Glioblastoma (GBM) is the most common primary intracranial malignancy with a very low survival rate. Exploring key molecular markers for GBM can help with early diagnosis, prognostic prediction, and recurrence monitoring. This study aims to explore novel biomarkers for GBM via bioinformatics analysis and experimental verification. Dataset GSE103229 was obtained from the GEO database to search differentially expressed lncRNA (DELs), mRNAs (DEMs), and miRNAs (DEMis). Hub genes were selected to establish competing endogenous RNA (ceRNA) networks. The GEPIA database was employed for the survival analysis and expression detection of hub genes. Hub gene expression in GBM tissue samples and cell lines was validated using RT-qPCR. Western blotting was employed for protein expression evaluation. SYT1 overexpression vector was transfected in GBM cells. CCK-8 assay and flow cytometry were performed to detect the malignant phenotypes of GBM cells. There were 901 upregulated and 1086 downregulated DEMs identified, which were prominently enriched in various malignancy-related functions and pathways. Twenty-two hub genes were selected from PPI networks. Survival analysis and experimental validation revealed that four hub genes were tightly associated with GBM prognosis and progression, including SYT1, GRIN2A, KCNA1, and SYNPR. The four genes were significantly downregulated in GBM tissues and cell lines. Overexpressing SYT1 alleviated the proliferation and promoted the apoptosis of GBM cells in vitro. We identify four genes that may be potential molecular markers of GBM, which may provide new ideas for improving early diagnosis and prediction of the disease.

Synaptic dysfunction is a core component of the pathophysiology of schizophrenia. However, the genetic risk factors and molecular mechanisms related to synaptic dysfunction are still not fully understood. The Stonin 2 (STON2) gene encodes a major adaptor for clathrin-mediated endocytosis (CME) of synaptic vesicles. In this study, we showed that the C-C (307Pro-851Ala) haplotype of STON2 increases the susceptibility to schizophrenia and examined whether STON2 variations cause schizophrenia-like behaviors through the regulation of CME. We found that schizophrenia-related STON2 variations led to protein dephosphorylation, which affected its interaction with synaptotagmin 1 (Syt1), a calcium sensor protein located in the presynaptic membrane that is critical for CME. STON2307Pro851Ala knockin mice exhibited deficits in synaptic transmission, short-term plasticity, and schizophrenia-like behaviors. Moreover, among seven antipsychotic drugs, patients with the C-C (307Pro-851Ala) haplotype responded better to haloperidol than did the T-A (307Ser-851Ser) carriers. The recovery of deficits in Syt1 sorting and synaptic transmission by acute administration of haloperidol effectively improved schizophrenia-like behaviors in STON2307Pro851Ala knockin mice. Our findings demonstrated the effect of schizophrenia-related STON2 variations on synaptic dysfunction through the regulation of CME, which might be attractive therapeutic targets for treating schizophrenia-like phenotypes.

Baker-Gordon Syndrome (BAGOS) is a genetically determined 4 (NDD), represented by a phenotypic spectrum of moderate to severe intellectual disability, resulting from mutations in the synaptotagmin 1 (SYT1) gene. Its prevalence is estimated at 1:1,000,000 and the known gene variants have indicated complete penetrance with variable expressivity. SYT1 is a membrane trafficking protein in presynaptic vesicles, which exerts a complex influence on synaptic transmission, with fundamental roles in the release of neurotransmitters and facilitators of endocytosis, impacting both neurotransmission and neuron plasticity. The current case report describes the first Brazilian male patient diagnosed at 17-year-old, and the 39th reported case globally using whole-exome sequencing. A de novo heterozygous missense mutation at chr12q:79448958 (NM_005639.2; c.1103T>C; p.Ile368Thr) in the SYT1 was found and classified as a pathogenic variant. The proband\'s clinical phenotype was compatible with BAGOS, involving behavioral changes such as irritability and severe intellectual disability. Knowledge about the mechanism of action and the extent of the genotypic and phenotypic presentations of the mutations in the SYT1 is still unfolding. Thus, we aimed to describe additional genotype-phenotype correlation for BAGOS, contributing to the expansion of the existing knowledge of such a heterogeneous ultra-rare syndrome, and, therefore, improve its diagnostic yield, case management, and therapeutic journey for future patients.

UNASSIGNED: Synaptotagmin 1 (SYT1), the predominant SYT isoform in the central nervous system, likely acts by promoting vesicle docking, deforming the plasma membrane via Ca2+-dependent membrane penetration.
UNASSIGNED: Here, we describe a 21-year-old woman harboring a novel variant in the SYT1 gene, who presents with a complex phenotype, featuring severe intellectual disability, absent speech, behavioral abnormalities, motor stereotypies, dystonic posturing of her hands, a hyperkinetic movement disorder in her childhood, infantile hypotonia, sialorrhea, mild dysmorphic features, epilepsy, peculiar EEG findings, and severe scoliosis.
UNASSIGNED: Based on our case and literature review on the 22 previously described patients, we can confirm a complex neurodevelopmental disorder in which, unlike other synaptopathies, epilepsy is present in a subset of cases (including our patient: 5/23, 22%), although characteristic EEG changes are far more common (10/23, 43.5%). Our patient\'s age allows us to provide long-term follow-up data and thus better delineate the SYT1-related clinical phenotype.

Synaptotagmin-1 (SYT1) plays a pivotal role in regulating presynaptic processes, including neurotransmitter release. SYT1 variants perturb synaptic vesicle endocytosis and exocytosis, resulting in a series of neurodevelopmental disorders defined as Baker-Gordon syndrome. Herein, we report the case of a newborn with dysmorphic facial appearance, severe hypotonia, poor feeding, gastroesophageal reflux, and an inability to eat and breathe, diagnosed with Baker-Gordon syndrome. A retrospective search was performed on a newborn with Baker-Gordon syndrome. Medical charts were reviewed, with focus on the clinical presentation, diagnostic process, and treatment outcomes. Whole-genome high-throughput DNA sequencing was performed to identify genetic variants. Whole-exome sequencing identified the likely pathogenic variant as SYT1 C.551 T > C(p.V184A). Sanger sequencing results indicated that this variant was a de novo mutation in a conservative site located in the C2A domain of the protein. The patient died at 57 days old because of severe feeding and breathing problems. Our findings of a novel lethal variant in the C2A domain of SYT1 in the youngest patient diagnosed infantile Baker-Gordon syndrome who presented with the most severe hypotonia reported to date expands the spectrum of SYT1- associated neurodevelopmental disorders.

Background: Split-hand/foot malformation type 1 (SHFM1) refers to the group of rare congenital limb disorders defined by the absence or hypoplasia of the central rays of the autopods with or without accompanying anomalies, such as hearing loss, craniofacial malformation, and ectodermal dysplasia. Consequently, the condition is characterized by clinical variability that hinders diagnostic and counseling procedures. SHFM1 is caused by pathogenic variants affecting the DLX5/6 genes and/or their tissue-specific enhancers at the 7q21.3 locus. Herein, we report on seven patients from five unrelated Polish families affected by variable symptoms of the SHFM1 spectrum, all harboring 7q21.3 or 7q21.2-q21.3 rearrangements, and provide a genotype-phenotype correlation in the studied cohort. Methods: We applied GTG banding, array-based comparative genomic hybridization (aCGH), and whole-genome sequencing (WGS) in order to identify the causative aberrations in all affected patients. Results: The identified pathogenic structural variants included deletions and/or translocations involving the 7q21.3 locus, i.e., t(7;10)(q21.3;q22.2) and t(7;12)(q21.3;q21.2) in all affected individuals. Interestingly, a sporadic carrier of the latter aberration presented the SHFM1 phenotype with additional features overlapping with Baker-Gordon syndrome (BAGOS), which resulted from the translocation breakpoint at chromosome 12 within the SYT1 gene. Conclusion: Clinical variability of the studied cohort reflects the composition of the DLX5/6 regulatory elements that were dislocated from their target genes by chromosomal rearrangements. The correlation of our data with the previously published observations enabled us to update the phenotypic subregions and regulatory units within the SHFM1 locus. In addition, we present the first case of SHFM1 and BAGOS-like phenotype that resulted from translocation breakpoints at chromosomes 7 and 12, both of which were pathogenic, and consequently, we show the first evidence that BAGOS can also result from the regulatory loss-of-function SYT1 mutations. In this paper, we emphasize the utility of sequence-based approaches in molecular diagnostics of disorders caused by regulatory structural variants.

MicroRNAs (miRNAs) are important post-transcriptional factors involved in the regulation of gene expression and play crucial roles in biological processes related to milk fat metabolism. Our previous study revealed that miR-19a expression was significantly higher in the mammary epithelial cells of high-milk fat cows than in those of low-milk fat cows. However, the precise molecular mechanisms underlying these differences remain unclear. In this study, we found a high expression of miR-19a in the mammary tissues of dairy cows. The regulatory effects of miR-19a on bovine mammary epithelial cells (BMECs) were analyzed using cell counting kit-8 and 5-ethynyl-2\'-deoxyuridine assays, which demonstrated that miR-19a significantly inhibited BMEC proliferation. Transfection of the miR-19a mimic into BMECs significantly upregulated the expression of milk fat marker genes LPL, SCAP, and SREBP1, promoting triglyceride (TG) synthesis and lipid droplet formation, whereas the miR-19a inhibitor exhibited the opposite function. TargetScan and miRWalk predictions revealed that synaptotagmin 1 (SYT1) is a target gene of miR-19a. A dual luciferase reporter gene assay, RT-qPCR, and western blot analyses revealed that miR-19a directly targets the 3\'-untranslated region (UTR) of SYT1 and negatively regulates SYT1 expression. Functional validation revealed that overexpression of SYT1 in BMECs significantly downregulated the expression of LPL, SCAP, and SREBP1, and inhibited TG synthesis and lipid droplet formation. Conversely, the knockdown of SYT1 had the opposite effect. Altogether, miR-19a plays a crucial role in regulating the proliferation and differentiation of BMECs and regulates biological processes related to TG synthesis and lipid droplet formation by suppressing SYT1 expression. These findings provide a strong foundation for further research on the functional mechanisms underlying milk fat metabolism in dairy cows.

BACKGROUND: Tau, Amyloid-beta (Aβ42), and Glycogen synthase kinase 3 (GSK3) contribute to synaptic dysfunction observed in Alzheimer\'s disease (AD), the most common form of dementia. In the current study, the effect of pan-neuronal expression of TauWT, Aβ42, or shaggy (orthologue of GSK3) in Drosophila melanogaster was assessed on the locomotor function, ethanol sensitivity, synaptic genes and CREB expression. The effect of TauWT and Aβ42 on the expression of shaggy was also determined.
RESULTS: Gene expression analysis was performed using quantitative real-time RT-PCR method. While syt1, SNAP25 and CREB (upstream transcription factor of syt1 and SNAP25) were upregulated in flies expressing TauWT or Aβ42, a prominent decline was observed in those genes in shaggy expressing flies. Although all transgenic flies showed climbing disability and higher sensitivity to ethanol, abnormality in these features was significantly more prominent in transgenic flies expressing shaggy compared to TauWT or Aβ42. Despite a significant upregulation of shaggy transcription in TauWT expressing flies, Aβ42 transgenic flies witnessed no significant changes.
CONCLUSIONS: TauWT, Aβ42, and shaggy may affect synaptic plasticity through dysregulation of synaptic genes and CREB, independently. However shaggy has more detrimental effect on synaptic genes expression, locomotor ability and sensitivity to ethanol. It is important when it comes to drug discovery. It appears that CREB is a direct effector of changes in synaptic genes expression as they showed similar pattern of alteration and it is likely to be a part of compensatory mechanisms independent of the GSK3/CREB pathway in TauWT or Aβ42 expressing flies.

Lipids and their metabolic enzymes are a critical point of regulation for the membrane curvature required to induce membrane fusion during synaptic vesicle recycling. One such enzyme is diacylglycerol kinase θ (DGKθ), which produces phosphatidic acid (PtdOH) that generates negative membrane curvature. Synapses lacking DGKθ have significantly slower rates of endocytosis, implicating DGKθ as an endocytic regulator. Importantly, DGKθ kinase activity is required for this function. However, protein regulators of DGKθ\'s kinase activity in neurons have never been identified. In this study, we employed APEX2 proximity labeling and mass spectrometry to identify endogenous interactors of DGKθ in neurons and assayed their ability to modulate its kinase activity. Seven endogenous DGKθ interactors were identified and notably, synaptotagmin-1 (Syt1) increased DGKθ kinase activity 10-fold. This study is the first to validate endogenous DGKθ interactors at the mammalian synapse and suggests a coordinated role between DGKθ-produced PtdOH and Syt1 in synaptic vesicle recycling.

In this study, A549/PQ cells with moderate resistance to paraquat (PQ) were obtained by treating A549 cells with PQ, their growth rate was slowed down, the accumulation concentration of PQ and the levels of growth inhibition, injury and early apoptosis induced by PQ were significantly lower than those of parental A549 cells. Microarray screening and RT-qPCR detection found that Synaptotagmin-1 (SYT1) expression in drug-resistant cells was significantly increased, and PQ further enhanced its expression. After inhibiting SYT1 expression in A549/PQ cells, cell viability, intracellular PQ concentration and the expression of Bcl-2, SNAP25 and RAB26 were significantly reduced, while the mortality, early apoptosis rate and Bax expression were significantly increased. In vivo experiments also further showed that PQ promoted the expression of SYT1, SNAP25 and RAB26 in PQ-poisoned mice; when inhibiting SYT1 expression, PQ concentration in lung tissues was significantly increased, and the levels of lung injury and apoptosis were also significantly enhanced, while the expression of SNAP25 and RAB26 was significantly reduced. This indicates that PQ poisoning leads to compensatory up-regulation of vesicle transport related proteins such as SYT1 in vivo, thereby promoting PQ transmembrane transport, and then reducing the pulmonary accumulation of PQ and PQ-caused lung injury.