Strategies for the efficient biosynthesis of ß-carotene through microbial fermentation.

ß-Carotene is an orange fat-soluble compound, which has been widely used in fields such as food, medicine and cosmetics owing to its anticancer, antioxidant and cardiovascular disease prevention properties. Currently, natural ß-carotene is mainly extracted from plants and algae, which cannot meet the growing market demand, while chemical synthesis of ß-carotene cannot satisfy the pursuit for natural products of consumers. The ß-carotene production through microbial fermentation has become a promising alternative owing to its high efficiency and environmental friendliness. With the rapid development of synthetic biology and in-depth study on the synthesis pathway of ß-carotene, microbial fermentation has shown promising applications in the ß-carotene synthesis. Accordingly, this review aims to summarize the research progress and strategies of natural carotenoid producing strain and metabolic engineering strategies in the heterologous synthesis of ß-carotene by engineered microorganisms. Moreover, it also summarizes the adoption of inexpensive carbon sources to synthesize ß-carotene as well as proposes new strategies that can further improve the ß-carotene production.

MAX deficiency impairs human endometrial decidualization through down-regulating OSR2 in women with recurrent spontaneous abortion.

Human uterine stromal cell undergoes decidualization for pregnancy establishment and maintenance, which involved extensive proliferation and differentiation. Increasing studies have suggested that recurrent spontaneous abortion (RSA) may result from defective endometrial stromal decidualization. However, the critical molecular mechanisms underlying impaired decidualization during RSA are still elusive. By using our recently published single-cell RNA sequencing (scRNA-seq) atlas, we found that MYC-associated factor X (MAX) was significantly downregulated in the stromal cells derived from decidual tissues of women with RSA, followed by verification with immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR). MAX knockdown significantly impairs human endometrial stromal cells (HESCs) proliferation as determined by MTS assay and Ki67 immunostaining, and decidualization determined by F-actin, and decidualization markers. RNA-seq together with chromatin immunoprecipitation sequencing (ChIP-seq) and cleavage under targets and release using nuclease sequencing (CUT&RUN-seq) analysis were applied to explore the molecular mechanisms of MAX in regulation of decidualization, followed by dual-luciferase reporter assay to verify that MAX targets to (odd-skipped related transcription factor 2) OSR2 directly. Reduced expression of OSR2 was also confirmed in decidual tissues in women with RSA by IHC and qRT-PCR. OSR2 knockdown also significantly impairs HESCs decidualization. OSR2-overexpression could at least partly rescue the downregulated insulin-like growth factor binding protein 1 (IGFBP1) expression level in response to MAX knockdown. Collectively, MAX deficiency observed in RSA stromal cells not only attenuates HESCs proliferation but also impairs HESCs decidualization by downregulating OSR2 expression at transcriptional level directly.

A clinical prognostic model related to T cells based on machine learning for predicting the prognosis and immune response of ovarian cancer.

Background: Ovarian cancer (OV) is regarded as one of the most lethal malignancies affecting the female reproductive system, with individuals diagnosed with OV often facing a dismal prognosis due to resistance to chemotherapy and the presence of an immunosuppressive environment. T cells serve as a crucial mediator for immune surveillance and cancer elimination. This study aims to analyze the mechanism of T cell-associated markers in OV and create a prognostic model for clinical use in enhancing outcomes for OV patients. Methods: Based on the single-cell dataset GSE184880, this study used single-cell data analysis to identify characteristic T cell subsets. Analysis of high dimensional weighted gene co-expression network analysis (hdWGCNA) is utilized to identify crucial gene modules along with their corresponding hub genes. A grand total of 113 predictive models were formed utilizing ten distinct machine learning algorithms along with the combination of the cancer genome atlas (TCGA)-OV dataset and the GSE140082 dataset. The most dependable clinical prognostic model was created utilizing the leave one out cross validation (LOOCV) framework. The validation process for the models was achieved by conducting survival curve analysis and receiver operating characteristic (ROC) analysis. The relationship between risk scores and immune cells was explored through the utilization of the Cibersort algorithm. Additionally, an analysis of drug sensitivity was carried out to anticipate chemotherapy responses across various risk groups. The genes implicated in the model were authenticated utilizing qRT-PCR, cell viability experiments, and EdU assay. Results: This study developed a clinical prognostic model that includes ten risk genes. The results obtained from the training set of the study indicate that patients classified in the low-risk group experience a significant survival advantage compared to those in the high-risk group. The ROC analysis demonstrates that the model holds significant clinical utility. These results were verified using an independent dataset, strengthening the model's precision and dependability. The risk assessment provided by the model also serves as an independent prognostic factor for OV patients. The study also unveiled a noteworthy relationship between the risk scores calculated by the model and various immune cells, suggesting that the model may potentially serve as a valuable tool in forecasting responses to both immune therapy and chemotherapy in ovarian cancer patients. Notably, experimental evidence suggests that PFN1, one of the genes included in the model, is upregulated in human OV cell lines and has the capacity to promote cancer progression in in vitro models. Conclusion: We have created an accurate and dependable clinical prognostic model for OV capable of predicting clinical outcomes and categorizing patients. This model effectively forecasts responses to both immune therapy and chemotherapy. By regulating the immune microenvironment and targeting the key gene PFN1, it may improve the prognosis for high-risk patients.

Impact of Abnormal DNA Methylation of Imprinted Loci on Human Spontaneous Abortion.

Currently, there is a growing concern regarding the safety of assisted reproductive technology (ART) due to increased risk of spontaneous abortion (SA) and imprinting disorders in ART-conceived offspring. Early investigations suggested that aberrant genetic imprinting may be related to pregnancy loss; however, few studies have used human tissue specimens. Here the DNA methylation patterns of 3 imprinted genes, including maternally inherited GRB10 and the paternally inherited IGF2 and PEG3 genes, were evaluated in human chorionic villus samples by pyrosequencing and bisulfite sequencing polymerase chain reaction. The samples were divided into 4 groups: (1) SA of natural conception (NC; n = 84), (2) induced abortion of NC (n = 94), (3) SA after ART (n = 73), and (4) fetal reduction after ART (n = 86). The methylation levels and the percentages of abnormal methylation of the IGF2, GRB10, and PEG3 genes between the ART group and the NC group showed no significant difference. Both IGF2 and GRB10 genes showed higher methylation levels in the SA group compared to the non-SA group. Additionally, determining the single-nucleotide polymorphisms of 4 loci, including IGF2 rs3741205, rs3741206, rs3741211, and GRB10 rs2237457, showed that the TC+CC genotype of IGF2 rs3741211 had a 1.91-fold increased risk of SA after ART. However, there was no association between the mutant genotype of IGF2 rs3741211 and the methylation levels of IGF2 and H19, and ART might not affect the distribution of the abovementioned genotypes. It provides support for the opinion that genetic imprinting defects may be associated with SA, which might not be due to ART treatments.

[Successful pregnancy following intracytoplasmic sperm injection?embryo transfer in a patient with premature ovarian insufficiency: a case report].

OBJECTIVE: We report a case of ovarian function fluctuation during long-term follow-up in a patient with premature ovarian insufficiency (POI). The patient finally obtained clinical pregnancy with subsequent uneventful full-term delivery after several intracytoplasmic sperm injection-embryo transfer (ICSI-ET) cycles. This case demonstrates that hormone replacement therapy (HRT) and assisted reproductive therapy should be applied as soon as possible to young patients with POI who have a strong desire for pregnancy in the absence of contraindications. This strategy helps such patients obtain pregnancy and delivery before the exhaustion of ovarian function.

[Pregnancy outcome in a woman with premature ovarian insufficiency complicated by systemic lupus erythematosus during pregnancy: a case report].

OBJECTIVE: We report a case of in vitro fertilization and embryo transfer (IVF?ET) with oocyte donation in a woman with premature ovarian insufficiency (POI) complicated by systemic lupus erythematosus (SLE) during pregnancy. The patient had a diagnosis of POI 4 years earlier and 11 weeks after successful pregnancy by IVF?ET with oocyte donation in 2003, she presented with facial edema, and further examinations confirmed the diagnosis of lupus nephritis. She received treatment with prednisone to control the activity of SLE and aspirin and low?molecular?weight heparin to improve placental blood flow with close monitoring of gravida and fetus throughout pregnancy. The condition of the patient remained unstable during pregnancy, and liver damage and placental circulation disorder occurred in late gestational weeks with suspected intrauterine growth retardation (IUGR) of the fetus. For maternal and fetal safety, the patient received elective caesarean section and delivered a premature boy at 31 weeks of gestation. She subsequently received further medications for SLE and showed good recovery of the immunological parameters and absence of SLE symptoms during the follow?up for 14 years, indicating a clinical cure of SLE. Her son shows normal growth and development. Based on the experience with this case and literature review, we believe that immunological factor is an important cause of POI and thus recommend full immunological examinations in cases of idiopathic POI.

An overview of chronic myeloid leukemia and its animal models.

Chronic myeloid leukemia (CML) is a form of leukemia characterized by the presence of clonal bone marrow stem cells with the proliferation of mature granulocytes (neutrophils, eosinophils, and basophils) and their precursors. CML is a type of myeloproliferative disease associated with a characteristic chromosomal translocation called the Philadelphia (Ph) chromosome or t (9;22) translocation (BCR-ABL). CML is now usually treated with targeted drugs called tyrosine kinase inhibitors (TKIs). The mechanism and natural history of CML is still unclear. Here, we summarize the present CML animal disease models and compare them with each other. Meanwhile, we propose that it is a very wise choice to establish zebrafish (Danio rerio) CML model mimics clinical CML. This model could be used to learn more about the mechanism of CML, and to aid in the development of new drugs to treat CML.