Whole-transcriptome sequencing uncovers core regulatory modules and gene signatures of human fetal growth restriction

Background

Fetal growth restriction (FGR) contributes the primary cause of perinatal mortality and morbidity with impacts on the long-term health. To determine the core gene expression network and gene signatures, which in combination with ultrasound confirmation will more effectively differentiate constitutionally normal small for gestational age and pathological FGR groups, we performed RNA sequencing for protein-coding genes, lncRNAs, and small RNAs in a case–control study of umbilical cord blood.

Results

Five pairs of FGR case and control umbilical cord blood samples were used for RNA sequencing and weighted gene co-expression network analysis (WGCNA). Results showed that 339 mRNAs, 295 lncRNAs, and 13 miRNAs were significantly differentially expressed between FGR cases and controls. Bioinformatics analysis indicated that these differentially expressed molecules were mainly involved in metabolism, neural, cardiac, and immune systems, and identified 18 WGCNA modules for FGR. Further quantitative verification was performed using umbilical cord blood and maternal peripheral blood from 12 pairs of FGR cases and controls. The logistic regression and receiver operating characteristic curve indicated that RP11_552M6.1, LINC01291, and Asgr1 in umbilical cord blood, while Sfrp2, miR-432-5p, and miR-1306-3p in maternal peripheral blood had potential significance for FGR.

Conclusions

We comprehensively profiled the whole-transcriptome landscape of human umbilical cord blood with FGR, constructed the core WGCNA modules, and delineated the critical gene signatures of FGR. These findings provide key insight into intrauterine perturbations and candidate signatures for FGR.

Linc1557 is critical for the initiation of embryonic stem cell differentiation by directly targeting the LIF/STAT3 signaling pathway

Embryonic stem cells (ESCs) have self-renewal and multi-lineage differentiation potential and perform critical functions in development and biomedicine. Several long noncoding RNAs (lncRNAs) have been reported as key regulators of stem cell pluripotency and differentiation. However, the function and regulatory mechanism of lncRNAs during the initiation of ESC differentiation remains unclear. Here, we found that linc1557 was highly expressed in mouse ESCs and required for the initiation of ESC differentiation. Knockdown of linc1557 increased the expression and phosphorylation levels of signal transducer and activator of transcription 3 (STAT3), a key factor in the leukemia inhibitory factor (LIF)/STAT3 signaling pathway. Furthermore, we found that linc1557 directly bound to Stat3 mRNA and affected its stability. The differentially expressed transcriptome after linc1557 knockdown in ESCs was involved primarily in multicellular organism development and cell differentiation as similar to that after Stat3 knockdown. Moreover, either knockdown of Stat3 or addition of a LIF/STAT3 signaling inhibitor rescued the suppressive effects of linc1557 knockdown on the initiation of mouse ESC differentiation. These findings not only elucidated the critical function of linc1557 in the initiation of mouse ESC differentiation but also clarified that its specific mechanism as directly affecting Stat3 mRNA stability, which enhanced the understanding of the lncRNA-mediated regulatory mechanism for mRNA stability and key signaling pathways in ESC pluripotency and differentiation.

[The efficacy and safety of tiotropium/olodaterol fixed-dose combination in Chinese patients with chronic obstructive pulmonary disease: a pooled subgroup analysis of TONADO 1+2]

Objective: To compare the efficacy and safety profiles of tiotropium/olodaterol with the mono-components in Chinese and total study population from TONADO trial. Methods: In the replicate, double-blind, parallel-group, active-controlled, randomized, 52-week, Phase Ⅲ TONADO studies (TONADO 1+2), patients received tiotropium/olodaterol, tiotropium, or olodaterol via the Respimat(®) Inhaler (Boehringer Ingelheim, Germany). Primary end points were forced expiratory volume in 1 second (FEV(1)) area under the curve from 0 to 3 hours (AUC(0-3h)) response and trough FEV(1) response, and St George's respiratory questionnaire (SGRQ) total score at 24 weeks. Adverse events were also collected. This subgroup analysis only focused on the efficacy and safety of the drug at the approved dose in China. Results: 548 Chinese patients were randomized, aged 41 to 82 years [mean age, (63±8) years] and most were male (526, 96%), 111 received tiotropium/olodaterol 5/5 μg, and 127 received tiotropium 5 μg and 95 received olodaterol 5 μg. The baseline characteristics of these groups were similar. After 24 weeks, treatment with tiotropium/olodaterol 5/5 μg, tiotropium 5 μg and olodaterol 5 μg resulted in an adjusted mean FEV(1) AUC(0-3h) response of 0.240, 0.157 and 0.079 L, and trough FEV(1) response of 0.117, 0.068 and-0.001 L, respectively. Tiotropium/olodaterol 5/5 μg significantly improved SGRQ scores in Chinese patients compared with olodaterol 5 μg (32.729 and 37.202, respectively). Generally, the safety profile of tiotropium/olodaterol was comparable with mono-components in 52 weeks. Conclusion: Compared with tiotropium or olodaterol, tiotropium/olodaterol in Chinese patients provided significant improvement in lung function and quality of life, and the safety profiles were similar.

Pwp1 regulates telomere length by stabilizing shelterin complex and maintaining histone H4K20 trimethylation

Telomere maintenance is critical for chromosome stability. Here we report that periodic tryptophan protein 1 (PWP1) is involved in regulating telomere length homeostasis. Pwp1 appears to be essential for mouse development and embryonic stem cell (ESC) survival, as homozygous Pwp1-knockout mice and ESCs have never been obtained. Heterozygous Pwp1-knockout mice had shorter telomeres and decreased reproductive capacity. Pwp1 depletion induced rapid telomere shortening accompanied by reduced shelterin complex and increased DNA damage in telomeric regions. Mechanistically, PWP1 bound and stabilized the shelterin complex via its WD40 domains and regulated the overall level of H4K20me3. The rescue of telomere length in Pwp1-deficient cells by PWP1 overexpression depended on SUV4-20H2 co-expression and increased H4K20me3. Therefore, our study revealed a novel protein involved in telomere homeostasis in both mouse and human cells. This knowledge will improve our understanding of how chromatin structure and histone modifications are involved in maintaining telomere integrity.

P6534Prognostic implication of serum cystatin C and creatinine-based glomerular filtration rate ratio in coronary disease patients receiving PCI: a surrogate of low muscle mass and a predictor of mortality

Background

Low muscle mass results in impaired exercise capacity and is related with poor prognosis in chronic diseases. Although the ratio of serum creatinine (Scr) to cystatin C (Scys) is known as a surrogate marker of body muscle mass, the value of this marker is unclear in the patients with coronary artery disease (CAD).

Purpose

We assessed the clinical significance of two markers representing body muscle mass, the ratio of Scr to Scys (Scr/Scys), and ratio of estimated glomerular filtration rate by Scys to Scr (eGFRcys/eGFRcr).

Methods

We analyzed patients enrolled in a single tertiary center prospective percutaneous coronary intervention (PCI) registry that had Scr and Scys levels simultaneously measured before PCI. Optimal cut-off values of Scr/Scys and eGFRcys/eGFRcr, and their prognostic impact on 3-year mortality after PCI were analyzed. Subgroup analysis according to various demographics and risk factors was performed.

Results

A total of 1,928 patients who underwent PCI for significant CAD were analyzed (age 65.2±9.9 years, 70.8% men). Both Scr/Scys and eGFRcys/eGFRcr showed strong correlation with estimated proportion of muscle mass. Cut-off values of Scr/Scys discriminating 3-year death were 1.0 for men and 0.8 for women, while those of eGFRcys/eGFRcr were 1.1 for men and 1.0 for women. Both Scr/Scys- and eGFRcys/eGFRcr-based low muscle mass groups showed significantly higher risk of death, after adjusting for 7 selected covariates including age. The additional discriminative power of low muscle mass group on the predictive model was greater in the group determined by eGFRcys/eGFRcr than Scr/Scys. Low eGFRcys/eGFRcr values showed additional prognostic impact especially in patients older than 65 years, non-obese, men, chronic kidney disease, and current smokers.

Conclusions

Low muscle mass was an independent prognostic indicator in the patients who underwent coronary stenting. eGFRcys/eGFRcr was identified as a useful surrogate of muscle mass, which may be used to detect vulnerable patients with low muscle mass at high risk for future events.

Acknowledgement/Funding

None

LincRNA-1614 coordinates Sox2/PRC2-mediated repression of developmental genes in pluripotency maintenance

Large-intergenic noncoding RNAs (lincRNAs) cooperate with core transcription factors to coordinate the pluripotency network of embryonic stem cells. The mechanisms by which lincRNAs affect chromatin structure and gene transcription remain mostly unknown. Here, we identified that a lincRNA (linc1614), occupied by pluripotency factors at its promoter, was indispensable for both maintenance and acquisition of pluripotency. Linc1614 served as a specific partner of core factor Sox2 in maintaining pluripotency, primarily by mediating the function of Sox2 in the repression of developmental genes. Moreover, Ezh2, an essential subunit of polycomb repressive complex 2 (PRC2), physically interacted with linc1614 and contributed to lincRNA-mediated transcriptional silencing. Thus, we propose that the interplay of linc1614 with Sox2 implicates this lincRNA as a recruitment platform that mediates transcriptional silencing by guiding the PRC2 complex to the loci of developmental genes.