-
Cellular and Molecular Life Sciences :... Jun 2024As human skin comes into contact with the tiny hairs or setae of the oak processionary caterpillar, Thaumetopoea processionea, a silent yet intense chemical...
As human skin comes into contact with the tiny hairs or setae of the oak processionary caterpillar, Thaumetopoea processionea, a silent yet intense chemical confrontation occurs. The result is a mix of issues: skin rashes and an intense itching that typically lasts days and weeks after the contact. This discomfort poses a significant health threat not only to humans but also to animals. In Western Europe, the alarming increase in outbreaks extends beyond areas near infested trees due to the dispersion of the setae. Predictions indicate a sustained rise in outbreaks, fueled by global changes favoring the caterpillar's survival and distribution. Currently, the absence of an efficient treatment persists due to significant gaps in our comprehension of the pathophysiology associated with this envenomation. Here, we explored the interaction between the venom extract derived from the setae of T. processionea and voltage- and ligand-gated ion channels and receptors. By conducting electrophysiological analyses, we discovered ex vivo evidence highlighting the significant role of TPTX-Tp1, a peptide toxin from T. processionea, in modulating TRPV1. TPTX-Tp1 is a secapin-like peptide and demonstrates a unique ability to modulate TRPV1 channels in the presence of capsaicin, leading to cell depolarization, itch and inflammatory responses. This discovery opens new avenues for developing a topical medication, suggesting the incorporation of a TRPV1 blocker as a potential solution for the local effects caused by T. processionea.
Topics: TRPV Cation Channels; Animals; Humans; Arthropod Venoms; Moths; Skin; Larva
PubMed: 38940922
DOI: 10.1007/s00018-024-05318-9 -
Molecular Medicine Reports Aug 2024Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia...
Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia promotes microglial pyroptosis by increasing the oxygen extraction rate in an acute ischemic stroke model. C57BL/6 mice that underwent middle cerebral artery occlusion were used for assessment of blood glucose level and neurological function. The cerebral oxygen extraction ratio (CERO), oxygen consumption rate (OCR) and partial pressure of brain tissue oxygen (PbtO) were measured. To investigate the significance of the NOD‑like receptor protein 3 (NLRP3) inflammasome, NLRP3 mice were used, and the expression levels of NLRP3, caspase‑1, full‑length gasdermin D (GSDMD‑FL), GSDMD‑N domain (GSDMD‑N), IL‑1β and IL‑18 were evaluated. In addition, Z‑YVAD‑FMK, a caspase‑1 inhibitor, was used to treat microglia to determine whether activation of the NLRP3 inflammasome was required for the enhancing effect of hyperglycemia on pyroptosis. It was revealed that hyperglycemia accelerated cerebral injury in the acute ischemic stroke model, as evidenced by decreased latency to fall and the percentage of foot fault. Hyperglycemia aggravated hypoxia by increasing the oxygen extraction rate, as evidenced by increased CERO and OCR, and decreased PbtO in response to high glucose treatment. Furthermore, hyperglycemia‑induced microglial pyroptosis was confirmed by detection of increased levels of caspase‑1, GSDMD‑N, IL‑1β and IL‑18 and a decreased level of GSDMD‑FL. However, the knockout of NLRP3 attenuated these effects. Pharmacological inhibition of caspase‑1 also reduced the expression levels of GSDMD‑N, IL‑1β and IL‑18 in microglial cells. These results suggested that hyperglycemia stimulated NLRP3 inflammasome activation by increasing the oxygen extraction rate, thus leading to the aggravation of pyroptosis following ischemic stroke.
Topics: Animals; Pyroptosis; Microglia; Ischemic Stroke; Mice; NLR Family, Pyrin Domain-Containing 3 Protein; Oxygen; Male; Hyperglycemia; Inflammasomes; Mice, Inbred C57BL; Caspase 1; Disease Models, Animal; Mice, Knockout; Interleukin-1beta; Phosphate-Binding Proteins; Oxygen Consumption; Gasdermins
PubMed: 38940333
DOI: 10.3892/mmr.2024.13270 -
Frontiers in Bioscience (Landmark... Jun 2024Alzheimer's disease is characterized by extracellular beta-amyloid plaques, intraneuronal tau neurofibrillary tangles and excessive neurodegeneration. The mechanisms of...
BACKGROUND
Alzheimer's disease is characterized by extracellular beta-amyloid plaques, intraneuronal tau neurofibrillary tangles and excessive neurodegeneration. The mechanisms of neuron degeneration and the potential of these neurons to form new nerve fibers for compensation remain elusive. The present study aimed to evaluate the impact of beta-amyloid and tau on new formations of nerve fibers from mouse organotypic brain slices connected to collagen-based microcontact prints.
METHODS
Organotypic brain slices of postnatal day 8-10 wild-type mice were connected to established collagen-based microcontact prints loaded with polyornithine to enhance nerve fiber outgrowth. Human beta-amyloid(42) or P301S mutated aggregated tau was co-loaded to the prints. Nerve fibers were immunohistochemically stained with neurofilament antibodies. The physiological activity of outgrown neurites was tested with neurotracer MiniRuby, voltage-sensitive dye FluoVolt, and calcium-sensitive dye Rhod-4.
RESULTS
Immunohistochemical staining revealed newly formed nerve fibers extending along the prints derived from the brain slices. While collagen-only microcontact prints stimulated nerve fiber growth, those loaded with polyornithine significantly enhanced nerve fiber outgrowth. Beta-amyloid(42) significantly increased the neurofilament-positive nerve fibers, while tau had only a weak effect. MiniRuby crystals, retrogradely transported along these newly formed nerve fibers, reached the hippocampus, while FluoVolt and Rhod-4 monitored electrical activity in newly formed nerve fibers.
CONCLUSIONS
Our data provide evidence that intact nerve fibers can form along collagen-based microcontact prints from mouse brain slices. The Alzheimer's peptide beta-amyloid(42) stimulates this growth, hinting at a neuroprotective function when physiologically active. This "brain-on-chip" model may offer a platform for screening bioactive factors or testing drug effects on nerve fiber growth.
Topics: Animals; Amyloid beta-Peptides; Mice; Nerve Fibers; Brain; tau Proteins; Humans; Immunohistochemistry; Peptide Fragments; Alzheimer Disease; Mice, Inbred C57BL
PubMed: 38940051
DOI: 10.31083/j.fbl2906232 -
Sheng Li Xue Bao : [Acta Physiologica... Jun 2024Hemoglobinopathies are one of the most common single-gene genetic disorders globally, with approximately 1% to 5% of the global population carrying the mutated gene for... (Review)
Review
Hemoglobinopathies are one of the most common single-gene genetic disorders globally, with approximately 1% to 5% of the global population carrying the mutated gene for thalassemia. Thalassemia are classified into transfusion-dependent thalassemia and non-transfusion-dependent thalassemia based on the need for blood transfusion. Traditional treatment modalities include blood transfusion, splenectomy, hydroxyurea therapy, and iron chelation therapy, which are now widely used for clinical treatment and constitute the main methods recommended in the β-thalassemia treatment guidelines. However, there are multiple barriers and limitations to the application of these approaches, and there is an urgent need to explore new therapeutic approaches. With the in-depth study of the pathophysiological process of β-thalassemia, a deeper understanding of the pathogenesis of the disease has been gained. It has been demonstrated that the pathogenesis of thalassemia is closely related to ineffective erythropoiesis (IE), imbalance in the ratio of α/β-globin protein chains and iron overload. New therapeutic approaches are emerging for different pathogenic mechanisms. Among them, new drugs for the treatment of IE mainly include activin receptor II trap ligands, Janus kinase 2 inhibitors, pyruvate kinase activators, and glycine transporter protein 1 inhibitors. Correcting the imbalance in the hemoglobin chain is mainly due to emerging technologies such as bone marrow transplantation and gene editing. Measures in reducing iron overload are associated with inhibiting the activity of transferrin and hepcidin. These new approaches provide new ideas and options for the treatment and management of β-thalassemia.
Topics: beta-Thalassemia; Humans; Genetic Therapy; Blood Transfusion; Janus Kinase 2; Activin Receptors, Type II; Splenectomy; Gene Editing; Iron Chelating Agents; Bone Marrow Transplantation; Iron Overload; Erythropoiesis; Immunoglobulin Fc Fragments; Recombinant Fusion Proteins
PubMed: 38939943
DOI: No ID Found -
JACS Au Jun 2024Computational study of the effect of drug candidates on intrinsically disordered biomolecules is challenging due to their vast and complex conformational space. Here, we...
Computational study of the effect of drug candidates on intrinsically disordered biomolecules is challenging due to their vast and complex conformational space. Here, we developed a comparative Markov state analysis (CoVAMPnet) framework to quantify changes in the conformational distribution and dynamics of a disordered biomolecule in the presence and absence of small organic drug candidate molecules. First, molecular dynamics trajectories are generated using enhanced sampling, in the presence and absence of small molecule drug candidates, and ensembles of soft Markov state models (MSMs) are learned for each system using unsupervised machine learning. Second, these ensembles of learned MSMs are aligned across different systems based on a solution to an optimal transport problem. Third, the directional importance of inter-residue distances for the assignment to different conformational states is assessed by a discriminative analysis of aggregated neural network gradients. This final step provides interpretability and biophysical context to the learned MSMs. We applied this novel computational framework to assess the effects of ongoing phase 3 therapeutics tramiprosate (TMP) and its metabolite 3-sulfopropanoic acid (SPA) on the disordered Aβ42 peptide involved in Alzheimer's disease. Based on adaptive sampling molecular dynamics and CoVAMPnet analysis, we observed that both TMP and SPA preserved more structured conformations of Aβ42 by interacting nonspecifically with charged residues. SPA impacted Aβ42 more than TMP, protecting α-helices and suppressing the formation of aggregation-prone β-strands. Experimental biophysical analyses showed only mild effects of TMP/SPA on Aβ42 and activity enhancement by the endogenous metabolization of TMP into SPA. Our data suggest that TMP/SPA may also target biomolecules other than Aβ peptides. The CoVAMPnet method is broadly applicable to study the effects of drug candidates on the conformational behavior of intrinsically disordered biomolecules.
PubMed: 38938816
DOI: 10.1021/jacsau.4c00182 -
Frontiers in Immunology 2024Human respiratory viruses are the most prevalent cause of disease in humans, with the highly infectious RSV being the leading cause of infant bronchiolitis and viral...
Human respiratory viruses are the most prevalent cause of disease in humans, with the highly infectious RSV being the leading cause of infant bronchiolitis and viral pneumonia. Responses to type I IFNs are the primary defense against viral infection. However, RSV proteins have been shown to antagonize type I IFN-mediated antiviral innate immunity, specifically dampening intracellular IFN signaling. Respiratory epithelial cells are the main target for RSV infection. In this study, we found RSV-NS1 interfered with the IFN-α JAK/STAT signaling pathway of epithelial cells. RSV-NS1 expression significantly enhanced IFN-α-mediated phosphorylation of STAT1, but not pSTAT2; and neither STAT1 nor STAT2 total protein levels were affected by RSV-NS1. However, expression of RSV-NS1 significantly reduced ISRE and GAS promoter activity and anti-viral IRG expression. Further mechanistic studies demonstrated RSV-NS1 bound STAT1, with protein modeling indicating a possible interaction site between STAT1 and RSV-NS1. Nuclear translocation of STAT1 was reduced in the presence of RSV-NS1. Additionally, STAT1's interaction with the nuclear transport adapter protein, KPNA1, was also reduced, suggesting a mechanism by which RSV blocks STAT1 nuclear translocation. Indeed, reducing STAT1's access to the nucleus may explain RSV's suppression of IFN JAK/STAT promoter activation and antiviral gene induction. Taken together these results describe a novel mechanism by which RSV controls antiviral IFN-α JAK/STAT responses, which enhances our understanding of RSV's respiratory disease progression.
Topics: STAT1 Transcription Factor; Humans; Signal Transduction; Interferon-alpha; Respiratory Syncytial Virus, Human; Viral Nonstructural Proteins; Respiratory Syncytial Virus Infections; Janus Kinases; Cell Nucleus; Phosphorylation; Active Transport, Cell Nucleus; Cell Line
PubMed: 38938568
DOI: 10.3389/fimmu.2024.1395809 -
Open Veterinary Journal May 2024Oxygen deprivation (OD) is a critical condition that can lead to brain damage and even death. Current hypoxia management approaches are limited in effectiveness. (CA),...
BACKGROUND
Oxygen deprivation (OD) is a critical condition that can lead to brain damage and even death. Current hypoxia management approaches are limited in effectiveness. (CA), known for its neuroprotective properties, offers a potential alternative for OD treatment.
AIMS
This study aims to investigate the neuroprotective effects of CA on the expression of brain-derived neurotrophic factor (BDNF) and vesicular glutamate transporter 1 (VGLUT1) in zebrafish larvae under oxygen-deficient conditions.
METHODS
Zebrafish embryos were subjected to low oxygen levels (1.5 mg/l) 0-2 hours post-fertilization (hpf) until 3 days post-fertilization (dpf), simulating the early stages of OD. Subsequent treatment involved varying concentrations of CA (1.25-5 µg/ml) up to 9 days post-fertilization. The expression levels of BDNF and VGLUT1 were measured using PCR methods. Statistical analysis was conducted using a two-way analysis of variance to evaluate the impact of CA on the expression of BDNF and VGLUT1 in zebrafish larvae aged 3 and 9 dpf in oxygen-deprived conditions.
RESULTS
CA significantly influenced the expression of BDNF and VGLUT1 under OD ( < 0.001). An increase in BDNF expression ( < 0.001) and a decrease in VGLUT1 ( < 0.01) were observed in zebrafish larvae experiencing OD and treated with CA. There was no significant difference in BDNF and VGLUT1 expression across age variations in zebrafish larvae at 3 dpf and 9 dpf in the treatment groups ( > 0.05). CA concentration of 2.5 µg/ml effectively enhanced BDNF and reduced VGLUT1 in 3-9 dpf zebrafish larvae.
CONCLUSION
CA demonstrates potential as a neuroprotective agent, modulating increased BDNF expression and reduced VGLUT1 under OD conditions. These findings lay a foundation for further research in developing therapies for oxygen deficiency.
Topics: Animals; Zebrafish; Centella; Plant Extracts; Larva; Triterpenes; Brain-Derived Neurotrophic Factor; Neuroprotective Agents; Oxygen; Fish Diseases; Hypoxia
PubMed: 38938421
DOI: 10.5455/OVJ.2024.v14.i5.9 -
Military Medical Research Jun 2024Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with...
BACKGROUND
Extracellular adenosine triphosphate (ATP) is an important signal molecule. In previous studies, intensive research had revealed the crucial roles of family with sequence similarity 3 member A (FAM3A) in controlling hepatic glucolipid metabolism, islet β cell function, adipocyte differentiation, blood pressure, and other biological and pathophysiological processes. Although mitochondrial protein FAM3A plays crucial roles in the regulation of glucolipid metabolism via stimulating ATP release to activate P2 receptor pathways, its mechanism in promoting ATP release in hepatocytes remains unrevealed.
METHODS
db/db, high-fat diet (HFD)-fed, and global pannexin 1 (PANX1) knockout mice, as well as liver sections of individuals, were used in this study. Adenoviruses and adeno-associated viruses were utilized for in vivo gene overexpression or inhibition. To evaluate the metabolic status in mice, oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT), insulin tolerance test (ITT), and magnetic resonance imaging (MRI) were conducted. Protein-protein interactions were determined by coimmunoprecipitation with mass spectrometry (MS) assays.
RESULTS
In livers of individuals and mice with steatosis, the expression of ATP-permeable channel PANX1 was increased (P < 0.01). Hepatic PANX1 overexpression ameliorated the dysregulated glucolipid metabolism in obese mice. Mice with hepatic PANX1 knockdown or global PANX1 knockout exhibited disturbed glucolipid metabolism. Restoration of hepatic PANX1 rescued the metabolic disorders of PANX1-deficient mice (P < 0.05). Mechanistically, ATP release is mediated by the PANX1-activated protein kinase B-forkhead box protein O1 (Akt-FOXO1) pathway to inhibit gluconeogenesis via P2Y receptors in hepatocytes. PANX1-mediated ATP release also activated calmodulin (CaM) (P < 0.01), which interacted with c-Jun N-terminal kinase (JNK) to inhibit its activity, thereby deactivating the transcription factor activator protein-1 (AP1) and repressing fatty acid synthase (FAS) expression and lipid synthesis (P < 0.05). FAM3A stimulated the expression of PANX1 via heat shock factor 1 (HSF1) in hepatocytes (P < 0.05). Notably, FAM3A overexpression failed to promote ATP release, inhibit the expression of gluconeogenic and lipogenic genes, and suppress gluconeogenesis and lipid deposition in PANX1-deficient hepatocytes and livers.
CONCLUSIONS
PANX1-mediated release of ATP plays a crucial role in maintaining hepatic glucolipid homeostasis, and it confers FAM3A's suppressive effects on hepatic gluconeogenesis and lipogenesis.
Topics: Animals; Connexins; Mice; Gluconeogenesis; Nerve Tissue Proteins; Adenosine Triphosphate; Lipogenesis; Liver; Mice, Knockout; Male; Humans; Diet, High-Fat; Cytokines
PubMed: 38937853
DOI: 10.1186/s40779-024-00543-6 -
Journal of Molecular Modeling Jun 2024Existing researches confirmed that β amyloid (Aβ) has a high affinity for the α7 nicotinic acetylcholine receptor (α7nAChR), associating closely to Alzheimer's...
CONTEXT
Existing researches confirmed that β amyloid (Aβ) has a high affinity for the α7 nicotinic acetylcholine receptor (α7nAChR), associating closely to Alzheimer's disease. The majority of related studies focused on the experimental reports on the neuroprotective role of Aβ fragment (Aβ), however, with a lack of investigation into the most suitable binding region and mechanism of action between Aβ fragment and α7nAChR. In the study, we employed four Aβ fragments Aβ, Aβ, Aβ, Aβ, and Aβ, of which the first three were confirmed to play neuroprotective roles upon directly binding, to interact with α7nAChR.
METHODS
The protein-ligand docking server of CABS-DOCK was employed to obtain the α7nAChR-Aβ complexes. Only the top α7nAChR-Aβ complexes were used to perform all-atom GROMACS dynamics simulation in combination with Charmm36 force field, by which α7nAChR-Aβ interactions' dynamic behavior and specific locations of these different Aβ fragments were identified. MM-PBSA calculations were also done to estimate the binding free energies and the different contributions from the residues in the Aβ. Two distinct results for the first three and fourth Aβ fragments in binding site, strength, key residue, and orientation, account for why the fourth fails to play a neuroprotective role at the molecular level.
Topics: Amyloid beta-Peptides; alpha7 Nicotinic Acetylcholine Receptor; Molecular Dynamics Simulation; Peptide Fragments; Protein Binding; Humans; Molecular Docking Simulation; Binding Sites; Ligands
PubMed: 38937296
DOI: 10.1007/s00894-024-06032-w -
Immunology and Allergy Clinics of North... Aug 2024A clear disease classification schema coupled with an understanding of the specific mechanisms involved in the different types of angioedema without hives informs the... (Review)
Review
A clear disease classification schema coupled with an understanding of the specific mechanisms involved in the different types of angioedema without hives informs the diagnostic assessment. The recommended approach involves several key steps. Foremost is the recognizing of the clinical clues which allow for the differentiation of mast cell-mediated disorders from bradykinin-mediated angioedema. Enhanced vascular permeability related to bradykinin is of critical importance to identify given the implications for disease morbidity and risk of mortality. The ability to efficiently categorize and diagnose all forms of angioedema results in improved patient outcomes.
Topics: Humans; Angioedema; Mast Cells; Bradykinin; Diagnosis, Differential; Capillary Permeability
PubMed: 38937014
DOI: 10.1016/j.iac.2024.03.010