Cacna1b alternative splicing impacts excitatory neurotransmission and is linked to behavioral responses to aversive stimuli

Electroacupuncture at GB20 improves cognitive ability and synaptic plasticity via the CaM-CaMKII-CREB signaling pathway following cerebral ischemia-reperfusion injury in rats

BACKGROUND

This study aimed to investigate the effects of electroacupuncture (EA) on cognitive recovery and synaptic remodeling in a rat model of middle cerebral artery occlusion (MCAO) followed by reperfusion and explore the possible mechanism.

METHOD

Focal cerebral ischemia was modeled in healthy adult Sprague-Dawley rats by MCAO. The MCAO rats were classified into four groups: sham, MCAO, MCAO + GB20 (receiving EA at GB20) and MCAO + NA (receiving EA at a "non-acupoint" location not corresponding to any traditional acupuncture point location about 10 mm above the iliac crest). Neurological deficit scores and behavior were assessed before and during the treatment. After intervention for 7 days, the hippocampus was dissected to analyze growth-associated protein (GAP)-43, synaptophysin (SYN) and postsynaptic density protein (PSD)-95 expression levels by Western blotting. Bioinformatic analysis and primary hippocampal neurons with calcium-voltage gated channel subunit alpha 1B (CACNA1B) gene overexpression were used to screen the target genes for EA against MCAO.

RESULTS

Significant amelioration of neurological deficits and learning/memory were found in MCAO + GB20 rats compared with MCAO or MCAO + NA rats. Protein levels of GAP-43, SYN and PSD-95 were significantly improved in MCAO + GB20-treated rats together with an increase in the number of synapses in the hippocampal CA1 region. CACNA1B appeared to be a target gene of EA in MCAO. There were increased mRNA levels of CACNA1B, calmodulin (CaM), Ca2+/calmodulin-dependent protein kinase type II (CaMKII) and cyclic adenosine monophosphate response element binding (CREB) and increased phosphorylation of CaM, CaMKII and CREB in the hippocampal region in MCAO + GB20 versus MCAO and MCAO + NA groups. CACNA1B overexpression modulated expression of the CaM-CaMKII-CREB axis.

CONCLUSION

EA treatment at GB20 may ameliorate the negative effects of MCAO on cognitive function in rats by enhancing synaptic plasticity. EA treatment at GB20 may exert this neuroprotective effect by regulating the CACNA1B-CaM-CaMKII-CREB axis.

Rbfox1 regulates alternative splicing of Nrcam in primary sensory neurons to mediate peripheral nerve injury-induced neuropathic pain

The primary sensory neurons of the dorsal root ganglia (DRG) are subject to transcriptional alterations following peripheral nerve injury. These alterations are believed to play a pivotal role in the genesis of neuropathic pain. Alternative RNA splicing is a process that generates multiple transcript variants from a single gene, significantly contributing to the complexity of the transcriptome. However, little is known about the functional significance and control of alternative RNA splicing in injured DRG after spinal nerve ligation (SNL). In our study, we conducted a comprehensive transcriptome profiling and bioinformatic analysis to approach and identified a neuron-specific isoform of an RNA splicing regulator, RNA-binding Fox1 (Rbfox1, also known as A2BP1), as a crucial regulator of alternative RNA splicing in injured DRG after SNL. Notably, Rbfox1 expression is markedly reduced in injured DRG following peripheral nerve injury. Restoring this reduction effectively mitigates nociceptive hypersensitivity. Conversely, mimicking the downregulation of Rbfox1 expression generates neuropathic pain symptoms. Mechanistically, we uncovered that Rbfox1 may be a key factor influencing alternative RNA splicing of neuron-glial related cell adhesion molecule (NrCAM), a key neuronal cell adhesion molecule. In injured DRG after SNL, the downregulation of Rbfox1amplifies the insertion of exon 10 in Nrcam transcripts, leading to an increase in long Nrcam variants (L-Nrcam) and a corresponding decrease in short Nrcam variants (S-Nrcam) within injured DRG. In summary, our study supports the essential role of Rbfox1 in neuropathic pain within DRG, probably via the regulation of Nrcam splicing. These findings suggest that Rbfox1 could be a potential target for neuropathic pain therapy.

A pilot pharmacogenetic study of calcium channel blocker treatment of bipolar mania

Common genetic variants located in calcium channel genes are important markers of genetic susceptibility for bipolar disorder (BD). Previous clinical trials with Calcium Channel Blocker (CCB) medication improved mood stability for some BD patients. We hypothesize that manic patients who carried calcium channel risk variants would differentially benefit from treatment with CCBs. In this pilot study, 50 BD patients (Chinese: 39; US: 11) who were hospitalized for manic episodes were given add-on CCB treatment. We determined genotypes for each patient. There was a significant decrease in the Young Mania Rating Scale (YMRS) after add-on medication treatment. Of note, two intronic variants of the Calcium Voltage-Gated Channel Subunit Alpha1 B (CACNA1B) were associated with treatment outcomes for manic patients: rs2739258 and rs2739260. BD rs2739258/rs2739260 AG-allele carriers had a better treatment response with add-on CCB than those carrying the AA or GG genotypes by survival analysis. Although these findings did not pass multiple testing correction, this study suggests that single-nucleotide polymorphisms (SNPs) residing in calcium channel genes could be predictors for response to add-on CCB treatment of bipolar mania patients, and that calcium channel genes may be involved in treatment responses for BD.

Effect of semaglutide and empagliflozin on cognitive function and hippocampal phosphoproteomic in obese mice

Objective: Based on the 4D label-free phosphoproteomic technique, we examined the differences in cognitive function and hippocampal phosphorylated protein expression in high-fat diet-induced obese mice after the intervention of semaglutide and empagliflozin, as well as the effects of both on protein activity and function in obese mice’s hippocampal tissues and the signaling pathways involved.

Methods: Thirty-two C57BL/6JC male mice were assigned to two groups randomly: A control group (group C, 10% of energy is from fat, n = 8) and a high-fat diet group (group H, 60% of energy is from fat, n = 24). The high-fat diet-induced obese mice were screened after 12 weeks of feeding based on the criterion that the bodyweight of mice in fat rich diet group was greater than or equal to 20% of the average body weight of the mice in the blank control group. Group H separate into group H (n = 8), group Semaglutide (group S, n = 8), and group empagliflozin (group E, n = 8). For a total of 12 weeks, group S received 30 nmol/kg/d bodyweight of semaglutide intraperitoneally, group E received 10 mg/kg/d bodyweight of empagliflozin via gavage, and groups C and H received equal amounts of saline by intraperitoneal injection and gavage. At the end of treatment, the mice were appraised for cognitive function employing the Morris water maze (MWM), and serum fasting glucose, lipids, and inflammatory parameters were measured. The 4D label-free phosphoproteomics method was employed to screen the differential phosphoproteins and loci in hippocampal tissues of mice in different treatment groups, and bioinformatics was used to analyze the biological processes, signaling pathways, and related protein–protein interaction (PPI) network analysis of these differentially phosphorylated proteins.

Results: In comparison to normal controls, The escape latency of obese mice induced by high-fat diet was prolonged, the percentage of swimming time in the target quadrant was reduced, and the number of times of crossing the platform was reduced, whereas semaglutide and empagliflozin treatment reduced escape latency, increase the percentage of swim time in the target quadrant and increase the frequency of passing through the platform area, although there is little difference in the effect of the two drugs. The phosphoproteomic results showed 20,493 unique phosphorylated peptides, representing 21,239 phosphorylation sites and 4,290 phosphorylated proteins. Further analysis revealed that the proteins corresponding to these differentially phosphorylated sites are jointly distributed in signaling pathways such as dopaminergic synapses and axon guidance, and are involved in biological processes such as neuronal projection development, synaptic plasticity, and axonogenesis. Notably, the key factors voltage-dependent L-type calcium channel subunit alpha-1D (CACNA1D), voltage-dependent P/Q-type calcium channel subunit alpha-1A (CACNA1A), and voltage-dependent N-type calcium channel subunit alpha-1B (CACNA1B) were all found to be involved in the dopaminergic synapse pathway, and their expression was upregulated by semaglutide and empagliflozin.

Conclusion: We found for the first time that a high-fat diet decreased CACNA1D, CACNA1A, and CACNA1B protein serine phosphorylation, which may affect neuronal development, synaptic plasticity, and cognitive function in mice. Notably, semaglutide and empagliflozin increased the phosphorylation of these proteins.

Network Pharmacology and Experimental Verification to Unveil the Mechanism of N-Methyl-D-Aspartic Acid Rescue Humantenirine-Induced Excitotoxicity

Gelsemium is a medicinal plant that has been used to treat various diseases, but it is also well-known for its high toxicity. Complex alkaloids are considered the main poisonous components in Gelsemium. However, the toxic mechanism of Gelsemium remains ambiguous. In this work, network pharmacology and experimental verification were combined to systematically explore the specific mechanism of Gelsemium toxicity. The alkaloid compounds and candidate targets of Gelsemium, as well as related targets of excitotoxicity, were collected from public databases. The crucial targets were determined by constructing a protein-protein interaction (PPI) network. Subsequently, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore the bioprocesses and signaling pathways involved in the excitotoxicity corresponding to alkaloids in Gelsemium. Then, the binding affinity between the main poisonous alkaloids and key targets was verified by molecular docking. Finally, animal experiments were conducted to further evaluate the potential mechanisms of Gelsemium toxicity. A total of 85 alkaloids in Gelsemium associated with 214 excitotoxicity-related targets were predicted by network pharmacology. Functional analysis showed that the toxicity of Gelsemium was mainly related to the protein phosphorylation reaction and plasma membrane function. There were also 164 pathways involved in the toxic mechanism, such as the calcium signaling pathway and MAPK signaling pathway. Molecular docking showed that alkaloids have high affinity with core targets, including MAPK3, SRC, MAPK1, NMDAR_2B and NMDAR_2A. In addition, the difference of binding affinity may be the basis of toxicity differences among different alkaloids. Humantenirine showed significant sex differences, and the LD₅₀ values of female and male mice were 0.071 mg·kg^-1 and 0.149 mg·kg^-1, respectively. Furthermore, we found that N-methyl-D-aspartic acid (NMDA), a specific NMDA receptor agonist, could significantly increase the survival rate of acute humantenirine-poisoned mice. The results also show that humantenirine could upregulate the phosphorylation level of MAPK3/1 and decrease ATP content and mitochondrial membrane potential in hippocampal tissue, while NMDA could rescue humantenirine-induced excitotoxicity by restoring the function of mitochondria. This study revealed the toxic components and potential toxic mechanism of Gelsemium. These findings provide a theoretical basis for further study of the toxic mechanism of Gelsemium and potential therapeutic strategies for Gelsemium poisoning.

Regulation of N-type calcium channels by nociceptin receptors and its possible role in neurological disorders

Activation of nociceptin opioid peptide receptors (NOP, a.k.a. opioid-like receptor-1, ORL-1) by the ligand nociceptin/orphanin FQ, leads to G protein-dependent regulation of Cav2.2 (N-type) voltage-gated calcium channels (VGCCs). This typically causes a reduction in calcium currents, triggering changes in presynaptic calcium levels and thus neurotransmission. Because of the widespread expression patterns of NOP and VGCCs across multiple brain regions, the dorsal horn of the spinal cord, and the dorsal root ganglia, this results in the alteration of numerous neurophysiological features. Here we review the regulation of N-type calcium channels by the NOP-nociceptin system in the context of neurological conditions such as anxiety, addiction, and pain.

Origins and Evolution of Human Tandem Duplicated Exon Substitution Events

The mutually exclusive splicing of tandem duplicated exons produces protein isoforms that are identical save for a homologous region that allows for the fine tuning of protein function. Tandem duplicated exon substitution events are rare, yet highly important alternative splicing events. Most events are ancient, their isoforms are highly expressed, and they have significantly more pathogenic mutations than other splice events. Here, we analyzed the physicochemical properties and functional roles of the homologous polypeptide regions produced by the 236 tandem duplicated exon substitutions annotated in the human gene set. We find that the most important structural and functional residues in these homologous regions are maintained, and that most changes are conservative rather than drastic. Three quarters of the isoforms produced from tandem duplicated exon substitution events are tissue-specific, particularly in nervous and cardiac tissues, and tandem duplicated exon substitution events are enriched in functional terms related to structures in the brain and skeletal muscle. We find considerable evidence for the convergent evolution of tandem duplicated exon substitution events in vertebrates, arthropods, and nematodes. Twelve human gene families have orthologues with tandem duplicated exon substitution events in both Drosophila melanogaster and Caenorhabditis elegans. Six of these gene families are ion transporters, suggesting that tandem exon duplication in genes that control the flow of ions into the cell has an adaptive benefit. The ancient origins, the strong indications of tissue-specific functions, and the evidence of convergent evolution suggest that these events may have played important roles in the evolution of animal tissues and organs.

Phenotypes, mechanisms and therapeutics: insights from bipolar disorder GWAS findings

Genome-wide association studies (GWAS) have reported substantial genomic loci significantly associated with clinical risk of bipolar disorder (BD), and studies combining techniques of genetics, neuroscience, neuroimaging, and pharmacology are believed to help tackle clinical problems (e.g., identifying novel therapeutic targets). However, translating findings of psychiatric genetics into biological mechanisms underlying BD pathogenesis remains less successful. Biological impacts of majority of BD GWAS risk loci are obscure, and the involvement of many GWAS risk genes in this illness is yet to be investigated. It is thus necessary to review the progress of applying BD GWAS risk genes in the research and intervention of the disorder. A comprehensive literature search found that a number of such risk genes had been investigated in cellular or animal models, even before they were highlighted in BD GWAS. Intriguingly, manipulation of many BD risk genes (e.g., ANK3, CACNA1C, CACNA1B, HOMER1, KCNB1, MCHR1, NCAN, SHANK2 etc.) resulted in altered murine behaviors largely restoring BD clinical manifestations, including mania-like symptoms such as hyperactivity, anxiolytic-like behavior, as well as antidepressant-like behavior, and these abnormalities could be attenuated by mood stabilizers. In addition to recapitulating phenotypic characteristics of BD, some GWAS risk genes further provided clues for the neurobiology of this illness, such as aberrant activation and functional connectivity of brain areas in the limbic system, and modulated dendritic spine morphogenesis as well as synaptic plasticity and transmission. Therefore, BD GWAS risk genes are undoubtedly pivotal resources for modeling this illness, and might be translational therapeutic targets in the future clinical management of BD. We discuss both promising prospects and cautions in utilizing the bulk of useful resources generated by GWAS studies. Systematic integrations of findings from genetic and neuroscience studies are called for to promote our understanding and intervention of BD.

Differential expression of 10 genes in the hypothalamus of two generations of rats selected for a reaction to humans

Individual behavioral differences are due to an interaction of the genotype and the environment. Phenotypic manifestation of aggressive behavior depends on the coordinated expression of gene ensembles. Nonetheless, the identification of these genes and of combinations of their mutual influence on expression remains a difficult task. Using animal models of aggressive behavior (gray rats that were selected for a reaction to humans; tame and aggressive rat strains), we evaluated the expression of 10 genes potentially associated with aggressiveness according to the literature: Cacna1b, Cacna2d3, Drd2, Egr1, Gad2, Gria2, Mapk1, Nos1, Pomc, and Syn1. To identify the genes most important for the manifestation of aggressiveness, we analyzed the expression of these genes in two generations of rats: 88th and 90th. Assessment of gene expression levels was carried out by real-time PCR in the hypothalamus of tame and aggressive rats. This analysis confirmed that 4 out of the 10 genes differ in expression levels between aggressive rats and tame rats in both generations. Specifically, it was shown that the expression of the Cacna1b, Drd2, Egr1, and Gad2 genes does not differ between the two generations (88th vs 90th) within each strain, but significantly differs between the strains: in the tame rats of both generations, the expression levels of these genes are significantly lower as compared to those in the aggressive rats. Therefore, these genes hold promise for further studies on behavioral characteristics. Thus, we confirmed polygenic causes of phenotypic manifestation of aggressive reactions.

BaseScope™ Approach to Visualize Alternative Splice Variants in Tissue

Defining the cell-specific alternative splicing landscape in complex tissues is an important goal to gain functional insights. Deep-sequencing techniques coupled to genetic strategies for cell identification has provided important cues on cell-specific exon usage in complex tissues like the nervous system. BaseScope™ has emerged as a powerful and highly sensitive alternative to in situ hybridization to determine exon composition in tissue with spatial and morphological context. In this protocol, we will review how BaseScope was utilized to detect the e37a-Cacna1b splice variant of the presynaptic calcium channel CaV2.2 or N-type. This splice variant arises from a pair of mutually exclusive exons (e37a and e37b). E37a-Cacna1b is heavily underrepresented relative to e37b-Cacna1b and both exons share 60% of their sequence. By using BaseScope™, we were able to discover that e37a-Cacna1b is expressed in excitatory pyramidal neurons of hippocampus and cortex, as well as motor neurons of the ventral horn of the spinal cord.

Transcriptome and chromatin alterations in social fear indicate association of MEG3 with successful extinction of fear

Social anxiety disorder is characterized by a persistent fear and avoidance of social situations, but available treatment options are rather unspecific. Using an established mouse social fear conditioning (SFC) paradigm, we profiled gene expression and chromatin alterations after the acquisition and extinction of social fear within the septum, a brain region important for social fear and social behaviors. Here, we particularly focused on the successful versus unsuccessful outcome of social fear extinction training, which corresponds to treatment responsive versus resistant patients in the clinics. Validation of coding and non-coding RNAs revealed specific isoforms of the long non-coding RNA (lncRNA) Meg3 regulated, depending on the success of social fear extinction. Moreover, PI3K/AKT was differentially activated with extinction success in SFC-mice. In vivo knockdown of specific Meg3 isoforms increased baseline activity of PI3K/AKT signaling, and mildly delayed social fear extinction. Using ATAC-Seq and CUT&RUN, we found alterations in the chromatin structure of specific genes, which might be direct targets of lncRNA Meg3.

More than a pore: How voltage-gated calcium channels act on different levels of neuronal communication regulation

Voltage-gated calcium channels (VGCCs) represent key regulators of the calcium influx through the plasma membrane of excitable cells, like neurons. Activated by the depolarization of the membrane, the opening of VGCCs induces very transient and local changes in the intracellular calcium concentration, known as calcium nanodomains, that in turn trigger calcium-dependent signaling cascades and the release of chemical neurotransmitters. Based on their central importance as concierges of excitation-secretion coupling and therefore neuronal communication, VGCCs have been studied in multiple aspects of neuronal function and malfunction. However, studies on molecular interaction partners and recent progress in omics technologies have extended the actual concept of these molecules. With this review, we want to illustrate some new perspectives of VGCCs reaching beyond their function as calcium-permeable pores in the plasma membrane. Therefore, we will discuss the relevance of VGCCs as voltage sensors in functional complexes with ryanodine receptors, channel-independent actions of auxiliary VGCC subunits, and provide an insight into how VGCCs even directly participate in gene regulation. Furthermore, we will illustrate how structural changes in the intracellular C-terminus of VGCCs generated by alternative splicing events might not only affect the biophysical channel characteristics but rather determine their molecular environment and downstream signaling pathways.

An Interactive Review on the Role of Tocotrienols in the Neurodegenerative Disorders

Neurodegenerative disorders, such as Parkinson's and Alzheimer's disease, are claimed to be of major concern causing a significant disease burden worldwide. Oxidative stress, mitochondrial dysfunction and nerve damage are the main reasons for the emergence of these diseases. The formation of reactive oxygen species (ROS) is the common chemical molecule that is formed from all these three interdependent mechanisms which is highly reactive toward the neuronal cells. For these reasons, the administration of tocotrienols (T3s), which is a potent antioxidant, is proven to cater to this problem, through in vitro and in vivo investigations. Interestingly, their therapeutic potentials are not only limited to antioxidant property but also to being able to reverse the neuronal damage and act as a shield for mitochondria dysfunction. Thereby, T3s prevents the damage to the neurons. In regards to this statement, in this review, we focused on summarizing and discussing the potential therapeutic role of T3s on Alzheimer's and Parkinson's diseases, and their protective mechanisms based on evidence from the in vitro and in vivo studies. However, there is no clinical trial conducted to prove the efficacy of T3s for Alzheimer's and Parkinson's subjects. As such, the therapeutic role of T3s for these neurodegenerative disorders is still under debate.

Chromatin-mediated alternative splicing regulates cocaine-reward behavior

Neuronal alternative splicing is a key gene regulatory mechanism in the brain. However, the spliceosome machinery is insufficient to fully specify splicing complexity. In considering the role of the epigenome in activity-dependent alternative splicing, we and others find the histone modification H3K36me3 to be a putative splicing regulator. In this study, we found that mouse cocaine self-administration caused widespread differential alternative splicing, concomitant with the enrichment of H3K36me3 at differentially spliced junctions. Importantly, only targeted epigenetic editing can distinguish between a direct role of H3K36me3 in splicing and an indirect role via regulation of splice factor expression elsewhere on the genome. We targeted Srsf11, which was both alternatively spliced and H3K36me3 enriched in the brain following cocaine self-administration. Epigenetic editing of H3K36me3 at Srsf11 was sufficient to drive its alternative splicing and enhanced cocaine self-administration, establishing the direct causal relevance of H3K36me3 to alternative splicing of Srsf11 and to reward behavior.

Phosphoproteomics reveals NMDA receptor-mediated excitotoxicity as a key signaling pathway in the toxicity of gelsenicine

Gelsenicine is one of the most toxic compounds in the genus Gelsemium, but the mechanism of toxicity is not clear. In this paper, tandem mass tag quantitative phosphoproteomics was used to study the changes in protein phosphorylation in different brain regions at different time points after gelsenicine poisoning in mice. The correlation between neurotransmitter receptors and the toxicity of gelsenicine was analyzed by molecular docking and rescue experiments. Parallel reaction monitoring (PRM) was used to verify the related proteins. A total of 17877 unique phosphosites were quantified and mapped to 4170 brain proteins to understand the signaling pathways. Phosphoproteomics revealed gelsenicine poisoning mainly affected protein phosphorylation levels in the hippocampus, and through bioinformatics analysis, it was found gelsenicine poisoning significantly affected neurotransmitter synaptic pathway. The molecular docking results showed that gelsenicine could bind to the N-methyl-D-aspartic acid receptor (NMDAR). In addition, we found that NMDA was effective in improving the survival rate of the animals tested, and this effect was associated with reduced protein phosphorylation by PRM validation. The results revealed that gelsenicine affects neurotransmitter release and receptor function. This is the first demonstration that NMDA receptor-mediated excitotoxicity is a key signaling pathway in the toxicity of gelsenicine.

N-type calcium channels control GABAergic transmission in brain areas related to fear and anxiety

N-type (CaV2.2) calcium channels are key for action potential-evoked transmitter release in the peripheral and central nervous system. Previous studies have highlighted the functional relevance of N-type calcium channels at both the peripheral and central level. In the periphery, the N-type calcium channels regulate nociceptive and sympathetic responses. At the central level, N-type calcium channels have been linked to aggression, hyperlocomotion, and anxiety. Among the areas of the brain that are involved in anxiety are the basolateral amygdala, medial prefrontal cortex, and ventral hippocampus. These three areas share similar characteristics in their neuronal circuitry, where pyramidal projection neurons are under the inhibitory control of a wide array of interneurons including those that express the peptide cholecystokinin. This type of interneuron is well-known to rely on N-type calcium channels to release GABA in the hippocampus, however, whether these channels control GABA release from cholecystokinin-expressing interneurons in the basolateral amygdala and medial prefrontal cortex is not known. Here, using mouse models to genetically label cholecystokinin-expressing interneurons and electrophysiology, we found that in the basolateral amygdala, N-type calcium channels control ~50% of GABA release from these neurons onto pyramidal cells. By contrast, in the medial prefrontal cortex N-type calcium channels are functionally absent in synapses of cholecystokinin-expressing interneurons, but control ~40% of GABA release from other types of interneurons. Our findings provide insights into the precise localization of N-type calcium channels in interneurons of brain areas related to anxiety.

CACNA1B facilitates breast cancer cell growth and migration by regulating cyclin D1 and EMT: the implication of CACNA1B in breast cancer

PURPOSE

This study mainly aimed to explore the influences of Calcium Voltage-Gated Channel Subunit Alpha1 B (CACNA1B) on the development of breast cancer and the related mechanism.

MATERIALS AND METHODS

The information of patients with breast cancer from TCGA database was used for analyses of CACNA1B expression and its prognostic value. Loss- and gain- of functions of CACNA1B were conducted in MCF7 and Bcap-37 cells, respectively. CCK-8, colony formation and transwell assays were applied for evaluating the cell viability and motility. Western blot was used for protein expression detection.

RESULTS

We revealed that highly expressed CACNA1B in breast cancer tissues was related to poor prognosis according to the data gained from TCGA database. The outcomes of functional assays showed that depletion of CACNA1B restrained MCF7 cell growth, invasion and migration and high-expression of CACNA1B fortified the growth, invasion and migration in Bcap-37 cells. Finally, we manifested that silencing CACNA1B obviously raised the protein expression level of E-cadherin and reduced the protein levels of Cyclin D1, N-cadherin and Snail in MCF7 cells, whilst, over-expression of CACNA1B reduced the level of E-cadherin and increased the expression of Cyclin D1, N-cadherin and Snail in Bcap-37 cells.

CONCLUSIONS

These results identified CACNA1B as a forwarder of the growth, invasion and migration in breast cancer cells.

Functional gene networks reveal distinct mechanisms segregating in migraine families

Migraine is the most common neurological disorder worldwide and it has been shown to have complex polygenic origins with a heritability of estimated 40-70%. Both common and rare genetic variants are believed to underlie the pathophysiology of the prevalent types of migraine, migraine with typical aura and migraine without aura. However, only common variants have been identified so far. Here we identify for the first time a gene module with rare mutations through a systems genetics approach integrating RNA sequencing data from brain and vascular tissues likely to be involved in migraine pathology in combination with whole genome sequencing of 117 migraine families. We found a gene module in the visual cortex, based on single nuclei RNA sequencing data, that had increased rare mutations in the migraine families and replicated this in a second independent cohort of 1930 patients. This module was mainly expressed by interneurons, pyramidal CA1, and pyramidal SS cells, and pathway analysis showed association with hormonal signalling (thyrotropin-releasing hormone receptor and oxytocin receptor signalling pathways), Alzheimer's disease pathway, serotonin receptor pathway and general heterotrimeric G-protein signalling pathways. Our results demonstrate that rare functional gene variants are strongly implicated in the pathophysiology of migraine. Furthermore, we anticipate that the results can be used to explain the critical mechanisms behind migraine and potentially improving the treatment regime for migraine patients.

Cell-specific exon methylation and CTCF binding in neurons regulate calcium ion channel splicing and function

Cell-specific alternative splicing modulates myriad cell functions and is disrupted in disease. The mechanisms governing alternative splicing are known for relatively few genes and typically focus on RNA splicing factors. In sensory neurons, cell-specific alternative splicing of the presynaptic Ca_V channel Cacna1b gene modulates opioid sensitivity. How this splicing is regulated is unknown. We find that cell and exon-specific DNA hypomethylation permits CTCF binding, the master regulator of mammalian chromatin structure, which, in turn, controls splicing in a DRG-derived cell line. In vivo, hypomethylation of an alternative exon specifically in nociceptors, likely permits CTCF binding and expression of Ca_V2.2 channel isoforms with increased opioid sensitivity in mice. Following nerve injury, exon methylation is increased, and splicing is disrupted. Our studies define the molecular mechanisms of cell-specific alternative splicing of a functionally validated exon in normal and disease states – and reveal a potential target for the treatment of chronic pain.