Background: Cell‐free messenger RNA (cf‐mRNA) and long non‐coding RNA (cf‐lncRNA) are becoming increasingly important in liquid biopsy by providing biomarkers for disease prediction, diagnosis and prognosis, but the simultaneous characterization of coding and non‐coding RNAs in human biofluids remains challenging.Methods: Here, we developed polyadenylation ligation‐mediated sequencing (PALM‐Seq), an RNA sequencing strategy employing treatment of RNA with T4 polynucleotide kinase to generate cell‐free RNA (cfRNA) fragments with 5′ phosphate and 3′ hydroxyl and RNase H to deplete abundant RNAs, achieving simultaneous quantification and characterization of cfRNAs.Results: Using PALM‐Seq, we successfully identified well‐known differentially abundant mRNA, lncRNA and microRNA in the blood plasma of pregnant women. We further characterized cfRNAs in blood plasma, saliva, urine, seminal plasma and amniotic fluid and found that the detected numbers of different RNA biotypes varied with body fluids. The profiles of cf‐mRNA reflected the function of originated tissues, and immune cells significantly contributed RNA to blood plasma and saliva. Short fragments (<50 nt) of mRNA and lncRNA were major in biofluids, whereas seminal plasma and amniotic fluid tended to retain long RNA. Body fluids showed distinct preferences of pyrimidine at the 3′ end and adenine at the 5′ end of cf‐mRNA and cf‐lncRNA, which were correlated with the proportions of short fragments.Conclusion: Together, PALM‐Seq enables a simultaneous characterization of cf‐mRNA and cf‐lncRNA, contributing to elucidating the biology and promoting the application of cfRNAs.

Gut microbiota (GM) is a micro-ecosystem composed of all microorganisms in the human intestine. The interaction between GM and the host plays an important role in maintaining normal physiological functions in the host. Dysbiosis of the GM may cause various diseases. GM has been demonstrated to be associated with human health and disease, and changes during individual development and disease. Pregnancy is a complicated physiological process. Hormones, the immune system, metabolism, and GM undergo drastic changes during preg nancy. Gastrointestinal diseases during pregnancy, such as hepatitis, intrahepatic cholestasis of pregnancy, and pre-eclampsia, can affect both maternal and fetal health. The dysregulation of GM during pregnancy may lead to a variety of diseases, including gastrointestinal diseases. Herein, we review recent research articles on GM in pregnancy-related gastrointestinal diseases, discuss the interaction of the GM with the host under normal physiological conditions, gastrointestinal diseases, and pregnancy-specific disorders. As more attention is paid to reproductive health, the pathogenic mechanism of GM in gastrointestinal diseases during pregnancy will be further studied to provide a theoretical basis for the use of probiotics to treat these diseases.

Background: Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder that specifically occurs in pregnancy. Elevated levels of liver transaminases aspartate aminotransferase, alanine aminotransferase and serum bilirubin levels are common biochemical characteristics in ICP. The disorder is associated with an increased risk of premature delivery and stillbirth. The characterization of the potential microbiota in ICP could go a long way in the prevention and treatment of this pregnancy disease. Methods: A total of 58 patients were recruited for our study: 27 ICP patients and 31 healthy pregnant subjects with no ICP. The V3 and V4 regions of the 16S rDNA collected from fecal samples of both diseased and control groups were amplified. 16S rRNA gene amplicon sequencing was then performed on gut microbiota. Sequencing data were analyzed and the correlation between components of microbiota and patient ICP status was found. Related metabolic pathways, relative abundance and significantly different operational taxonomic units (OTUs) between ICP and controls were also identified. Results: Elevated levels of total bile acid, ALT, AST, Dbil and Tbil were recorded or observed in ICP subjects as compared to the control. Gut microbiota in pregnant women was dominated by four major phyla and 27 core genera. PCoA analysis results indicated that there was no significant clustering in Bray–Curtis distance matrices. Our results showed that there was a correlation between specific OTUs and measured clinical parameters of pregnant women. Comparison at the different taxonomy levels revealed high levels of abundance of Blautia and Citrobacter in ICP patients. At the family level, Enterobacteriaceae and Leuconostocaceae were higher in ICP patients. 638 KEGG Orthologs and 138 pathways significantly differed in the two groups. PLS-DA model with VIP plots indicated a total of eight genera and seven species were key taxa in ICP and control groups. Conclusions: Our research indicated that although there was no significant clustering by PCoA analysis, patients with ICP have increased rare bacteria at different phylogenetic levels. Our results also illustrated that all 638 KEGG Orthologs and 136 in 138 KEGG pathways were less abundant in ICP patients compared to the controls.

The role of metabolic syndrome (MetS) on stroke has been explored only in many observational studies. We conducted Mendelian randomization (MR) to clarify whether or not the genetically predicted MetS and its components are causally associated with stroke and its subtypes. Genetic instruments of MetS and its components and outcome data sets for stroke and its subtypes came from the gene-wide association study in the UK Biobank and MEGASTROKE consortium, respectively. Inverse variance weighting was utilized as the main method. Genetically predicted MetS, waist circumference (WC), and hypertension increase the risk of stroke. WC and hypertension are related to increased risk of ischemic stroke. MetS, WC, hypertension, and triglycerides (TG) are causally associated with the increasing of large artery stroke. Hypertension increased the risk of cardioembolic stroke. Hypertension and TG lead to 77.43- and 1.19-fold increases, respectively, in small vessel stroke (SVS) risk. The protective role of high-density lipoprotein cholesterol on SVS is identified. Results of the reverse MR analyses show that stroke is related to hypertension risk. From the genetical variants perspective, our study provides novel evidence that early management of MetS and its components are effective strategies to decrease the risk of stroke and its subtypes.