Maternal circulating levels of the adipokine chemerin are elevated in preeclampsia, but its origin and contribution to preeclampsia remain unknown. We therefore studied (1) placental chemerin ...expression and release in human pregnancy, and (2) the consequences of chemerin overexpression via lentivirus-mediated trophoblast-specific gene manipulation in both mice and immortalized human trophoblasts. Placental chemerin expression and release were increased in women with preeclampsia, and their circulating chemerin levels correlated positively with the soluble Fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio, a well-known biomarker of preeclampsia severity. Placental trophoblast chemerin overexpression in mice induced a preeclampsia-like syndrome, involving hypertension, proteinuria, and endotheliosis, combined with diminished trophoblast invasion, a disorganized labyrinth layer, and up-regulation of sFlt-1 and the inflammation markers nuclear factor-κB (NFκB), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β. It also led to embryo resorption, while maternal serum chemerin levels correlated negatively with fetal weight in mice. Chemerin overexpression in human trophoblasts up-regulated sFlt-1, reduced vascular endothelial factor-A, and inhibited migration and invasion, as well as tube formation during co-culture with human umbilical vein endothelial cells (HUVECs). The chemokine-like receptor 1 (CMKLR1) antagonist α-NETA prevented the latter phenomenon, although it did not reverse the chemerin-induced down-regulation of the phosphoinositide 3-kinase/Akt pathway. In conclusion, up-regulation of placental chemerin synthesis disturbs normal placental development via its CMKLR1 receptor, thereby contributing to fetal growth restriction/resorption and the development of preeclampsia. Chemerin might be a novel biomarker of preeclampsia, and inhibition of the chemerin/CMKLR1 pathway is a promising novel therapeutic strategy to treat preeclampsia.
Circulating peptides and G protein-coupled receptors (GPCRs) have gained much attention because of their biofunctions in metabolic disorders including obesity and non-alcoholic fatty liver disease ...(NAFLD). Herein, we aimed to characterize the role and therapeutic potential of a newly identified peptide hormone in NAFLD.
Using bioinformatics, we identified a murine circulating pentadecapeptide flanked by potential convertase cleavage sites of osteocalcin (OCN), which we named ‘metabolitin (MTL)’. We used ligand-receptor binding, receptor internalization, bioluminescence resonance energy transfer and Nano isothermal titration calorimetry assays to study the binding relationship between MTL and GPRC6A. For in vivo biological studies, wild-type mice kept on a high-fat diet (HFD) were injected or gavaged with MTL to study its function in NAFLD.
We confirmed that MTL binds to GPRC6A and OCN interacts with GPRC6A using in vitro biological studies. Both intraperitoneal and oral administration of MTL greatly improved NAFLD and insulin resistance in a mouse model. Interacting with GPRC6A expressed in intestines, MTL can significantly inhibit intestinal neurotensin secretion, which in turn inhibits triglyceride but not cholesterol gut absorption, mediated by the 5′AMP-activated protein kinase pathway. In addition, glucagon like peptide–1 secretion was induced by MTL treatment.
Oral or intraperitoneal MTL significantly improves the symptoms of NAFLD by inhibiting lipid absorption and insulin resistance. MTL could be a potential therapeutic candidate for the treatment of NAFLD.
A novel murine peptide hormone, herein named ‘metabolitin’, inhibits fatty acid absorption and improves systemic insulin resistance in a murine model of obesity and non-alcoholic fatty liver disease. Thus, metabolitin has therapeutic potential for the treatment of patients with non-alcoholic fatty liver disease.
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•Metabolitin is a newly identified peptide hormone that significantly improves fatty liver.•The major mechanism by which metabolitin improves NAFLD is by inhibiting fat absorption in the intestines.•Metabolitin acts by binding and interacting with its receptor GPRC6A.
Coordination of neurite extension with surrounding glia development is critical for neuronal function, but the underlying molecular mechanisms remain poorly understood. Through a genome-wide ...mutagenesis screen in C. elegans, we identified dyf-4 and daf-6 as two mutants sharing similar defects in dendrite extension. DAF-6 encodes a glia-specific patched-related membrane protein that plays vital roles in glial morphogenesis. We cloned dyf-4 and found that DYF-4 encodes a glia-secreted protein. Further investigations revealed that DYF-4 interacts with DAF-6 and functions in a same pathway as DAF-6 to regulate sensory compartment formation. Furthermore, we demonstrated that reported glial suppressors of daf-6 could also restore dendrite elongation and ciliogenesis in both dyf-4 and daf-6 mutants. Collectively, our data reveal that DYF-4 is a regulator for DAF-6 which promotes the proper formation of the glial channel and indirectly affects neurite extension and ciliogenesis.
Ghrelin, a circulating appetite-inducing hormone, is derived from a prohormone by posttranslational processing. On the basis of the bioinformatic prediction that another peptide also derived from ...proghrelin exists, we isolated a hormone from rat stomach and named it obestatin-a contraction of obese, from the Latin "obedere," meaning to devour, and "statin," denoting suppression. Contrary to the appetite-stimulating effects of ghrelin, treatment of rats with obestatin suppressed food intake, inhibited jejunal contraction, and decreased body-weight gain. Obestatin bound to the orphan G protein-coupled receptor GPR39. Thus, two peptide hormones with opposing action in weight regulation are derived from the same ghrelin gene. After differential modification, these hormones activate distinct receptors.
Background
Immunotherapy has achieved remarkable efficacy in treating oesophageal squamous cell carcinoma (ESCC). However, this treatment has limited efficacy in some patients. An increasing number ...of evidence suggested that immune cells within the tumour microenvironment (TME) are strongly related to immunotherapy response and patient prognosis. Thus, the landscape of immune cell infiltration (ICI) in ESCC needs to be mapped.
Methods
In the study, the ICI pattern in 206 cases of ESCC was characterised by two algorithms, namely, CIBERSORT and single-sample gene set enrichment analysis (ssGSEA). The ICI score of each specimen was calculated by principal component analysis (PCA) according to ICI signature genes A (ICISGA) and B (ICISGB). The prognostic difference was evaluated by using the Kaplan–Meier method. The related pathways of ICI score were investigated by applying gene set enrichment analysis (GSEA). The R packages of ‘regplot’, ‘timeROC’ and ‘rms’ were applied for the construction of nomogram model.
Result
Three TME subtypes were identified with no prognostic implication. A total of 333 differentially expressed genes (DEGs) among immune subtypes were determined, among which ICISGA and ICISGB were identified. Finally, ICI scores were constructed, and the patients were grouped into high or low ICI score group. Compared with the low ICI score group, the high ICI score group had better prognosis. GSEA revealed that the high ICI score group referred to multiple signalling pathways, including B cell receptor, Fc gamma R-mediated phagocytosis, NOD-like receptor and TGF-β signalling pathways. In addition, the nomogram model was constructed to evaluate 1-, 3- and 5-year probability of death in an ESCC patient. The ROC and calibration curves indicated that the model has a good discrimination ability.
Conclusion
We depicted a comprehensive ICI landscape in ESCC. ICI score may be used as a predictor of survival rate, which may be helpful for guiding immunotherapy in the future.
Human pluripotent stem cells (PSCs) are known to differentiate into almost all the blood lineage cells in vitro and hold a great promise for studying human early hematopoietic development and have a ...huge potential in the treatment of hematological disorders. Although several methods of hematopoietic stem/progenitor cell (HSPC) differentiation have been developed, the HSPC yields achieved using these strategies are not yet available for clinical application. Recently, bioreactor-based devices and biochemical factors synergistically have been used to induce hematopoietic differentiation and showed a potential role in hematopoiesis. This chapter describes a protocol for using a random positioning machine bioreactor to culture human PSCs and the large-scale production of HPCs. Techniques for characterizing the differentiated cells and assessing the efficiency of hematopoietic differentiation in the bioreactor with immunostaining and flow cytometry are also presented.
Abstract
Circular RNAs (circRNAs), which exert critical functions in the regulation of transcriptional and post-transcriptional gene expression, are found in mammalian cells but their functions in ...mammalian preimplantation embryo development remain poorly understood. Here, we showed that circKDM5B mediated miRNA-128 (miR-128) to regulate porcine early embryo development. We screened circRNAs potentially expressed in porcine embryos through an integrated analysis of sequencing data from mouse and human embryos, as well as porcine oocytes. An authentic circRNA originating from histone demethylase KDM5B (referred to as circKDM5B) was abundantly expressed in porcine embryos. Functional studies revealed that circKDM5B knockdown not only significantly reduced blastocyst formation but also decreased the number of total cells and trophectoderm (TE) cells. Moreover, the knockdown of circKDM5B resulted in the disturbance of tight junction assembly and impaired paracellular sealing within the TE epithelium. Mechanistically, miR-128 inhibitor injection could rescue the early development of circKDM5B knockdown embryos. Taken together, the findings revealed that circKDM5B functions as a miR-128 sponge, thereby facilitating early embryonic development in pigs through the modulation of gene expression linked to tight junction assembly.
Obesity has become a global concern because of increasing the risk of many diseases. Alterations in human gut microbiota have been proven to be associated with obesity, yet the mechanism of how the ...microbiota are altered by high salt diet (HSD) remains obscure. In this study, the changes of Small Intestinal Microbiota (SIM) in obesity-T2DM mice were investigated. High-throughput sequencing was applied for the jejunum microbiota analysis. Results revealed that high salt intake (HS) could suppress the body weight (B.W.) in some extent. In addition, significant T2DM pathological features were revealed in high salt-high food diet (HS-HFD) group, despite of relatively lower food intake. High-throughput sequencing analysis indicated that the F/B ratio in HS intake groups increased significantly (P < 0.001), whereas beneficial bacteria, such as lactic acid or short chain fatty acid producing bacteria, were significantly decreased in HS-HFD group (P < 0.01 or P < 0.05). Furthermore, Halorubrum luteum were observed in small intestine for the first time. Above results preliminary suggested that in obesity-T2DM mice, high dietary salt could aggravate the imbalance of composition of SIM to unhealthy direction.
Histone lysine crotonylation, an evolutionarily conserved modification differing from acetylation, exerts pivotal control over diverse biological processes. Among these are gene transcriptional ...regulation, spermatogenesis, and cell cycle processes. However, the dynamic changes and functions of histone crotonylation in preimplantation embryonic development in mammals remain unclear. Here, we show that the transcription coactivator P300 functions as a writer of histone crotonylation during embryonic development. Depletion of P300 results in significant developmental defects and dysregulation of the transcriptome of embryos. Importantly, we demonstrate that P300 catalyzes the crotonylation of histone, directly stimulating transcription and regulating gene expression, thereby ensuring successful progression of embryo development up to the blastocyst stage. Moreover, the modification of histone H3 lysine 18 crotonylation (H3K18cr) is primarily localized to active promoter regions. This modification serves as a distinctive epigenetic indicator of crucial transcriptional regulators, facilitating the activation of gene transcription. Together, our results propose a model wherein P300-mediated histone crotonylation plays a crucial role in regulating the fate of embryonic development.Histone crotonylation has been shown to regulate transcription in multiple settings, but its role during preimplantation development has not been examined. Here they show that P300 regulated crotonylation during embryonic development and that H3K18cr marks active promoters in embryos, crucial for transcriptional activation and embryonic fate determination.
The patterns of communication among different chondrocyte subtypes in human cartilage degeneration and regeneration help us understand the microenvironment of osteoarthritis and optimize ...cell-targeted therapies. Here, a single-cell transcriptome dataset of chondrocytes is used to explore the synergistic and communicative patterns of different chondrocyte subtypes. We collected 1600 chondrocytes from 10 patients with osteoarthritis and analyzed the active communication patterns for the first time based on network analysis and pattern recognition at the single-cell level. Manifold learning and quantitative contrasts were performed to analyze conserved and specific communication pathways. We found that ProCs (Proliferative chondrocytes), ECs (Effector chondrocytes), preHTCs (Prehypertrophic chondrocytes), HTCs (Hypertrophic chondrocytes), and FCs (Fibrocartilage chondrocytes) are more active in incoming and outgoing signaling patterns, which is consistent with studies on their close functional cooperation. Among them, preHTCs play multiple roles in chondrocyte communication, and ProCs and preHTCs have many overlapping pathways. These two subtypes are the most active among all chondrocyte subtypes. Interestingly, ECs and FCs are a pair of "mutually exclusive" subtypes, of which ECs are predominant in incoming patterns and FCs in outgoing patterns. The active signaling pathways of ECs and FCs largely do not overlap. COLLAGEN and LAMININ are the main pivotal pathways, which means they are very important in the repair and expansion of joint homeostasis. Notably, only preHTCs assume multiple roles (including sender, receiver, mediator, and influencer) and are involved in multiple communication pathways. We have examined their communication patterns from the perspective of cellular interactions, revealed the relationships among different chondrocyte subtypes, and, in particular, identified a number of active subtypes and pathways that are important for targeted therapy in the osteoarthritic microenvironment. Our findings provide a new research paradigm and new insights into understanding chondrocyte activity patterns in the osteoarthritic microenvironment.
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