rats were injected with Freund's complete adjuvant to establish a rat model of AA. Then, some modeled rats were given normal saline or drugs only, and some modeled rats were injected with adeno-associated viruses or necrosulfonamide (NSA; a pyroptosis inhibitor) before drug administration. Toe swelling and arthritis index (AI) were calculated. Pathological and morphological changes in synovial and myocardial tissues were analyzed with hematoxylin-eosin staining, and pyroptotic vesicles and the ultrastructural changes of myocardial tissues were observed with transmission electron microscopy. The serum levels of interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor (TNF)-α were detected, and lactate dehydrogenase (LDH) release was measured in myocardial tissues, accompanied by the examination of GAS5, miR-21, TLR4, nuclear factor-kB (NF-κB) p65, nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), Caspase-1, and Gasdermin D (GSDMD) expression in myocardial tissues.
RESULTS
After AA modeling, rats presented with significantly increased toe swelling and AI scores, synovial and myocardial tissue damage, elevated pyroptotic vesicles, and markedly enhanced serum levels of IL-1β, IL-18, IL-6, and TNF-α, accompanied by significantly diminished GAS5 expression, substantially augmented miR-21, TLR4, NF-κB p65, NLRP3, Caspase-1, and GSDMD expression, greatly increased LDH release in myocardial tissues. XFC treatment significantly declined toe swelling, AI scores, synovial and myocardial tissue damage, and the serum levels of IL-1β, IL-18, IL-6, and TNF-α in AA rats. Additionally, XFC treatment markedly elevated GAS5 expression and substantially lowered LDH release and miR-21, TLR4, NF-κB p65, NLRP3, Caspase-1, and GSDMD expression in myocardial tissues of AA rats. Moreover, the above effects of XFC in AA rats were further promoted by GAS5 overexpression or NSA treatment.
CONCLUSION
XFC alleviated myocardial injury in AA rats by regulating the GAS5/miR-21/TLR4 axis and inhibiting pyroptosis and pro-inflammatory cytokine secretion.
Topics: Animals; Toll-Like Receptor 4; Pyroptosis; Rats; Arthritis, Experimental; MicroRNAs; Drugs, Chinese Herbal; Rats, Sprague-Dawley; Male; Phosphate-Binding Proteins; Freund's Adjuvant; Gasdermins
PubMed: 38915862
DOI: 10.2147/DDDT.S456783