ABSTRACT
Accumulation of alpha-synuclein (α-syn) is a key pathological hallmark of synucleinopathies and has been shown to negatively impact neuronal function and activity. α-syn is an important factor contributing to astrocyte overactivation, though the effect of astrocyte overactivation on neurons remains unclear. Single-cell RNA sequencing data of mouse brain frontal cortex and midbrain from Hua-Syn (A53T) and wild type mice were utilized from the GEO database. Enrichment analysis, protein-protein interaction networks, and cell-cell interaction networks all indicated enhanced communication between astrocytes and neurons, along with the involvement of TNF and inflammation-related signaling pathways. In vitro experiments were performed to further explore the mechanism of neurotoxicity in astrocyte-neuron crosstalk. Astrocytes were treated by α-syn, neuronal TNFR1 receptors were antagonized by R-7050, and the cells were co-cultured after 24 h treatment. ELISA results revealed that cytokines such as TNF-α and IL-6 were significantly upregulated in astrocytes following the endocytosis of α-syn. Immunofluorescence (IF) showed neuronal dendritic reduction, axon elongation and increased co-localisation of TNFR1 receptor expression. Western blot showed up-regulation of PKR, P-eIF2α and ATF4 protein expression. Conversely, after antagonizing neuronal TNFR1 receptors with the R-7050 chemical inhibitor, neuronal synaptic structure was significantly restored and the expression of PKR, P-eIF2α and ATF4 was down-regulated. In summary, TNF-α acts as a signaling molecule mediating the up-regulated astrocyte-neuron crosstalk, providing new insights into the pathogenesis of α-syn-related neurological disorders.
Subject(s)
Astrocytes , Cell Communication , Neurons , Receptors, Tumor Necrosis Factor, Type I , Single-Cell Analysis , alpha-Synuclein , Animals , Astrocytes/drug effects , Astrocytes/metabolism , Neurons/drug effects , Neurons/metabolism , Mice , Receptors, Tumor Necrosis Factor, Type I/metabolism , Receptors, Tumor Necrosis Factor, Type I/genetics , alpha-Synuclein/metabolism , alpha-Synuclein/genetics , Coculture Techniques , Cells, Cultured , Sequence Analysis, RNA , Tumor Necrosis Factor-alpha/metabolism , Signal Transduction , Mice, TransgenicABSTRACT
Given the paucity of interventions to treat pancreatitis, it is imperative to identify and intervene upon modifiable risk factors such as heavy alcohol use. Current trends indicate a concerning increase in alcohol misuse and alcohol-related disease since the onset of the coronavirus disease-2019 pandemic.1 The incidence of pancreatitis associated with alcohol misuse has increased by approximately 3% annually from 1961 to 2016.2 Alcohol recidivism may be the most important risk factor for pancreatitis recurrence and development of chronic pancreatitis in the United States.3 Early identification of alcohol misuse as a modifiable risk factor is paramount to mitigating pancreatitis-related morbidity. However, blood ethanol and urine ethyl glucuronide levels may be low in symptomatic individuals because they clear rapidly and patients may abstain from drinking in the days before their clinical presentation. Patient self-report may underestimate the quantity of alcohol intake and falsely reassure the provider that this is not a contributing factor to the presentation.4.
ABSTRACT
BACKGROUND: Methamphetamine (METH) is a highly addictive stimulant that has become one of the top five risk substances cause deaths from substance abuse. METH exposure increases the risk of neurodegenerative disease (ND), such as Parkinson's disease (PD), leading to disability and death. Activation of reactive astrocytes is an essential factor in neurodegeneration, and their complex role in METH exposure remains unclear. This study explored the role of reactive astrocyte overactivation in neurodegeneration after METH exposure. METHODS: METH bulk RNA sequencing data (GSE107015 and GSE98793) and single-cell RNA sequencing data (GSE119861) were obtained from the GEO database. We performed immune infiltration analysis on the bulk RNA data. After cell clustering using the single-cell RNA data, astrocytes were extracted for downstream analysis. Differentially expressed genes (DEGs) were identified from the bulk and single-cell RNA sequencing datasets, and GO, KEGG, and GSEA pathway analyses were performed. The PPI network and random forest methods were performed on the overlapping genes of the DEGs to screen hub genes. To explore the common ground between METH exposure and neurodegenerative diseases, we applied a random forest algorithm to PD chip data (GSE99039 and GSE72267) to establish a diagnostic model using the hub genes in METH. New object recognition and the Morris water maze were used to examine cognitive function in mice exposed to METH for 14 days in vivo. Astrocytes were cocultured with neurons for the detection of intercellular crosstalk. RESULTS: DEGs in the METH group significantly enriched pathways related to NDs, inflammation, and the NF-κB signaling pathway. Immune infiltration analysis revealed significantly increased infiltration of monocytes, T cells, and NK cells and decreased infiltration of neutrophils in the METH group. An intersection of 44 hub genes was screened based on the PPI network and random forest algorithm. These genes suggest that there might be similar pathogenesis between METH exposure and PD. METH exposure resulted in learning memory impairment, hippocampal astrocyte activation, and upregulation of NF-κB expression in mice. Activation of reactive astrocytes cocultured with neurons causes neural damage. CONCLUSIONS: This study explored the crosstalk between astrocytes and neurons in METH exposure, providing a potential pathogenesis to explore the altered immune microenvironment involving reactive astrocytes after METH exposure.
Subject(s)
Methamphetamine , Neurodegenerative Diseases , Animals , Mice , Methamphetamine/adverse effects , NF-kappa B/metabolism , Astrocytes/metabolism , Neurodegenerative Diseases/chemically induced , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/metabolism , Signal Transduction , RNA , Computational BiologyABSTRACT
The α-synuclein (α-syn) is involved in methamphetamine (METH)-induced neurotoxicity. Neurons can transfer excessive α-syn to neighboring neurons and glial cells. The effects of α-syn aggregation in astrocytes after METH exposure on the blood-brain barrier (BBB) remains unclear. Our previous study demonstrated that nuclear receptor-related protein 1 (Nurr1), a member of the nuclear receptor family widely expressed in the brain, was involved in the process of METH-induced α-syn accumulated in astrocytes to activate neuroinflammation. The role Nurr1 plays in astrocyte-mediated neuroinflammation, which results in BBB injury induced by METH, remains uncertain. This study found that METH up-regulated α-syn expression in neurons extended to astrocytes, thereby eliciting astrocyte activation, increasing and decreasing IL-1ß, IL-6, TNF-α, and GDNF levels by down-regulating Nurr1 expression, and ultimately damaging the BBB. Specifically, the permeability of BBB to Evans blue and sodium fluorescein (NaF) increased; IgG deposits in the brain parenchyma increased; the Claudin5, Occludin, and PDGFRß levels decreased. Several ultrastructural pathological changes occurred in the BBB, such as abnormal cerebral microvascular diameter, astrocyte end-foot swelling, decreased pericyte coverage, and loss of tight junctions. However, knockout or inhibition of α-syn or astrocyte-specific overexpression of Nurr1 partially alleviated these symptoms and BBB injury. Moreover, the in vitro experiments confirmed that METH increased α-syn level in the primary cultured neurons, which could be further transferred to primary cultured astrocytes, resulting in decreased Nurr1 levels. The decreased Nurr1 levels mediated the increase of IL-1ß, IL-6, and TNF-α, and the decrease of GDNF, thereby changing the permeability to NaF, transendothelial electrical resistance, and Claudin5 and Occludin levels of primary cultured brain microvascular endothelial cells. Based on our findings, we proposed a new mechanism to elucidate METH-induced BBB injury and presented α-syn and Nurr1 as promising drug intervention targets to reduce BBB injury and resulting neurotoxicity in METH abusers.
Subject(s)
Central Nervous System Stimulants , Methamphetamine , Neurotoxicity Syndromes , Astrocytes/metabolism , Blood-Brain Barrier/metabolism , Central Nervous System Stimulants/pharmacology , Endothelial Cells/metabolism , Evans Blue/metabolism , Evans Blue/pharmacology , Fluorescein/metabolism , Fluorescein/pharmacology , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Glial Cell Line-Derived Neurotrophic Factor/pharmacology , Humans , Immunoglobulin G , Interleukin-6/metabolism , Methamphetamine/metabolism , Neuroinflammatory Diseases , Neurons/metabolism , Neurotoxicity Syndromes/metabolism , Occludin/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Tumor Necrosis Factor-alpha/metabolism , alpha-Synuclein/metabolismABSTRACT
INTRODUCTION: This is the first randomized controlled diet intervention trial to investigate both the amount and type of carbohydrate on symptomatic gastroesophageal reflux disease (GERD). METHODS: Ninety-eight veterans with symptomatic GERD were randomly assigned to high total/high simple, high total/low simple, low total/high simple, or low total/low simple carbohydrate diet for 9 weeks. The primary outcomes were esophageal acid exposure time (AET) and total number of reflux episodes derived from 24-hour ambulatory pH monitoring. Secondary outcomes were esophageal reflux symptoms rated using the Gastroesophageal Reflux Disease Questionnaire (GERDQ) and GERD Symptom Assessment Scale (GSAS). RESULTS: Half of the subjects were White and half African American (mean age, 60.0 ± 12.5 years; mean body mass index, 32.7 ± 5.4 kg/m 2 ). There was a significant main effect of diet treatment on AET ( P = 0.001) and on the total number of reflux episodes ( P = 0.003). The change in AET in the high total/low simple group (-4.3% ± 3.8%) differed significantly from the high total/high simple control group (+3.1% ± 3.7%), (P = 0.04). The reduction in simple sugar intake averaged 62 g less per day. Subjects' ratings of symptoms improved in all carbohydrate modification groups, including significant reductions in heartburn frequency, heartburn severity, acid taste in the mouth, lump/pain in the throat or chest, and sleep disturbance. DISCUSSION: A modification of dietary carbohydrate intake that targeted a substantial reduction in the intakes of simple sugars improved pH monitoring outcomes and symptoms of GERD that profoundly affect daily life. These findings provide a feasible and clinically applicable contribution to the limited objective data existing for efficacious dietary recommendations in the routine treatment and management of GERD.
Subject(s)
Esophagitis, Peptic , Gastroesophageal Reflux , Aged , Humans , Middle Aged , Dietary Carbohydrates , Esophageal pH Monitoring , Gastroesophageal Reflux/diagnosis , Heartburn/etiology , MonosaccharidesABSTRACT
Background: Rising prevalence of gastroesophageal reflux disease (GERD) in US Veterans is concurrent with increasing excess body weight. Objective: The objective of this cross-sectional study is to examine relationships between dietary macronutrients, gastrointestinal hormones, and GERD status. Methods: Ninety-eight veterans with overweight/obesity and empiric proton pump inhibitor (PPI) treatment were enrolled from the Tennessee Valley Healthcare System. Subjects had esophageal manometry and 24-h pH monitoring. Subjective symptoms were assessed with Gastroesophageal Reflux Disease Questionnaire (GERDQ) and Symptom Assessment Scale (GSAS). The primary outcomes, total acid exposure time (AET) and number of reflux episodes, enabled categorizing subjects as either pathologic GERD or inconclusive GERD. Data analysis included independent T-tests, Spearman Rho correlations, and multivariable linear regression modeling. Results: Higher intake of sugar-sweetened beverages (sugar-sweetened tea, soda, and fruit juice) associated with higher AET. Higher saturated-to-unsaturated fat intake is associated with higher AET and number of reflux episodes. Overall, sugar-sweetened beverage intake, saturated-to-unsaturated fat ratio, tomato-based food items, glucagon-like polypeptide 1 (GLP-1) level, time of first meal, and education status accounted for a significant amount of the variability in AET. Pathologic GERD subjects reported more heartburn (p = 0.006), regurgitation (p = 0.01), acid taste (0.001), and nausea severity (p = 0.04). GERDQ score associated with AET (r = 0.31, p = 0.005), but GSAS did not (r = 0.12, p = 0.28). Conclusion: Of the many foods and nutrients tested, the type (not amount) of carbohydrate (simple sugars) and the type (not amount) of fat (saturated vs unsaturated fat) consumed associated with objective and/or subjective GERD testing. These novel findings contribute to the evidence base guiding specific dietary recommendations in the clinical management of GERD.
ABSTRACT
Methamphetamine (Meth) is a predominantly abused neurostimulant, and its abuse is often associated with multiple neurological symptoms. Olfaction, the sense of smell, is a highly neurotransmission-dependent physiological process; however, the effect of Meth on olfactory function and its underlying mechanisms remain largely unknown. This study aimed to explore the impact of Meth abuse on the olfactory system and the potential mechanisms. Chronic Meth abuse was induced by daily administration of Meth in male mice for 4 weeks, and we then systematically examined olfactory performance. Behavioral tests found that Meth-treated animals showed increased olfactory threshold, decreased olfactory sensitivity, reduced olfactory-dependent discrimination, and difficulty in seeking buried food. Notably, the increased deposition of α-synuclein (α-syn) in the olfactory bulb was detected. Adeno-associated virus (AAV)-mediated α-syn intervention therapy in the olfactory bulb significantly alleviated Meth-induced olfactory function impairment, and 8 weeks of aerobic exercise showed similar effects through the same principle of α-syn intervention. Notably, exercise-mediated reduction of α-syn inhibited abnormal firing activity and restored the inhibitory synaptic regulation of mitral cells in the olfactory bulb. These findings suggest the involvement of α-syn in the pathogenic mechanisms of Meth-induced olfactory dysfunction and shed light on the possible therapeutic applications of aerobic exercise in Meth-induced olfactory dysfunction.
ABSTRACT
BACKGROUNDS: Y-chromosomal haplotypes based on Y-short tandem repeats (STRs) and Y-single nucleotide polymorphisms/insertion and deletion polymorphisms (SNPs/InDels) are used to characterize paternal lineages of unknown male trace donors. However, Y-chromosomal genetic markers are not currently sufficient for precise individual identification. Microhaplotype (MH), generally < 200 bp on autosomes and consisting of two or more SNPs, was recently introduced in forensic genetics with the development of massive parallel sequencing technology and may facilitate identification and DNA mixture deconvolution. Therefore, combining the two kinds of genetic markers may be beneficial in many forensic scenarios, especially crime scenes with male suspects, such as sexual assault cases. METHODS: In the present study, we developed a novel MPS-based panel, Microhaplotype and Y-SNP/STR (MY), by multiplex PCR and 150-bp paired-end sequencing, including 114 Y-SNPs (twelve dominant Y-DNA haplogroups), 45 Y-STRs (N-1 stutter < 0.09; estimated mutation rate < 5 × 10-3), and 22 MHs (allele coverage ratio > 0.91; pairwise distance > 10 Mb). Additionally, MY system-based genotype pattern recognition (GPR), a regression-based method to identify the genotype pattern for each MH locus, is proposed for two-person DNA mixture deconvolution. We integrated 26 two-person genotype combinations into nine genotype patterns and validated the application range of GPR based on DNA profiles of ten sets of simulated male-male DNA mixtures (1:10-1:2). RESULTS: The effective number of alleles (Ae) ranged from 3.62 to 14.72, with an average of 7.17, in 100 Chinese Guangdong Han individuals. The cumulative discrimination power was 1-5.00 × 10-31, and the cumulative power of exclusion was 1-5.00 × 10-8 and 1-4.85 × 10-12 for duo and trio paternity testing, respectively. Furthermore, the actual mixing ratio-depth of coverage (DoC) ratio (RDoC) regression relationships were established for different genetic markers and genotype patterns. In five overlapping areas, genotype differentiation of the major and minor contributors required likelihood ratio methods. In nonoverlapping areas, the genotype pattern could be recognized by comparing the observed RDoC and RDoC ranges. CONCLUSION: The GPR can be used to deconvolute two-person DNA mixtures (application range: 1:10-1:2) for individual identification.
Subject(s)
DNA Fingerprinting , Polymorphism, Single Nucleotide , DNA/analysis , DNA/genetics , DNA Fingerprinting/methods , Genetic Markers , Genotype , Haplotypes , High-Throughput Nucleotide Sequencing , Humans , Male , Microsatellite RepeatsABSTRACT
Neuroimaging studies demonstrate associations of brain structure and function with children's eating behaviour and body weight, and the feasibility of integrating brain measures into obesity risk assessment and intervention is growing. However, little is known about lay perceptions of how the brain influences obesity. We investigated parent perceptions of brain contributions to obesity in three separate studies: 1) a study of mothers of adolescents recruited for neuroimaging research (n = 88), 2) a study of ethnically Chinese parents of 5-13 year olds participating in a parent feeding survey (n = 277), and 3) a study of parents of 3-15 year olds completing an online survey (n = 113). In general, parents believed that brain factors influence obesity, but considered them less influential than behaviours such as diet and exercise. Causal attributions for brain factors were correlated with attributions for genetic factors and biological factors (e.g., metabolism). Parents who perceived their child to be overweight or had a high concern about their child becoming overweight in the future rated brain factors as more important in determining their child's weight and more likely to lessen their child's ability to control their weight. Our results suggest that parents attribute obesity to the brain to a moderate degree, and that education or feedback regarding brain influences on obesity could be a promising obesity intervention component.
Subject(s)
Overweight , Pediatric Obesity , Adolescent , Body Mass Index , Body Weight , Brain , Child , Female , Humans , Obesity/epidemiology , Obesity/etiology , Overweight/complications , Parents , Pediatric Obesity/complications , Pediatric Obesity/epidemiology , Surveys and QuestionnairesABSTRACT
Parents' food-related and general parenting behaviors may vary according to cultural background, with consequences for child eating behavior and weight. A better understanding of food-related and general parenting behaviors adopted by Chinese-American parents, and the relationships of all of these behaviors with child weight, is essential to aid the development of culturally appropriate interventions to prevent obesity in Chinese-American children. We investigated cross-sectional relationships of acculturation with parental feeding behaviors assessed with the Child Feeding Questionnaire, Parent Feeding Styles Questionnaire and Caregiver's Feeding Styles Questionnaire, and general parenting behaviors assessed with the Parenting Styles and Dimensions Questionnaire, in a sample of Chinese-American parents of 5-12 year-old children (n = 233). Parental level of acculturation was assessed using the Suinn-Lew Asian Self-Identity Acculturation scale. We performed generalized linear regressions to explore associations of acculturation levels with parental feeding and general parenting subscales and also associations of these factors with child body mass index (BMI) z-score. Acculturation was associated with higher scores on Responsiveness in feeding, lower scores on subscales assessing controlling feeding behaviors (Restriction, Pressure to eat, Demandingness in feeding), lower scores on non-nutritive feeding behaviors (Emotional feeding, Instrumental feeding), and greater likelihood of an indulgent feeding style. With regard to general parenting, acculturation was associated with lower scores on subscales assessing authoritarian parenting. Parental Prompting/Encouragement to eat was associated with lower child BMI z-score, while authoritarian parenting subscales were associated with higher BMI z-score. An appreciation of the impact of cultural variation on food-related and general parenting may help to inform the development of culturally-sensitive obesity prevention interventions.
Subject(s)
Acculturation , Parenting , Body Mass Index , Body Weight , Child , Child, Preschool , Feeding Behavior , Humans , Obesity , Parent-Child Relations , Surveys and QuestionnairesABSTRACT
Childhood obesity is prevalent among ethnic minorities in the UK but little is known about parent feeding practices in these populations. We administered questionnaires assessing parental feeding behaviors and perceptions and concerns relating to child weight to White British (n = 271), South Asian (n = 59), and Black Afro-Caribbean (n = 42) parents of UK 3-5 year-olds. Child BMI z-scores were determined from measured heights and weights. South Asian and Black Afro-Caribbean parents exhibited greater pressure to eat than White British parents. Black Afro-Caribbean parents additionally scored higher on instrumental feeding and lower on monitoring, while South Asian parents scored higher on emotional feeding. Black Afro-Caribbean parents reported the greatest concern about both child overweight and underweight. Ethnic differences were unchanged by controlling for perceptions and concerns relating to child weight, or for actual BMI z, parent education, or household income. Exploratory analyses suggested some evidence for sex differences within ethnic groups. For example, South Asian parents of daughters scored higher than White British parents of daughters on emotional feeding, with no ethnic differences apparent for parents of sons. Our findings support considering variation in parent feeding behaviors and weight-related attitudes by parental ethnicity and child sex when developing obesity interventions.