MicroRNA-451a is a candidate biomarker and therapeutic target for major depressive disorder.

Background: Increasing evidence supports the role of microRNAs (miRNAs) in major depressive disorder (MDD), but the pathophysiological mechanism remains elusive. Aims: To explore the mechanism of microRNA-451a (miR-451a) in the pathology and behaviours of depression. Methods: Abnormal miRNAs such as miR-451a reported previously in the serum of patients with MDD were screened and then confirmed in a mouse model of depression induced by chronic restraint stress (CRS). Eight-week-old male C57BL/6 mice had miR-451a overexpression in the medial prefrontal cortex (mPFC) via adeno-associated virus serotype 9 vectors encoding a pri-mmu-miR-451a-GFP fusion protein followed by behavioural and pathological analyses. Finally, molecular biological experiments were conducted to investigate the potential mechanism of miR-451a against depression. Results: The serum levels of miRNA-451a were significantly lower in patients with MDD, with a negative correlation with the Hamilton Depression Scale scores. Additionally, a negative association between serum miR-451a and behavioural despair or anhedonia was observed in CRS mice. Notably, miR-451a expression was significantly downregulated in the mPFC of CRS-susceptible mice. Overexpressing miR-451a in the mPFC reversed the loss of dendritic spines and the depression-like phenotype of CRS mice. Mechanistically, miR-451a could inhibit CRS-induced corticotropin-releasing factor receptor 1 expression via targeting transcription factor 2, subsequently protecting dendritic spine plasticity. Conclusions: Together, these results highlighted miR-451a as a candidate biomarker and therapeutic target for MDD.

[Relationship between Yingyangbao consumption and anemia status among infants and young children in impoverish areas of Henan Province:a cross-sectional study based on latent class analysis].

OBJECTIVE: To explore latent classes of Yingyangbao(YYB) consumption among infants and young children in impoverished areas of Henan Province, and to analyze the relationship between these classes and anemia status. METHODS: We recruited 4433 children aged 6 to 24 months by multi-stage random sampling in 14 poverty-stricken counties of Henan Province between June and September 2018. We conducted hemoglobin concentration measurement among children and questionnaire survey among their caregivers. Then we used latent class analysis to classify the characteristics of YYB consumption among the children and two-level Logistic regression was used to explore relationship between YYB consumption and anemia status. RESULTS: The prevalence of anemia was 15.1% in poor areas of Henan Province in 2018. There were two latent classes of YYB consumption among children: the one was "effective consumption", latent class probability was 0.889; the other called "ineffective consumption", latent class probability was 0.111. Compared with effective consumption, children who never have consumed YYB(odds ratio(OR)=1.365, P<0.001) or were in "ineffective consumption" class(OR=1.265, P=0.034) were both positive related to anemia. CONCLUSION: Prevalence of anemia among children in impoverished areas has been significantly reduced since the launch of Program of Children's Nutrition Improvement in Impoverished Areas. Effective consumption is a key to ensuring YYB's anemia intervention effect.

[Relationship between 2-week prevalence of fever and diarrhea and Yingyangbao consumption among infants and young children in impoverished area of Henan Province].

OBJECTIVE: To identify the relationship between fever and diarrhea 2-week prevalence and Yingyangbao(YYB) effective consumption among infants and young children. METHODS: A total of 2952 infants and young children aged from 6 to 24 month in 10 impoverished counties of Henan province were selected by multi-stage random sampling between June and September 2017. To acquire 2-week prevalence information of infants and young children, their caregivers were investigated by self-made questionnaire. The structural equation model was utilized in multi-factor analysis. RESULTS: After adjusting potential confounders, YYB effective consumption reduced2-week prevalence of fever(ß=-0. 279, P=0. 001) and diarrhea(ß=-0. 182, P=0. 042) among infants and young children. Nutrition knowledge and YYB benefit cognition of caregivers reduced2-week prevalence of fever(γ=-0. 002, 95%CI-0. 004～-0. 001, P=0. 003) and diarrhea(γ=-0. 001, 95%CI-0. 003～0. 000, P=0. 049) indirectly through chain mediation path of "nutrition knowledge-YYB benfit cognition-YYB effective consumption-fever/diarrheal". CONCLUSION: YYB effective consumption can reduce 2-week prevalence of fever and diarrhea among infants and young children. Nutrition knowledge and YYB benefit cognition can improve YYB effective consumption and thus reduce 2-week prevalence of fever and diarrhea indirectly.

Telomerase activity measurement in magnetically captured epithelial cells: comparison of slab-gel and capillary electrophoresis.

We have compared telomerase activity measurements by slab-gel and capillary electrophoresis in cultured cells (A549 and H125 human cancer cell lines) and in cells isolated from clinical peripheral blood specimens epithelial cells of patients with lung and esophageal cancer. Telomerase activity was determined using the telomerase repeat amplification protocol (TRAP) assay with phosphoimager scanning of slab-gels and by laser-induced fluorescence capillary electrophoresis (LIF-CE). Experiments using A549 and H125 cells were performed to determine the reproducibility of each method and to identify the contribution of each stage of the TRAP/polymerase chain reaction (PCR) assay to the variability. In these experiments, it was found that more than half of the overall variability (coefficient of variation, CV = 35%) of the slab-gel method and almost all of the overall variability (CV = 20%) of the CE method was due to the PCR stage of the TRAP assay. In the clinical samples, classification as positive or negative was by visual inspection of the slab-gel and CE electropherograms for the presence of the characteristic 6 base-pair TRAP ladder and by GeneScan analysis of the CE. We examined several criteria including the use of 3, 4, or 5 TRAP bands as the definition of a positive test. Using the slab-gel method, the 5-band criterion gave 40% sensitivity with 100% specificity (no false positives in inactive controls). The CE method yielded a comparable 38% sensitivity and 100% specificity using this criterion. These data indicate that detection of telomerase activity in epithelial cells isolated from peripheral blood has a useful level of sensitivity and specificity and may be useful in the detection and monitoring of aerodigestive cancers. However, analysis by slab-gel is cumbersome and the precision is poor (inter-replicate CV = 20%) compared to LIF-CE (CV = 5%). A high-throughput CE-LIF detection platform will be indispensable for validation studies of telomerase activity measurements.

Telomere length and the expression of natural telomeric genes in human fibroblasts.

Progressive telomere shortening occurs with division of normal human cells, and eventually leads to replicative senescence. The mechanism by which the shortened telomeres cause growth arrest is largely unknown. Transcriptional silencing of genes adjacent to telomeres, also called telomere position effect, has been hypothesized as a possible mechanism of telomere-mediated senescence. However, there is no report regarding telomere position effect on natural telomeric genes in human cells. To address whether the expression of natural telomeric genes is regulated by telomere length, we combined quantitative RT-PCR with quantitative fluorescence in situ hybridization to comparatively analyze the expression of 34 telomeric genes and telomere length of their 24 corresponding chromosome ends in young and senescent human fibroblasts. We have demonstrated here that telomere length alone is not sufficient to determine the expression status of natural telomeric genes. An extended analysis of a tandem of eight telomeric genes on a single chromosome end revealed a discontinuous pattern of changed expression during telomere shortening and some of the changes are senescence-specific rather than non-dividing-related. These results suggest that the expression of natural telomeric genes may be influenced by alteration of local heterochromatin structure.

High-throughput analysis of telomerase by capillary electrophoresis.

The enzyme telomerase is expressed in (85-90)% of all human cancers, but not in normal, non-stem cell somatic tissues. Clinical assays for telomerase in easily obtained body fluids would have great utility as noninvasive, cost-effective methods for the early detection of cancer. The most commonly used method for the detection and quantification of telomerase enzyme activity is the polymerase chain reaction (PCR)-based assay known as the telomerase repeat amplification protocol or TRAP assay. Most of the TRAP assay systems use a slab-gel based electrophoresis system to size and quantify the PCR-amplified extension products. We are developing high-throughput capillary electrophoresis (CE) methods for the analysis of TRAP/PCR products. The TRAP assay was conducted on lysates of the human lung cancer cell line A-549 in reactions containing 5-100 cells. TRAP/PCR products were generated using a fluorescent 4,7,2'4'5'7',-hexachloro-6-carboxyfluorescein(HEX)-labeled TS primer and analyzed on the Applied Biosystems Model 310 CE system using POP4 polymer. After analysis with GeneScan and Genotyper software, the total peak areas of the TRAP ladder extension products were computed using Microsoft Excel. Results were compared with unlabeled TRAP/PCR products analyzed on the Bio-Rad BioFocus 3000 CE system using 6% high molecular weight polyvinylpyrrolidone (HMW PVP) polymer and SYBR Green I dye. Both CE systems were able to resolve the TRAP ladder products with high reproducibility and sensitivity (5-15 cells). With the appropriate robotic sample handling system, these CE methods would enable performing the telomerase TRAP assay with increased sensitivity, reproducibility and automation over slab-gel methods.

Coordinate late expression of trefoil peptide genes (pS2/TFF1 and ITF/TFF3) in human breast, colon, and gastric tumor cells exposed to X-rays.

The trefoil factors (TFFs) are pleiotropic factors involved in organization and homeostasis of the gastrointestinal tract, estrogen responsiveness, inflammatory disorders, and carcinogenesis. In an earlier study using cDNA array technologies to identify new genes expressed in irradiated cell survivors, we isolated a cDNA clone corresponding to the reported human TFF1 gene (E. K. Balcer-Kubiczek et al., Int. J. Radiat. Biol., 75: 529-541, 1999). To determine whether expression of other TFFs is altered by ionizing radiation, we quantified changes in expression of TFF3 as well as TFF1 in RNA samples obtained from irradiated and control human tumor breast, colon, and gastric tumor cells and examined expression kinetics up to 2 weeks after irradiation. X-ray-induced TFF1 and TFF3 expression profiles were compared with those induced by hydrogen peroxide (H2O2) or 17beta-estradiol (ES). The results revealed that TFF1 and TFF3 mRNA are coinduced by X-irradiation in a subset of the lines, but substantial heterogeneity in their responses was observed in cells derived from a single cell type. TFF1 and TFF3 transcriptional response to X-irradiation differed from that to H2O2 or ES in the timing of their induction as well as tissue-type dependence, i.e., their induction pattern after X-irradiation was late and sustained, whereas their induction by H2O2 or ES was early and transient. TFF1 mRNA, protein production in the cytoplasm, and secretion in the culture supernatant were coordinately regulated after X-irradiation. There was no requirement for TP53 in this induction. These results demonstrate the existence of a novel class of radiation-responsive genes that might be involved in bystander effects.