Pubmed du 07/04/24
1. Afshari M, Gharibzadeh S, Pouretemad H, Roghani M. Reversing valproic acid-induced autism-like behaviors through a combination of low-frequency repeated transcranial magnetic stimulation and superparamagnetic iron oxide nanoparticles. Sci Rep. 2024; 14(1): 8082.
Transcranial magnetic stimulation (TMS) is a neurostimulation device used to modulate brain cortex activity. Our objective was to enhance the therapeutic effectiveness of low-frequency repeated TMS (LF-rTMS) in a rat model of autism spectrum disorder (ASD) induced by prenatal valproic acid (VPA) exposure through the injection of superparamagnetic iron oxide nanoparticles (SPIONs). For the induction of ASD, we administered prenatal VPA (600 mg/kg, I.P.) on the 12.5th day of pregnancy. At postnatal day 30, SPIONs were injected directly into the lateral ventricle of the brain. Subsequently, LF-rTMS treatment was applied for 14 consecutive days. Following the treatment period, behavioral analyses were conducted. At postnatal day 60, brain tissue was extracted, and both biochemical and histological analyses were performed. Our data revealed that prenatal VPA exposure led to behavioral alterations, including changes in social interactions, increased anxiety, and repetitive behavior, along with dysfunction in stress coping strategies. Additionally, we observed reduced levels of SYN, MAP2, and BDNF. These changes were accompanied by a decrease in dendritic spine density in the hippocampal CA1 area. However, LF-rTMS treatment combined with SPIONs successfully reversed these dysfunctions at the behavioral, biochemical, and histological levels, introducing a successful approach for the treatment of ASD.
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2. Molinaro G, Bowles JE, Croom K, Gonzalez D, Mirjafary S, Birnbaum SG, Razak KA, Gibson JR, Huber KM. Female-specific dysfunction of sensory neocortical circuits in a mouse model of autism mediated by mGluR5 and estrogen receptor α. Cell Rep. 2024; 43(4): 114056.
Little is known of the brain mechanisms that mediate sex-specific autism symptoms. Here, we demonstrate that deletion of the autism spectrum disorder (ASD)-risk gene, Pten, in neocortical pyramidal neurons ((NSE)Pten knockout [KO]) results in robust cortical circuit hyperexcitability selectively in female mice observed as prolonged spontaneous persistent activity states. Circuit hyperexcitability in females is mediated by metabotropic glutamate receptor 5 (mGluR5) and estrogen receptor α (ERα) signaling to mitogen-activated protein kinases (Erk1/2) and de novo protein synthesis. Pten KO layer 5 neurons have a female-specific increase in mGluR5 and mGluR5-dependent protein synthesis. Furthermore, mGluR5-ERα complexes are generally elevated in female cortices, and genetic reduction of ERα rescues enhanced circuit excitability, protein synthesis, and neuron size selectively in (NSE)Pten KO females. Female (NSE)Pten KO mice display deficits in sensory processing and social behaviors as well as mGluR5-dependent seizures. These results reveal mechanisms by which sex and a high-confidence ASD-risk gene interact to affect brain function and behavior.
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3. Zhuang K, Leng L, Su X, Wang S, Su Y, Chen Y, Yuan Z, Zi L, Li J, Xie W, Yan S, Xia Y, Wang H, Li H, Chen Z, Yuan T, Zhang J. Menin Deficiency Induces Autism-Like Behaviors by Regulating Foxg1 Transcription and Participates in Foxg1-Related Encephalopathy. Adv Sci (Weinh). 2024: e2307953.
FOXG1 syndrome is a developmental encephalopathy caused by FOXG1 (Forkhead box G1) mutations, resulting in high phenotypic variability. However, the upstream transcriptional regulation of Foxg1 expression remains unclear. This report demonstrates that both deficiency and overexpression of Men1 (protein: menin, a pathogenic gene of MEN1 syndrome known as multiple endocrine neoplasia type 1) lead to autism-like behaviors, such as social defects, increased repetitive behaviors, and cognitive impairments. Multifaceted transcriptome analyses revealed that Foxg1 signaling is predominantly altered in Men1 deficiency mice, through its regulation of the Alpha Thalassemia/Mental Retardation Syndrome X-Linked (Atrx) factor. Atrx recruits menin to bind to the transcriptional start region of Foxg1 and mediates the regulation of Foxg1 expression by H3K4me3 (Trimethylation of histone H3 lysine 4) modification. The deficits observed in menin deficient mice are rescued by the over-expression of Foxg1, leading to normalized spine growth and restoration of hippocampal synaptic plasticity. These findings suggest that menin may have a putative role in the maintenance of Foxg1 expression, highlighting menin signaling as a potential therapeutic target for Foxg1-related encephalopathy.
