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1.
Nat Immunol ; 24(11): 1854-1866, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37857825

ABSTRACT

Microglial involvement in Alzheimer's disease (AD) pathology has emerged as a risk-determining pathogenic event. While apolipoprotein E (APOE) is known to modify AD risk, it remains unclear how microglial apoE impacts brain cognition and AD pathology. Here, using conditional mouse models expressing apoE isoforms in microglia and central nervous system-associated macrophages (CAMs), we demonstrate a cell-autonomous effect of apoE3-mediated microglial activation and function, which are negated by apoE4. Expression of apoE3 in microglia/CAMs improves cognitive function, increases microglia surrounding amyloid plaque and reduces amyloid pathology and associated toxicity, whereas apoE4 expression either compromises or has no effects on these outcomes by impairing lipid metabolism. Single-cell transcriptomic profiling reveals increased antigen presentation and interferon pathways upon apoE3 expression. In contrast, apoE4 expression downregulates complement and lysosomal pathways, and promotes stress-related responses. Moreover, in the presence of mouse endogenous apoE, microglial apoE4 exacerbates amyloid pathology. Finally, we observed a reduction in Lgals3-positive responsive microglia surrounding amyloid plaque and an increased accumulation of lipid droplets in APOE4 human brains and induced pluripotent stem cell-derived microglia. Our findings establish critical isoform-dependent effects of microglia/CAM-expressed apoE in brain function and the development of amyloid pathology, providing new insight into how apoE4 vastly increases AD risk.


Subject(s)
Alzheimer Disease , Mice , Animals , Humans , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Apolipoprotein E4/genetics , Apolipoprotein E4/metabolism , Microglia/metabolism , Apolipoprotein E3/genetics , Apolipoprotein E3/metabolism , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Apolipoproteins E/genetics , Apolipoproteins E/metabolism , Brain , Homeostasis , Mice, Transgenic
2.
Proc Natl Acad Sci U S A ; 120(1): e2209990120, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36577069

ABSTRACT

Microglia play a critical role in the clearance of myelin debris, thereby ensuring functional recovery from neural injury. Here, using mouse model of demyelination following two-point LPC injection, we show that the microglial autophagic-lysosomal pathway becomes overactivated in response to severe demyelination, leading to lipid droplet accumulation and a dysfunctional and pro-inflammatory microglial state, and finally failed myelin debris clearance and spatial learning deficits. Data from genetic approaches and pharmacological modulations, via microglial Atg5 deficient mice and intraventricular BAF A1 administration, respectively, demonstrate that staged suppression of excessive autophagic-lysosomal activation in microglia, but not sustained inhibition, results in better myelin debris degradation and exerts protective effects against demyelination. Combined multi-omics results in vitro further showed that enhanced lipid metabolism, especially the activation of the linoleic acid pathway, underlies this protective effect. Supplementation with conjugated linoleic acid (CLA), both in vivo and in vitro, could mimic these effects, including attenuating inflammation and restoring microglial pro-regenerative properties, finally resulting in better recovery from demyelination injuries and improved spatial learning function, by activating the peroxisome proliferator-activated receptor (PPAR-γ) pathway. Therefore, we propose that pharmacological inhibition targeting microglial autophagic-lysosomal overactivation or supplementation with CLA could represent a potential therapeutic strategy in demyelinated disorders.


Subject(s)
Demyelinating Diseases , Microglia , Mice , Animals , Microglia/metabolism , Linoleic Acid/metabolism , Autophagy , Demyelinating Diseases/metabolism , Regeneration
3.
Mol Psychiatry ; 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38499656

ABSTRACT

Autism spectrum disorder (ASD) is a major neurodevelopmental disorder affecting 1 in 36 children in the United States. While neurons have been the focus of understanding ASD, an altered neuro-immune response in the brain may be closely associated with ASD, and a neuro-immune interaction could play a role in the disease progression. As the resident immune cells of the brain, microglia regulate brain development and homeostasis via core functions including phagocytosis of synapses. While ASD has been traditionally considered a polygenic disorder, recent large-scale human genetic studies have identified SCN2A deficiency as a leading monogenic cause of ASD and intellectual disability. We generated a Scn2a-deficient mouse model, which displays major behavioral and neuronal phenotypes. However, the role of microglia in this disease model is unknown. Here, we reported that Scn2a-deficient mice have impaired learning and memory, accompanied by reduced synaptic transmission and lower spine density in neurons of the hippocampus. Microglia in Scn2a-deficient mice are partially activated, exerting excessive phagocytic pruning of post-synapses related to the complement C3 cascades during selective developmental stages. The ablation of microglia using PLX3397 partially restores synaptic transmission and spine density. To extend our findings from rodents to human cells, we established a microglia-incorporated human cerebral organoid model carrying an SCN2A protein-truncating mutation identified in children with ASD. We found that human microglia display increased elimination of post-synapse in cerebral organoids carrying the SCN2A mutation. Our study establishes a key role of microglia in multi-species autism-associated models of SCN2A deficiency from mouse to human cells.

4.
Brain ; 147(1): 163-176, 2024 01 04.
Article in English | MEDLINE | ID: mdl-37740498

ABSTRACT

Microglia-mediated neuroinflammation contributes to acute demyelination in neuromyelitis optica spectrum disorders (NMOSD). Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in the CSF has been associated with microglial activation in several neurodegenerative diseases. However, the basis for this immune-mediated attack and the pathophysiological role of sTREM2 in NMOSD remain to be elucidated. Here, we performed Mendelian randomization analysis and identified a genetic association between increased CSF sTREM2 and NMOSD risk. CSF sTREM2 was elevated in patients with NMOSD and was positively correlated with neural injury and other neuroinflammation markers. Single-cell RNA sequencing of human macrophage/microglia-like cells in CSF, a proxy for microglia, showed that increased CSF sTREM2 was positively associated with microglial dysfunction in patients with NMOSD. Furthermore, we demonstrated that sTREM2 is a reliable biomarker of microglial activation in a mouse model of NMOSD. Using unbiased transcriptomic and lipidomic screens, we identified that excessive activation, overwhelmed phagocytosis of myelin debris, suppressed lipid metabolism and enhanced glycolysis underlie sTREM2-mediated microglial dysfunction, possibly through the nuclear factor kappa B (NF-κB) signalling pathway. These molecular and cellular findings provide a mechanistic explanation for the genetic association between CSF sTREM2 and NMOSD risk and indicate that sTREM2 could be a potential biomarker of NMOSD progression and a therapeutic target for microglia-mediated neuroinflammation.


Subject(s)
Alzheimer Disease , Neuromyelitis Optica , Animals , Mice , Humans , Microglia/metabolism , Alzheimer Disease/metabolism , Neuromyelitis Optica/genetics , Neuromyelitis Optica/metabolism , Neuroinflammatory Diseases , Biomarkers/metabolism , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Receptors, Immunologic/genetics
5.
Brain ; 147(2): 566-589, 2024 02 01.
Article in English | MEDLINE | ID: mdl-37776513

ABSTRACT

Cerebral malaria is the deadliest complication that can arise from Plasmodium infection. CD8 T-cell engagement of brain vasculature is a putative mechanism of neuropathology in cerebral malaria. To define contributions of brain endothelial cell major histocompatibility complex (MHC) class I antigen-presentation to CD8 T cells in establishing cerebral malaria pathology, we developed novel H-2Kb LoxP and H-2Db LoxP mice crossed with Cdh5-Cre mice to achieve targeted deletion of discrete class I molecules, specifically from brain endothelium. This strategy allowed us to avoid off-target effects on iron homeostasis and class I-like molecules, which are known to perturb Plasmodium infection. This is the first endothelial-specific ablation of individual class-I molecules enabling us to interrogate these molecular interactions. In these studies, we interrogated human and mouse transcriptomics data to compare antigen presentation capacity during cerebral malaria. Using the Plasmodium berghei ANKA model of experimental cerebral malaria (ECM), we observed that H-2Kb and H-2Db class I molecules regulate distinct patterns of disease onset, CD8 T-cell infiltration, targeted cell death and regional blood-brain barrier disruption. Strikingly, ablation of either molecule from brain endothelial cells resulted in reduced CD8 T-cell activation, attenuated T-cell interaction with brain vasculature, lessened targeted cell death, preserved blood-brain barrier integrity and prevention of ECM and the death of the animal. We were able to show that these events were brain-specific through the use of parabiosis and created the novel technique of dual small animal MRI to simultaneously scan conjoined parabionts during infection. These data demonstrate that interactions of CD8 T cells with discrete MHC class I molecules on brain endothelium differentially regulate development of ECM neuropathology. Therefore, targeting MHC class I interactions therapeutically may hold potential for treatment of cases of severe malaria.


Subject(s)
Malaria, Cerebral , Mice , Humans , Animals , Malaria, Cerebral/pathology , Malaria, Cerebral/prevention & control , Endothelial Cells/pathology , Brain/pathology , Blood-Brain Barrier/pathology , CD8-Positive T-Lymphocytes , Endothelium/pathology , Mice, Inbred C57BL , Disease Models, Animal
6.
Cereb Cortex ; 34(2)2024 01 31.
Article in English | MEDLINE | ID: mdl-38216542

ABSTRACT

The mutual interaction between bone characteristics and brain had been reported previously, yet whether the cortical structure has any relevance to osteoporosis is questionable. Therefore, we applied a two-sample bidirectional Mendelian randomization analysis to investigate this relationship. We utilized the bone mineral density measurements of femoral neck (n = 32,735) and lumbar spine (n = 28,498) and data on osteoporosis (7300 cases and 358,014 controls). The global surficial area and thickness and 34 specific functional regions of 51,665 patients were screened by magnetic resonance imaging. For the primary estimate, we utilized the inverse-variance weighted method. The Mendelian randomization-Egger intercept test, MR-PRESSO, Cochran's Q test, and "leave-one-out" sensitivity analysis were conducted to assess heterogeneity and pleiotropy. We observed suggestive associations between decreased thickness in the precentral region (OR = 0.034, P = 0.003) and increased chance of having osteoporosis. The results also revealed suggestive causality of decreased bone mineral density in femoral neck to declined total cortical surface area (ß = 1400.230 mm2, P = 0.003), as well as the vulnerability to osteoporosis and reduced thickness in the Parstriangularis region (ß = -0.006 mm, P = 0.002). Our study supports that the brain and skeleton exhibit bidirectional crosstalk, indicating the presence of a mutual brain-bone interaction.


Subject(s)
Mendelian Randomization Analysis , Osteoporosis , Humans , Osteoporosis/diagnostic imaging , Osteoporosis/genetics , Brain , Nonoxynol , Radiopharmaceuticals , Genome-Wide Association Study
7.
Mol Cancer ; 23(1): 15, 2024 01 15.
Article in English | MEDLINE | ID: mdl-38225603

ABSTRACT

Mounting evidence suggests a strong association between tumor immunity and epigenetic regulation. The histone-lysine N-methyltransferase 2 (KMT2) family plays a crucial role in the methylation of histone H3 at lysine 4. By influencing chromatin structure and DNA accessibility, this modification serves as a key regulator of tumor progression and immune tolerance across various tumors. These findings highlight the potential significance of the KMT2 family in determining response to immune checkpoint inhibitor (ICI) therapy, which warrants further exploration. In this study, we integrated four ICI-treated cohorts (n = 2069) across 10 cancer types and The Cancer Genome Atlas pan-cancer cohort and conducted a comprehensive clinical and bioinformatic analysis. Our study indicated that patients with KMT2 family gene mutations benefited more from ICI therapy in terms of overall survival (P < 0.001, hazard ratio [HR] = 0.733 [95% confidence interval (CI): 0.632-0.850]), progression-free survival (P = 0.002, HR = 0.669 [95% CI: 0.518-0.864]), durable clinical benefit (P < 0.001, 54.1% vs. 32.6%), and objective response rate (P < 0.001, 40.6% vs. 22.0%). Through a comprehensive analysis of the tumor microenvironment across different KMT2 mutation statuses, we observed that tumors harboring the KMT2 mutation exhibited enhanced immunogenicity, increased infiltration of immune cells, and higher levels of immune cell cytotoxicity, suggesting a propensity towards a "hot tumor" phenotype. Therefore, our study indicates a potential association between KMT2 mutations and a more favorable response to ICI therapy and implicates different tumor microenvironments associated with ICI therapy response.


Subject(s)
Epigenesis, Genetic , Neoplasms , Humans , Immune Checkpoint Inhibitors/therapeutic use , Tumor Microenvironment , Mutation , Neoplasms/drug therapy , Neoplasms/genetics
8.
Ann Neurol ; 93(4): 830-843, 2023 04.
Article in English | MEDLINE | ID: mdl-36546684

ABSTRACT

OBJECTIVE: Recent evidence supports a link between increased TDP-43 burden and the presence of an APOE4 gene allele in Alzheimer's disease (AD); however, it is difficult to conclude the direct effect of APOE on TDP-43 pathology due to the presence of mixed AD pathologies. The goal of this study is to address how APOE isoforms impact TDP-43 pathology and related neurodegeneration in the absence of typical AD pathologies. METHODS: We overexpressed human TDP-43 via viral transduction in humanized APOE2, APOE3, APOE4 mice, and murine Apoe-knockout (Apoe-KO) mice. Behavior tests were performed across ages. Animals were harvested at 11 months of age and TDP-43 overexpression-related neurodegeneration and gliosis were assessed. To further address the human relevance, we analyzed the association of APOE with TDP-43 pathology in 160 postmortem brains from autopsy-confirmed amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with motor neuron disease (FTLD-MND) in the Mayo Clinic Brain Bank. RESULTS: We found that TDP-43 overexpression induced motor function deficits, neuronal loss, and gliosis in the motor cortex, especially in APOE2 mice, with much milder or absent effects in APOE3, APOE4, or Apoe-KO mice. In the motor cortex of the ALS and FTLD-MND postmortem human brains, we found that the APOE2 allele was associated with more severe TDP-43-positive dystrophic neurites. INTERPRETATION: Our data suggest a genotype-specific effect of APOE on TDP-43 proteinopathy and neurodegeneration in the absence of AD pathology, with the strongest association seen with APOE2. ANN NEUROL 2023;93:830-843.


Subject(s)
Alzheimer Disease , Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Frontotemporal Lobar Degeneration , Motor Neuron Disease , Humans , Animals , Mice , Amyotrophic Lateral Sclerosis/genetics , Apolipoprotein E2/genetics , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Apolipoprotein E4/genetics , Apolipoprotein E3 , Gliosis/genetics , DNA-Binding Proteins/genetics , Apolipoproteins E/genetics , Frontotemporal Lobar Degeneration/pathology
9.
Brain Behav Immun ; 115: 406-418, 2024 01.
Article in English | MEDLINE | ID: mdl-37926132

ABSTRACT

Microglia are key players in maintaining brain homeostasis and exhibit phenotypic alterations in response to epileptic stimuli. However, it is still relatively unknown if these alterations are pro- or anti-epileptic. To unravel this dilemma, we employed chemogenetic manipulation of microglia using the artificial Gi-Dreadd receptor within a kainic acid (KA) induced murine seizure model. Our results indicate that acute Gi-Dreadd activation with Clozapine-N-Oxide can reduce seizure severity. Additionally, we observed increased interaction between microglia and neuronal soma, which correlated with reduced neuronal hyperactivity. Interestingly, prolonged activation of microglial Gi-Dreadds by repeated doses of CNO over 3 days, arrested microglia in a less active, homeostatic-like state, which associated with increased neuronal loss after KA induced seizures. RNAseq analysis revealed that prolonged activation of Gi-Dreadd interferes with interferon ß signaling and microglia proliferation. Thus, our findings highlight the importance of microglial Gi signaling not only during status epilepticus (SE) but also within later seizure induced pathology.


Subject(s)
Microglia , Status Epilepticus , Mice , Animals , Microglia/pathology , Seizures/chemically induced , Status Epilepticus/chemically induced , Anticonvulsants , Brain/pathology , Kainic Acid/pharmacology
10.
Brain Behav Immun ; 119: 416-430, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38636563

ABSTRACT

The role of microglia in triggering the blood-brain barrier (BBB) impairment and white matter damage after chronic cerebral hypoperfusion is unclear. Here we demonstrated that the vessel-adjacent microglia were specifically activated by the leakage of plasma low-density lipoprotein (LDL), which led to BBB breakdown and ischemic demyelination. Interestingly, we found that LDL stimulation enhanced microglial phagocytosis, causing excessive engulfment of myelin debris and resulting in an overwhelming lipid burden in microglia. Surprisingly, these lipid-laden microglia exhibited a suppressed profile of inflammatory response and compromised pro-regenerative properties. Microglia-specific knockdown of LDLR or systematic medication lowering circulating LDL-C showed protective effects against ischemic demyelination. Overall, our findings demonstrated that LDL-stimulated vessel-adjacent microglia possess a disease-specific molecular signature, characterized by suppressed regenerative properties, which is associated with the propagation of demyelination during ischemic white matter damage.


Subject(s)
Blood-Brain Barrier , Brain Ischemia , Lipoproteins, LDL , Microglia , White Matter , Microglia/metabolism , Animals , White Matter/metabolism , White Matter/pathology , Mice , Lipoproteins, LDL/metabolism , Lipoproteins, LDL/pharmacology , Brain Ischemia/metabolism , Blood-Brain Barrier/metabolism , Male , Mice, Inbred C57BL , Demyelinating Diseases/metabolism , Demyelinating Diseases/pathology , Phagocytosis/physiology , Myelin Sheath/metabolism
11.
Mol Psychiatry ; 28(7): 2857-2871, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37365239

ABSTRACT

Chemogenetic approaches using Designer Receptors Exclusively Activated by Designer Drugs (DREADD, a family of engineered GPCRs) were recently employed in microglia. Here, we used Cx3cr1CreER/+:R26hM4Di/+ mice to express Gi-DREADD (hM4Di) on CX3CR1+ cells, comprising microglia and some peripheral immune cells, and found that activation of hM4Di on long-lived CX3CR1+ cells induced hypolocomotion. Unexpectedly, Gi-DREADD-induced hypolocomotion was preserved when microglia were depleted. Consistently, specific activation of microglial hM4Di cannot induce hypolocomotion in Tmem119CreER/+:R26hM4Di/+ mice. Flow cytometric and histological analysis showed hM4Di expression in peripheral immune cells, which may be responsible for the hypolocomotion. Nevertheless, depletion of splenic macrophages, hepatic macrophages, or CD4+ T cells did not affect Gi-DREADD-induced hypolocomotion. Our study demonstrates that rigorous data analysis and interpretation are needed when using Cx3cr1CreER/+ mouse line to manipulate microglia.


Subject(s)
Microglia , Neurons , Mice , Animals , Neurons/metabolism , Macrophages
12.
Mol Psychiatry ; 28(10): 4374-4389, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37280283

ABSTRACT

Activation of innate immunity in the brain is a prominent feature of Alzheimer's disease (AD). The present study investigated the regulation of innate immunity by wild-type serum injection in a transgenic AD mouse model. We found that treatment with wild-type mouse serum significantly reduced the number of neutrophils and microglial reactivity in the brains of APP/PS1 mice. Mimicking this effect, neutrophil depletion via Ly6G neutralizing antibodies resulted in improvements in AD brain functions. Serum proteomic analysis identified vascular endothelial growth factor-A (VEGF-A) and chemokine (C-X-C motif) ligand 1 (CXCL1) as factors enriched in serum samples, which are crucial for neutrophil migration and chemotaxis, leukocyte migration, and cell chemotaxis. Exogenous VEGF-A reversed amyloid ß (Aß)-induced decreases in cyclin-dependent kinase 5 (Cdk5) and increases in CXCL1 in vitro and blocked neutrophil infiltration into the AD brain. Endothelial Cdk5 overexpression conferred an inhibitory effect on CXCL1 and neutrophil infiltration, thereby restoring memory abilities in APP/PS1 mice. Our findings uncover a previously unknown link between blood-derived VEGF signaling and neutrophil infiltration and support targeting endothelial Cdk5 signaling as a potential therapeutic strategy for AD.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Mice , Animals , Mice, Transgenic , Vascular Endothelial Growth Factor A , Neutrophil Infiltration , Proteomics , Alzheimer Disease/therapy , Memory Disorders , Disease Models, Animal , Amyloid beta-Protein Precursor/genetics , Presenilin-1/genetics
13.
PLoS Biol ; 19(3): e3001154, 2021 03.
Article in English | MEDLINE | ID: mdl-33739978

ABSTRACT

Spinal microglia are highly responsive to peripheral nerve injury and are known to be a key player in pain. However, there has not been direct evidence showing that selective microglial activation in vivo is sufficient to induce chronic pain. Here, we used optogenetic approaches in microglia to address this question employing CX3CR1creER/+: R26LSL-ReaChR/+ transgenic mice, in which red-activated channelrhodopsin (ReaChR) is inducibly and specifically expressed in microglia. We found that activation of ReaChR by red light in spinal microglia evoked reliable inward currents and membrane depolarization. In vivo optogenetic activation of microglial ReaChR in the spinal cord triggered chronic pain hypersensitivity in both male and female mice. In addition, activation of microglial ReaChR up-regulated neuronal c-Fos expression and enhanced C-fiber responses. Mechanistically, ReaChR activation led to a reactive microglial phenotype with increased interleukin (IL)-1ß production, which is likely mediated by inflammasome activation and calcium elevation. IL-1 receptor antagonist (IL-1ra) was able to reverse the pain hypersensitivity and neuronal hyperactivity induced by microglial ReaChR activation. Therefore, our work demonstrates that optogenetic activation of spinal microglia is sufficient to trigger chronic pain phenotypes by increasing neuronal activity via IL-1 signaling.


Subject(s)
Chronic Pain/etiology , Microglia/physiology , Spinal Nerves/metabolism , Animals , CX3C Chemokine Receptor 1/genetics , CX3C Chemokine Receptor 1/metabolism , Channelrhodopsins/metabolism , Chronic Pain/physiopathology , Female , Inflammation/metabolism , Interleukin-1beta/metabolism , Macrophages/metabolism , Male , Mice , Mice, Transgenic , Microglia/metabolism , Optogenetics/methods , Signal Transduction/physiology , Spinal Cord/metabolism , Spinal Nerves/physiology
14.
Environ Sci Technol ; 58(25): 11027-11040, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38857061

ABSTRACT

Conversion from natural lands to cropland, primarily driven by agricultural expansion, could significantly alter soil microbiome worldwide; however, influences of forest-to-cropland conversion on microbial hierarchical interactions and ecosystem multifunctionality have not been fully understood. Here, we examined the effects of forest-to-cropland conversion on intratrophic and cross-trophic microbial interactions and soil ecosystem multifunctionality and further disclosed their underlying drivers at a national scale, using Illumina sequencing combined with high-throughput quantitative PCR techniques. The forest-to-cropland conversion significantly changed the structure of soil microbiome (including prokaryotic, fungal, and protistan communities) while it did not affect its alpha diversity. Both intrakingdom and interkingdom microbial networks revealed that the intratrophic and cross-trophic microbial interaction patterns generally tended to be more modular to resist environmental disturbance introduced from forest-to-cropland conversion, but this was insufficient for the cross-trophic interactions to maintain stability; hence, the protistan predation behaviors were still disturbed under such conversion. Moreover, key soil microbial clusters were declined during the forest-to-cropland conversion mainly because of the increased soil total phosphorus level, and this drove a great degradation of the ecosystem multifunctionality (by 207%) in cropland soils. Overall, these findings comprehensively implied the negative effects of forest-to-cropland conversion on the agroecosystem, from microbial hierarchical interactions to ecosystem multifunctionality.


Subject(s)
Ecosystem , Forests , Soil Microbiology , Microbiota , Agriculture , Soil , Crops, Agricultural
15.
Environ Sci Technol ; 58(13): 5866-5877, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38504110

ABSTRACT

Soil microbes, the main driving force of terrestrial biogeochemical cycles, facilitate soil organic matter turnover. However, the influence of the soil fauna on microbial communities remains poorly understood. We investigated soil microbiota dynamics by introducing competition and predation among fauna into two soil ecosystems with different fertilization histories. The interactions significantly affected rare microbial communities including bacteria and fungi. Predation enhanced the abundance of C/N cycle-related genes. Rare microbial communities are important drivers of soil functional gene enrichment. Key rare microbial taxa, including SM1A02, Gammaproteobacteria, and HSB_OF53-F07, were identified. Metabolomics analysis suggested that increased functional gene abundance may be due to specific microbial metabolic activity mediated by soil fauna interactions. Predation had a stronger effect on rare microbes, functional genes, and microbial metabolism compared to competition. Long-term organic fertilizer application increased the soil resistance to animal interactions. These findings provide a comprehensive understanding of microbial community dynamics under soil biological interactions, emphasizing the roles of competition and predation among soil fauna in terrestrial ecosystems.


Subject(s)
Microbiota , Soil , Soil Microbiology , Bacteria/genetics , Fungi/genetics , Fungi/metabolism
16.
Neurourol Urodyn ; 43(2): 516-526, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38108523

ABSTRACT

BACKGROUND: Partial bladder outlet obstruction (pBOO) may lead to bladder remodeling, including fibrosis and extracellular matrix (ECM) deposition. Despite the extensive research on the mechanisms underlying pBOO, potential therapeutic targets for the treatment of pBOO require further research. Dysregulated expression of thrombospondin-1 (Thbs1) has been reported in various human fibrotic diseases; however, its relationship with pBOO remains unclear. AIMS: Investigate the effects of Thbs1 on bladder remodeling caused by pBOO. METHODS: We established a pBOO model in Sprague-Dawley rats and performed urodynamic analyses to estimate functional changes in the bladder, validated the histopathological changes in the bladder by using haematoxylin-eosin and Masson's trichrome staining, identified key target genes by integrating RNA sequencing (RNA-seq) and bioinformatics analyses, validated the expression of related factors using Western blot analysis and RT-qPCR, and used immunofluorescence staining to probe the potential interaction factors of Thbs1. RESULTS: Urodynamic results showed that pressure-related parameters were significantly increased in rats with pBOO. Compared with the sham group, the pBOO group demonstrated significant increases in bladder morphology, bladder weight, and collagen deposition. Thbs1 was significantly upregulated in the bladder tissues of rats with pBOO, consistent with the RNA-seq data. Thbs1 upregulation led to increased expression of matrix metalloproteinase (MMP) 2, MMP9, and fibronectin (Fn) in normal human urinary tract epithelial cells (SV-HUC-1), whereas anti-Thbs1 treatment inhibited the production of these cytokines in TGF-ß1-treated SV-HUC-1. Further experiments indicated that Thbs1 affected bladder remodeling in pBOO via the fibroblast growth factor receptor 3 (FGFR3) pathway. CONCLUSIONS: Thbs1 plays a crucial role in bladder remodeling caused by pBOO. Targeting Thbs1 might alleviate ECM damage. Mechanistically, Thbs1 may function via the FGFR signaling pathway by regulating the FGFR3 receptor, identified as the most relevant disease target of pBOO, and FGF2 may be a mediator. These findings suggest that Thbs1 plays a role in BOO development and is a therapeutic target for this condition.


Subject(s)
Urinary Bladder Neck Obstruction , Urinary Bladder , Animals , Humans , Rats , Disease Models, Animal , Rats, Sprague-Dawley , Receptor, Fibroblast Growth Factor, Type 3/metabolism , Receptor, Fibroblast Growth Factor, Type 3/pharmacology , Signal Transduction
17.
Anesth Analg ; 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38345932

ABSTRACT

Neurovascular coupling (NVC) is the mechanism that drives the neurovascular response to neural activation, and NVC dysfunction has been implicated in various neurologic diseases. NVC is driven by (1) nonmetabolic feedforward mechanisms that are mediated by various signaling pathways and (2) metabolic feedback mechanisms that involve metabolic factors. However, the interplay between these feedback and feedforward mechanisms remains unresolved. We propose that feedforward mechanisms normally drive a swift, neural activation-induced regional cerebral blood flow (rCBF) overshoot, which floods the tissue beds, leading to local hypocapnia and hyperoxia. The feedback mechanisms are triggered by the resultant hypocapnia (not hyperoxia), which causes cerebral vasoconstriction in the neurovascular unit that counterbalances the rCBF overshoot and returns rCBF to a level that matches the metabolic activity. If feedforward mechanisms function improperly (eg, in a disease state), the rCBF overshoot, tissue-bed flooding, and local hypocapnia fail to occur or occur on a smaller scale. Consequently, the neural activation-related increase in metabolic activity results in local hypercapnia and hypoxia, both of which drive cerebral vasodilation and increase rCBF. Thus, feedback mechanisms ensure the brain milieu's stability when feedforward mechanisms are impaired. Our proposal integrates the feedforward and feedback mechanisms underlying NVC and suggests that these 2 mechanisms work like a fail-safe system, to a certain degree. We also discussed the difference between NVC and cerebral metabolic rate-CBF coupling and the clinical implications of our proposed framework.

18.
BMC Pulm Med ; 24(1): 205, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38664747

ABSTRACT

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is an interstitial pneumonia caused by pneumocystis jirovecii (PJ). The diagnosis of PJP primarily relies on the detection of the pathogen from lower respiratory tract specimens. However, it faces challenges such as difficulty in obtaining specimens and low detection rates. In the clinical diagnosis process, it is necessary to combine clinical symptoms, serological test results, chest Computed tomography (CT) images, molecular biology techniques, and metagenomics next-generation sequencing (mNGS) for comprehensive analysis. PURPOSE: This study aims to overcome the limitations of traditional PJP diagnosis methods and develop a non-invasive, efficient, and accurate diagnostic approach for PJP. By using this method, patients can receive early diagnosis and treatment, effectively improving their prognosis. METHODS: We constructed an intelligent diagnostic model for PJP based on the different Convolutional Neural Networks. Firstly, we used the Convolutional Neural Network to extract CT image features from patients. Then, we fused the CT image features with clinical information features using a feature fusion function. Finally, the fused features were input into the classification network to obtain the patient's diagnosis result. RESULTS: In this study, for the diagnosis of PJP, the accuracy of the traditional PCR diagnostic method is 77.58%, while the mean accuracy of the optimal diagnostic model based on convolutional neural networks is 88.90%. CONCLUSION: The accuracy of the diagnostic method proposed in this paper is 11.32% higher than that of the traditional PCR diagnostic method. The method proposed in this paper is an efficient, accurate, and non-invasive early diagnosis approach for PJP.


Subject(s)
Neural Networks, Computer , Pneumocystis carinii , Pneumonia, Pneumocystis , Polymerase Chain Reaction , Tomography, X-Ray Computed , Humans , Pneumonia, Pneumocystis/diagnosis , Pneumocystis carinii/isolation & purification , Pneumocystis carinii/genetics , Polymerase Chain Reaction/methods , Male , Middle Aged , Female , Early Diagnosis , Adult , Aged
19.
Biochem Genet ; 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38345758

ABSTRACT

In the present study, we aimed to explore the effect and underlying mechanism of metformin on lipopolysaccharide (LPS)-induced acute kidney injury (AKI). A total of 24 BALB/C mice were randomly divided into four groups: control group, LPS group and metformin group (50 or 100 mg/kg). The histological changes and cell apoptosis in kidney tissues were detected by hematoxylin-eosin staining and terminal-deoxynucleotidyl transferase-mediated nick end labeling assay, respectively. Enzyme-linked immunosorbent assay was applied to determine serum levels of blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), creatinine (Cre), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß). Western blotting analysis were carried out to confirm the expressions of monocyte chemotactic protein-inducible protein 1 (MCPIP1), silent information regulator sirtuin 1 (SIRT1), and NF-κB p65 (acetyl K310). Compared with the control group, the mice in LPS group had glomerular capillary dilatation, renal interstitial edema, tubular cell damage and apoptosis. The serum levels of BUN, KIM-1, Cre, TNF-α, and IL-1ß in LPS group were significantly higher than those in control group. Moreover, LPS also elevated the expressions of MCPIP1 and NF-κB p65 (acetyl K310) but decreased the expression of SIRT1 in kidney tissues. However, metformin distinctly decreased LPS-induced renal dysfunction, the serum levels of BUN, KIM-1, Cre, TNF-α, and IL-1ß. In addition, metformin markedly increased the expressions of MCPIP1 and SIRT1 but decreased the expression of NF-κB p65 (acetyl K310) in kidney tissues. Metformin prevented LPS-induced AKI by up-regulating the MCPIP1/SIRT1 signaling pathway and subsequently inhibiting NF-κB-mediated inflammation response.

20.
BMC Cancer ; 23(1): 1018, 2023 Oct 23.
Article in English | MEDLINE | ID: mdl-37872516

ABSTRACT

OBJECTIVE: Although the current European Association of Urology(EAU) guideline recommends that patients with intermediate-risk non-muscle-invasive bladder cancer (NMIBC) should accept intravesical chemotherapy or Calmette-Guerin (BCG) for no more than one year after transurethral resection of bladder tumor(TURBT), there is no consensus on the optimal duration of chemotherapy. Hence, we explored the optimal duration of maintenance intravesical chemotherapy in patients with intermediate-risk NMIBC. SUBJECTS AND METHODS: This was a real-world single-center retrospective cohort study. In total 158 patients with pathologically confirmed intermediate-risk NMIBC were included, who were divided into 4 subgroups based on the number of instillations given. We used Cox regression analysis and survival analysis chart to explore the 3-yr recurrence outcomes of tumor.The optimal duration was determined by receive operating characteristic curve (ROC). RESULTS: The median follow-up was 5.2 years. Compared with instillation for 1-2 months, the Hazard Ratios(HR) values of instillation for less than 1 month, maintenance instillation for 3-6 months and > 6 months were 3.57、1.57 and 0.22(95% CI 1.27-12.41;0.26-9.28;0.07-0.80, P = 0.03;0.62;0.02, respectively). We found a significant improvement in 3-yr relapse-free survival in intermediate-risk NMIBC patients who maintained intravesical instillation chemotherapy for longer than 6 months, and the best benefit was achieved with 10.5 months of maintenance chemotherapy by ROC. CONCLUSIONS: In our scheme, the optimal duration of intravesical instillation with pirrubicin is 10.5 months. This new understanding provides valuable experience for the precise medical treatment model of intermediate-risk NMIBC.


Subject(s)
Non-Muscle Invasive Bladder Neoplasms , Urinary Bladder Neoplasms , Humans , Administration, Intravesical , Maintenance Chemotherapy , Retrospective Studies , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/pathology , Urinary Bladder Neoplasms/pathology , BCG Vaccine/therapeutic use , Neoplasm Invasiveness
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