Microbiota profiling reveals alteration of gut microbial neurotransmitters in a mouse model of autism-associated 16p11.2 microduplication.

The gut-brain axis is evident in modulating neuropsychiatric diseases including autism spectrum disorder (ASD). Chromosomal 16p11.2 microduplication 16p11.2dp/+ is among the most prevalent genetic copy number variations (CNV) linked with ASD. However, the implications of gut microbiota status underlying the development of ASD-like impairments induced by 16p11.2dp/+ remains unclear. To address this, we initially investigated a mouse model of 16p11.2dp/+, which exhibits social novelty deficit and repetitive behavior characteristic of ASD. Subsequently, we conducted a comparative analysis of the gut microbial community and metabolomic profiles between 16p11.2dp/+ and their wild-type counterparts using 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC/MS). Our microbiota analysis revealed structural dysbiosis in 16p11.2dp/+ mice, characterized by reduced biodiversity and alterations in species abundance, as indicated by α/ß-diversity analysis. Specifically, we observed reduced relative abundances of Faecalibaculum and Romboutsia, accompanied by an increase in Turicibacter and Prevotellaceae UCG_001 in 16p11.2dp/+ group. Metabolomic analysis identified 19 significantly altered metabolites and unveiled enriched amino acid metabolism pathways. Notably, a disruption in the predominantly histamine-centered neurotransmitter network was observed in 16p11.2dp/+ mice. Collectively, our findings delineate potential alterations and correlations among the gut microbiota and microbial neurotransmitters in 16p11.2dp/+ mice, providing new insights into the pathogenesis of and treatment for 16p11.2 CNV-associated ASD.

The gut metabolite indole-3-propionic acid activates ERK1 to restore social function and hippocampal inhibitory synaptic transmission in a 16p11.2 microdeletion mouse model.

BACKGROUND: Microdeletion of the human chromosomal region 16p11.2 (16p11.2 + / - ) is a prevalent genetic factor associated with autism spectrum disorder (ASD) and other neurodevelopmental disorders. However its pathogenic mechanism remains unclear, and effective treatments for 16p11.2 + / -  syndrome are lacking. Emerging evidence suggests that the gut microbiota and its metabolites are inextricably linked to host behavior through the gut-brain axis and are therefore implicated in ASD development. Despite this, the functional roles of microbial metabolites in the context of 16p11.2 + / -  are yet to be elucidated. This study aims to investigate the therapeutic potential of indole-3-propionic acid (IPA), a gut microbiota metabolite, in addressing behavioral and neural deficits associated with 16p11.2 + / - , as well as the underlying molecular mechanisms. RESULTS: Mice with the 16p11.2 + / -  showed dysbiosis of the gut microbiota and a significant decrease in IPA levels in feces and blood circulation. Further, these mice exhibited significant social and cognitive memory impairments, along with hyperactivation of hippocampal dentate gyrus neurons and reduced inhibitory synaptic transmission in this region. However, oral administration of IPA effectively mitigated the histological and electrophysiological alterations, thereby ameliorating the social and cognitive deficits of the mice. Remarkably, IPA treatment significantly increased the phosphorylation level of ERK1, a protein encoded by the Mapk3 gene in the 16p11.2 region, without affecting the transcription and translation of the Mapk3 gene. CONCLUSIONS: Our study reveals that 16p11.2 + / -  leads to a decline in gut metabolite IPA levels; however, IPA supplementation notably reverses the behavioral and neural phenotypes of 16p11.2 + / -  mice. These findings provide new insights into the critical role of gut microbial metabolites in ASD pathogenesis and present a promising treatment strategy for social and cognitive memory deficit disorders, such as 16p11.2 microdeletion syndrome. Video Abstract.

Efficacy and safety of leuprorelin 3-month depot (11.25 mg) for idiopathic central precocious puberty treatment of Chinese girls: a single-center retrospective study.

OBJECTIVES: This study aimed to evaluate the efficacy and safety of 3-month leuprorelin acetate (3-month LA, 11.25 mg) for the treatment of idiopathic central precocious puberty (ICPP) in Chinese girls. METHODS: We conducted a single-center retrospective study in China on 28 girls with ICPP who received at least one year of 3-month LA treatment. Data from anthropometry, biochemistry, bone age (BA), and pelvic ultrasonography were assessed before and every 6 months during medication. RESULTS: At CPP diagnosis, the mean chronological age (CA) was 7.8±0.8 years, with bone age advancement (BA-CA) of 1.5±0.8 years. After treatment initiation, growth velocity decreased significantly from 8.5±1.6 cm/year to 5.8±1.1 cm/year at month 12 (p<0.001). GnRH-stimulated peak LH ≤3IU/L, the primary efficacy criterion, was observed in 27 out of 28 (96.4 %) children at month 3. Basal estradiol <20 pg/mL was achieved by all 28 girls (100 %) at month 6 and remained stable at month 12. Basal follicle-stimulating hormone (FSH) decreased from 4.1±3.5 to 1.7±0.9 (p<0.001), and basal LH was also significantly reduced from 3.3±6.5 to 0.7±0.8 (p=0.035) at month 12. The mean predicted adult height (PAH) at treatment initiation was 152.7±5.8 cm, it increased significantly to 157.5±5.5 cm (p=0.007) after one-year treatment. Pubertal development was slowed in most patients, and in some cases, it was even reversed. Only one patient (3.6 %) reported local intolerance. CONCLUSIONS: Three-month leuprorelin acetate is a safe and effective treatment for suppressing the pituitary-gonadal axis and restoring impaired adult height in Chinese girls.

Chronic salmon calcitonin exerts an antidepressant effect via modulating the p38 MAPK signaling pathway.

Depression is a common recurrent psychiatric disorder with a high lifetime prevalence and suicide rate. At present, although several traditional clinical drugs such as fluoxetine and ketamine, are widely used, medications with a high efficiency and reduced side effects are of urgent need. Our group has recently reported that a single administration of salmon calcitonin (sCT) could ameliorate a depressive-like phenotype via the amylin signaling pathway in a mouse model established by chronic restraint stress (CRS). However, the molecular mechanism underlying the antidepressant effect needs to be addressed. In this study, we investigated the antidepressant potential of sCT applied chronically and its underlying mechanism. In addition, using transcriptomics, we found the MAPK signaling pathway was upregulated in the hippocampus of CRS-treated mice. Further phosphorylation levels of ERK/p38/JNK kinases were also enhanced, and sCT treatment was able only to downregulate the phosphorylation level of p38/JNK, with phosphorylated ERK level unaffected. Finally, we found that the antidepressant effect of sCT was blocked by p38 agonists rather than JNK agonists. These results provide a mechanistic explanation of the antidepressant effect of sCT, suggesting its potential for treating the depressive disorder in the clinic.

Salmon Calcitonin Exerts an Antidepressant Effect by Activating Amylin Receptors.

Depressive disorder is defined as a psychiatric disease characterized by the core symptoms of anhedonia and learned helplessness. Currently, the treatment of depression still calls for medications with high effectiveness, rapid action, and few side effects, although many drugs, including fluoxetine and ketamine, have been approved for clinical usage by the Food and Drug Administration (FDA). In this study, we focused on calcitonin as an amylin receptor polypeptide, of which the antidepressant effect has not been reported, even if calcitonin gene-related peptides have been previously demonstrated to improve depressive-like behaviors in rodents. Here, the antidepressant potential of salmon calcitonin (sCT) was first evaluated in a chronic restraint stress (CRS) mouse model of depression. We observed that the immobility duration in CRS mice was significantly increased during the tail suspension test and forced swimming test. Furthermore, a single administration of sCT was found to successfully rescue depressive-like behaviors in CRS mice. Lastly, AC187 as a potent amylin receptor antagonist was applied to investigate the roles of amylin receptors in depression. We found that AC187 significantly eliminated the antidepressant effects of sCT. Taken together, our data revealed that sCT could ameliorate a depressive-like phenotype probably via the amylin signaling pathway. sCT should be considered as a potential therapeutic candidate for depressive disorder in the future.

Microduplication of 16p11.2 locus Potentiates Hypertrophic Obesity in Association with Imbalanced Triglyceride Metabolism in White Adipose Tissue.

SCOPE: Copy number variation (CNV) of 16p11.2 is a common genetic factor contributing to the etiology of abnormal weight status, while the underlying mechanism is not fully elucidated yet. METHODS AND RESULTS: The 16p11.2 CNV mouse model with microduplication of the 7Slx1b-Sept1 region (dp/+) is evaluated under normal chow conditions. Compared to the wild type littermates (WT), the dp/+ mice exhibit obvious obese phenotype characterized by significant increase in body mass index, fat pad mass, and fat ratio, with visceral-dominant fat deposits at 12-week age. White adipose tissue (WAT), liver tissue, and plasma are sampled to assess the comorbid metabolic syndrome. In dp/+ mice, histopathologic analyses reveal hypertrophic adipocytes and hepatic steatosis; serological examinations show hyperlipemia and hyperinsulinemia. Further, by comparing lipidomic and transcriptomic profiling of epididymal WAT between dp/+ and WT mice, the study finds the triglyceride (TG) accumulation in dp/+ mice in association with the dysfunction of lipid droplets. Validation of TG-metabolism-associated genes in WAT and in primary cultured adipocytes show enhanced TG synthesis and declined TG hydrolysis in the dp/+ model. CONCLUSION: This study elucidates that the imbalanced TG synthesis/hydrolysis in adipocytic lipid droplets may contribute to the hypertrophic obesity and metabolic disorders in mice with 16p11.2 microduplication.

Structural and Lipidomic Alterations of Striatal Myelin in 16p11.2 Deletion Mouse Model of Autism Spectrum Disorder.

Myelin abnormalities have been observed in autism spectrum disorder (ASD). In this study, we seek to discover myelin-related changes in the striatum, a key brain region responsible for core ASD features, using the 16p11.2 deletion (16p11.2±) mouse model of ASD. We found downregulated expression of multiple myelin genes and decreased myelin thickness in the striatum of 16p11.2± mice versus wild type controls. Moreover, given that myelin is the main reservoir of brain lipids and that increasing evidence has linked dysregulation of lipid metabolism to ASD, we performed lipidomic analysis and discovered decreased levels of certain species of sphingomyelin, hexosyl ceramide and their common precursor, ceramide, in 16p11.2± striatum, all of which are major myelin components. We further identified lack of ceramide synthase 2 as the possible reason behind the decrease in these lipid species. Taken together, our data suggest a role for myelin and myelin lipids in ASD development.

Closure versus Medical Therapy for Patent Foramen Ovale in Patients with Cryptogenic Stroke: An Updated Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Debate continues about whether percutaneous closure of patent foramen ovale (PFO) is a better strategy for the treatment of patients with cryptogenic stroke in comparison with medical therapy alone. We performed an updated meta-analysis of 6 randomized controlled trials (RCTs) to assess the effectiveness and safety of percutaneous closure of PFO as secondary prevention for patients with previous cryptogenic stroke compared to medical therapy. MATERIALS AND METHODS: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, conference proceedings, and Internet-based resources were retrieved in March 2018 for eligible RCTs. The primary effectiveness outcome was recurrent strokes. RESULTS: Six studies meeting our selection criteria were identified. Among 3560 participants, 1889 patients were assigned to PFO closure and 1671 patients to medical therapy. There were no significant differences among the baseline characteristics. The pooled incidence of recurrent strokes was 1.96% in the PFO closure group and 4.60% in the medical therapy group (Relative risk [RR] .39, 95% confidence interval [CI] .18-.82, P = .01). Newly detected atrial fibrillation occurred in 77 of 1844 (4.18%) patients in the PFO closure group and in 12 of 1667 (.72%) patients in the medical therapy group (RR 4.56, 95% CI 2.21-9.41, P <.0001). There was no difference in terms of serious adverse events, total mortality or bleeding between 2 groups. CONCLUSIONS: Our updated meta-analysis suggests that in patients with PFO and cryptogenic stroke, the rate of recurrent stroke is significantly reduced with percutaneous closure of PFO compared to the medical therapy.

Novel TBC1D24 Mutations in a Case of Nonconvulsive Status Epilepticus.

Objective: Nonconvulsive status epilepticus (NCSE) is an uncommon clinical manifestation in patients with TBC1D24 mutations. In addition, NCSE has not been reported as a syndrome together with cerebellar ataxia and ophthalmoplegia. Methods: We herein report the clinical and genetic features of a four-year-old patient with NCSE, cerebellar ataxia, and ophthalmoplegia caused by hitherto unidentified TBC1D24 mutations. We performed 24-h video electroencephalogram (EEG), magnetic resonance imaging, and gene sequencing on the patient and her parents to determine the diagnosis. Results: We identified a novel c.1416_1437del (p.Ser473Argfs*43) mutation, as well as the previously identified c.1499C>T (p.Ala500Val) mutation in TBC1D24, by using targeted next-generation sequencing. The novel mutation (inherited from the mother) is the first reported deletion mutation longer than 20 bp in TBC1D24. The p.Ala500Val mutation inherited from father has been reported in a German patient with infantile myoclonic, for whom results from the EEG and neuroimaging were normal. These two mutations resulted in the severe phenotypes observed in our patient Conclusions: The identification of the novel TBC1D24 mutation and consequent complicated clinical manifestations suggest that patients with NCSE and ataxia demand more attention. We further recommend that genetic test should be administered to these patients to avoid genetic inheritance of this mutation.

Cerebral Venous Collagen Remodeling in a Modified White Matter Lesions Animal Model.

To mimic the expected pathological changes of white matter lesions (WMLs) and increase the stability, we applied modified two-vessel occlusion (modified 2VO) (1-week interval bilateral carotid artery occlusion) in stroke-prone renovascular hypertensive rats (RHRSP) and established a modified WMLs model (RHRSP/modified 2VO) that compared their phenotypes with RHRSP and sham-operated rats. In addition, we tried to differentiate small veins from small arteries through the presence of smooth muscle to study the pathological changes of small veins detailed in the model. RHRSP/modified 2VO rats showed higher stability and more extensive white matter damage without an obvious increase in mortality rate at 12 weeks after the modified 2VO operation compared to RHRSP rats. RHRSP/modified 2VO rats showed more severe small venous collagen deposition than RHRSP rats, and the majority of the deposition was collagen I and IV rather than collagen III. In addition, RHRSP/modified 2VO rats possessed cognitive impairment, mild wall thickness and blood-brain barrier disruption. Our findings suggest that the modified WMLs model (RHRSP/modified 2VO) mimics cognitive impairment and small vessel pathological changes similar to WMLs in humans. Differentiating small veins from small arteries through smooth muscle is feasible, and marked small venous deposition may play an important role in the hypertensive white matter lesions.

Autonomic Neuropathy and Albuminocytologic Dissociation in Cerebrospinal Fluid As the Presenting Features of Primary Amyloidosis: A Case Report.

OBJECTIVE: Primary amyloidosis is a disease with a poor prognosis and multi-organ involvement. Here, we report the clinical and pathological features of a patient with primary amyloidosis featuring autonomic neuropathy as the initial symptom and albuminocytologic dissociation in the cerebrospinal fluid (CSF). METHODS: The patient was a 60-year-old Chinese male with numbness, orthostatic hypotension, and gastrointestinal symptoms. For diagnosis, we performed an electromyogram (EMG), lumbar puncture, Bence Jones protein urine test, serum electrophoresis blood test, sural nerve and rectal membrane biopsies, transthyretin (TTR) gene sequencing, and bone marrow puncture. RESULTS: Congo red staining of sural nerve and rectal membrane biopsies showed amyloid deposition and apple-green birefringence was visualized under polarized light microscopy. TTR gene sequencing showed no causative mutation. Following lumbar puncture, normal CSF cell counts and elevated CSF protein concentration (1,680 mg/L) were detected. Bone marrow puncture showed that out of the total number of whole blood cells, 0.56% were abnormal plasma cells and that 87.4% of the total number of plasma cells were abnormal. EMG results showed mixed peripheral nerve damage predominately in the sensory nerve fibers. CONCLUSION: Obvious symptoms of neuropathy, particularly autonomic neuropathy, albuminocytologic dissociation, and organ function damage suggested a diagnosis of amyloidosis. In such patients, neurologists should use caution to differentiate between chronic inflammatory demyelinating polyneuropathy, primary amyloidosis, and familial amyloid neuropathy.

Multiple Factors Involved in the Pathogenesis of White Matter Lesions.

White matter lesions (WMLs), also known as leukoaraiosis (LA) or white matter hyperintensities (WMHs), are characterized mainly by hyperintensities on T2-weighted or fluid-attenuated inversion recovery (FLAIR) images. With the aging of the population and the development of imaging technology, the morbidity and diagnostic rates of WMLs are increasing annually. WMLs are not a benign process. They clinically manifest as cognitive decline and the subsequent development of dementia. Although WMLs are important, their pathogenesis is still unclear. This review elaborates on the advances in the understanding of the pathogenesis of WMLs, focusing on anatomy, cerebral blood flow autoregulation, venous collagenosis, blood brain barrier disruption, and genetic factors. In particular, the attribution of WMLs to chronic ischemia secondary to venous collagenosis and cerebral blood flow autoregulation disruption seems reasonable. With the development of gene technology, the effect of genetic factors on the pathogenesis of WMLs is gaining gradual attention.