Deep metagenomic characterization of the gut virome in pregnant women with preeclampsia

Preeclampsia (PE), a pregnancy-specific syndrome, has been associated with the gut bacteriome. Here, to investigate the impact of the gut virome on the development of PE, we identified over 8,000 nonredundant viruses from the fecal metagenomes of 40 early-onset PE and 37 healthy pregnant women and profiled their abundances. Comparison and correlation analysis showed that PE-enriched viruses frequently connected to Blautia species enriched in PE. By contrast, bacteria linked to PE-depleted viruses were often the Bacteroidaceae members such as Bacteroides spp., Phocaeicola spp., Parabacteroides spp., and Alistipes shahii. In terms of viral function, PE-depleted viruses had auxiliary metabolic genes that participated in the metabolism of simple and complex polysaccharides, sulfur metabolism, lipopolysaccharide biosynthesis, and peptidoglycan biosynthesis, while PE-enriched viruses had a gene encoding cyclic pyranopterin monophosphate synthase, which seemed to be special, that participates in the biosynthesis of the molybdenum cofactor. Furthermore, the classification model based on gut viral signatures was developed to discriminate PE patients from healthy controls and showed an area under the receiver operating characteristic curve of 0.922 that was better than that of the bacterium-based model. This study opens up new avenues for further research, providing valuable insights into the PE gut virome and offering potential directions for future mechanistic and therapeutic investigations, with the ultimate goal of improving the diagnosis and management of PE.IMPORTANCEThe importance of this study lies in its exploration of the previously overlooked but potentially critical role of the gut virome in preeclampsia (PE). While the association between PE and the gut bacteriome has been recognized, this research takes a pioneering step into understanding how the gut virome, represented by over 8,000 nonredundant viruses, contributes to this condition. The findings reveal intriguing connections between PE-enriched viruses and specific gut bacteria, such as the prevalence of Blautia species in individuals with PE, contrasting with bacteria linked to PE-depleted viruses, including members of the Bacteroidaceae family. These viral interactions and associations provide a deeper understanding of the complex dynamics at play in PE.

Deep metagenomic characterization of gut microbial community and function in preeclampsia

Preeclampsia (PE) is a pregnancy complication characterized by severe hypertension and multiple organ damage. Gut microbiota has been linked to PE by previous amplicon sequencing studies. To resolve the PE gut microbiota in a higher taxonomy resolution, we performed shotgun metagenomic sequencing on the fecal samples from 40 early-onset PE and 37 healthy pregnant women. We recovered 1,750 metagenome-assembled genomes (representing 406 species) from the metagenomic dataset and profiled their abundances. We found that PE gut microbiota had enriched in some species belonging to Blautia, Pauljensenia, Ruminococcus, and Collinsella and microbial functions such as the bacitracin/lantibiotics transport system, maltooligosaccharide transport system, multidrug efflux pump, and rhamnose transport system. Conversely, the gut microbiome of healthy pregnant women was enriched in species of Bacteroides and Phocaeicola and microbial functions including the porphyrin and chlorophyll metabolism, pyridoxal-P biosynthesis, riboflavin metabolism, and folate biosynthesis pathway. PE diagnostic potential of gut microbial biomarkers was developed using both species and function profile data. These results will help to explore the relationships between gut bacteria and PE and provide new insights into PE early warning.

Early-Onset Preeclampsia Is Associated With Gut Microbial Alterations in Antepartum and Postpartum Women

Background: Imbalances in gut microbiota composition are linked to hypertension, host metabolic abnormalities, systemic inflammation, and other conditions. In the present study, we examined the changes of gut microbiota in women with early-onset preeclampsia (PE) and in normotensive, uncomplicated pregnant women during late pregnancy and at 1 and 6 weeks postpartum.

Methods: Gut microbiota profiles of women with PE and healthy pregnant women in the third trimester and at 1 and 6 weeks postpartum were assessed by 16S rRNA gene amplicon sequencing. Plasma levels of interleukin-6 (IL-6), intestinal fatty acid-binding protein (I-FABP), zonulin, and lipopolysaccharide (LPS) were measured in the third trimesters.

Results: At the genus level, 8 bacterial genera were significantly enriched in the antepartum samples of PE patients compared to healthy controls, of which Blautia, Ruminococcus2, Bilophila, and Fusobacterium represented the major variances in PE microbiomes. Conversely, 5 genera, including Faecalibacterium, Gemmiger, Akkermansia, Dialister, and Methanobrevibacter, were significantly depleted in antepartum PE samples. Maternal blood pressure and liver enzyme levels were positively correlated to the PE-enriched genera such as Anaerococcus, Ruminococcus2, Oribacterium, and Bilophila, while the fetal features (e.g., Apgar score and newborn birth weight) were positively correlated with PE-depleted genera and negatively correlated with PE-enriched genera. Moreover, maternal blood IL-6 level was positively associated with gut Bilophila and Oribacterium, whereas LPS level was negatively associated with Akkermansia. In terms of postpartum women, both the gut microbial composition and the PE-associated microbial alterations were highly consistent with those of the antepartum women.

Conclusion: PE diagnosed in the third trimester of pregnancy is associated with a disrupted gut microbiota composition compared with uncomplicated pregnant women, which are associated with maternal clinical features (blood pressure level and liver dysfunction) and newborn birth weight. Moreover, these antepartum alterations in gut microbiota persisted 6 weeks postpartum.

[Value of Analyzing Hemoglobin A2 by ROC Curve for Screening Thalassemia]

OBJECTIVE

To investigate the value of hemoglobin A₂(HbA₂) for screening thalassemia.

METHODS

A total of 2 000 adults' peripheral blood samples from Guangdong Women and Children Hospital from June 2013 to January 2014 were collected. The hemoglobin A₂ (HbA₂) level was analyzed by the full automatic capillary electrophoresis technique, and the genotypes of thalassemia were detected.

RESULTS

The optimal cutoff values of HbA₂ for screening silent α-thalassemia, α-thalassemia trait, intermedia α-thalassemia and β-thalassemia trait were 2.85%, 2.65%, 2.25% and 3.45%, respectively; the areas under receiver operator characteristic (ROC) curve were 0.709, 0.839, 0.979 and 0.997 respectively; the sensitivities were 0.481, 0.721, 0.953 and 0.994, and the specificities were 0.846, 0.837, 0.929 and 0.969 respectively.

CONCLUSION

The optimal cutoff values of HbA₂ for screening different type of thalassemia based on our laboratory data are established by using ROC curve. According to the area under ROC curve, a satisfactory accuracy for screening intermedia α-thalassemia and β-thalassemia trait can be achieved by detecting hemoglobin A₂ level.

[Prokaryotic expression of human mast cell chymase gene and preparation of its polyclonal antibody]

AIM

To express the human mast cell chymase cDNA in E.coli and prepare the antibody against human mast cell chymase with recombinant chymase.

METHODS

The human mast cell chymase cDNA was cloned by RT-PCR. The recombinant chymase was expressed in E.coli with L-Arabinose induction and purified by Ni-NTA agarose column. Then the purified chymase was used as immunogen to immunize the rabbit. The titer and specificity of the anti-chymase antibody from the rabbit were analyzed by indirect ELISA and Western blot, respectively.

RESULTS

The recombinant chymase was successfully expressed in E.coli, and the polyclonal anit-chymase antibody was prepared by immunizing the rabbit with the purified recombinant chymase. The titer of the generated antiserum was detected to be 1:12 800 by ELISA. Western blot analysis showed this antibody bound specifically with chymase.

CONCLUSION

The anti-chymase antibody from the rabbit with high titer and specificity has been prepared with purified recombinant chymase as immunogen, which lays a foundation for further research into detection and function of chymase.