Cytoskeleton-associated Protein Research Articles

Dynamic Changes of Arc Expression in Dorsal Striatum of Mice After Self-Administration of Sucrose.

Region-specific plasticity in the striatal circuit plays an important role in the development and long-term maintenance of skills and sequential movement procedures. Studies investigating the molecular substrates that contribute to the plasticity changes during motor skill processes have documented a transition in expression from the dorsomedial striatum (DMS) to the dorsolateral striatum (DLS); however, few studies have explored the expression pattern of molecular substrates in the dorsal striatum during progression of instrumental learning. To address this issue, the activity-regulated cytoskeleton-associated protein (Arc) expressions in the subregional dorsal striatum were analyzed during the early and late learning phases of the 10-day sucrose self-administration process. We found that Arc protein is primarily detected in the DMS only in the initial learning stage; however, it is expressed in the DLS during both early and late learning stages. Moreover, Arc expression in the DMS correlated with the number of rewards received later in the training. These data indicated that the Arc expression in subregions of the dorsal striatum shows region-specific transfer and that Arc expression in the DMS contributes to obtaining reward in later learning stage during the process of instrumental learning.

Crystal and solution structures reveal oligomerization of individual capsid homology domains of Drosophila Arc.

Synaptic plasticity is vital for brain function and memory formation. One of the key proteins in long-term synaptic plasticity and memory is the activity-regulated cytoskeleton-associated protein (Arc). Mammalian Arc forms virus-like capsid structures in a process requiring the N-terminal domain and contains two C-terminal lobes that are structural homologues to retroviral capsids. Drosophila has two isoforms of Arc, dArc1 and dArc2, with low sequence similarity to mammalian Arc, but lacking a large N-terminal domain. Both dArc isoforms are related to the Ty3/gypsy retrotransposon capsid, consisting of N- and C-terminal lobes. Structures of dArc1, as well as capsids formed by both dArc isoforms, have been recently determined. We carried out structural characterization of the four individual dArc lobe domains. As opposed to the corresponding mammalian Arc lobe domains, which are monomeric, the dArc lobes were all oligomeric in solution, indicating a strong propensity for homophilic interactions. A truncated N-lobe from dArc2 formed a domain-swapped dimer in the crystal structure, resulting in a novel dimer interaction that could be relevant for capsid assembly or other dArc functions. This domain-swapped structure resembles the dimeric protein C of flavivirus capsids, as well as the structure of histones dimers, domain-swapped transcription factors, and membrane-interacting BAK domains. The strong oligomerization properties of the isolated dArc lobe domains explain the ability of dArc to form capsids in the absence of any large N-terminal domain, in contrast to the mammalian protein.

A γ-adducin cleavage fragment induces neurite deficits and synaptic dysfunction in Alzheimer's disease.

Neurite deficits and synaptic dysfunction contribute to cognitive impairments in Alzheimer's disease (AD). However, the underlying molecular mechanisms remain unclear. Here, we show that γ-adducin, a cytoskeleton-associated protein that assembles the spectrin-actin framework, is cleaved by a lysosomal cysteine proteinase named asparagine endopeptidase (AEP). AEP is upregulated and activated during aging and cleaves γ-adducin at N357, disrupting spectrin-actin assembly. Moreover, γ-adducin (1-357) fragment downregulates the expression of Rac2, leading to defects in neurite outgrowth. Expression of the γ-adducin (1-357) fragment in the hippocampus of tau P301S transgenic mice resulted in significant AD-like pathology and cognitive deficits. In summary, AEP-mediated fragmentation of γ-adducin plays a vital role in AD. Blocking the activity of AEP might be a novel therapeutic target for AD.

Patterns of Cellular Overlap in Expression of c‐Fos and Arc Activity‐Regulated Genes in the Mouse Brain Regions During Acquisition and Retrieval of Contextual Conditioned Fear

Consolidation of long-term memory requires expression of immediate early genes (IEGs) encoding regulatory and effector proteins, such as inducible transcription factor c-Fos and activity-regulated cytoskeleton-associated protein Arc/Arg3.1. Since these IEGs are involved in various forms of behavioral and stimulus-induced plasticity, their products are often used to label active neurons, and their promoters are employed to tag and manipulate active engram cells. However, little is still known as to whether c-Fos and Arc proteins are induced identically and in the same neurons of different brain structures under various behavioral conditions. In the present work we compared expression patterns of c-Fos and Arc proteins in the mouse brain after acquisition and retrieval of contextual fear and analyzed cellular overlap of their expression in both conditions. Our hypothesis was that the activity patterns of two genes would not be identical though would substantially overlap according to similarities and differences in signaling cascades driving their expression. Both cohorts of mice were subjected to standard contextual fear conditioning with an electric footshock. One group of animals was sacrificed 90 minutes after the training session and the other was tested for retrieval of contextual memory on the next day and sacrificed 90 minutes later. The percentage of freezing in the conditioning context was measured as an index of memory. Brain sections were collected from hippocampus, amygdala and associative cortices of experimental mice, active control mice and home cage control mice. Double immunohistochemical staining with anti-Fos and anti-Arc antibodies was performed, and stained sections were scanned with a confocal microscope. The cell count showed behavioral induction of both c-Fos and Arc in all the examined brain structures. However, there was only a partial overlap of about 30% between the two labelled cell populations. Arc-positive cells predominated over c-Fos-positive cells in the hippocampus regardless of cognitive task, and in cingulate and parietal cortex Arc prevalence was stronger in after memory retrieval compared to learning. Moreover, within the above structures localization of c-Fos- and Arc-positive cells had different distribution across cortical layers and hippocampal subfields. Our results indicate that c-Fos and Arc proteins are not equivalent markers of stimulus-induced neural activity, as they are expressed in cell populations that differ by more than 60%. This data imposes a significant restraint on the use of these IEGs as interchangeable markers of neuronal activity/plasticity and calls for a further study of the differences in their regulation during behavior and learning.

Repeated treatment with alpha 7 nicotinic acetylcholine receptor ligands enhances cognitive processes and stimulates Erk1/2 and Arc genes in rats

The α7 nicotinic acetylcholine receptor (α7 nAChR) is a potential target for the treatment of cognitive decline in patients with schizophrenia, Alzheimer’s disease, and attention-deficit/hyperactivity disorder.Here we examined the promnesic activity of the α7 nAChR agonist (A582941), the type I (CCMI), and the type II (PNU120596) positive allosteric modulators (PAMs) in rats following single and repeated (once daily for seven days) treatment. To determine the neuronal mechanisms underlying the procognitive activity of the tested compounds, levels of the extracellular signal-regulated kinases (Erk1/2) and the activity-regulated cytoskeleton-associated protein (Arc) mRNAs were assessed in the frontal cortical and hippocampal brain regions.Using the novel object recognition test, we demonstrate that the lower doses of A582941 (0.1 mg/kg), CCMI (1 mg/kg), and PNU120596 (0.3 mg/kg) improved recognition memory after repeated but not single administration, suggesting a cumulative effect of repeated dosing. In contrast, the higher doses of A582941 (0.3 mg/kg), CCMI (3 mg/kg) and PNU120596 (1 mg/kg) demonstrated promnesic efficacy following both single and repeated administration. Subsequent in situ hybridization revealed that repeated treatment with A582941 and CCMI, but not PNU120596 enhanced mRNA expression of the Erk1/2 and Arc in the frontal cortex and hippocampus.Present data suggest that both the α7 nAChR agonist and PAMs exhibit procognitive effects after single and repeated administration. The increased level of the Erk1/2 and Arc genes is likely to be at least partially involved in this effect.

Paraventricular Thalamic Regulation of Habituation to Repeated Stress

Habituation is the progressive decline in responses to repeated exposure to predictable, moderately intense stressors. Learning and memory underlie the ability to habituate and these are disrupted in disorders such as PTSD. We previously identified the posterior paraventricular thalamic nucleus (pPVT) as crucial in regulating habituation. Here, we investigated the activity-regulated cytoskeleton-associated protein (Arc), an immediate early gene that promotes synaptic and structural plasticity underlying learning and memory, in the regulation of habituation.

Elevated GAS2L3 Expression Correlates With Poor Prognosis in Patients With Glioma: A Study Based on Bioinformatics and Immunohistochemical Analysis

BackgroundGrowth arrest–specific 2 like 3 (GAS2L3) is a cytoskeleton-associated protein that interacts with actin filaments and tubulin. Abnormal GAS2L3 expression has been reported to be associated with carcinogenesis. However, the biological role of GAS2L3 in glioma remains to be determined.MethodsThe transcriptome level of GAS2L3 and its relationship with clinicopathological characteristics were analyzed among multiple public databases and clinical specimens. Bioinformatics analyses were conducted to explore biological functions and prognostic value of GAS2L3 in glioma.ResultsGAS2L3 was substantially expressed in glioma, and high GAS2L3 expression correlated with shorter overall survival time and poor clinical variables. Gene set enrichment analysis (GSEA), single-sample gene-set enrichment analysis, and CIBERSORT algorithm analyses showed that GAS2L3 expression was closely linked to immune-related pathways, inflammatory activities, and immune cell infiltration. Moreover, GAS2L3 was synergistic with T cell–inflamed gene signature, immune checkpoints, T-cell receptor diversities, and neoantigen numbers.ConclusionThis study suggests that GAS2L3 is a prognostic biomarker for glioma, providing a reference for further study of the potential role of GAS2L3 in the immunomodulation of glioma.

Deletion of BDNF in Pax2 Lineage-Derived Interneuron Precursors in the Hindbrain Hampers the Proportion of Excitation/Inhibition, Learning, and Behavior

Numerous studies indicate that deficits in the proper integration or migration of specific GABAergic precursor cells from the subpallium to the cortex can lead to severe cognitive dysfunctions and neurodevelopmental pathogenesis linked to intellectual disabilities. A different set of GABAergic precursors cells that express Pax2 migrate to hindbrain regions, targeting, for example auditory or somatosensory brainstem regions. We demonstrate that the absence of BDNF in Pax2-lineage descendants of BdnfPax2KOs causes severe cognitive disabilities. In BdnfPax2KOs, a normal number of parvalbumin-positive interneurons (PV-INs) was found in the auditory cortex (AC) and hippocampal regions, which went hand in hand with reduced PV-labeling in neuropil domains and elevated activity-regulated cytoskeleton-associated protein (Arc/Arg3.1; here: Arc) levels in pyramidal neurons in these same regions. This immaturity in the inhibitory/excitatory balance of the AC and hippocampus was accompanied by elevated LTP, reduced (sound-induced) LTP/LTD adjustment, impaired learning, elevated anxiety, and deficits in social behavior, overall representing an autistic-like phenotype. Reduced tonic inhibitory strength and elevated spontaneous firing rates in dorsal cochlear nucleus (DCN) brainstem neurons in otherwise nearly normal hearing BdnfPax2KOs suggests that diminished fine-grained auditory-specific brainstem activity has hampered activity-driven integration of inhibitory networks of the AC in functional (hippocampal) circuits. This leads to an inability to scale hippocampal post-synapses during LTP/LTD plasticity. BDNF in Pax2-lineage descendants in lower brain regions should thus be considered as a novel candidate for contributing to the development of brain disorders, including autism.

Single-cell RNA Sequencing Analysis Identifies Key Genes in Brain Metastasis from Lung Adenocarcinoma.

Lung adenocarcinoma (LADC) is the most common type of lung cancer and is a subtype of non-small-cell lung cancer (NSCLC). Approximately 40% of LADC patients experience brain metastases (BMs) during the course of the disease. In this study, integrated bioinformatics methods were applied to identify key genes related to brain metastasis in lung adenocarcinoma. We derived and characterized genes differentially expressed between the primary tumour and brain metastases using tumour cells isolated from two lung cancer Patient-derived xenografts (PDX) cases (GSE 69405). Gene ontology (GO) and KEGG pathway enrichment analyses were applied, and protein-protein interaction (PPI) networks and Cytoscape software were utilized to identify key genes. Four key genes, including CKAP4 (Cytoskeleton Associated Protein 4), SERPINA1 (Serpin Family A Member 1), SDC2 (Syndecan 2) and GNG11 (G Protein Subunit Gamma 11) were identified for BM-LADC by the Venn diagram. We believe these key genes may be potential biomarkers for improved prognosis and treatment of lung adenocarcinoma.

Structural properties and peptide ligand binding of the capsid homology domains of human Arc

The activity-regulated cytoskeleton-associated protein (Arc) is important for synaptic plasticity and the normal function of the brain. Arc interacts with neuronal postsynaptic proteins, but the mechanistic details of its function have not been fully established. The C-terminal domain of Arc consists of tandem domains, termed the N- and C-lobe. The N-lobe harbours a peptide binding site, able to bind multiple targets. By measuring the affinity of human Arc towards various peptides from stargazin and guanylate kinase-associated protein (GKAP), we have refined its specificity determinants. We found two sites in the GKAP repeat region that bind to Arc and confirmed these interactions by X-ray crystallography. Phosphorylation of the stargazin peptide did not affect binding affinity but caused changes in thermodynamic parameters. Comparison of the crystal structures of three high-resolution human Arc-peptide complexes identifies three conserved C–H…π interactions at the binding cavity, explaining the sequence specificity of short linear motif binding by Arc. We further characterise central residues of the Arc lobe fold, show the effects of peptide binding on protein dynamics, and identify acyl carrier proteins as structures similar to the Arc lobes. We hypothesise that Arc may affect protein-protein interactions and phase separation at the postsynaptic density, affecting protein turnover and re-modelling of the synapse. The present data on Arc structure and ligand binding will help in further deciphering these processes.

Conversion of the death inhibitor ARC to a killer activates pancreatic β cell death in diabetes.

Loss of insulin-secreting pancreatic β cells through apoptosis contributes to the progression of type 2 diabetes, but underlying mechanisms remain elusive. Here, we identify a pathway in which the cell death inhibitor ARC paradoxically becomes a killer during diabetes. While cytoplasmic ARC maintains β cell viability and pancreatic architecture, a pool of ARC relocates to the nucleus to induce β cell apoptosis in humans with diabetes and several pathophysiologically distinct mouse models. β cell death results through the coordinate downregulation of serpins (serine protease inhibitors) not previously known to be synthesized and secreted by β cells. Loss of the serpin α1-antitrypsin from the extracellular space unleashes elastase, triggering the disruption of β cell anchorage and subsequent cell death. Administration of α1-antitrypsin to mice with diabetes prevents β cell death and metabolic abnormalities. These data uncover a pathway for β cell loss in type 2 diabetes and identify an FDA-approved drug that may impede progression of this syndrome.

Inhibition of casein kinase 1 \u03b4/\u03b5 improves cognitive performance in adult C57BL/6J mice

Time-of-day effects have been noted in a wide variety of cognitive behavioral tests, and perturbation of the circadian system, either at the level of the master clock in the SCN or downstream, impairs hippocampus-dependent learning and memory. A number of kinases, including the serine-threonine casein kinase 1 (CK1) isoforms CK1δ/ε, regulate the timing of the circadian period through post-translational modification of clock proteins. Modulation of these circadian kinases presents a novel treatment direction for cognitive deficits through circadian modulation. Here, we tested the potential for PF-670462, a small molecule inhibitor of CK1δ/ε, to improve cognitive performance in C57BL/6J mice in an array of behavioral tests. Compared to vehicle-treated mice tested at the same time of the circadian day, mice treated with PF-670462 displayed better recall of contextual fear conditioning, made fewer working memory errors in the radial arm water maze, and trained more efficiently in the Morris Water Maze. These benefits were accompanied by increased expression of activity-regulated cytoskeleton-associated protein (Arc) in the amygdala in response to an acute learning paradigm. Our results suggest the potential utility of CK1δ/ε inhibition in improving time-of-day cognitive performance.

Cytoskeleton-Associated Protein 4, a Promising Biomarker for Tumor Diagnosis and Therapy.

Cytoskeleton-associated protein 4 (CKAP4) is located in the rough endoplasmic reticulum (ER) and plays an important role in stabilizing the structure of ER. Meanwhile, CKAP4 is also found to act as an activated receptor at the cell surface. The multifunction of CKAP4 was gradually discovered with growing research evidence. In addition to the involvement in various physiological events including cell proliferation, cell migration, and stabilizing the structure of ER, CKAP4 has been implicated in tumorigenesis. However, the role of CKAP4 is still controversial in tumor biology, which may be related to different signal transduction pathways mediated by binding to different ligands in various microenvironments. Interestingly, CKAP4 has been recently recognized as a serological marker of several tumors and CKAP4 is expected to be a tumor therapeutic target. Therefore, deciphering the gene status, expression regulation, functions of CKAP4 in different diseases may shed new light on CKAP4-based cancer diagnosis and therapeutic strategy. This review discusses the publications that describe CKAP4 in various diseases, especially on tumor promotion and suppression, and provides a detailed discussion on the discrepancy.

Analysis of m6A RNA Methylation-Related Genes in Liver Hepatocellular Carcinoma and Their Correlation with Survival.

N6-methyladenosine (m6A) modification on RNA plays an important role in tumorigenesis and metastasis, which could change gene expression and even function at multiple levels such as RNA splicing, stability, translocation, and translation. In this study, we aim to conduct a comprehensive analysis on m6A RNA methylation-related genes, including m6A RNA methylation regulators and m6A RNA methylation-modified genes, in liver hepatocellular carcinoma, and their relationship with survival and clinical features. Data, which consist of the expression of widely reported m6A RNA methylation-related genes in liver hepatocellular carcinoma from The Cancer Genome Atlas (TCGA), were analyzed by one-way ANOVA, Univariate Cox regression, a protein–protein interaction network, gene enrichment analysis, feature screening, a risk prognostic model, correlation analysis, and consensus clustering analysis. In total, 405 of the m6A RNA methylation-related genes were found based on one-way ANOVA. Among them, DNA topoisomerase 2-alpha (TOP2A), exodeoxyribonuclease 1 (EXO1), ser-ine/threonine-protein kinase Nek2 (NEK2), baculoviral IAP repeat-containing protein 5 (BIRC5), hyaluronan mediated motility receptor (HMMR), structural maintenance of chromosomes protein 4 (SMC4), bloom syndrome protein (BLM), ca-sein kinase I isoform epsilon (CSNK1E), cytoskeleton-associated protein 5 (CKAP5), and inner centromere protein (INCENP), which were m6A RNA methylation-modified genes, were recognized as the hub genes based on the protein–protein interaction analysis. The risk prognostic model showed that gender, AJCC stage, grade, T, and N were significantly different between the subgroup with the high and low risk groups. The AUC, the evaluation parameter of the prediction model which was built by RandomForest, was 0.7. Furthermore, two subgroups were divided by consensus clustering analysis, in which stage, grade, and T differed. We identified the important genes expressed significantly among two clusters, including uridine-cytidine kinase 2 (UCK2), filensin (BFSP1), tubulin-specific chaperone D (TBCD), histone-lysine N-methyltransferase PRDM16 (PRDM16), phosphorylase b ki-nase regulatory subunit alpha (PHKA2), serine/threonine-protein kinase BRSK2 (BRSK2), Arf-GAP with coiled-coil (ACAP3), general transcription factor 3C polypep-tide 2 (GTF3C2), and guanine nucleotide exchange factor MSS4 (RABIF). In our study, the m6A RNA methylation-related genes in liver hepatocellular carcinoma were analyzed systematically, including the expression, interaction, function, and prognostic values, which provided an important theoretical basis for m6A RNA methylation in liver cancer. The nine important m6A-related genes could be prognostic markers in the survival time of patients.

CKAP2L Promotes Non-Small Cell Lung Cancer Progression through Regulation of Transcription Elongation.

Chromosomal instability (CIN) is a driver of clonal diversification and intratumor heterogeneity, providing genetic diversity that contributes to tumor progression. It is estimated that approximately 80% of solid cancers, including non-small cell lung cancer (NSCLC), exhibit features of CIN, which affects tumor growth and response to therapy. However, the molecular mechanisms connecting CIN to tumor progression are still poorly understood. Through an RNAi screen performed on genes involved in CIN and overexpressed in human lung adenocarcinoma samples, we identified the cytoskeleton-associated protein 2-like (CKAP2L) as a potential oncogene that promotes lung cancer proliferation and growth in vitro and in vivo. Mechanistically, CKAP2L directly interacted with RNA Pol II and regulated transcription elongation of key genes involved in spindle assembly checkpoint, chromosome segregation, cell cycle, and E2F signaling. Furthermore, depletion of CKAP2L increased the sensitivity of NSCLC cells to alvocidib, a pan-CDK inhibitor, leading to a significant reduction of cell proliferation and an increase in cell death. Altogether, these findings shed light on the molecular mechanisms through which CKAP2L, a protein involved in CIN, promotes cancer progression and suggest that its inhibition represents a novel therapeutic strategy in NSCLC. SIGNIFICANCE: These findings demonstrate the oncogenic function of CKAP2L through regulation of transcription elongation and suggest that targeting CKAP2L could enhance therapeutic response in patients with NSCLC.

A novel Q93H missense mutation in DCTN1 caused distal hereditary motor neuropathy type 7B and Perry syndrome from a Chinese family.

The Dynactin 1 (DCTN1) encodes the p150 subunit of dynactin, which engages retrograde axonal transport. Missense mutations in DCTN1 have been linked to a series of neurodegenerative diseases, including distal hereditary motor neuropathies (dHMN) and Perry syndrome. A few pathogenic DCTN1 mutations related with Perry syndrome have been described within, or adjacent to, the highly conserved N-terminal cytoskeleton-associated protein, glycine-rich (CAP-Gly) domain. But to our best knowledge, only the pathogenic G59S mutation in DCTN1 has been reported in dHMN7B families. Herein, we provided a novel heterozygous mutation in DCTN1 which caused both dHMN7B and Perry syndrome from a Chinese family. Whole exome sequencing (WES) was performed to identify the disease-associated genes. Single nucleotide variants (SNVs) and small insertions/deletions (INDELs) were further predicted with Mutation Taster, Polymorphism Phenotyping v2 (PolyPhen-2), and Sorting Intolerant From Tolerant (SIFT) and compared to the Single Nucleotide Polymorphism Database(dbSNP), Exome Aggregation Consortium (ExAC), and the 1000 Genomes Project. Furthermore, a novel missense mutation c.279G>C (Q93H) in DCTN1 was identified as the candidate loci. The mutation was confirmed with Sanger sequencing in the family members and cosegregated with various phenotypes. In silico analysis and molecular structural modeling, the mutation not only caused the loss of a hydrogen bond within the p150 protein but also affected the formation of hydrogen bonds between p150 and EB. Therefore, the new Q93H mutation in DCTN1 caused both familial dHMN7B and Perry syndrome. Our findings could expand the clinical and pathogenic spectrum and strengthen the clinical diagnostic role of the DCTN1 gene.

CHIP promotes Wnt signaling and regulates Arc stability by recruiting and polyubiquitinating LEF1 or Arc

The carboxyl terminus of Hsc70-interacting protein (CHIP), an E3 ubiquitin ligase, participates in many cellular processes such as protein degradation, trafficking, autophagy, apoptosis, and multiple signaling transductions. The mutant of CHIP (p.T246M) causes the spinocerebellar autosomal recessive 16 (SCAR16), a neurodegenerative disease characterized by spinocerebellar atrophy. Previous studies have shown that Wnt signaling and activity-regulated cytoskeleton-associated protein (Arc) play important roles in neurodegenerative diseases. However, the mechanisms by which CHIP regulates Wnt signaling and the stability of Arc that may affect SCAR16 are still unclear. We show that overexpression of CHIP promoted the activation of Wnt signaling, and enhanced the interaction between LEF1 and β-catenin through heightening the K63-linked polyubiquitin chains attached to LEF1, while the knockdown of CHIP had the opposite effect. Moreover, we verified that Wnt signaling was inhibited in the rat models of SCAR16 induced by the CHIP (p.T246M) mutant. CHIP also accelerated the degradation of Arc and regulated the interaction between Arc and GSK3β by heightening the K48- or K63-linked polyubiquitin chains, which further potentiated the interaction between GSK3β and β-catenin. Our data identify that CHIP is an undescribed regulator of Wnt signaling and Arc stability which may be related to the occurrence of SCAR16.

CKAP2L Knockdown Exerts Antitumor Effects by Increasing miR-4496 in Glioblastoma Cell Lines.

Despite advances in the diagnosis and treatment of the central nervous system malignancy glioma, overall survival remains poor. Cytoskeleton-associated protein 2-like (CKAP2L), which plays key roles in neural progenitor cell division, has also been linked to poor prognosis in lung cancer. In the present study, we investigated the role of CKAP2L in glioma. From bioinformatics analyses of datasets from The Cancer Gene Atlas and the Chinese Glioma Genome Atlas, we found that CKAP2L expression correlates with tumor grade and overall survival. Gene set enrichment analysis (GSEA) showed that MITOTIC_SPINDLE, G2M_CHECKPOINT, and E2F_TARGETS are crucially enriched phenotypes associated with high CKAP2L expression. Using U87MG, U118MG, and LNZ308 human glioma cells, we confirmed that CKAP2L knockdown with siCKAP2L inhibits glioma cell proliferation, migration, invasion, and epithelial-mesenchymal transition. Interestingly, CKAP2L knockdown also induced cell cycle arrest at G2/M phase, which is consistent with the GSEA finding. Finally, we observed that CKAP2L knockdown led to significant increases in miR-4496. Treating cells with exogenous miR-4496 mimicked the effect of CKAP2L knockdown, and the effects of CKAP2L knockdown could be suppressed by miR-4496 inhibition. These findings suggest that CKAP2L is a vital regulator of miR-4496 activity and that CKAP2L is a potentially useful prognostic marker in glioma.

Proteomic changes in Trypanosoma cruzi epimastigotes treated with the proapoptotic compound PAC-1

Apoptosis is a highly regulated process of cell death in metazoans. Therefore, understanding the biochemical changes associated with apoptosis-like death in Trypanosoma cruzi is key to drug development. PAC-1 was recently shown to induce apoptosis in T. cruzi; with this as motivation, we used quantitative proteomics to unveil alterations of PAC-1-treated versus untreated epimastigotes. The PAC-1 treatment reduced the abundance of putative vesicle-associated membrane protein, putative eukaryotic translation initiation factor 1 eIF1, coatomer subunit beta, putative amastin, and a putative cytoskeleton-associated protein. Apoptosis-like signaling also increases the abundance of proteins associated with actin cytoskeleton remodeling, cell polarization, apoptotic signaling, phosphorylation, methylation, ergosterol biosynthesis, vacuolar proteins associated with autophagy, and flagellum motility. We shortlist seventeen protein targets for possible use in chemotherapy for Chagas disease. Almost all differentially abundant proteins belong to a family of proteins previously associated with apoptosis in metazoans, suggesting that the apoptotic pathway's key functions have been preserved from trypanosomatids and metazoans. SignificanceApproximately 8 million people worldwide are infected with Trypanosoma cruzi. The treatment of Chagas disease comprises drugs with severe side effects, thus limiting their application. Thus, developing new pharmaceutical solutions is relevant, and several molecules targeting apoptosis are therapeutically efficient for parasitic, cardiac, and neurological diseases. Apoptotic processes lead to specific morphological features that have been previously observed in T. cruzi. Here, we investigate changes in epimastigotes' proteomic profile treated with the proapoptotic compound PAC-1, providing data concerning the regulation of both metabolic and cellular processes in nonmetazoan apoptotic cells. We shortlist seventeen protein target candidates for use in chemotherapy for Chagas disease.

Identification of Key Genes Associated with Changes in the Host Response to Severe Burn Shock: A Bioinformatics Analysis with Data from the Gene Expression Omnibus (GEO) Database.

BackgroundPatients with severe burns continue to display a high mortality rate during the initial shock period. The precise molecular mechanism underlying the change in host response during severe burn shock remains unknown. This study aimed to identify key genes leading to the change in host response during burn shock.MethodsThe GSE77791 dataset, which was utilized in a previous study that compared hydrocortisone administration to placebo (NaCl 0.9%) in the inflammatory reaction of severe burn shock, was downloaded from the Gene Expression Omnibus (GEO) database and analyzed to identify the differentially expressed genes (DEGs). Functional enrichment analyses of Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed. The protein–protein interaction (PPI) network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and then visualized in Cytoscape. In addition, important modules in this network were selected using the Molecular Complex Detection (MCODE) algorithm, and hub genes were identified in cytoHubba, a Cytoscape plugin.ResultsA total of 1059 DEGs (508 downregulated genes and 551 upregulated genes) were identified from the dataset. The DEGs enriched in GO terms and KEGG pathways were related to immune response. The PPI network contained 439 nodes and 2430 protein pairs. Finally, important modules and hub genes were identified using the different Cytoscape plugins. The key genes in burn shock were identified as arginase 1 (ARG1), cytoskeleton-associated protein (CKAP4), complement C3a receptor (C3AR1), neutrophil elastase (ELANE), gamma-glutamyl hydrolase (GGH), orosomucoid (ORM1), and quiescin sulfhydryl (QSOX1).ConclusionThe DEGs, functional terms and pathways, and hub genes identified in the present study can help shed light on the molecular mechanism underlying the changes in host response during burn shock and provide potential targets for early detection and treatment of burn shock.