Highly efficient biosynthesis of 3'-sialyllactose in engineered Escherichia coli.

3'-Sialyllactose (3'-SL), one of the abundant and important sialylated human milk oligosaccharides, is an emerging food ingredient used in infant formula milk. We previously developed an efficient route for 3'-SL biosynthesis in metabolically engineered Escherichia coli BL21(DE3). Here, several promising α2,3-sialyltransferases were re-evaluated from the byproduct synthesis perspective. The α2,3-sialyltransferase from Neisseria meningitidis MC58 (NST) with great potential and the least byproducts was selected for subsequent molecular modification. Computer-assisted mutation sites combined with a semi-rational modification were designed and performed. A combination of two mutation sites (P120H/N113D) of NST was finally confirmed as the best one, which significantly improved 3'-SL biosynthesis, with extracellular titers of 24.5 g/L at 5-L fed-batch cultivations. When NST-P120H/N113D was additionally integrated into the genome of host EZAK (E. coli BL21(DE3)ΔlacZΔnanAΔnanT), the final strain generated 32.1 g/L of extracellular 3'-SL in a 5-L fed-batch fermentation. Overall, we underscored the existence of by-products and improved 3'-SL production by engineering N. meningitidis α2,3-sialyltransferase.

Silkworm Hemolymph and Cocoon Metabolomics Reveals Valine Improves Feed Efficiency of Silkworm Artificial Diet.

Artificial silkworm diets significantly impact farm profitability. Sustainable cocoon production depends on the continuous improvement of feed efficiency to reduce costs and nutrient losses in the feed. This study used metabolomics to explore the differences in silkworm cocoons and hemolymph under two modes of rearing: an artificial diet and a mulberry-leaf diet. Nine metabolites of silkworm cocoons and hemolymph in the mulberry-leaf group were higher than those in the artificial-diet group. Enrichment analysis of the KEGG pathways for these metabolites revealed that they were mainly enriched in the valine, leucine, and isoleucine biosynthesis and degradation pathways. Hence, the artificial silkworm diet was supplemented various concentrations of valine were supplemented to with the aim of examining the impact of valine on their feeding and digestion of the artificial diet. The results indicated that valine addition had no significant effect on feed digestibility in the fifth-instar silkworm. Food intake in the 2% and 4% valine groups was significantly lower than that in the 0% valine group. However, the 2% and 4% valine groups showed significantly improved cocoon-production efficiency, at 11.3% and 25.1% higher, respectively. However, the cocoon-layer-production efficiencies of the 2% and 4% valine groups decreased by 7.7% and 13.9%, respectively. The research confirmed that valine is an effective substance for enhancing the feed efficiency of silkworms.

Stimulated Human Umbilical Cord Mesenchymal Stem Cells Enhance the Osteogenesis and Cranial Bone Regeneration through IL-32 Mediated P38 Signaling Pathway.

Objective: Our previous study found that it could significantly increase the expression of IL32 after stimulating the human umbilical cord mesenchymal stem cells (S-HuMSCs). However, its role on the osteogenesis and cranial bone regeneration is still largely unknown. Here, we investigated the possible mechanism of this effect. Material and Methods. A series of experiments, including single-cell sequencing, flow cytometry, quantitative real-time polymerase chain reaction, and western blotting, were carried out to evaluate the characteristic and adipogenic-osteogenic differentiation potential of IL-32 overexpression HuMSCs (IL-32highHuMSCs) through mediating the P38 signaling pathway. Moreover, a rat skull bone defect model was established and treated by directly injecting the IL-32highHuMSCs to conduct its role on the cranial bone regeneration. Results: In total, it found that compared to HuMSCs, IL32 was significantly increased and promoted the osteogenic differentiation (lower expressions of PPARγ, Adiponectin, and C/EBPα, and increased expressions of RUNX2, ALP, BMP2, OPN, SP7, OCN, and DLX5) in the S-HuMSCs (P < 0.05). Meanwhile, the enhanced osteogenic differentiation of HuMSCs was recovered by IL-32 overexpression (IL-32highHuMSCs) through activating the P38 signaling pathway, like as the S-HuMSCs (P < 0.05). However, the osteogenic differentiation potential of IL-32highHuMSCs was significantly reversed by the P38 signaling pathway inhibitor SB203580 (P < 0.05). Additionally, the HuMSCs, S-HuMSCs, and IL-32highHuMSCs all presented adipogenic-osteogenic differentiation potential, with higher levels of CD73, CD90, and CD105, and lower CD14, CD34, and CD45 (P > 0.05). Furthermore, these findings were confirmed by the rat skull bone defect model, in which the cranial bone regeneration was more pronounced in the IL-32highHuMSCs treated group compared to those in the HuMSCs group, with higher expressions of RUNX2, ALP, BMP2, and DLX5 (P < 0.05). Conclusion: We have confirmed that S-HuMSCs can enhance the osteogenesis and cranial bone regeneration through promoting IL-32-mediated P38 signaling pathway, which is proved that IL-32 may be a therapeutic target, or a biomarker for the treatment of cranial bone injuries.

Gated CNN-Transformer Network for Automatic Cardiovascular Diagnosis using 12-lead Electrocardiogram.

12-lead electrocardiogram (ECG) is a widely used method in the diagnosis of cardiovascular disease (CVD). With the increase in the number of CVD patients, the study of accurate automatic diagnosis methods via ECG has become a research hotspot. The use of deep learning-based methods can reduce the influence of human subjectivity and improve the diagnosis accuracy. In this paper, we propose a 12-lead ECG automatic diagnosis method based on channel features and temporal features fusion. Specifically, we design a gated CNN-Transformer network, in which the CNN block is used to extract signal embeddings to reduce data complexity. The dual-branch transformer structure is used to effectively extract channel and temporal features in low-dimensional embeddings, respectively. Finally, the features from the two branches are fused by the gating unit to achieve automatic CVD diagnosis from 12-lead ECG. The proposed end-to-end approach has more competitive performance than other deep learning algorithms, which achieves an overall diagnostic accuracy of 85.3% in the 12-lead ECG dataset of CPSC-2018.

Engineering Escherichia coli MG1655 for Highly Efficient Biosynthesis of 2'-Fucosyllactose by De Novo GDP-Fucose Pathway.

2'-Fucosyllactose (2'-FL), the most typical human milk oligosaccharide, is used as an additive in premium infant formula. Herein, we constructed two highly effective 2'-FL synthesis producers via a de novo GDP-fucose pathway from engineered Escherichia coli MG1655. First, lacZ and wcaJ, two competitive pathway genes, were disrupted to block the invalid consumption of lactose and GDP-fucose, respectively. Next, the lacY gene was strengthened by switching its native promoter to PJ23119. To enhance the supply of endogenous GDP-fucose, the promoters of gene clusters manC-manB and gmd-fcl were strengthened individually or in combination. Subsequently, chromosomal integration of a constitutive PJ23119 promoter-based BKHT expression cassette (PJ23119-BKHT) was performed in the arsB and recA loci. The most productive plasmid-based and plasmid-free strains produced 76.9 and 50.1 g/L 2'-FL by fed-batch cultivation, respectively. Neither of them generated difucosyl lactose nor 3-fucosyllactose as byproducts.

Cross-Sectional and Prospective Relationships Between Neuroticism and Depressive Symptoms Among College Students: The Mediating Role of Loneliness.

High levels of neuroticism are associated with an increased risk of depression. The mechanisms for this association are still unclear. This study investigated loneliness, a pervasive negative human emotion linked to depressive symptoms, as a potential mediator. Data were collected from 739 college students (71.6% females; mean age = 18.47, SD = .87) at two times points through 3 years. Self-report questionnaires were administered to assess neuroticism, loneliness, and depressive symptoms. Cross-sectional analyses of the baseline data suggested that loneliness mediates the association between neuroticism and depressive symptoms. Prospective analyses with two-wave data further prove that baseline neuroticism can predict the changes in depressive symptoms, and changes in loneliness sequentially mediated this association. These findings suggest a possibility of developing interventions for loneliness to interrupt the association between neuroticism and poorer mental health outcomes among college students.

Elimination of Byproduct Generation and Enhancement of 2'-Fucosyllactose Synthesis by Expressing a Novel α1,2-Fucosyltransferase in Engineered Escherichia coli.

2'-Fucosyllactose (2'-FL) is a kind of fucosylated human milk oligosaccharide (HMO), representing the most abundant oligosaccharide in breast milk. We conducted systematic studies on three canonical α1,2-fucosyltransferases (WbgL, FucT2, and WcfB) to quantify the byproducts in a lacZ- and wcaJ-deleted Escherichia coli BL21(DE3) basic host strain. Further, we screened a highly active α1,2-fucosyltransferase from Helicobacter sp. 11S02629-2 (BKHT), which exhibits high in vivo 2'-FL productivity without the formation of byproducts difucosyl lactose (DFL) and 3-FL. The maximum 2'-FL titer and yield reached 11.13 g/L and 0.98 mol/mol of lactose, respectively, in shake-flask cultivation, both approaching the theoretical maximum value. In a 5 L fed-batch cultivation, the maximum 2'-FL titer reached 94.7 g/L extracellularly with a yield of 0.98 mol of 2'-FL/mol of lactose and productivity of 1.14 g L-1 h-1. Our reported 2'-FL yield is the highest from lactose reported to date.

De novo biosynthesis of 2'-fucosyllactose in a metabolically engineered Escherichia coli using a novel ɑ1,2-fucosyltransferase from Azospirillum lipoferum.

Human milk oligosaccharides are complex, indigestible oligosaccharides that provide ideal nutrition for infant development. Here, 2'-fucosyllactose was efficiently produced in Escherichia coli by using a biosynthetic pathway. For this, both lacZ and wcaJ (encoding ß-galactosidase and UDP-glucose lipid carrier transferase, respectively) were deleted to enhance the 2'-fucosyllactose biosynthesis. To further enhance 2'-fucosyllactose production, SAMT from Azospirillum lipoferum was inserted into the chromosome of the engineered strain, and the native promoter was replaced with a strong constitutive promoter (PJ23119). The titer of 2'-fucosyllactose was increased to 8.03 g/L by introducing the regulators rcsA and rcsB into the recombinant strains. Compared to wbgL-based strains, only 2'-fucosyllactose was produced in SAMT-based strains without other by-products. Finally, the highest titer of 2'-fucosyllactose reached 112.56 g/L in a 5 L bioreactor by fed-batch cultivation, with a productivity of 1.10 g/L/h and a yield of 0.98 mol/mol lactose, indicating a strong potential in industrial production.

Upregulation of miRNA-10a-5p promotes tumor progression in cervical cancer by suppressing UBE2I signaling.

Cervical cancer (CC) is a common malignant neoplasm in gynecology. There is increasing evidence to suggest that microRNAs (miRNAs) act as crucial regulators of CC. However, whether miR-10a-5p plays a role in CC is under investigation. The aim of this stuy was to assess the miR-10a-5p expression pattern in the development of CC and investigate its downstream target. MiR-10a-5p inhibition decreased CC cell proliferation and impaired CC cell invasion and migration but enhanced apoptosis. UBE2I was a direct target of miR-10a-5p. QRT-PCR results showed a down-regulation of UBE2I in CC cells, opposing miR-10a-5p. Besides, overexpression of miR-10a-5p down-regulated UBE2I. Functional rescue experiments further indicated the miR-10a-5p-UBE2I axis was linked to CC cell growth, apoptosis and metastasis. MiR-10a-5p upregulation promotes cervical cancer development by inhibiting UBE2I. These results also predict that miR-10a-5p may be a potential target for the clinical treatment of CC.IMPACT STATEMENTWhat is already known on this subject? As a widely researched cancer-related miRNA, the overexpression of miR-10a-5p has been verified in various cancers. It has been described in a meta-analysis report that there were 42 miRNAs up-regulated and 21 miRNAs down-regulated in different stages of cervical cancer tissue versus healthy tissue.What do the results of this study add? We verified that miR-10a-5p initiates and promotes tumor cell development by decreasing UBE2I abundance. This miR-10a-5p-mediated post-transcriptional regulation of UBE2I is involved in the tumorigenesis, invasion and migration of human cervical cancer.What are the implications of these findings for clinical practice and/or further research? These findings provide mechanistic insights into how miR-10a-5p regulates cervical cancer hyper-proliferation and metastasis, as well as a new target for clinical treatment. Nevertheless, whether miR-10a-5p/UBE2I axis can be regulated by non-invasive methods need further exploration, which will be the focus of our future research.

Human umbilical cord mesenchymal stem cell-derived TGFBI attenuates streptozotocin-induced type 1 diabetes mellitus by inhibiting T-cell proliferation.

MSCs have been demonstrated to have a great benefit for type 1 diabetes mellitus (T1DM) due to their strong immunosuppressive and regenerative capacity. However, the comprehensive mechanism is still unclear. Our previous study indicated that transforming growth factor beta induced (TGFBI) is highly expressed in human umbilical cord-derived mesenchymal stem or stromal cells (hUC-MSCs), which are also implicated in T1DM. In this study, we found that infusion of TGFBI knockdown hUC-MSCs displayed impaired therapeutic effects in T1DM mice and decreased immunosuppressive capability. TGFBI knockdown hUC-MSCs could increase the proportion of T-cell infiltration while increasing the expression of IFN-gamma and interleukin-17A in the spleen. In addition, we also revealed that hUC-MSC-derived TGFBI could repress activated T-cell proliferation by interfering with G1/S checkpoint CyclinD2 expression. Our results demonstrate that TGFBI plays a critical role in MSC immunologic regulation. TGFBI could be a new immunoregulatory molecule controlling MSC function for new treatments of T1DM. Schematic Representation of the Immunosuppression capacity of hUC-MSC by TGFBI.

Microbial Synthesis of l-Fucose with High Productivity by a Metabolically Engineered Escherichia coli.

l-Fucose is a natural deoxy hexose found in a variety of organisms. It possesses many physiological effects and has potential applications in pharmaceutical, cosmetic, and food industries. Microbial synthesis via metabolic engineering attracts increasing attention for efficient production of important chemicals. Previously, we reported the construction of a metabolically engineered Escherichia coli strain with high 2'-fucosyllactose productivity. Herein, we further introduced Bifidobacterium bifidum α-l-fucosidase via both plasmid expression and genomic integration and blocked the l-fucose assimilation pathway by deleting fucI, fucK, and rhaA. The highest l-fucose titers reached 6.31 and 51.05 g/L in shake-flask and fed-batch cultivation, respectively. l-Fucose synthesis was little affected by lactose added, and there was almost no 2'-fucosyllactose residue throughout the cultivation processes. The l-fucose productivity reached 0.76 g/L/h, indicating significant potential for large-scale industrial applications.

Maternal vitamin D deficiency aggravates the dysbiosis of gut microbiota by affecting intestinal barrier function and inflammation in obese male offspring mice.

OBJECTIVES: The colonization of gut microbiota during early life may play a critical role in the progression of metabolic syndrome in adulthood. Targeting gut-based genes in the barrier function, inflammation, and lipid transportation are potential therapies for obesity. Therefore, this study focused on whether maternal deficient vitamin D (VD) intake could aggravate the dysbiosis of gut microbiota by affecting the expressions of these genes in the ileum and colon of obese male offspring mice. METHODS: Four-week-old female C57 BL/6 J mice were fed normal (VD-C) or VD-deficient (VD-D) reproductive diets throughout pregnancy and lactation (n = 15/group). Weaning male pups (n = 10/group) were fed either a high-fat (HFD; VD-C-HFD, VD-D-HFD) or normal-fat diet (control) for 16 wk. All biologic samples were obtained after the mice were anesthetized by cervical dislocation. Subsequently, the compositions of the gut microbiota in cecal contents were analyzed using 16 S ribosomal RNA sequencing. Messenger RNA expression in the ileum and colon was determined using real-time reverse transcription-polymerase chain reaction. The distributions of ZO-1 and Claudin-1 were determined using immunohistochemistry testing. RESULTS: Maternal deficient VD intake significantly aggravated the dysbiosis of gut microbiota persisting into adulthood from phylum to genus levels in the cecal contents among obese male offspring mice. This aggravation led to significantly depleted Bacteroidetes and Verrucomicrobia (Akkermansia, Alliprevotella, and Bacteroides), with higher relative abundance of Firmicutes (Lactobacillus, Lachnoclostridium, Romboutsia, and Ruminiclostridium_9) and Firmicutes/Bacteroidetes. The gene expressions of proinflammatory cytokines (Ccl2, Ccl4 and interleukin-1ß) and lipid transportation molecules (Ffar3, Fabp4, and Fabp1) were higher, and the levels of intestinal barrier function (Occludin, ZO-1, and Claudin-1) were lower in the VD-D-HFD group than those in the VD-C-HFD group. Furthermore, there were significant correlations between the dysbiosis of intestinal microbials and expressions of genes related to barrier function, inflammation, and lipid transportation in the ileum and/or colon. CONCLUSIONS: Maternal VD deficiency during pregnancy and lactation could aggravate the dysbiosis of gut microbiota to affect the progression of obesity among male offspring, which might be regulated by genes associated with barrier function, inflammation, and lipid transportation. So early life appropriate VD intake could play a significant role in preventing later obesity.

Spatial organization of pathway enzymes via self-assembly to improve 2'-fucosyllactose biosynthesis in engineered Escherichia coli.

As one of the most abundant components in human milk oligosaccharides, 2'-fucosyllactose (2'-FL) possesses versatile beneficial health effects. Although most studies focused on overexpressing or fine-tuning the expression of pathway enzymes and achieved a striking increase of 2'-FL production, directly facilitating the metabolic flux toward the key intermediate GDP-l-fucose seems to be ignored. Here, multienzyme complexes consisting of sequential pathway enzymes were constructed by using specific peptide interaction motifs in recombinant Escherichia coli to achieve a higher titer of 2'-FL. Specifically, we first fine-tuned the expression level of pathway enzymes and balanced the metabolic flux toward 2'-FL synthesis. Then, two key enzymes (GDP-mannose 4,6-dehydratase and GDP- l-fucose synthase) were self-assembled into enzyme complexes in vivo via a short peptide interaction pair RIAD-RIDD (RI anchoring disruptor-RI dimer D/D domains), resulting in noticeable improvement of 2'-FL production. Next, to further strengthen the metabolic flux toward 2'-FL, three pathway enzymes were further aggregated into multienzyme assemblies by using another orthogonal protein interaction motif (Spycatcher-SpyTag or PDZ-PDZlig). Intracellular multienzyme assemblies remarkably enlarged the flux toward 2'-FL biosynthesis and showed a 2.1-fold increase of 2'-FL production compared with a strain expressing free-floating and unassembled enzymes. The optimally engineered strain EZJ23 accumulated 4.8 g/L 2'-FL in shake flask fermentation and was capable of producing 25.1 g/L 2'-FL by fed-batch cultivation. This work provides novel approaches for further improvement and large-scale production of 2'-FL and demonstrates the effectiveness of spatial assembly of pathway enzymes to improve the production of valuable products in the engineered host strain.

Maternal inappropriate calcium intake aggravates dietary-induced obesity in male offspring by affecting the differentiation potential of mesenchymal stem cells.

BACKGROUND: The effects of inappropriate dietary calcium intake in early life on later obesity have not been fully elucidated. AIM: To raise the mechanism of maternal calcium intake on the multi-differentiation potential of mesenchymal stem cells among their male offspring. METHODS: Four-week-old female C57BL/6N mice were fed by deficient, low, normal and excessive calcium reproductive diets throughout pregnancy and lactation. Bone MSCs (BMSCs) were obtained from 7-day-old male offspring to measure the adipogenic differentiation potential by the Wnt/ß-catenin signaling pathway. The other weaning male pups were fed a high-fat diet for 16 wk, along with normal-fat diet as the control. Then the serum was collected for the measurement of biochemical indicators. Meanwhile, the adipose tissues were excised to analyze the adipocyte sizes and inflammatory infiltration. And the target gene expressions on the adipogenic differentiation and Wnt/ß-catenin signaling pathway in the adipose tissues and BMSCs were determined by real-time reverse transcription polymerase chain reaction. RESULTS: Compared with the control group, maternal deficient, low and excessive calcium intake during pregnancy and lactation aggravated dietary-induced obesity, with larger adipocytes, more serious inflammatory infiltration and higher serum metabolism indicators by interfering with higher expressions of adipogenic differentiation (PPARγ, C/EBPα, Fabp4, LPL, Adiponectin, Resistin and/or Leptin) among their male offspring (P < 0.05). And there were significantly different expression of similar specific genes in the BMSCs to successfully polarize adipogenic differentiation and suppress osteogenic differentiation in vivo and in vitro, respectively (P < 0.05). Meanwhile, it was accompanied by more significant disorders on the expressions of Wnt/ß-catenin signaling pathway both in BMSCs and adulthood adipose tissues among the offspring from maternal inappropriate dietary calcium intake groups. CONCLUSION: Early-life abnormal dietary calcium intake might program the adipogenic differentiation potential of BMSCs from male offspring, with significant expressions on the Wnt/ß-catenin signaling pathway to aggravate high-fat-diet-induced obesity in adulthood.

hUC-MSCs Attenuate Acute Graft-Versus-Host Disease through Chi3l1 Repression of Th17 Differentiation.

Mesenchymal stem cells (MSCs) have already demonstrated definitive evidence of their clinical benefits in acute graft-versus-host disease (aGvHD) and other inflammatory diseases. However, the comprehensive mechanism of MSCs' immunomodulation properties has not been elucidated. To reveal their potential immunosuppressive molecules, we used RNA sequencing to analyze gene expression in different tissue-derived MSCs, including human bone marrow, umbilical cord, amniotic membrane, and placenta, and found that chitinase-3-like protein 1 (Chi3l1) was highly expressed in human umbilical cord mesenchymal stem cells (hUC-MSCs). We found that hUC-MSCs treated with interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) exhibited increased expression of Chi3l1 and concurrently repressed T-helper 17 cell (Th17) differentiation through inhibition of signal transducer and activator of transcription 3 (STAT3) activation. Furthermore, Chi3l1 knockdown hUC-MSCs exhibited impaired therapeutic efficacy in aGvHD mice with an increased inflammatory response by promoting Th17 cell differentiation, including an increase in IL-17A in the spleen, intestine, and serum. Collectively, these results reveal a new immunosuppressive molecule, Chi3l1, in hUC-MSCs in the treatment of aGvHD that regulates Th17 differentiation and inhibits STAT3 activation. These novel insights into the mechanisms of hUC-MSC immunoregulation may lead to the consistent production of hUC-MSCs with strong immunosuppressive functions and thus improved clinical utility.

Identification of key monocytes/macrophages related gene set of the early-stage abdominal aortic aneurysm by integrated bioinformatics analysis and experimental validation.

Objective: Abdominal aortic aneurysm (AAA) is a lethal peripheral vascular disease. Inflammatory immune cell infiltration is a central part of the pathogenesis of AAA. It's critical to investigate the molecular mechanisms underlying immune infiltration in early-stage AAA and look for a viable AAA marker. Methods: In this study, we download several mRNA expression datasets and scRNA-seq datasets of the early-stage AAA models from the NCBI-GEO database. mMCP-counter and CIBERSORT were used to assess immune infiltration in early-stage experimental AAA. The scRNA-seq datasets were then utilized to analyze AAA-related gene modules of monocytes/macrophages infiltrated into the early-stage AAA by Weighted Correlation Network analysis (WGCNA). After that, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis for the module genes was performed by ClusterProfiler. The STRING database was used to create the protein-protein interaction (PPI) network. The Differentially Expressed Genes (DEGs) of the monocytes/macrophages were explored by Limma-Voom and the key gene set were identified. Then We further examined the expression of key genes in the human AAA dataset and built a logistic diagnostic model for distinguishing AAA patients and healthy people. Finally, real-time quantitative polymerase chain reaction (RT-qPCR) and Enzyme Linked Immunosorbent Assay (ELISA) were performed to validate the gene expression and serum protein level between the AAA and healthy donor samples in our cohort. Results: Monocytes/macrophages were identified as the major immune cells infiltrating the early-stage experimental AAA. After pseudocell construction of monocytes/macrophages from scRNA-seq datasets and WGCNA analysis, four gene modules from two datasets were identified positively related to AAA, mainly enriched in Myeloid Leukocyte Migration, Collagen-Containing Extracellular matrix, and PI3K-Akt signaling pathway by functional enrichment analysis. Thbs1, Clec4e, and Il1b were identified as key genes among the hub genes in the modules, and the high expression of Clec4e, Il1b, and Thbs1 was confirmed in the other datasets. Then, in human AAA transcriptome datasets, the high expression of CLEC4E, IL1B was confirmed and a logistic regression model based on the two gene expressions was built, with an AUC of 0.9 in the train set and 0.79 in the validated set. Additionally, in our cohort, we confirmed the increased serum protein levels of IL-1ß and CLEC4E in AAA patients as well as the increased expression of these two genes in AAA aorta samples. Conclusion: This study identified monocytes/macrophages as the main immune cells infiltrated into the early-stage AAA and constructed a logistic regression model based on monocytes/macrophages related gene set. This study could aid in the early diagnostic of AAA.

Strategies for Enhancing Microbial Production of 2'-Fucosyllactose, the Most Abundant Human Milk Oligosaccharide.

Human milk oligosaccharides (HMOs), a group of structurally diverse unconjugated glycans in breast milk, act as important prebiotics and have plenty of unique health effects for growing infants. 2'-Fucosyllactose (2'-FL) is the most abundant HMO, accounting for approximately 30%, among approximately 200 identified HMOs with different structures. 2'-FL can be enzymatically produced by α1,2-fucosyltransferase, using GDP-l-fucose as donor and lactose as acceptor. Metabolic engineering strategies have been widely used for enhancement of GDP-l-fucose supply and microbial production of 2'-FL with high productivity. GDP-l-fucose supply can be enhanced by two main pathways, including de novo and salvage pathways. 2'-FL-producing α1,2-fucosyltransferases have widely been identified from various microorganisms. Metabolic pathways for 2'-FL synthesis can be basically constructed by enhancing GDP-l-fucose supply and introducing α1,2-fucosyltransferase. Various strategies have been attempted to enhance 2'-FL production, such as acceptor enhancement, donor enhancement, and improvement of the functional expression of α1,2-fucosyltransferase. In this review, current progress in GDP-l-fucose synthesis and bacterial α1,2-fucosyltransferases is described in detail, various metabolic engineering strategies for enhancing 2'-FL production are comprehensively reviewed, and future research focuses in biotechnological production of 2'-FL are suggested.

High-Level De Novo Biosynthesis of 2'-Fucosyllactose by Metabolically Engineered Escherichia coli.

2'-Fucosyllactose (2'-FL) is the most abundant oligosaccharide in human milk. In this study, a highly efficient biosynthetic route for 2'-FL production was designed via the de novo pathway of GDP-l-fucose using engineered Escherichia coli BL21(DE3). Specifically, plasmid-based strains with previously deleted lacZ and wcaJ were further reconstructed by introducing de novo pathway genes and α1,2-fucosyltransferase-encoding wbgL to realize 2'-FL synthesis. The 2'-FL titer was enhanced to 3.92 g/L by further introducing rcsA and rcsB. Subsequently, the additional wbgL expression cassette was chromosomally integrated into recA locus to strengthen fucosylation reaction and a strong constitutive promoter (PJ23119) was used to replace the original promoters of manC-manB and gmd-wcaG to improve 2'-FL synthesis. The maximal 2'-FL titer reached 9.06 and 79.23 g/L in shake-flask and fed-batch cultivation, respectively. The 2'-FL productivity reached 1.45 g/L/h, showing remarkable production potential in large-scale industrial application.

MiR-195-5p facilitates the proliferation, migration, and invasion of human trophoblast cells by targeting FGF2.

BACKGROUND: Preeclampsia (PE), the most significant adverse exposure to cardiovascular risk during pregnancy, is one of the three major factors contributing to maternal and fetal mortality and the leading cause of preterm birth. Recently, various miRNAs have been reported to participate in PE occurrence and development. Nevertheless, the regulatory impact of miR-195-5p in PE is still indistinct. METHODS: Quantitative realtime-PCR (qRT-PCR), western blot, and fluorescence in situ hybridization (FISH) assay were performed to examine miR-195-5p and FGF2 expressions in PE serum samples or HTR-8/SVneo and TEV-1 cells. CCK8, flow cytometry, wound scratch, and transwell assays were conducted to determine cell viability, cycle, apoptosis, migration, and invasion. Dual-luciferase reporter assay unveiled the relationship between miR-195-5p and FGF2. Migration-related and invasion-related protein expressions were measured by western blot assay. RESULTS: miR-195-5p was prominently downregulated while FGF2 was increased in serum samples from PE patients and hypoxia-treated human trophoblast cells. FGF2 was predicted as a downstream target of miR-195-5p and targeted association was verified by dual-luciferase reporter assay. Functional experiments elaborated that miR-195-5p could facilitate trophoblast cell proliferation and metastasis but hinder cell cycle and apoptosis. Inversely, overexpressing of FGF2 could reverse the effects of miR-195-5p on trophoblast cell growth. DISCUSSION: miR-195-5p was decreased in PE serum samples and cell lines, serving as a potential biomarker in protecting PE exacerbation by targeting FGF2.