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OBJECTIVES: Although early-life dental care is crucial for preventing early childhood caries and has numerous benefits, the utilization rate of such care remains remarkably low worldwide, especially in families of low socioeconomic status. The aim of this study was to systematically review the scientific evidence relating to the effectiveness of interventions on improving early-life dental care utilization of very young children. METHOD AND MATERIALS: We reviewed scientific evidence relating to these positive changes, with 7 randomized controlled trials after qualitative evaluation. Interventions assessed included prenatal oral health promotion, motivational interviewing, intraoral camera use alongside social work consultations to aid in decreasing barriers to care, monetary incentives for tooth brushing, fluoride varnish applications, and probiotic usage. RESULTS: The intervention was significantly effective in reducing the incidence of dental caries among children, especially in caries risk. Caries reduction was significant when oral health information was provided at frequent intervals prenatally. Caries increment was also reduced when probiotics were introduced when administered daily. Interventions that attempted to increase parental involvement in oral health care by increasing motivation and decreasing barriers had inconclusive results within the study groups. CONCLUSIONS: Considering high rates ECC, early establishment and preservation of a dental home should be a focus in public health measures. Continuous monitoring and parental involvement are key components to maintaining healthy oral conditions. Future studies could explore and test various innovative strategies that utilize technological platforms to engage with parents and promote early-life dental care utilization among the underserved population.
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Objective: This study aimed to identify the salivary levels of six hormones (progesterone, estradiol, testosterone, cortisol, thyroxine T3, and triiodothyronine T4) in pregnant women, and to assess the association between salivary hormones, dental caries, and cariogenic microorganisms. Methods: This cross-sectional study included 181 low-income US pregnant women who were in their third trimester. Demographic details, oral hygiene practices, and medical backgrounds were obtained via questionnaires and medical records. Calibrated dentists obtained data on plaque index and caries status through comprehensive oral examinations. Unstimulated saliva was collected 2 h before eating and brushing. Salivary hormones were measured with a multiplex assay. Oral Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) were quantified via colony-forming unit (CFU) counts. A latent model was used to generate clusters of pregnant women based on salivary hormone levels, followed by post-clustering analysis. Factors associated with salivary cariogenic microorganisms were further evaluated via multiple regression analyses. Results: Estradiol, progesterone, testosterone, cortisol, T3, and T4 in saliva were detectable at rates of 92%, 97%, 77%, 99%, 71%, and 50%, respectively. Three distinct participant clusters (high, intermediate, and low) were identified based on salivary hormone levels. Intermediate-level and high-level clusters had increased numbers of decayed teeth, decayed surfaces, ICDAS scores, and salivary S. mutans and C. albicans, compared to the low-level cluster (p < 0.05). Covariate analysis demonstrated that the high-level cluster was positively associated with salivary carriage of S. mutans (CFU/mL) (p < 0.05). Participants with higher levels of progesterone, estradiol, testosterone, and cortisol were associated with a high carriage status of S. mutans in saliva (>105 CFU/mL) (p < 0.05). Conclusions: This study demonstrated the feasibility of detecting salivary hormones during pregnancy and revealed the positive association between salivary steroid hormones and cariogenic pathogens.
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To ensure effective administration of probiotics in clinical practice, it is crucial to comprehend the specific strains and their association with human health. Therefore, we conducted a systematic review and meta-analysis to evaluate the scientific evidence on the impact of Lactiplantibacillus plantarum probiotic consumption on human health. Out of 11,831 records, 135 studies were assessed qualitatively, and 18 studies were included in the meta-analysis. This systematic review demonstrated that probiotic supplementation with L. plantarum, either alone or in combination, can significantly improve outcomes for patients with specific medical conditions. Meta-analysis revealed notable benefits in periodontal health, evidenced by reduced pocket depth and bleeding on probing (p < 0.001); in gastroenterological health, marked by significant reductions in abdominal pain (p < 0.001); and in infectious disease, through a reduction in C-reactive protein levels (p < 0.001). Cardiovascular benefits included lowered total cholesterol and low-density lipoprotein cholesterol in the L. plantarum intervention group (p < 0.05). Our study's clinical significance highlights the importance of considering probiotic strain and their application to specific diseases when planning future studies and clinical interventions, emphasizing the need for further research in this area.
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PURPOSE: There is no approved targeted therapy for chordoma at present. Although several preclinical studies have implied the potential applicability of CDK4/6 inhibitor for this rare tumor, no clinical evidence has been documented so far. The purpose of this study was to elucidate the therapeutic efficacy of CDK4/6 inhibitor for chordoma. METHODS: The next generation sequencing (as for whole-exome sequencing, WES assay) and immunohistochemical (IHC) staining of the chordoma tissue from a patient with an advanced lesion were performed before treatment. Then, the patient was treated with Palbociclib for 4 months until progression occurred in the 5th month. Surgical resection was implemented and the tumor tissue was obtained postoperatively for assessment of molecular alterations. RESULTS: Molecular features of the tumor before medical treatment suggested applicability of CDK4/6 inhibitor and the patient showed partial response (PR) according to Choi Criteria after 4 months treating with Palbociclib until progression occurred. Then, a drastic molecular alteration of the tumor as represented by emergence of dramatic E2F amplification, which is known to induce CDK4/6 independent cell-cycle entry and progression after treatment, was detected. The findings in this patient demonstrated tumor evolution under drug pressure. CONCLUSION: The findings of the present study suggest the feasibility of Palbociclib for the clinical treatment of chordoma, and imply the necessity of combination therapies rather single drug administration due to the quick resistance of the tumor to Palbociclib treatment.
Subject(s)
Chordoma , Piperazines , Humans , Retrospective Studies , Chordoma/drug therapy , Chordoma/genetics , Chordoma/pathology , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Pyridines , Cyclin-Dependent Kinase 4/genetics , Protein Kinase Inhibitors/pharmacologyABSTRACT
Ecological approaches can help to correct oral microbial dysbiosis and drive the advent and persistence of a symbiotic oral microbiome, which benefits long-term dental caries control. The aim of this study was to investigate the impact of the prebiotic Galacto-oligosaccharide (GOS) on the growth of probiotics L. plantarum 14,917 and its effect on the inhibitory ability of L. plantarum 14,917 against the growth of Streptococcus mutans and Candida albicans in an in vitro model. Single-species growth screenings were conducted in TSBYE broth with 1% glucose and 1-5% GOS. Interaction experiments were performed using duo- and multi-species models with inoculation of 105 CFU/mL S. mutans, 103 CFU/mL C. albicans, and 108 CFU/mL L. plantarum 14,917 under 1%, 5% GOS or 1% glucose. Viable cells and pH changes were measured. Real-time PCR was utilized to assess expression of C. albicans and S. mutans virulence genes. Six replicates were used for each group. Student's t-test, one-way ANOVA, and Kruskal-Wallis were employed to compare the outcomes of different groups. GOS significantly inhibited the growth of C. albicans and S. mutans in terms of growth quantity and speed when the two strains were grown individually. However, GOS did not affect the growth of L. plantarum 14,917. Moreover, 1% and 5% GOS enhanced the anti-fungal performance of L. plantarum 14,917 in comparison to 1% glucose. GOS as the carbon source resulted in a less acidic environment in the C. albicans and S. mutans duo-species model and multispecies model where L. plantarum 14,917 was added. When GOS was utilized as the carbohydrate substrate, S. mutans and C. albicans had a significant reduction in the expression of the HWP1, ECE1, atpD, and eno genes (p < 0.05). To our knowledge, this is the first study that reported the ability of GOS to neutralize S. mutans-C. albicans high caries of medium pH and to disrupt virulence gene expression. Moreover, as a prebiotic, GOS augmented the inhibitory ability of L. plantarum against C. albicans in vitro. The current study revealed the anti-caries potential of prebiotics GOS and shed light on novel caries prevention strategies from the perspective of prebiotics and probiotics. These findings provide a rationale for future biofilm or clinical studies to elucidate the effect of GOS on modulating oral microbiota and caries control.
Subject(s)
Dental Caries , Lactobacillus plantarum , Humans , Cariostatic Agents , Dental Caries/prevention & control , Prebiotics , Oligosaccharides/pharmacology , Candida albicans , GlucoseABSTRACT
Dental caries is one of the most common chronic diseases worldwide. Streptococcus mutans and Candida albicans are two major pathogens associated with dental caries. Several recent studies revealed that Lactobacillus plantarum inhibits S. mutans and C. albicans in biofilms and in a rodent model of dental caries. The aim of this study was to investigate the dose-dependent effect of L. plantarum against S. mutans and C. albicans in a planktonic model that simulated a high-caries-risk clinical condition. Mono-, dual-, and multi-species models were utilized, with five doses of L. plantarum (ranging from 1.0 × 104 to 1.0 × 108 CFU/mL). Real-time PCR was used to assess the expression of the virulence genes of C. albicans and S. mutans and the genes of L. plantarum. Student's t-tests and one-way ANOVA, followed by post hoc tests, were employed to compare the cell viability and gene expression among groups. A dose-dependent inhibition on C. albicans and S. mutans was observed with increased dosages of L. plantarum. L. plantarum at 108 CFU/mL demonstrated the highest antibacterial and antifungal inhibitory effect in the dual- and multi-species models. Specifically, at 20 h, the growth of C. albicans and S. mutans was suppressed by 1.5 and 5 logs, respectively (p < 0.05). The antifungal and antibacterial effects were attenuated in lower doses of L. plantarum (104-107 CFU/mL). The expression of C. albicans HWP1 and ECE 1 genes and S. mutans lacC and lacG genes were significantly downregulated with an added 108 CFU/mL of L. plantarum (p < 0.05). The addition of 108 CFU/mL L. plantarum further inhibited the hyphae or pseudohyphae formation of C. albicans. In summary, L. plantarum demonstrated dose-dependent antifungal and antibacterial effects against C. albicans and S. mutans. L. plantarum emerged as a promising candidate for the creation of novel antimicrobial probiotic products targeting dental caries prevention. Further research is warranted to identify the functional metabolites produced by L. plantarum at different dosages when interacting with C. albicans and S. mutans.
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Papillary thyroid carcinoma (PTC), a common malignancy, poses a threat to human health. It has been identified that tRNA-derived fragments (tRFs) can be new putative biomarkers and targets for cancer treatment. The object of this research was to investigate the biological role and mechanism of main tRF-18-H7PU4HD2 (tRF-18) in PTC. The biological effects of tRF-18 on PTC cell proliferation and apoptosis were explored by Cell Counting Kit-8 assays, colony formation assays, and flow cytometry analysis. Additionally, Western blot analysis was performed to quantify protein levels of apoptotic markers in PTC cells. Moreover, xenograft model in nude mice was established to investigate the impact of tRF-18 on tumor growth in vivo. The interaction between tRF-18 and messenger RNA kinesin family member 1B (KIF1B) was validated via RNA immunoprecipitation assays and luciferase reporter assays. tRF-18 exhibited high expression in PTC tissues. Further, the upregulation of tRF-18 was also detected in TPC-1 and IHH4 cell lines. Importantly, tRF-18 inhibition restrained PTC cell proliferation and promoted cell apoptosis. In addition, tRF-18 inhibition suppressed xenograft tumor growth. Mechanistically, tRF-18 was confirmed to target KIF1B and negatively regulate KIF1B expression in PTC cells. tRF-18 facilitates PTC cell proliferation and inhibits cell apoptosis by targeting KIF1B.
Subject(s)
Carcinoma, Papillary , MicroRNAs , Thyroid Neoplasms , Animals , Apoptosis/genetics , Carcinoma, Papillary/genetics , Carcinoma, Papillary/metabolism , Carcinoma, Papillary/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Humans , Kinesins/genetics , Mice , Mice, Nude , MicroRNAs/genetics , RNA, Transfer , Thyroid Cancer, Papillary/genetics , Thyroid Cancer, Papillary/metabolism , Thyroid Neoplasms/genetics , Thyroid Neoplasms/metabolism , Thyroid Neoplasms/pathologyABSTRACT
Methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1 like (MTHFD1L) is a mitochondrial enzyme involved in the synthesis of tetrahydrofolate (THF). This study aimed to investigate the effect of MTHFD1L in papillary thyroid cancer (PTC). Tumor tissues and adjacent tissues from 11 patients with PTC were collected, the expression level of MTHFD1L mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cancer genome atlas (TCGA) database was used for analysis MTHFD1L differentially expressed between tumor tissue and adjacent tissues. MTHFD1L was knocked down by a lentivirus-based system and CRISPR-Cas9. Affymetrix genechip human transcriptome array 2.0 was used to assess gene expression. Cell growth and motility were evaluated in vivo and in vitro. Cell apoptosis and cell cycle were investigated by flow cytometry assay. The expression levels of proteins were detected by western blotting. MTHFD1L mRNA and protein expression levels significantly increased in tumor tissues and CAL-62, K1 and TPC-1 cell lines. After knockdown MTHFD1L, the growth of cells were reduced while cell apoptosis was increased. In addition, tumor growth was inhibited after MTHFD1L knockdown in nude mice. Affymetrix genechip human transcriptome array 2.0 was founded that MTHFD1L knockdown can inhibit the expression levels of CCND1 and Notch2. Furthermore, we identified that MTHFD1L knockdown inhibited cells growth and induced cell apoptosis in PTC. Importantly, MTHFD1L knockdown decreased the expression levels of Notch2, Hes1 CCND1, Bcl-2, and PCNA protein, whereas the level of Bax increased. Our study suggested MTHFD1L knockdown could diminished PTC cell proliferation. MTHFD1L serves as a valuable therapeutic target.
Subject(s)
Thyroid Neoplasms , Animals , Apoptosis/genetics , Cell Cycle/genetics , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Humans , Mice , Mice, Nude , RNA, Messenger , Thyroid Cancer, Papillary/genetics , Thyroid Cancer, Papillary/metabolism , Thyroid Neoplasms/genetics , Thyroid Neoplasms/metabolism , Thyroid Neoplasms/pathologyABSTRACT
Increasing evidence suggests the involvement of microRNA-381 (miR-381) in chemoresistance of cancer treatment. However, its function and molecular mechanisms in breast cancer chemoresistance are still not well elucidated. In the present study, we aimed to investigate the functional role of miR-381 in cisplatin (DDP) resistance of breast cancer and discover the underlying molecular mechanism. The expression levels of miR-381 and MDR1 were detected by quantitative real-time PCR (qRT-PCR) and Western blot analysis in breast cancer tissues and cell lines. The DDP sensitivity and cell apoptosis of breast cancer cells were determined by MTT assay and flow cytometric analysis, respectively. The relationship between miR-381 and MDR1 was explored by target prediction and luciferase reporter analysis. miR-381 was decreased in DDP-resistant breast cancer tissues and cell lines. Low miR-381 expression was correlated with poor prognosis of breast cancer patients. miR-381 overexpression improved DDP sensitivity of MCF-7/DDP and MDA-MB-231/DDP cells. Conversely, miR-381 inhibition lowered the response of MCF-7 and MDA-MB-231 to DPP. Moreover, miR-381 could directly suppress multidrug resistance 1 (MDR1) expression. MDR1 knockdown could overcome DDP resistance in MCF-7/DDP and MDA-MB-231/DDP cells, while MDR1 overexpression led to DDP resistance in MCF-7 and MDA-MB-231 cells. Notably, MDR1 overexpression counteracted the inductive effect of miR-381 mimics on DDP sensitivity of MCF-7/DDP and MDA-MB-231/DDP cells. On the contrary, miR-381 inhibition-mediated DDP resistance in MCF-7 and MDA-MB-231 cells was reversed by MDR1 knockdown. In summary, miR-381 could overcome DDP resistance of breast cancer by directly targeting MDR1, providing a novel therapeutic target for breast cancer chemoresistance.
Subject(s)
Breast Neoplasms/genetics , Cisplatin/pharmacology , Drug Resistance, Neoplasm/genetics , MicroRNAs/metabolism , ATP Binding Cassette Transporter, Subfamily B/metabolism , Base Sequence , Cell Line, Tumor , Down-Regulation/drug effects , Down-Regulation/genetics , Drug Resistance, Neoplasm/drug effects , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , MicroRNAs/geneticsABSTRACT
Nonsense-mediated mRNA decay (NMD) is essential for removing premature termination codon-containing transcripts from cells. Studying the NMD pathway in model organisms can help to elucidate the NMD mechanism in humans and improve our understanding of how this biologically important process has evolved. Ciliates are among the earliest branching eukaryotes; their NMD mechanism is poorly understood and may be primordial. We demonstrate that highly conserved Upf proteins (Upf1a, Upf2 and Upf3) are involved in the NMD pathway of the ciliate, Tetrahymena thermophila. We further show that a novel protozoa-specific nuclease, Smg6L, is responsible for destroying many NMD-targeted transcripts. Transcriptome-wide identification and characterization of NMD-targeted transcripts in vegetative Tetrahymena cells showed that many have exon-exon junctions downstream of the termination codon. However, Tetrahymena may lack a functional exon junction complex (EJC), and the Tetrahymena ortholog of an EJC core component, Mago nashi (Mag1), is dispensable for NMD. Therefore, NMD is EJC independent in this early branching eukaryote.
Subject(s)
Nonsense Mediated mRNA Decay , Protozoan Proteins/physiology , RNA, Messenger/metabolism , Ribonucleases/physiology , Tetrahymena thermophila/genetics , Amino Acid Sequence , Conserved Sequence , Exons , RNA, Protozoan/metabolism , Tetrahymena thermophila/enzymology , TranscriptomeABSTRACT
Inositol hexaphosphate (IP6) and inositol (Ins), naturally occurring carbohydrates present in most mammals and plants, inhibit the growth of numerous cancers both in vitro and in vivo. In this study, we first examined the anti-metastatic effects of IP6 and Ins using a liver metastasis model of colorectal cancer (CRC) in BALB/c mice. CT-26 cells were injected into the splenic capsule of 48 BALB/c mice. The mice were then randomly divided into four groups: IP6, Ins, IP6 + Ins and normal saline control (n = 12 per group). IP6 and/or Ins (80 mg/kg each, 0.2 mL/day) were injected into the gastrointestinal tracts of the mice on the second day after surgery. All mice were sacrificed after 20 days, and the tumor inhibition rates were determined. The results demonstrated that the tumor weights of liver metastases and the tumor inhibition rates were reduced in the experimental groups compared to the control group and that treatment with the combination of IP6 and Ins resulted in greater inhibition of tumor growth than treatment with either compound alone. These findings suggest that IP6 and Ins prevent the development and metastatic progression of colorectal cancer to the liver in mice by altering expression of the extracellular matrix proteins collagen IV, fibronectin and laminin; the adhesion factor receptor integrin-ß1; the proteolytic enzyme matrix metalloproteinase 9; and the angiogenic factors vascular endothelial growth factor, basic fibroblast growth factor, and transforming growth factor beta in the tumor metastasis microenvironment. In conclusion, IP6 and Ins inhibited the development and metastatic progression of colorectal cancer to the liver in BALB/c mice, and the effect of their combined application was significantly greater than the effect of either compound alone. This evidence supports further testing of the combined application of IP6 and Ins for the prevention of colorectal cancer metastasis to the liver in clinical studies.
Subject(s)
Adenocarcinoma/drug therapy , Colorectal Neoplasms/pathology , Inositol/therapeutic use , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Phytic Acid/therapeutic use , Adenocarcinoma/pathology , Adenocarcinoma/prevention & control , Adenocarcinoma/secondary , Animals , Colorectal Neoplasms/drug therapy , Female , Inositol/administration & dosage , Mice , Mice, Inbred BALB C , Neoplasm Metastasis/prevention & control , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Neoplasms, Experimental/secondary , Phytic Acid/administration & dosage , Random AllocationABSTRACT
BACKGROUND: The prevalence of dementia differs among racial groups, the highest prevalence being in Latin America (8.5%) compared to sub-Saharan African regions (2-4%). The most common type of dementia is Alzheimer's disease (AD). OBJECTIVE: To estimate the prevalence of AD in the Qinghai-Tibet plateau and to investigate the related factors. METHODS: This was a cross-sectional, multistage cluster sampling design survey. Data was collected from May 2014 to September 2014 from 4,060 Tibetan aged >60 years. Participants underwent clinical examinations and neuropsychological evaluations. MALDI-TOF was used to test the genotypes of CLU, TFAM, TP53INP1, IGHV1-67, CR1, ApoE, and BIN1. Logistic regression models were used to ascertain the associations with AD. RESULTS: The prevalence of AD among Tibetan individuals aged >60 years was 1.33% (95% CI: 0.98-1.69). The CLU haplotypes AA+GA (odds ratio (OR)â=â4.483; 95% CI: 1.069-18.792) of rs2279590 was correlated with AD. The CLU haplotypes GG+GC (ORâ=â0.184; 95% CI: 0.038-0.888) of rs9331888 and kowtow (ORâ=â0.203; 95% CI 0.046-0.896) were negatively correlated with AD. CONCLUSION: A low prevalence of AD was found in Tibetans from the Qinghai-Tibet plateau. Multivariate analysis might suggest that regular "mind-body" religious meditative activities may be negatively associated with AD in this population, as well as the CLU genotype at rs9331888.
Subject(s)
Alzheimer Disease , Clusterin/genetics , Genetic Predisposition to Disease/genetics , Polymorphism, Single Nucleotide/genetics , Religion , Aged , Aged, 80 and over , Alzheimer Disease/complications , Alzheimer Disease/epidemiology , Alzheimer Disease/genetics , Alzheimer Disease/psychology , Cognition Disorders/diagnosis , Cognition Disorders/etiology , Cross-Sectional Studies , Female , Genetic Association Studies , Genetic Predisposition to Disease/epidemiology , Humans , Logistic Models , Male , Middle Aged , Neuropsychological Tests , Psychiatric Status Rating Scales , Risk Factors , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tibet/epidemiology , Tibet/ethnologyABSTRACT
BACKGROUND: The ciliated protozoan Tetrahymena thermophila is a well-studied single-celled eukaryote model organism for cellular and molecular biology. However, the lack of extensive T. thermophila cDNA libraries or a large expressed sequence tag (EST) database limited the quality of the original genome annotation. METHODOLOGY/PRINCIPAL FINDINGS: This RNA-seq study describes the first deep sequencing analysis of the T. thermophila transcriptome during the three major stages of the life cycle: growth, starvation and conjugation. Uniquely mapped reads covered more than 96% of the 24,725 predicted gene models in the somatic genome. More than 1,000 new transcribed regions were identified. The great dynamic range of RNA-seq allowed detection of a nearly six order-of-magnitude range of measurable gene expression orchestrated by this cell. RNA-seq also allowed the first prediction of transcript untranslated regions (UTRs) and an updated (larger) size estimate of the T. thermophila transcriptome: 57 Mb, or about 55% of the somatic genome. Our study identified nearly 1,500 alternative splicing (AS) events distributed over 5.2% of T. thermophila genes. This percentage represents a two order-of-magnitude increase over previous EST-based estimates in Tetrahymena. Evidence of stage-specific regulation of alternative splicing was also obtained. Finally, our study allowed us to completely confirm about 26.8% of the genes originally predicted by the gene finder, to correct coding sequence boundaries and intron-exon junctions for about a third, and to reassign microarray probes and correct earlier microarray data. CONCLUSIONS/SIGNIFICANCE: RNA-seq data significantly improve the genome annotation and provide a fully comprehensive view of the global transcriptome of T. thermophila. To our knowledge, 5.2% of T. thermophila genes with AS is the highest percentage of genes showing AS reported in a unicellular eukaryote. Tetrahymena thus becomes an excellent unicellular model eukaryote in which to investigate mechanisms of alternative splicing.
Subject(s)
Gene Expression Profiling/methods , RNA, Protozoan/genetics , Sequence Analysis, RNA/methods , Tetrahymena thermophila/genetics , Genes, Protozoan , Molecular Sequence Annotation , TranscriptomeABSTRACT
ATP-binding cassette transporters (ABCT) could generate multiple transcripts through alternative splicing (AS) in mammalian. Some AS introduced PTC (premature terminal codon)-containing isoforms of ABCT couple with NMD (nonsense-mediated mRNA decay) to regulate relevant functions. However, there are no similar reports in lower organisms. This paper focuses on the unicellular protozoa Tetrahymena thermophila, based on the RNA-seq data of Tetrahymena thermophila, identified two alternative splicing variants of gene ABCC10 (SV1 and SV2). The SV2 contained an intron retention event at the fifth intron, and this 49 bp intron resulted in shift-frame and introduced PTC. Then, a knock-down Tetrahymena strain of gene UPF1 which is a key factor of NMD was constructed, and the expression levels of SV2 were performed using a real-time quantitative PCR. The results showed the expression levels of SV2 were up-regulated significantly in knock-down strain, indicating that SV2 was targeted by NMD, which is consistent to the mechanism which the AS introduced PTC-containing isoforms of ABCC proteins can be targeted by NMD in mammalian. Thus, we infer that this mechanism is highly evolutionary conserved in eukaryotes and was already functional in the last eukaryotic common ancestor.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Alternative Splicing , Tetrahymena thermophila/genetics , ATP-Binding Cassette Transporters/metabolism , Base Sequence , Introns , Molecular Sequence Data , Nonsense Mediated mRNA Decay , Tetrahymena thermophila/metabolismABSTRACT
BACKGROUND: Genome-wide expression data of gene microarrays can be used to infer gene networks. At a cellular level, a gene network provides a picture of the modules in which genes are densely connected, and of the hub genes, which are highly connected with other genes. A gene network is useful to identify the genes involved in the same pathway, in a protein complex or that are co-regulated. In this study, we used different methods to find gene networks in the ciliate Tetrahymena thermophila, and describe some important properties of this network, such as modules and hubs. METHODOLOGY/PRINCIPAL FINDINGS: Using 67 single channel microarrays, we constructed the Tetrahymena gene network (TGN) using three methods: the Pearson correlation coefficient (PCC), the Spearman correlation coefficient (SCC) and the context likelihood of relatedness (CLR) algorithm. The accuracy and coverage of the three networks were evaluated using four conserved protein complexes in yeast. The CLR network with a Z-score threshold 3.49 was determined to be the most robust. The TGN was partitioned, and 55 modules were found. In addition, analysis of the arbitrarily determined 1200 hubs showed that these hubs could be sorted into six groups according to their expression profiles. We also investigated human disease orthologs in Tetrahymena that are missing in yeast and provide evidence indicating that some of these are involved in the same process in Tetrahymena as in human. CONCLUSIONS/SIGNIFICANCE: This study constructed a Tetrahymena gene network, provided new insights to the properties of this biological network, and presents an important resource to study Tetrahymena genes at the pathway level.
Subject(s)
Gene Regulatory Networks/genetics , Tetrahymena thermophila/genetics , Animals , Ciliophora Infections/genetics , Genes, Protozoan/genetics , Humans , Life Cycle Stages/genetics , Proteasome Endopeptidase Complex/genetics , Sequence Homology, Nucleic Acid , Tetrahymena thermophila/growth & developmentABSTRACT
Tetrahymena thermophila is a model eukaryotic organism. Functional genomic analyses in Tetrahymena present rich opportunities to address fundamental questions of cell and molecular biology. The Tetrahymena Gene Expression Database (TGED; available at http://tged.ihb.ac.cn) is the first expression database of a ciliated protozoan. It covers three major physiological and developmental states: growth, starvation, and conjugation, and can be accessed through a user-friendly web interface. The gene expression profiles and candidate co-expressed genes for each gene can be retrieved using Gene ID or Gene description searches. Descriptions of standardized methods of sample preparation and the opportunity to add new Tetrahymena microarray data will be of great interest to the Tetrahymena research community. TGED is intended to be a resource for all members of the scientific research community who are interested in Tetrahymena and other ciliates.