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Nature Communications Jun 2024Extracellular ATP (eATP) signaling through the P2X7 receptor pathway is widely believed to trigger NLRP3 inflammasome assembly in microglia, potentially contributing to...
Extracellular ATP (eATP) signaling through the P2X7 receptor pathway is widely believed to trigger NLRP3 inflammasome assembly in microglia, potentially contributing to depression. However, the cellular stress responses of microglia to both eATP and stress itself remain largely unexplored. Mitochondria-associated membranes (MAMs) is a platform facilitating calcium transport between the endoplasmic reticulum (ER) and mitochondria, regulating ER stress responses and mitochondrial homeostasis. This study aims to investigate how MAMs influence microglial reaction and their involvement in the development of depression-like symptoms in response to chronic social defeat stress (CSDS). CSDS induced ER stress, MAMs' modifications, mitochondrial damage, and the formation of the IP3R3-GRP75-VDAC1 complex at the ER-mitochondria interface in hippocampal microglia, all concomitant with depression-like behaviors. Additionally, exposing microglia to eATP to mimic CSDS conditions resulted in analogous outcomes. Furthermore, knocking down GRP75 in BV2 cells impeded ER-mitochondria contact, calcium transfer, ER stress, mitochondrial damage, mitochondrial superoxide production, and NLRP3 inflammasome aggregation induced by eATP. In addition, reduced GRP75 expression in microglia of Cx3cr1Hspa9 mice lead to reduce depressive behaviors, decreased NLRP3 inflammasome aggregation, and fewer ER-mitochondria contacts in hippocampal microglia during CSDS. Here, we show the role of MAMs, particularly the formation of a tripartite complex involving IP3R3, GRP75, and VDAC1 within MAMs, in facilitating communication between the ER and mitochondria in microglia, thereby contributing to the development of depression-like phenotypes in male mice.
Topics: Animals; Mitochondria; Depression; Microglia; Mice; Social Defeat; Male; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Stress, Psychological; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Voltage-Dependent Anion Channel 1; Hippocampus; Adenosine Triphosphate; Inflammasomes; Inositol 1,4,5-Trisphosphate Receptors; Calcium; Membrane Proteins; Behavior, Animal; Mitochondria Associated Membranes; HSP70 Heat-Shock Proteins
PubMed: 38890305
DOI: 10.1038/s41467-024-49597-z -
Frontiers in Immunology 2024Aquaporin-4 antibodies (AQP4-Abs) are a diagnostic marker for patients with a demyelinating disease called neuromyelitis optica spectrum disorder (NMOSD). Anti-Argonaute...
Aquaporin-4 antibodies (AQP4-Abs) are a diagnostic marker for patients with a demyelinating disease called neuromyelitis optica spectrum disorder (NMOSD). Anti-Argonaute antibodies (AGO-Abs) present as potential biomarkers of the overlap syndrome between NMOSD and other autoimmune diseases. In this paper, we present the case of an adult woman with numbness, tingling, and burning sensations in her arms and subsequent bilateral internuclear ophthalmoplegia. Brain-cervical-thoracic magnetic resonance imaging (MRI) showed T2 hyperintensities in the dorsal brainstem and around the midbrain aqueduct and longitudinally transverse myelitis with homogeneous enhancement on gadolinium-enhanced MRI. The contemporaneous detection of AQP4- and AGO-Abs led to a definite diagnosis of overlap syndrome of NMOSD with AGO-Abs. The patient was treated with immunosuppressive agents, including corticosteroids and immunoglobulins, and achieved remission. This case highlights a novel phenotype of NMOSD with AGO-Abs overlap syndrome, which presents with relapsing brainstem syndrome and longitudinally extensive myelitis with acute severe neurological involvement. The promising prognosis of the disease could serve as a distinct clinical profile. Broad screening for antibodies against central nervous system autoimmune antigens is recommended in suspected patients with limited or atypical clinical manifestations.
Topics: Humans; Neuromyelitis Optica; Female; Autoantibodies; Aquaporin 4; Adult; Biomarkers; Magnetic Resonance Imaging; Middle Aged; Immunosuppressive Agents
PubMed: 38887290
DOI: 10.3389/fimmu.2024.1366531 -
CNS Neuroscience & Therapeutics Jun 2024The glymphatic system is cerebrospinal fluid-brain tissue fluid exchange flow mediated by aquaporin-4 (AQP4) on the end feet of astrocytes for a system, which is capable... (Review)
Review
The glymphatic system is cerebrospinal fluid-brain tissue fluid exchange flow mediated by aquaporin-4 (AQP4) on the end feet of astrocytes for a system, which is capable of rapidly removing brain metabolites and thus maintaining brain homeostasis, and is known as the central immune system. Dysfunction of the glymphatic system causes accumulation of misfolded and highly phosphorylated proteins (amyloid-β and Tau proteins), which destabilizes the proteins, and the body's neuroinflammatory factors are altered causing aging of the immune system and leading to neurodegenerative diseases. Damage to the glymphatic system and aging share common manifestations, as well as unstudied biological mechanisms that are also linked, such as mitochondria, oxidative stress, chronic inflammation, and sleep. In this paper, we first summarize the structure, function, and research methods of the glymphatic system and the relationship between the glymphatic system and the peripheral immune system, and second, sort out and summarize the factors of the glymphatic system in removing metabolites and resolving aging-related diseases and factors affecting aging, to explore its related biological mechanisms, and moreover, to provide a new way of thinking for treating or intervening aging-related diseases.
Topics: Humans; Glymphatic System; Aging; Animals; Astrocytes; Brain; Aquaporin 4
PubMed: 38887168
DOI: 10.1111/cns.14803 -
Neurology(R) Neuroimmunology &... Jul 2024AQP4 antibody-positive NMOSD (AQP4-NMOSD), MOG antibody-associated disease (MOGAD), and seronegative NMOSD (SN-NMOSD) are neuroautoimmune conditions that have...
BACKGROUND AND OBJECTIVES
AQP4 antibody-positive NMOSD (AQP4-NMOSD), MOG antibody-associated disease (MOGAD), and seronegative NMOSD (SN-NMOSD) are neuroautoimmune conditions that have overlapping clinical manifestations. Yet, important differences exist in these diseases, particularly in B-cell depletion (BCD) efficacy. Yet, the biology driving these differences remains unclear. Our study aims to clarify biological pathways distinguishing these diseases beyond autoantibodies and investigate variable BCD effects through proteomic comparisons.
METHODS
In a retrospective study, 1,463 serum proteins were measured in 53 AQP4-NMOSD, 25 MOGAD, 18 SN-NMOSD, and 49 healthy individuals. To identify disease subtype-associated signatures, we examined serum proteins in patients without anti-CD20 B-cell depletion (NoBCD). We then assessed the effect of BCD treatment within each subtype by comparing proteins between BCD-treated and NoBCD-treated patients.
RESULTS
In NoBCD-treated patients, serum profiles distinguished the 3 diseases. AQP4-NMOSD showed elevated type I interferon-induced chemokines (CXCL9 and CXCL10) and TFH chemokine (CXCL13). MOGAD exhibited increased cytotoxic T-cell proteases (granzyme B and granzyme H), while SN-NMOSD displayed elevated Wnt inhibitory factor 1, a marker for nerve injury. Across all subtypes, BCD-treated patients showed reduction of B-cell-associated proteins. In AQP4-NMOSD, BCD led to a decrease in several inflammatory pathways, including IL-17 signaling, cytokine storm, and macrophage activation. By contrast, BCD elevated these pathways in patients with MOGAD. BCD had no effect on these pathways in SN-NMOSD.
DISCUSSION
Proteomic profiles show unique biological pathways that distinguish AQP4-NMOSD, MOGAD, or SN-NMOSD. Furthermore, BCD uniquely affects inflammatory pathways in each disease type, providing an explanation for the disparate therapeutic response in AQP4-NMOSD and MOGAD.
Topics: Humans; Neuromyelitis Optica; Myelin-Oligodendrocyte Glycoprotein; Female; Middle Aged; Male; Adult; Retrospective Studies; Proteomics; B-Lymphocytes; Aquaporin 4; Autoantibodies; Aged
PubMed: 38885457
DOI: 10.1212/NXI.0000000000200268 -
Cancer Medicine Jun 2024Ovarian cancer is a common gynecological tumor with high malignant potential and poor prognosis. TRIM8, is involved in the development of various tumors, but its precise...
BACKGROUND
Ovarian cancer is a common gynecological tumor with high malignant potential and poor prognosis. TRIM8, is involved in the development of various tumors, but its precise regulatory role in ovarian cancer is still unknown.
AIMS
The aim of this study was to explore the specific mechanism by which TRIM8 regulates ovarian cancer.
MATERIALS AND METHODS
We used bioinformatics analysis to screen for high expression of TRIM8 in ovarian cancer. The expression of TRIM8 in healthy and cancerous ovarian tissues was assessed by immunofluorescence. TRIM8 was silenced or overexpressed in ovarian cancer cell lines, with cell proliferation and migration evaluated by CCK8, transwell and clonal formation assays. The effect of TRIM8 on ovarian cancer cells in vivo was assessed by subcutaneous tumor formation experiments in nude mice. The potential interacting protein VDAC2 was identified by mass spectrometry. The mechanism underlying TRIM8 regulation of VDAC2 was evaluated by co-immunoprecipitation and western blotting.
RESULTS
TRIM8 was overexpressed in ovarian cancer. TRIM8 promoted the proliferation and migration of ovarian cancer cells in vitro and the growth of subcutaneous tumors in mice in vivo. TRIM8 interacted with VDAC2, weakened the stability of the protein, and promoted its polyubiquitination and subsequent degradation. Knockdown of VDAC2 increased the resistance of ovarian cancer cells to iron death, whereas overexpression of VDAC2 attenuated ovarian cancer progression induced by TRIM8 overexpression.
DISCUSSION
TRIM8 promotes ovarian cancer proliferation and migration by targeting VDAC2 for ubiquitination and degradation, these finding may provide new targets for the treatment of ovarian cancer.
CONCLUSION
TRIM8 degraded VDAC2 through the ubiquitination pathway, increased the resistance of ovarian cancer cells to iron death, and promoted the proliferation and migration of ovarian cancer.
Topics: Humans; Female; Ovarian Neoplasms; Cell Proliferation; Ubiquitination; Cell Movement; Animals; Mice; Voltage-Dependent Anion Channel 2; Cell Line, Tumor; Mice, Nude; Proteolysis; Gene Expression Regulation, Neoplastic; Xenograft Model Antitumor Assays
PubMed: 38881325
DOI: 10.1002/cam4.7396 -
Accounts of Chemical Research Jun 2024ConspectusTransmembrane pores are currently at the forefront of nanobiotechnology, nanopore chemistry, and synthetic chemical biology research. Over the past few...
ConspectusTransmembrane pores are currently at the forefront of nanobiotechnology, nanopore chemistry, and synthetic chemical biology research. Over the past few decades, significant studies in protein engineering have paved the way for redesigning membrane protein pores tailored for specific applications in nanobiotechnology. Most previous efforts predominantly centered on natural β-barrel pores designed with atomic precision for nucleic acid sequencing and sensing of biomacromolecules, including protein fragments. The requirement for a more efficient single-molecule detection system has driven the development of synthetic nanopores. For example, engineering channels to conduct ions and biomolecules selectively could lead to sophisticated nanopore sensors. Also, there has been an increased interest in synthetic pores, which can be fabricated to provide more control in designing architecture and diameter for single-molecule sensing of complex biomacromolecules. There have been impressive advancements in developing synthetic DNA-based pores, although their application in nanopore technology is limited. This has prompted a significant shift toward building synthetic transmembrane α-helical pores, a relatively underexplored field offering novel opportunities. Recently, computational tools have been employed to design and construct α-helical barrels of defined structure and functionality.We focus on building synthetic α-helical pores using naturally occurring transmembrane motifs of membrane protein pores. Our laboratory has developed synthetic α-helical transmembrane pores based on the natural porin PorACj (Porin A derived from ) that function as nanopore sensors for single-molecule sensing of cationic cyclodextrins and polypeptides. Our breakthrough lies in being the first to create a functional and large stable synthetic transmembrane pore composed of short synthetic α-helical peptides. The key highlight of our work is that these pores can be synthesized using easy chemical synthesis, which permits its easy modification to include a variety of functional groups to build charge-selective sophisticated pores. Additionally, we have demonstrated that stable functional pores can be constructed from D-amino acid peptides. The analysis of pores composed of D- and L-amino acids in the presence of protease showed that only the D pores are highly functional and stable. The structural models of these pores revealed distinct surface charge conformation and geometry. These new classes of synthetic α-helical pores are highly original systems of general interest due to their unique architecture, functionality, and potential applications in nanopore technology and chemical biology. We emphasize that these simplified transmembrane pores have the potential to be components of functional nanodevices and therapeutic tools. We also suggest that such designed peptides might be valuable as antimicrobial agents and can be targeted to cancer cells. This article will focus on the evolutions in assembling α-helical transmembrane pores and highlight their advantages, including structural and functional versatility.
PubMed: 38875523
DOI: 10.1021/acs.accounts.4c00101 -
Small Methods Jun 2024DL-Lactic acid and D-glucose are important human health indicators. Their aberrant levels in body fluids may indicate a variety of human pathological conditions,...
DL-Lactic acid and D-glucose are important human health indicators. Their aberrant levels in body fluids may indicate a variety of human pathological conditions, suggesting an urgent need of daily monitoring. However, simultaneous and rapid analysis of DL-lactic acid and D-glucose using a sole but simple sensing system has never been reported. Here, an engineered Mycobacterium smegmatis porin A (MspA) nanopore is used to simultaneously identify DL-lactic acid and D-glucose. Highly distinguishable nanopore event features are reported. Assisted with a custom machine learning algorithm, direct identification of DL-lactic acid and D-glucose is performed with human serum, demonstrating its sensing reliability against complex and heterogeneous samples. This sensing strategy is further applied in the analysis of different animal serum samples, according to which gluconic acid is further identified. The serum samples from different animals report distinguishable levels of DL-lactic acid, D-glucose and gluconic acid, suggesting its potential applications in agricultural science and breeding industry. This sensing strategy is generally direct, rapid, economic and requires only ≈µL of input serum, suitable for point of care testing (POCT) applications.
PubMed: 38864527
DOI: 10.1002/smtd.202400664 -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Jun 2024To unveil the pathological changes associated with demyelination in schizophrenia (SZ) and its consequential impact on interstitial fluid (ISF) drainage, and to...
OBJECTIVE
To unveil the pathological changes associated with demyelination in schizophrenia (SZ) and its consequential impact on interstitial fluid (ISF) drainage, and to investigate the therapeutic efficacy of ursolic acid (UA) in treating demyelination and the ensuing abnormalities in ISF drainage in SZ.
METHODS
Female C57BL/6J mice, aged 6-8 weeks and weighing (20±2) g, were randomly divided into three groups: control, SZ model, and UA treatment. The control group received intraperitoneal injection (ip) of physiological saline and intragastric administration (ig) of 1% carboxymethylcellulose sodium (CMC-Na). The SZ model group was subjected to ip injection of 2 mg/kg dizocilpine maleate (MK-801) and ig administration of 1% CMC-Na. The UA treatment group underwent ig administration of 25 mg/kg UA and ip injection of 2 mg/kg MK-801. The treatment group received UA pretreatment via ig administration for one week, followed by a two-week drug intervention for all the three groups. Behavioral assessments, including the open field test and prepulse inhibition experiment, were conducted post-modeling. Subsequently, changes in the ISF partition drainage were investigated through fluorescent tracer injection into specific brain regions. Immunofluorescence analysis was employed to examine alterations in aquaporin 4 (AQP4) polarity distribution in the brain and changes in protein expression. Myelin reflex imaging using Laser Scanning Confocal Microscopy (LSCM) was utilized to study modifications in myelin within the mouse brain. Quantitative data underwent one-way ANOVA, followed by TukeyHSD for post hoc pairwise comparisons between the groups.
RESULTS
The open field test revealed a significantly longer total distance [(7 949.39±1 140.55) cm . (2 831.01±1 212.72) cm, < 0.001] and increased central area duration [(88.43±22.06) s . (56.85±18.58) s, =0.011] for the SZ model group compared with the controls. The UA treatment group exhibited signifi-cantly reduced total distance [(2 415.80±646.95) cm . (7 949.39±1 140.55) cm, < 0.001] and increased central area duration [(54.78±11.66) s . (88.43±22.06) s, =0.007] compared with the model group. Prepulse inhibition test results demonstrated a markedly lower inhibition rate of the startle reflex in the model group relative to the controls ( < 0.001 for both), with the treatment group displaying significant improvement ( < 0.001 for both). Myelin sheath analysis indicated significant demyelination in the model group, while UA treatment reversed this effect. Fluorescence tracing exhibited a significantly larger tracer diffusion area towards the rostral cortex and reflux area towards the caudal thalamus in the model group relative to the controls [(13.93±3.35) mm . (2.79±0.94) mm, < 0.001 for diffusion area; (2.48±0.38) mm . (0.05±0.12) mm, < 0.001 for reflux area], with significant impairment of drainage in brain regions. The treatment group demonstrated significantly reduced tracer diffusion and reflux areas [(7.93±2.48) mm . (13.93±3.35) mm, < 0.001 for diffusion area; (0.50±0.30) mm . (2.48±0.38) mm, < 0.001 for reflux area]. Immunofluorescence staining revealed disrupted AQP4 polarity distribution and reduced AQP4 protein expression in the model group compared with the controls [(3 663.88±733.77) μm . (13 354.92±4 054.05) μm, < 0.001]. The treatment group exhibited restored AQP4 polarity distribution and elevated AQP4 protein expression [(11 104.68±3 200.04) μm . (3 663.88±733.77) μm, < 0.001].
CONCLUSION
UA intervention ameliorates behavioral performance in SZ mice, Thus alleviating hyperactivity and anxiety symptoms and restoring sensorimotor gating function. The underlying mechanism may involve the improvement of demyelination and ISF drainage dysregulation in SZ mice.
Topics: Animals; Mice; Triterpenes; Schizophrenia; Mice, Inbred C57BL; Female; Disease Models, Animal; Demyelinating Diseases; Extracellular Fluid; Ursolic Acid; Dizocilpine Maleate; Aquaporin 4
PubMed: 38864135
DOI: 10.19723/j.issn.1671-167X.2024.03.016 -
Microbiology Spectrum Jun 2024The impact of chromosomally encoded wild-type or extended-spectrum (ESAC) AmpC β-lactamases of on susceptibility to ceftazidime, cefepime, and cefiderocol was...
UNLABELLED
The impact of chromosomally encoded wild-type or extended-spectrum (ESAC) AmpC β-lactamases of on susceptibility to ceftazidime, cefepime, and cefiderocol was evaluated in different genetic backgrounds, including wild-type, PBP3-modified, and porin-deficient strains. Recombinant strains possessing the different backgrounds and producing variable ESACs were evaluated. Although ESAC enzymes conferred resistance to ceftazidime and decreased susceptibility to cefepime as expected, we showed here that cefiderocol was also a substrate of ESAC enzymes.
IMPORTANCE
We showed here that chromosomally encoded intrinsic extended-spectrum cephalosporinases of may impact susceptibility not only to ceftazidime and cefepime but also to cefiderocol.
PubMed: 38860818
DOI: 10.1128/spectrum.00704-24 -
Physiologia Plantarum 2024The present study aims to explore the potential of a plasma-membrane localized PIP2-type aquaporin protein sourced from the halophyte Salicornia brachiata to alleviate...
The present study aims to explore the potential of a plasma-membrane localized PIP2-type aquaporin protein sourced from the halophyte Salicornia brachiata to alleviate salinity and water deficit stress tolerance in a model plant through transgenic intervention. Transgenic plants overexpressing SbPIP2 gene showed improved physio-biochemical parameters like increased osmolytes (proline, total sugar, and amino acids), antioxidants (polyphenols), pigments and membrane stability under salinity and drought stresses compared to control plants [wild type (WT) and vector control (VC) plants]. Multivariate statistical analysis showed that, under water and salinity stresses, osmolytes, antioxidants and pigments were correlated with SbPIP2-overexpressing (SbPIP2-OE) plants treated with salinity and water deficit stress, suggesting their involvement in stress tolerance. As aquaporins are also involved in CO transport, SbPIP2-OE plants showed enhanced photosynthesis performance than wild type upon salinity and drought stresses. Photosynthetic gas exchange (net CO assimilation rate, PSII efficiency, ETR, and non-photochemical quenching) were significantly higher in SbPIP2-OE plants compared to control plants (wild type and vector control plants) under both unstressed and stressed conditions. The higher quantum yield for reduction of end electron acceptors at the PSI acceptor side [Φ ] in SbPIP2-OE plants compared to control plants under abiotic stresses indicates a continued PSI functioning, leading to retained electron transport rate, higher carbon assimilation, and less ROS-mediated injuries. In conclusion, the SbPIP2 gene functionally validated in the present study could be a potential candidate for engineering abiotic stress resilience in important crops.
Topics: Photosynthesis; Plants, Genetically Modified; Nicotiana; Plant Proteins; Stress, Physiological; Droughts; Chenopodiaceae; Aquaporins; Salinity; Gene Expression Regulation, Plant; Antioxidants
PubMed: 38859697
DOI: 10.1111/ppl.14384