A Prelimbic Cortex-Thalamus Circuit Bidirectionally Regulates Innate and Stress-Induced Anxiety-Like Behavior.

Anxiety-related disorders respond to cognitive behavioral therapies, which involved the medial prefrontal cortex (mPFC). Previous studies have suggested that subregions of the mPFC have different and even opposite roles in regulating innate anxiety. However, the specific causal targets of their descending projections in modulating innate anxiety and stress-induced anxiety have yet to be fully elucidated. Here, we found that among the various downstream pathways of the prelimbic cortex (PL), a subregion of the mPFC, PL-mediodorsal thalamic nucleus (MD) projection, and PL-ventral tegmental area (VTA) projection exhibited antagonistic effects on anxiety-like behavior, while the PL-MD projection but not PL-VTA projection was necessary for the animal to guide anxiety-related behavior. In addition, MD-projecting PL neurons bidirectionally regulated remote but not recent fear memory retrieval. Notably, restraint stress induced high-anxiety state accompanied by strengthening the excitatory inputs onto MD-projecting PL neurons, and inhibiting PL-MD pathway rescued the stress-induced anxiety. Our findings reveal that the activity of PL-MD pathway may be an essential factor to maintain certain level of anxiety, and stress increased the excitability of this pathway, leading to inappropriate emotional expression, and suggests that targeting specific PL circuits may aid the development of therapies for the treatment of stress-related disorders.

Mature astrocytes as source for astrocyte repopulation after deletion in the medial prefrontal cortex: Implications for depression.

The adult brain retains a high repopulation capacity of astrocytes after deletion, and both mature astrocytes in the neocortex and neural stem cells in neurogenic regions possess the potential to generate astrocytes. However, the origin and the repopulation dynamics of the repopulating astrocytes after deletion remain largely unclear. The number of astrocytes is reduced in the medial prefrontal cortex (mPFC) of patients with depression, and selective elimination of mPFC astrocytes is sufficient to induce depression-like behaviors in rodents. However, whether astrocyte repopulation capacity is impaired in depression is unknown. In this study, we used different transgenic mouse lines to genetically label different cell types and demonstrated that in the mPFC of normal adult mice of both sexes, mature astrocytes were a major source of the repopulating astrocytes after acute deletion induced by an astrocyte-specific toxin, L-alpha-aminoadipic acid (L-AAA), and astrocyte regeneration was accomplished within two weeks accompanied by reversal of depression-like behaviors. Furthermore, re-ablation of mPFC astrocytes post repopulation led to reappearance of depression-like behaviors. In adult male mice subjected to 14-day chronic restraint stress, a well-validated mouse model of depression, the number of mPFC astrocytes was reduced; however, the ability of mPFC astrocytes to repopulate after L-AAA-induced deletion was largely unaltered. Our study highlights a potentially beneficial role for repopulating astrocytes in depression and provides novel therapeutic insights into enhancing local mature astrocyte generation in depression.

Dopamine D2 receptors in pyramidal neurons in the medial prefrontal cortex regulate social behavior.

Drugs acting on dopamine D2 receptors are widely used for the treatment of several neuropsychiatric disorders, including schizophrenia and depression. Social deficits are a core symptom of these disorders. Pharmacological manipulation of dopamine D2 receptors (Drd2), a Gi-coupled subtype of dopamine receptors, in the medial prefrontal cortex (mPFC) has shown that Drd2 is implicated in social behaviors. However, the type of neurons expressing Drd2 in the mPFC and the underlying circuit mechanism regulating social behaviors remain largely unknown. Here, we show that Drd2 were mainly expressed in pyramidal neurons in the mPFC and that the activation of the Gi-pathway in Drd2+ pyramidal neurons impaired social behavior in male mice. In contrast, the knockdown of D2R in pyramidal neurons in the mPFC enhanced social approach behaviors in male mice and selectively facilitated the activation of mPFC neurons projecting to the nucleus accumbens (NAc) during social interaction. Remarkably, optogenetic activation of mPFC-to-NAc-projecting neurons mimicked the effects of conditional D2R knockdown on social behaviors. Altogether, these results demonstrate a cell type-specific role for Drd2 in the mPFC in regulating social behavior, which may be mediated by the mPFC-to-NAc pathway.

EphB6 deficiency in intestinal neurons promotes tumor growth in colorectal cancer by neurotransmitter GABA signaling.

EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism of EphB6 in the progression of CRC need further study. In addition, EphB6 was mainly expressed in intestinal neurons. But how EphB6 is involved in functions of intestinal neurons has not been known. In our study, we constructed a mouse xenograft model of CRC by injecting CMT93 cells into the rectum of EphB6-deficient mice. We found that the deletion of EphB6 in mice promoted tumor growth of CMT93 cells in a xenograft model of CRC, which was independent of changes in the gut microbiota. Interestingly, inhibition of intestinal neurons by injecting botulinum toxin A into rectum of EphB6-deficient mice could eliminate the promotive effect of EphB6 deficiency on tumor growth in the xenograft model of CRC. Mechanically, the deletion of EphB6 in mice promoted the tumor growth in CRC by increasing GABA in the tumor microenvironment. Furthermore, EphB6 deficiency in mice increased the expression of synaptosomal-associated protein 25 in the intestinal myenteric plexus, which mediated the release of GABA. Our study concluded that EphB6 knockout in mice promotes tumor growth of CMT93 cells in a xenograft model of CRC by modulating GABA release. Our study found a new regulating mechanism of EphB6 on the tumor progression in CRC that is dependent on intestinal neurons.

Distinct roles of astroglia and neurons in synaptic plasticity and memory.

Long-term potentiation (LTP) in the hippocampus is the most studied form of synaptic plasticity. Temporal integration of synaptic inputs is essential in synaptic plasticity and is assumed to be achieved through Ca2+ signaling in neurons and astroglia. However, whether these two cell types play different roles in LTP remain unknown. Here, we found that through the integration of synaptic inputs, astrocyte inositol triphosphate (IP3) receptor type 2 (IP3R2)-dependent Ca2+ signaling was critical for late-phase LTP (L-LTP) but not early-phase LTP (E-LTP). Moreover, this process was mediated by astrocyte-derived brain-derived neurotrophic factor (BDNF). In contrast, neuron-derived BDNF was critical for both E-LTP and L-LTP. Importantly, the dynamic differences in BDNF secretion play a role in modulating distinct forms of LTP. Moreover, astrocyte- and neuron-derived BDNF exhibited different roles in memory. These observations enriched our knowledge of LTP and memory at the cellular level and implied distinct roles of astrocytes and neurons in information integration.

PV network plasticity mediated by neuregulin1-ErbB4 signalling controls fear extinction.

Neuroplasticity in the medial prefrontal cortex (mPFC) is essential for fear extinction, the process of which forms the basis of the general therapeutic process used to treat human fear disorders. However, the underlying molecules and local circuit elements controlling neuronal activity and concomitant induction of plasticity remain unclear. Here we show that sustained plasticity of the parvalbumin (PV) neuronal network in the infralimbic (IL) mPFC is required for fear extinction in adult male mice and identify the involvement of neuregulin 1-ErbB4 signalling in PV network plasticity-mediated fear extinction. Moreover, regulation of fear extinction by basal medial amygdala (BMA)-projecting IL neurons is dependent on PV network configuration. Together, these results uncover the local molecular circuit mechanisms underlying mPFC-mediated top-down control of fear extinction, suggesting alterative therapeutic approaches to treat fear disorders.

The decreased risk of hepatocellular carcinoma in hepatitis B virus-related cirrhotic portal hypertension patients after laparoscopic splenectomy and azygoportal disconnection.

BACKGROUND: Posthepatitic cirrhosis is one of the leading risk factors for hepatocellular carcinoma (HCC) worldwide, among which hepatitis B cirrhosis is the dominant one. This study explored whether laparoscopic splenectomy and azygoportal disconnection (LSD) can reduce the risk of HCC among patients with hepatitis B virus (HBV)-related cirrhotic portal hypertension (CPH). METHODS: A total of 383 patients with HBV-related CPH diagnosed as gastroesophageal variceal bleeding and secondary hypersplenism were identified in our hepatobiliary pancreatic center between April 2012 and April 2022, and conducted an 11-year retrospective follow-up. We used inverse probability of treatment weighting (IPTW) to correct for potential confounders, weighted Kaplan-Meier curves, and logistic regression to estimate survival and risk differences. RESULTS: Patients were divided into two groups based on treatment method: LSD (n = 230) and endoscopic therapy (ET; n = 153) groups. Whether it was processed through IPTW or not, LSD group showed a higher survival benefit than ET group according to Kaplan-Meier analysis (P < 0.001). The incidence density of HCC was higher in the ET group compared to LSD group at the end of follow-up [32.1/1000 vs 8.0/1000 person-years; Rate ratio: 3.998, 95% confidence intervals (CI) 1.928-8.293]. Additionally, in logistic regression analyses weighted by IPTW, LSD was an independent protective predictor of HCC incidence compared to ET (odds ratio 0.516, 95% CI 0.343-0.776; P = 0.002). CONCLUSION: Considering the ability of LSD to improve postoperative survival and prevent HCC in HBV-related CPH patients with gastroesophageal variceal bleeding and secondary hypersplenism, it is worth promoting in the context of the shortage of liver donors.

The growth rate of hepatocellular carcinoma is different with different TNM stages at diagnosis.

BACKGROUND: Hepatocellular carcinoma (HCC) progresses fast and has a poor prognosis, but the growth rate in different TNM stages is not clear. The present study was to estimate the growth rate of HCC with different TNM stages at diagnosis. METHODS: Baseline demographics and tumor characteristics were analyzed for 10145 patients in Surveillance, Epidemiology, and End Results (SEER) Program-registered HCC. Multiple linear regression models were used for age adjustment with patient race, sex, marital status, and HCC grade. RESULTS: The age at diagnosis was younger in Caucasians and males. The adjusted average age of patients with stage I HCC was 65.26 years. The adjusted age of patients with stage II, IIIA, IIIB, and IIIC was -0.17, -0.25, -0.29, and -0.55 adjusted-year younger compared with patients with stage I HCC (all P < 0.001). The adjusted average age of patients with T1 was 65.26 years. The age adjustment was -0.17, -0.26, and -0.55 respectively (all P < 0.001) for T2, T3 or T4 tumors without distant metastases. CONCLUSIONS: These findings demonstrated that the more advanced the HCC stage at diagnosis, the younger the age at diagnosis and the faster the HCC growth from tumor occurrence.

erbb4 Deficits in Chandelier Cells of the Medial Prefrontal Cortex Confer Cognitive Dysfunctions: Implications for Schizophrenia.

erbb4 is a known susceptibility gene for schizophrenia. Chandelier cells (ChCs, also known as axo-axonic cells) are a distinct GABAergic interneuron subtype that exclusively target the axonal initial segment, which is the site of pyramidal neuron action potential initiation. ChCs are a source of ErbB4 expression and alterations in ChC-pyramidal neuron connectivity occur in the medial prefrontal cortex (mPFC) of schizophrenic patients and animal models of schizophrenia. However, the contribution of ErbB4 in mPFC ChCs to the pathogenesis of schizophrenia remains unknown. By conditional deletion or knockdown of ErbB4 from mPFC ChCs, we demonstrated that ErbB4 deficits led to impaired ChC-pyramidal neuron connections and cognitive dysfunctions. Furthermore, the cognitive dysfunctions were normalized by L-838417, an agonist of GABAAα2 receptors enriched in the axonal initial segment. Given that cognitive dysfunctions are a core symptom of schizophrenia, our results may provide a new perspective for understanding the etiology of schizophrenia and suggest that GABAAα2 receptors may be potential pharmacological targets for its treatment.

Neuronal mTORC1 Is Required for Maintaining the Nonreactive State of Astrocytes.

Astrocytes respond to CNS insults through reactive astrogliosis, but the underlying mechanisms are unclear. In this study, we show that inactivation of mechanistic target of rapamycin complex (mTORC1) signaling in postnatal neurons induces reactive astrogliosis in mice. Ablation of Raptor (an mTORC1-specific component) in postmitotic neurons abolished mTORC1 activity and produced neurons with smaller soma and fewer dendrites, resulting in microcephaly and aberrant behavior in adult mice. Interestingly, extensive astrogliosis without significant astrocyte proliferation and glial scar formation was observed in these mice. The inhibition of neuronal mTORC1 may activate astrogliosis by reducing neuron-derived fibroblast growth factor 2 (FGF-2), which might trigger FGF receptor signaling in astrocytes to maintain their nonreactive state, and FGF-2 injection successfully prevented astrogliosis in Raptor knock-out mice. This study demonstrates that neuronal mTORC1 inhibits reactive astrogliosis and plays an important role in CNS pathologies.

An astroglial basis of major depressive disorder? An overview.

Depression is a chronic, recurring, and serious mood disorder that afflicts up to 20% of the global population. The monoamine hypothesis has dominated our understanding of the pharmacotherapy of depression for more than half a century; however, our understanding of the pathophysiology and pathogenesis of major depression has lagged far behind. Astrocytes are the most abundant and versatile cells in the brain, participating in most, if not all, of brain functions as both a passive housekeeper and an active player. Mounting evidence from clinical, preclinical and post-mortem studies has revealed a decrease in the number or density of astrocytes and morphological and functional astroglial atrophy in patients with major depressive disorder (MDD) and in animal models of depression. Furthermore, currently available antidepressant treatments at least partially exert their therapeutic effects on astrocytes. More importantly, dysfunctional astrocytes lead to depressive-like phenotypes in animals. Together, current studies point to astroglial pathology as the potential root cause of MDD. Thus, a shift from a neuron-centric to an astrocyte-centric cause of MDD has gained increasing attention during the past two decades. Here we will summarize the current evidence supporting the hypothesis that MDD is a disease of astrocyte pathology and highlight previous studies on promising strategies that directly target astrocytes for the development of novel antidepressant treatments.

A novel antibody targeting sequence 31-35 in amyloid ß protein attenuates Alzheimer's disease-related neuronal damage.

Amyloid ß protein (Aß) plays a critical role in pathogenesis of Alzheimer's disease (AD). Our previous studies indicated that the sequence 31-35 in Aß molecule is an effective active center responsible for Aß neurotoxicity in vivo and in vitro. In the present study, we prepared a novel antibody specifically targeting the sequence 31-35 of amyloid ß protein, and investigated the neuroprotection of the anti-Aß31-35 antibody against Aß1-42 -induced impairments in neuronal viability, spatial memory, and hippocampal synaptic plasticity in rats. The results showed that the anti-Aß31-35 antibody almost equally bound to both Aß31-35 and Aß1-42 , and pretreatment with the antibody dose-dependently prevented Aß1-42 -induced cytotoxicity on cultured primary cortical neurons. In behavioral study, intracerebroventricular (i.c.v.) injection of anti-Aß31-35 antibody efficiently attenuated Aß1-42 -induced impairments in spatial learning and memory of rats. In vivo electrophysiological experiments further indicated that Aß1-42 -induced suppression of hippocampal synaptic plasticity was effectively reversed by the antibody. These results demonstrated that the sequence 31-35 of Aß may be a new therapeutic target, and the anti-Aß31-35 antibody could be a novel immunotheraputic approach for the treatment of AD. © 2016 Wiley Periodicals, Inc.

Elevated expression of Erbin destabilizes ERα protein and promotes tumorigenesis in hepatocellular carcinoma.

BACKGROUND & AIMS: Aberrant estrogen receptor-α (ERα) expression and signaling are implicated in the development of hepatocellular carcinoma (HCC), but its regulation in HCC remains enigmatic. Herein, we aimed to identify a new mechanism by which ERα signaling is regulated in HCC, which may lead to a potential new strategy for HCC therapy. METHODS: Expression levels of Erbin and ERα in human HCC samples were evaluated by immunohistochemistry. In vitro and in vivo experiments were used to assess the effect of Erbin and ERα signaling on HCC cell growth. Crosstalk between Erbin and ERα signaling was analyzed by molecular methods. Animal models of diethylnitrosamine (DEN) or DEN/CCl4-induced HCC in wild-type Erbin+/+ and mutant ErbinΔC/ΔC mice were observed. The regulatory effects of Erbin on tamoxifen treatment of HCC were evaluated in vitro and in vivo. RESULTS: Erbin inactivated ERα signaling to drive tumorigenesis of HCC, acting to enhance binding of Chip to ERα via its interaction with ERα and thereby promoting ubiquitination and degradation of ERα. Deletion of the PDZ domain of Erbin in ErbinΔC/ΔC mice, disrupted the interaction of Chip and ERα, increased the stability of ERα protein, and thus inhibited tumorigenesis of HCC. Silencing of Erbin effectively sensitized the response of HCC after tamoxifen treatment in vitro and in vivo. CONCLUSIONS: Our data uncovered an important role of Erbin in regulating HCC tumorigenesis through inactivating ERα-mediated tumor-suppressive signaling, suggesting a new strategy for tamoxifen therapy in HCC by targeting Erbin/ERα signaling axis. LAY SUMMARY: Erbin expression is significantly elevated in human hepatocellular carcinoma (HCC) tissue. This elevated expression of Erbin contributes to tumorigenesis of HCC by negatively regulating ERα signaling. However, restoring ERα signaling by inhibiting Erbin expression enhances the sensitivity of HCC cells to tamoxifen treatment, providing a new approach for tamoxifen treatment in HCC.

Erbin interacts with c-Cbl and promotes tumourigenesis and tumour growth in colorectal cancer by preventing c-Cbl-mediated ubiquitination and down-regulation of EGFR.

The epidermal growth factor receptor (EGFR) is implicated in many types of cancer, including colorectal cancer (CRC), and has become one of the most common candidates for targeted therapy. Here, we found that Erbin, a member of the leucine-rich repeat and PDZ domain (LAP) family, plays a key role in EGFR signalling. Erbin inhibited EGFR ubiquitination and stabilized the EGFR protein by interacting with c-Cbl. Moreover, the PDZ domain of Erbin was critical for the interaction between Erbin and c-Cbl and EGFR ubiquitination. Interestingly, Erbin expression was elevated in tumour samples from CRC patients, increased in advanced clinical stage disease and correlated with EGFR expression. In vivo studies using mouse xenograft models of CRC showed that Erbin promotes tumour growth, and that the effects of Erbin on tumour growth are mainly related to the regulatory effects of Erbin on EGFR. The azoxymethane (AOM)-induced colon carcinogenesis model in Erbin(ΔC) (/) (ΔC) mice, with the PDZ domain of Erbin deleted, demonstrated that the PDZ domain of Erbin and its regulation of EGFR signalling are necessary for the tumourigenesis and tumour growth of CRC. We found that Erbin promotes tumourigenesis and tumour growth in CRC by stabilizing EGFR. Our study sheds light on developing Erbin, especially its PDZ domain, as a potential target for CRC treatment.

Regulation of spine formation by ErbB4 in PV-positive interneurons.

The trophic factor neuregulin 1 (Nrg1) and its receptor ErbB4 are schizophrenia candidate genes. NRG1-ErbB4 signaling was thought to regulate spine formation and function in a cell-autonomous manner. Yet, recent studies indicate that ErbB4 expression is largely restricted to GABAergic interneurons and is very low or absent in pyramidal cells. Here, we generated and characterized cell type-specific ErbB4 mutant and transgenic mice. Spine density and the number of excitatory synapses were unaltered by neither deletion nor overexpression of ErbB4 in pyramidal neurons. However, spine density and excitatory synapse number were reduced in PV-ErbB4(-/-) mice where ErbB4 was selectively ablated in parvalbumin-positive GABAergic interneurons. Concurrently, basal glutamate transmission was impaired in PV-ErbB4(-/-) mice, but not in mice where ErbB4 was deleted or overexpressed in pyramidal neurons. Our results demonstrate a role of ErbB4 in PV-positive interneurons for spine formation in excitatory neurons.

Astrocytic adenosine 5'-triphosphate release regulates the proliferation of neural stem cells in the adult hippocampus.

Astrocytes are key components of the niche for neural stem cells (NSCs) in the adult hippocampus and play a vital role in regulating NSC proliferation and differentiation. However, the exact molecular mechanisms by which astrocytes modulate NSC proliferation have not been identified. Here, we identified adenosine 5'-triphosphate (ATP) as a proliferative factor required for astrocyte-mediated proliferation of NSCs in the adult hippocampus. Our results indicate that ATP is necessary and sufficient for astrocytes to promote NSC proliferation in vitro. The lack of inositol 1,4,5-trisphosphate receptor type 2 and transgenic blockage of vesicular gliotransmission induced deficient ATP release from astrocytes. This deficiency led to a dysfunction in NSC proliferation that could be rescued via the administration of exogenous ATP. Moreover, P2Y1-mediated purinergic signaling is involved in the astrocyte promotion of NSC proliferation. As adult hippocampal neurogenesis is potentially involved in major mood disorder, our results might offer mechanistic insights into this disease.

Preparation of Healthy Single Neuron or Astrocyte Suspension from Adult Mouse Brain for RNA-seq.

Single-cell RNA sequencing (scRNA-seq) has been widely applied in neuroscience research, enabling the investigation of cellular heterogeneity at the transcriptional level, the characterization of rare cell types, and the detailed analysis of the stochastic nature of gene expression. Isolation of single nerve cells in good health, especially from the adult rodent brain, is the most difficult and critical process for scRNA-seq. Here, we describe methods to optimize protease digestion of brain slices, which enable yield of millions of cells in good health from the adult brain.

Extracellular ATP Is a Homeostatic Messenger That Mediates Cell-Cell Communication in Physiological Processes and Psychiatric Diseases.

Neuronal activity is the basis of information encoding and processing in the brain. During neuronal activation, intracellular ATP (adenosine triphosphate) is generated to meet the high-energy demands. Simultaneously, ATP is secreted, increasing the extracellular ATP concentration and acting as a homeostatic messenger that mediates cell-cell communication to prevent aberrant hyperexcitability of the nervous system. In addition to the confined release and fast synaptic signaling of classic neurotransmitters within synaptic clefts, ATP can be released by all brain cells, diffuses widely, and targets different types of purinergic receptors on neurons and glial cells, making it possible to orchestrate brain neuronal activity and participate in various physiological processes, such as sleep and wakefulness, learning and memory, and feeding. Dysregulation of extracellular ATP leads to a destabilizing effect on the neural network, as found in the etiopathology of many psychiatric diseases, including depression, anxiety, schizophrenia, and autism spectrum disorder. In this review, we summarize advances in the understanding of the mechanisms by which extracellular ATP serves as an intercellular signaling molecule to regulate neural activity, with a focus on how it maintains the homeostasis of neural networks. In particular, we also focus on neural activity issues that result from dysregulation of extracellular ATP and propose that aberrant levels of extracellular ATP may play a role in the etiopathology of some psychiatric diseases, highlighting the potential therapeutic targets of ATP signaling in the treatment of these psychiatric diseases. Finally, we suggest potential avenues to further elucidate the role of extracellular ATP in intercellular communication and psychiatric diseases.

Astrocytes in the Ventral Hippocampus Bidirectionally Regulate Innate and Stress-Induced Anxiety-Like Behaviors in Male Mice.

The mechanisms of anxiety disorders, the most common mental illness, remain incompletely characterized. The ventral hippocampus (vHPC) is critical for the expression of anxiety. However, current studies primarily focus on vHPC neurons, leaving the role for vHPC astrocytes in anxiety largely unexplored. Here, genetically encoded Ca2+ indicator GCaMP6m and in vivo fiber photometry calcium imaging are used to label vHPC astrocytes and monitor their activity, respectively, genetic and chemogenetic approaches to inhibit and activate vHPC astrocytes, respectively, patch-clamp recordings to measure glutamate currents, and behavioral assays to assess anxiety-like behaviors. It is found that vHPC astrocytic activity is increased in anxiogenic environments and by 3-d subacute restraint stress (SRS), a well-validated mouse model of anxiety disorders. Genetic inhibition of vHPC astrocytes exerts anxiolytic effects on both innate and SRS-induced anxiety-related behaviors, whereas hM3Dq-mediated chemogenetic or SRS-induced activation of vHPC astrocytes enhances anxiety-like behaviors, which are reversed by intra-vHPC application of the ionotropic glutamate N-methyl-d-aspartate receptor antagonists. Furthermore, intra-vHPC or systemic application of the N-methyl-d-aspartate receptor antagonist memantine, a U.S. FDA-approved drug for Alzheimer's disease, fully rescues SRS-induced anxiety-like behaviors. The findings highlight vHPC astrocytes as critical regulators of stress and anxiety and as potential therapeutic targets for anxiety and anxiety-related disorders.

Astrocytic ALKBH5 in stress response contributes to depressive-like behaviors in mice.

Epigenetic mechanisms bridge genetic and environmental factors that contribute to the pathogenesis of major depression disorder (MDD). However, the cellular specificity and sensitivity of environmental stress on brain epitranscriptomics and its impact on depression remain unclear. Here, we found that ALKBH5, an RNA demethylase of N6-methyladenosine (m6A), was increased in MDD patients' blood and depression models. ALKBH5 in astrocytes was more sensitive to stress than that in neurons and endothelial cells. Selective deletion of ALKBH5 in astrocytes, but not in neurons and endothelial cells, produced antidepressant-like behaviors. Astrocytic ALKBH5 in the mPFC regulated depression-related behaviors bidirectionally. Meanwhile, ALKBH5 modulated glutamate transporter-1 (GLT-1) m6A modification and increased the expression of GLT-1 in astrocytes. ALKBH5 astrocyte-specific knockout preserved stress-induced disruption of glutamatergic synaptic transmission, neuronal atrophy and defective Ca2+ activity. Moreover, enhanced m6A modification with S-adenosylmethionine (SAMe) produced antidepressant-like effects. Our findings indicate that astrocytic epitranscriptomics contribute to depressive-like behaviors and that astrocytic ALKBH5 may be a therapeutic target for depression.