Lower plasma linoleic acids as a risk factor for gout: an integrated analysis of population-based cohort and genetic data.

Background: Gout is a nutrition-related, highly prevalent inflammatory arthritis with undesirable effects on the quality of life. The relationships between circulating fatty acids (FAs) and gout remain poorly understood. Method: We included 268 174 participants with plasma FAs measured using nuclear magnetic resonance at the baseline (2006-2010) from the UK Biobank, of which 15 194 participants had repeated measures of FAs between 2012 and 2013. Cox proportional hazards models were used to assess the association of the baseline and longitudinal changes in relative levels of plasma FAs (% total FAs) with incident gout. Mendelian randomization (MR) analyses were conducted to assess the potential causality of the examined association. Results: Over a median follow-up of 12.8 years, 5160 incident cases of gout occurred. Baseline polyunsaturated fatty acids (PUFAs), n-6 PUFAs, and linoleic acids (LAs) were inversely associated with incident gout (all P-trend values < 0.0001). Baseline monounsaturated fatty acids (MUFAs), n-3 PUFAs, and docosahexaenoic acids (DHAs) were positively associated with incident gout (all P-trend values < 0.0001). Longitudinal increments of n-6 PUFAs and LAs were associated with a lower risk of subsequent gout, whereas an increment of n-3 PUFAs was associated with a higher risk. In two-sample MR analyses, genetically determined higher levels of PUFAs, n-6 PUFAs, and LAs were associated with a decreased risk of gout (all P values < 0.05). Conclusions: Our findings consistently indicate a causal relationship of elevated levels of n-6 PUFAs, especially LAs, with a reduced risk of gout.

Lhx2 promotes axon regeneration of adult retinal ganglion cells and rescues neurodegeneration in mouse models of glaucoma.

The axons of retinal ganglion cells (RGCs) form the optic nerve, transmitting visual information from the eye to the brain. Damage or loss of RGCs and their axons is the leading cause of visual functional defects in traumatic injury and degenerative diseases such as glaucoma. However, there are no effective clinical treatments for nerve damage in these neurodegenerative diseases. Here, we report that LIM homeodomain transcription factor Lhx2 promotes RGC survival and axon regeneration in multiple animal models mimicking glaucoma disease. Furthermore, following N-methyl-D-aspartate (NMDA)-induced excitotoxicity damage of RGCs, Lhx2 mitigates the loss of visual signal transduction. Mechanistic analysis revealed that overexpression of Lhx2 supports axon regeneration by systematically regulating the transcription of regeneration-related genes and inhibiting transcription of Semaphorin 3C (Sema3C). Collectively, our studies identify a critical role of Lhx2 in promoting RGC survival and axon regeneration, providing a promising neural repair strategy for glaucomatous neurodegeneration.

Plant-based diets, mediating biomarkers, and mortality risk among adults with diabetes or prediabetes.

Background: A healthy eating pattern characterized by a higher intake of healthy plant foods has been associated with a lower risk of premature mortality, but whether this applies to individuals with varying glycemic status remains unclear. Methods: This study included 4621 participants with diabetes and 8061 participants with prediabetes from the US National Health and Nutrition Examination Survey (2007-2016). Using the dietary data assessed by two 24 h dietary recalls, a healthful plant-based diet index (hPDI) and an unhealthful plant-based diet index (uPDI) were created based on 15 food groups and were assessed for their relationships with mortality risk. Results: Over a median follow-up of 7.2 years, there were 1021 deaths in diabetes and 896 deaths in prediabetes. A higher hPDI (highest vs. lowest quartile) was associated with a 41% (HR = 0.59, 95% CI: 0.49-0.72; P-trend < 0.001) lower risk of all-cause mortality in diabetes and a 31% (HR = 0.69, 95% CI: 0.55-0.85; P-trend < 0.001) lower risk in prediabetes. A higher uPDI was associated with an 88% (HR = 1.88, 95% CI: 1.55-2.28; P-trend < 0.001) higher risk of mortality in diabetes and a 63% (HR = 1.63, 95% CI: 1.33-1.99; P-trend < 0.001) higher risk in prediabetes. Mediation analysis suggested that C-reactive protein and γ-glutamine transaminase explained 6.0% to 10.9% of the relationships between hPDI or uPDI and all-cause mortality among participants with diabetes. Conclusions: For adults with diabetes as well as those with prediabetes, adhering to a plant-based diet rich in healthier plant foods is associated with a lower mortality risk, whereas a diet that incorporates less healthy plant foods is associated with a higher mortality risk.

Association of phthalate exposure with all-cause mortality across renal function status: The U.S. National Health and Nutrition Examination Survey, 2005-2018.

BACKGROUND: Wide phthalate exposure has been associated with both declines in renal function and an elevated risk of mortality. Whether phthalate-associated risk of premature mortality differs by renal function status remains unclear. METHODS: This study included 9605 adults from the U.S. National Health and Nutrition Examination Survey. Urinary concentrations of 11 phthalate metabolites were assessed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. According to estimated glomerular filtration rate (eGFR), participants were grouped as having normal or modestly declined renal functions, or chronic kidney disease (CKD). Multivariable Cox regression models estimated all-cause mortality associated with phthalate exposure, overall and by renal function status. RESULTS: Overall, Mono-n-butyl phthalate (MnBP), Mono-benzyl phthalate (MBzP), Mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono-(2-ethyl-5-carbox-ypentyl) phthalate (MECPP) were associated with an elevated risk of mortality (P-trend across tertile <0.05). Moreover, significant interactions were observed between eGFR and MEHHP, MEOHP, MECPP, DEHP in the whole population (P for interactions <0.05). After stratification by renal function, total Di (2-ethylhexyl) phthalate (DEHP) was additionally found to be associated with mortality risk in the CKD group (HR = 1.12; 95% CI: 1.01, 1.25). Co-exposure to the 11 phthalate metabolites was associated with a higher risk of all-cause mortality in the CKD (HR = 1.47; 95% CI: 1.18, 1.84) and modestly declined renal function group (HR = 1.25; 95% CI: 1.09, 1.44). CONCLUSIONS: The associations between phthalate exposure and risk of all-cause mortality were primarily observed in CKD patients, reinforcing the need for monitoring phthalate exposure in this patient population.

The association between maternal healthy lifestyle factors during pregnancy and the neonatal anthropometric indicators based on a prospective cohort study.

BACKGROUND AND OBJECTIVES: We aimed to evaluate the associations between a combined healthy lifestyle during the second and third trimesters and offspring anthropometric outcomes in China. METHODS AND STUDY DESIGN: We examined these associations among 548 participants from nine community health centers and three hospitals in the North China cohort. A pregnant women's healthy lifestyle score (HLS) was constructed based on six lifestyle factors: smoking, alcohol consumption, physical activity, sedentary behavior, diet, and gestational weight gain. Anthropometric indicators at birth like birth weight (BW), head circumference (HC), and birth length (BL) were collected, and weight to head circumference ratio (WHC, kg/m), body mass index (BMI, kg/m2) and Ponderal Index (PI, kg/m3) were calculated. Multivariate linear and logistic regression models were used to examine the effects of HLS during the second and third trimesters on anthropometric outcomes at birth, respectively. RESULTS: In fully adjusted models, we found a negative association between second and third-trimester HLS and offspring HC and a positive relationship between second-trimester HLS and BL (p<0.05). Neonates with mothers in the highest HLS tertile had a 5.6% relatively lower HC and 2.3% relatively longer body length than women in the lowest tertile. Each additional unit in third-trimester HLS had an associated decrease in HC by 0.96 cm. None of the associations between HLS and BW, WHC, BMI, and PI of offspring were observed. CONCLUSIONS: A healthy lifestyle score may significantly impact offspring head circumference and body length, supporting the important role of healthy lifestyles in improving the health of offspring.

High LYRM4-AS1 predicts poor prognosis in patients with glioma and correlates with immune infiltration.

Background: Many researches proved that non-coding RNAs are important in glioma development. We screened the differentially expressed genes through The Cancer Genome Atlas (TCGA) database and identified the molecule LYRM4-AS1 associated with prognosis. As a lncRNA, the expression level and role of LYRM4-AS1 in glioma are inconclusive. Therefore, we attempted to assess the clinical significance, expression and related mechanisms of LYRM4-AS1 in glioma by employing cell experiments and an integrative in silico methodology. Methods: RNA-seq data were obtained from UCSC XENA and TCGA datasets. The Gene Expression Omnibus (GEO) database was used to download glioma-related expression profile data. The LYRM4-AS1 expression level was evaluated. Survival curves were constructed by the Kaplan-Meier method. Cox regression analysis was used to analyze independent variables. Patients were divided into high and low expression group base on the median LYRM4-AS1 expression value in glioma tissues. The DESeq2 R package was used to identify differentially expressed genes (DEGs) between two different expression LYRM4-AS1 groups. Gene set enrichment analysis (GSEA) was conducted. Next, the single-sample Gene Set Enrichment Analysis (ssGSEA) was done to quantify the immune infiltration of immune cells in glioma tissues. Gene expression profiles for glioma tumor tissues were used to quantify the relative enrichment score for each immune cell. Spearman correlation analysis was used to analyze the correlation between LYRM4-AS1 and biomarkers of immune cells as well as immune checkpoints in glioma. Finally, assays for cell apoptosis, cell viability and wound healing were conducted to evaluate the function on U87 MG and U251 cells after knocking down LYRM4-AS1. Results: We found that LYRM4-AS1 was upregulated and related to the grade and malignancy of glioma. Survival analyses showed that high expression LYRM4-AS1 patients had poor clinical outcomes (P < 0.01). Cox regression analyses demonstrated that LYRM4-AS1 was an independent risk factor for overall survival (OS) in glioma (HR: 274 1.836; CI [1.278-2.639]; P = 0.001). Enrichment and immune infiltration analysis showed interferon signaling and cytokine-cytokine receptor interaction enriched in the LYRM4-AS1 high-expression phenotype, and LYRM4-AS1 showed significantly positively related to immune infiltration as well as immune checkpoints (P < 0.01). The knockdown of LYRM4-AS1 in U87 MG and U251 cells can inhibit migration and proliferation of cells (P < 0.05). Conclusions: These findings indicated that the increased LYRM4-AS1 may be useful for the diagnosis and prognosis of glioma and might participate in the immune infiltration.

High-throughput functional screen identifies YWHAZ as a key regulator of pancreatic cancer metastasis.

Pancreatic cancer is a leading cause of cancer death due to its early metastasis and limited response to the current therapies. Metastasis is a complicated multistep process, which is determined by complex genetic alterations. Despite the identification of many metastasis-related genes, distinguishing the drivers from numerous passengers and establishing the causality in cancer pathophysiology remains challenging. Here, we established a high-throughput and piggyBac transposon-based genetic screening platform, which enables either reduced or increased expression of chromosomal genes near the incorporation site of the gene search vector cassette that contains a doxycycline-regulated promoter. Using this strategy, we identified YWHAZ as a key regulator of pancreatic cancer metastasis. We demonstrated that functional activation of Ywhaz by the gene search vector led to enhanced metastatic capability in mouse pancreatic cancer cells. The metastasis-promoting role of YWHAZ was further validated in human pancreatic cancer cells. Overexpression of YWHAZ resulted in more aggressive metastatic phenotypes in vitro and a shorter survival rate in vivo by modulating epithelial-to-mesenchymal transition. Hence, our study established a high-throughput screening method to investigate the functional relevance of novel genes and validated YWHAZ as a key regulator of pancreatic cancer metastasis.

ASH2L regulates postnatal neurogenesis through Onecut2-mediated inhibition of TGF-ß signaling pathway.

The ability of neural stem/progenitor cells (NSPCs) to proliferate and differentiate is required through different stages of neurogenesis. Disturbance in the regulation of neurogenesis causes many neurological diseases, such as intellectual disability, autism, and schizophrenia. However, the intrinsic mechanisms of this regulation in neurogenesis remain poorly understood. Here, we report that Ash2l (Absent, small or homeotic discs-like 2), one core component of a multimeric histone methyltransferase complex, is essential for NSPC fate determination during postnatal neurogenesis. Deletion of Ash2l in NSPCs impairs their capacity for proliferation and differentiation, leading to simplified dendritic arbors in adult-born hippocampal neurons and deficits in cognitive abilities. RNA sequencing data reveal that Ash2l primarily regulates cell fate specification and neuron commitment. Furthermore, we identified Onecut2, a major downstream target of ASH2L characterized by bivalent histone modifications, and demonstrated that constitutive expression of Onecut2 restores defective proliferation and differentiation of NSPCs in adult Ash2l-deficient mice. Importantly, we identified that Onecut2 modulates TGF-ß signaling in NSPCs and that treatment with a TGF-ß inhibitor rectifies the phenotype of Ash2l-deficient NSPCs. Collectively, our findings reveal the ASH2L-Onecut2-TGF-ß signaling axis that mediates postnatal neurogenesis to maintain proper forebrain function.

Microglial transglutaminase 2 deficiency causes impaired synaptic remodelling and cognitive deficits in mice.

Microglia are the primary source of transglutaminase 2 (TGM2) in the brain; however, the roles of microglial TGM2 in neural development and disease are still not well known. The aim of this study is to elucidate the role and mechanisms of microglial TGM2 in the brain. A mouse line with a specific knockout of Tgm2 in microglia was generated. Immunohistochemistry, Western blot and qRT-PCR assays were performed to evaluate the expression levels of TGM2, PSD-95 and CD68. Confocal imaging, immunofluorescence staining and behavioural analyses were conducted to identify phenotypes of microglial TGM2 deficiency. Finally, RNA sequencing, qRT-PCR and co-culture of neurons and microglia were used to explore the potential mechanisms. Deletion of microglial Tgm2 causes impaired synaptic pruning, reduced anxiety and increased cognitive deficits in mice. At the molecular level, the phagocytic genes, such as Cq1a, C1qb and Tim4, are significantly down-regulated in TGM2-deficient microglia. This study elucidates a novel role of microglial TGM2 in regulating synaptic remodelling and cognitive function, indicating that microglia Tgm2 is essential for proper neural development.

The Role and Mechanism of Transglutaminase 2 in Regulating Hippocampal Neurogenesis after Traumatic Brain Injury.

Traumatic brain injury usually results in neuronal loss and cognitive deficits. Promoting endogenous neurogenesis has been considered as a viable treatment option to improve functional recovery after TBI. However, neural stem/progenitor cells (NSPCs) in neurogenic regions are often unable to migrate and differentiate into mature neurons at the injury site. Transglutaminase 2 (TGM2) has been identified as a crucial component of neurogenic niche, and significantly dysregulated after TBI. Therefore, we speculate that TGM2 may play an important role in neurogenesis after TBI, and strategies targeting TGM2 to promote endogenous neural regeneration may be applied in TBI therapy. Using a tamoxifen-induced Tgm2 conditional knockout mouse line and a mouse model of stab wound injury, we investigated the role and mechanism of TGM2 in regulating hippocampal neurogenesis after TBI. We found that Tgm2 was highly expressed in adult NSPCs and up-regulated after TBI. Conditional deletion of Tgm2 resulted in the impaired proliferation and differentiation of NSPCs, while Tgm2 overexpression enhanced the abilities of self-renewal, proliferation, differentiation, and migration of NSPCs after TBI. Importantly, injection of lentivirus overexpressing TGM2 significantly promoted hippocampal neurogenesis after TBI. Therefore, TGM2 is a key regulator of hippocampal neurogenesis and a pivotal therapeutic target for intervention following TBI.

A systematic review and meta-analysis of observational studies of the association between the use of incretin-based therapies and the risk of pancreatic cancer.

BACKGROUND: Some early reports in the medical literature have raised concern about a possible increased risk of pancreatic cancer associated with the use of two broad classes of incretin-based therapies, dipeptidyl peptidase-4 inhibitors, and glucagon-like peptide-1 receptor agonists. This possibility has been somewhat mitigated by the null findings meta-analyses of randomized controlled trials, but the usefulness of their findings was hampered by serious shortcomings of lack of power and representativeness. These shortcomings can typically be addressed by observational studies, but observational studies on the topic have yielded conflicting findings. A systematic review and meta-analysis of observational studies was performed to qualitatively and quantitatively appraise the totality of evidence on the association between the use of incretin-based therapies and the risk of pancreatic cancer in routine clinical practice. METHODS: The PubMed, Web of Science, Embase, and Google Scholar databases were searched. The study quality was appraised using the ROBINS-I tool and based on the presence of pharmacoepidemiology biases. A random-effects model was used to estimate the summary relative risks with corresponding CIs. RESULTS: A total of 14 studies were included. The qualitative assessment revealed that all studies had inadequate follow-up (≤5 years), 12 studies were suspected to suffer from time-lag bias (due to inappropriate choice of comparator group) to varying extent, five studies included prevalent users, five studies did not implement exposure lag period, five studies had a serious risk of bias due to confounding, and one study had a time-window bias. The quantitative assessment showed no indication of an increased risk when all studies were pooled together (RR 1.04, 95% CI 0.87, 1.24) and when the analysis was restricted to the studies with the least bias (RR 0.77, 95% CI 0.51, 1.17). However, the pooled RRs were more frequently higher in the studies with less rigorous design and analysis. Specifically, a tendency toward an increased risk was observed in the studies with (RR 1.34, 95% CI 1.04, 1.72) or possibly with (RR 1.10, 95% CI 0.89, 1.36) time-lag bias, in the studies that did not apply (RR 1.23, 95% CI 0.93, 1.63) or with potentially inadequate exposure lag period of 6 months (RR 1.13, 95% CI 0.66, 1.94), in the studies that inappropriate comparator group of a combination of unspecified (RR 1.49, 95% CI 1.25, 1.78) or non-insulin (RR 1.15, 95% CI 0.93, 1.42) antidiabetic drugs, and in the studies with serious risk of bias due to confounding (RR 1.18, 95% CI 0.56, 2.49). CONCLUSIONS: In summary, the totality of evidence from observational studies does not support the claim that the use of incretin-based therapies is associated with an increased risk of pancreatic cancer in routine clinical practice. The increased risk of pancreatic cancer observed in observational studies reflects bias resulting from suboptimal methodological approaches, which need to be avoided by future studies.

Understanding the Development of Heterocyclic Aromatic Amines in Fried Bacon and in the Remaining Oil after Pan-Frying in Five Different Vegetable Oils.

The physicochemical properties of five vegetable oils (peanut, corn, rapeseed, sunflower seed, and soybean) and their impact on the development of heterocyclic aromatic amines (HAAs) in pan-fried bacon and in the remaining oil were investigated. Corn oil led to the lowest total free amino acids (FAAs) contents and glucose content of fried bacon (p < 0.05) and rapeseed oil led to the lowest creatine content of fried bacon (p < 0.05). Bacon fried in corn oil had the highest HAA contents (p < 0.05). The total HAA contents of the oils after frying were lowest in rapeseed and soybean oils (p < 0.05). The type of vegetable oil used affected the color of the fried bacon but not the flavor and taste (p < 0.05). To reduce the HAA concentrations of fried bacon, the type of vegetable oil should be considered.

Acetate supplementation restores cognitive deficits caused by ARID1A haploinsufficiency in excitatory neurons.

Mutations in AT-rich interactive domain-containing protein 1A (ARID1A) cause Coffin-Siris syndrome (CSS), a rare genetic disorder that results in mild to severe intellectual disabilities. However, the biological role of ARID1A in the brain remains unclear. In this study, we report that the haploinsufficiency of ARID1A in excitatory neurons causes cognitive impairment and defects in hippocampal synaptic transmission and dendritic morphology in mice. Similarly, human embryonic stem cell-derived excitatory neurons with deleted ARID1A exhibit fewer dendritic branches and spines, and abnormal electrophysiological activity. Importantly, supplementation of acetate, an epigenetic metabolite, can ameliorate the morphological and electrophysiological deficits observed in mice with Arid1a haploinsufficiency, as well as in ARID1A-null human excitatory neurons. Mechanistically, transcriptomic and ChIP-seq analyses demonstrate that acetate supplementation can increase the levels of H3K27 acetylation at the promoters of key regulatory genes associated with neural development and synaptic transmission. Collectively, these findings support the essential roles of ARID1A in the excitatory neurons and cognition and suggest that acetate supplementation could be a potential therapeutic intervention for CSS.

Correction: He et al. Intranasal Administration of Agomir-let-7i Improves Cognitive Function in Mice with Traumatic Brain Injury. Cells 2022, 11, 1348.

The authors wish to make the following changes to their paper [...].

Glycemic index, glycemic load, and lung cancer risk: A meta-analysis of cohort and case-control studies.

OBJECTIVE: Glycemic index (GI) or glycemic load (GL) has been investigated in the field of cancer research for several years. However, the relationship between GI or GL and lung cancer risk remains inconsistent. Therefore, this study aimed to summarize previous findings on this relationship. METHODS: PubMed, Embase, Scopus, Web of Science databases, and Cochrane Library were searched by July 2021. This review was conducted in accordance with the PRISMA guidelines. A fixed or random-effects model was adopted for meta-analysis to compute the pooled relative risks (RR) and their corresponding 95% confidence intervals (CIs). Subgroup analyses, sensitivity analyses, and publication bias analyses were also performed. RESULTS: In total, nine articles were included, with four case-control studies and five cohort studies, including 17,019 cases and 786,479 controls. After merging the studies, pooled multivariable RRs of lung cancer based on the highest versus the lowest intake were 1.14 (95%CI: 1.03-1.26) and 0.93 (95%CI: 0.84-1.02) for GI and GL. Results persisted in most stratifications after stratifying by potential confounders in the relationship between GI and lung cancer risk. There was a non-linear dose response relation for GI with lung caner risk. CONCLUSION: GI typically has a positive relationship with lung cancer risk. However, no associations between GL and lung cancer risk were observed based on current evidence, suggesting that this issue should be studied and verified further to substantiate these findings.

Flavor Differences of Edible Parts of Grass Carp between Jingpo Lake and Commercial Market.

This study investigated the flavor differences among three individual parts (abdomen, back, and tail) of Jingpo Lake grass carp (JPGC) and commercial grass carp (CGC). The growing environment and fish parts influenced the volatile compounds of the fish. The highest total contents of alcohols and ethers were found in the back of JPGC (p < 0.05). The combination of an electronic tongue and electronic nose (E-nose) could effectively distinguish the flavor differences between the different parts of JPGC and CGC by principal component analysis. Both the content of total free amino acids (FAAs) and content of amino acids contributing to the sweet and fresh flavors were higher in JPGC than CGC (p < 0.05). Among the ATP-associated products, the inosine 5'-monophosphate (IMP) contents of the back and tail of JPGC were higher (p < 0.05), but the abdomen content was lower (p > 0.05) than the respective contents in the corresponding parts of CGC. Sensory evaluation shows that JPGC had a better texture, odor, and taste, compared to CGC. Correlation analysis showed that the E-nose data and FAAs were highly correlated with the content of alcohols, aldehydes, and ethers. This study showed that the flavors of the different parts of JPGC differed significantly from those of CGC.

The validity of ASMI, RASM, and L3 SMI in assessing skeletal muscle mass in patients with lung cancer.

BACKGROUND AND OBJECTIVES: Both bioelectrical impedance analysis (BIA) and electron computed tomography (CT) can be used as tools for assessing skeletal muscle mass. In order to find a more suitable method for assessing skeletal muscle mass in lung cancer patients, this study conducted a comprehensive comparative analysis of the two methods. METHODS AND STUDY DESIGN: We collected baseline data from patients admitted to the oncology department of the First Hospital of Hebei Medical University from October 2017 to December 2021, and collected data through physical examination, body composition analysis measurements and CT examinations. Then we calculated skeletal muscle mass index (ASMI), relative skeletal muscle index (RASM), and third lumbar spine skeletal muscle index (L3 SMI), respectively. Finally we analyzed the correlation between the three methods and body composition and biochemical indicators and the validity of the three methods. RESULTS: A total of 63 patients, 41 males and 22 females, were screened and eligible for enrollment, and the validity of RASM and ASMI was analyzed using L3 SMI as the diagnostic criteria: the sensitivity of RASM and ASMI were 66.67% and 13.33%, respectively, and the specificity was 70.83% and 39.58%, respectively, and the AUC of ROC was 0.736 (p<0.05), 0.264 (p<0.05). CONCLUSIONS: In this study, L3 SMI was used as the diagnostic criterion and after calculating and comparing the valid parameters of RASM and ASMI, RASM was recommended as the assessment criterion for skeletal muscle mass in Chinese lung cancer patients.

The epigenetic state of EED-Gli3-Gli1 regulatory axis controls embryonic cortical neurogenesis.

Mutations in the embryonic ectoderm development (EED) cause Weaver syndrome, but whether and how EED affects embryonic brain development remains elusive. Here, we generated a mouse model in which Eed was deleted in the forebrain to investigate the role of EED. We found that deletion of Eed decreased the number of upper-layer neurons but not deeper-layer neurons starting at E16.5. Transcriptomic and genomic occupancy analyses revealed that the epigenetic states of a group of cortical neurogenesis-related genes were altered in Eed knockout forebrains, followed by a decrease of H3K27me3 and an increase of H3K27ac marks within the promoter regions. The switching of H3K27me3 to H3K27ac modification promoted the recruitment of RNA-Pol2, thereby enhancing its expression level. The small molecule activator SAG or Ptch1 knockout for activating Hedgehog signaling can partially rescue aberrant cortical neurogenesis. Taken together, we proposed a novel EED-Gli3-Gli1 regulatory axis that is critical for embryonic brain development.

Abnormal microglial polarization induced by Arid1a deletion leads to neuronal differentiation deficits.

OBJECTIVE: Microglia, the prototypical innate immune cells of the central nervous system (CNS), are highly plastic and assume their phenotypes dependent on intrinsically genetic, epigenetic regulation or extrinsically microenvironmental cues. Microglia has been recognized as key regulators of neural stem/progenitor cells (NSPCs) and brain functions. Chromatin accessibility is implicated in immune cell development and functional regulation. However, it is still unknown whether and how chromatin remodelling regulates the phenotypic plasticity of microglia and exerts what kind of effects on NSPCs. METHODS: We investigated the role of chromatin accessibility in microglia by deleting chromatin remodelling gene Arid1a using microglia-specific Cx3cr1-cre and Cx3cr1-CreERT2 mice. RNA-seq and ATAC-seq were performed to dissect the molecular mechanisms. In addition, we examined postnatal M1/M2 microglia polarization and analysed neuronal differentiation of NSPCs. Finally, we tested the effects of microglial Arid1a deletion on mouse behaviours. RESULTS: Increased chromatin accessibility upon Arid1a ablation resulted in enhanced M1 microglial polarization and weakened M2 polarization, which led to abnormal neurogenesis and anxiety-like behaviours. Switching the polarization state under IL4 stimulation could rescue abnormal neurogenesis, supporting an essential role for chromatin remodeler ARID1A in balancing microglial polarization and brain functions. CONCLUSIONS: Our study identifies ARID1A as a central regulator of microglia polarization, establishing a mechanistic link between chromatin remodelling, neurogenesis and mouse behaviours, and highlights the potential development of innovative therapeutics exploiting the innate regenerative capacity of the nervous system.