BACKGROUND

Managing low ovarian response remains challenging despite advancements in assisted reproductive technology (ART). Although several approaches have been proposed, there is no strong evidence that a particular stimulation protocol is superior over the other in terms of improving reproductive outcomes in this group of women. The double stimulation protocol (DuoStim) suggests ovarian stimulation during both the follicular phase and the luteal phase of the same ovarian cycle; hence, facilitating two oocyte retrievals in the shortest amount of time.

This study assessed the effect of the double stimulation protocol (DuoStim) on poor ovarian responders in terms of cumulative live birth rates and clinical pregnancy rates, and compared these outcomes to conventional stimulation protocols.

This is a systematic review and meta-analysis of randomized controlled trials (RCT), cohort and cross-sectional studies in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Data from eligible journals were tabulated and analyzed using Cochran’s Q and I² tests.

Eight studies involving poor ovarian responders were included in the meta-analysis. Pooled analysis demonstrated no significant difference between DuoStim and conventional ovarian stimulation protocols in clinical pregnancy rate (OR 0.99, 95% CI 0.75–1.30) and cumulative live birth rate (OR 0.87, 95% CI 0.59–1.28). Fertilization rates were likewise comparable between groups. Nevertheless, several included studies reported higher oocyte yield and greater numbers of mature oocytes and blastocysts with DuoStim

Current evidence does not demonstrate significant superiority of DuoStim over conventional ovarian stimulation protocols in terms of clinical pregnancy rates, cumulative live birth rates, or fertilization rates among poor ovarian responders. However, DuoStim appears to be an effective strategy for increasing oocyte yield within a shorter treatment timeframe. Its use may be particularly relevant in selected patients with diminished ovarian reserve, advanced maternal age, or urgent fertility preservation needs. Further high-quality prospective trials are warranted to clarify its impact on reproductive outcomes.

BACKGROUND

The benefits of preimplantation genetic testing for aneuploidy (PGT-A) in the advanced maternal age group are unclear.

This study aims to determine whether PGT-A improves pregnancy outcomes.

This is a retrospective cohort study of PGT-A outcomes using next generation sequencing for advanced maternal age women undergoing IVF at CARMI from May 2017 to May 2021. Women were grouped by age: those 35-39 and those 40 and above. Pregnancy rate (PR), live birth rate (LBR), and miscarriage rate (MR) were computed per transfer and per cycle and compared with women who underwent single day-5 frozen transfer of a morphologically chosen embryo.

Overall euploid blastocyst rate was 38.5%: 16.9% for 40 and above and 47.6% for 35- 39 group. There were no transfers in 41.4% due to absence of a euploid embryo. PR and LBR per embryo transfer were higher in the PGT-A versus the non-PGT-A group (61.9% vs 24.1% p = < 0.001 and 42.9% vs 19% p = < 0.001). By age, the findings were similar: higher PR and LBR per-embryo transfer in PGT-A versus non-PGT-A in the 35-39 group (58.4% and 29%, p = 0.006 and 42.9% vs 22.6%, p < 0.001 respectively) and 40 and above (71.4% vs 18.5%, p < 0.001 and 53.6% vs 14.8%, p < 0.001 respectively). MR was increased in the PGT-A versus non-PGT-A group, but this may be due to the small number of events in the population.

The study suggests an increase in PR and LBR per embryo transfer in advanced maternal age women undergoing PGT-A. A larger sample size is needed to validate the results.

OBJECTIVE: To observe the effect of "Zhibian" (BL54)-to-"Shuidao" (ST28) needling technique on the reproductive function of the mice with poor ovarian response (POR) and explore the molecular mechanism of acupuncture on early embryos after in vitro fertilization-embryo transfer (IVF-ET) in POR mice. METHODS: Of 70 female C57BL/6 mice, 60 mice with regular estrous cycle were screened and 30 of them were randomly divided into a blank group, a model group, and an acupuncture group, 10 mice in each one. Mice in the model and acupuncture groups were administered with tripterygium glycosides suspension (50 mg·kg^-1·d^-1) via gavage for 2 weeks to prepare POR models; while in the blank group, the mice received an equal volume of 0.9% sodium chloride solution via gavage. After successful modeling, mice in the acupuncture group underwent "Zhibian" (BL54)-to-"Shuidao" (ST28) needling technique, once daily, for 20 min each time and lasting 2 consecutive weeks. After intervention completion, subsequently, all the three groups underwent ovulation induction, orbital blood collection, and ovary extraction and fresh denuded oocyte collection. Denuded oocytes, after incubated, together with the sperms from 15 male C57BL/6 mice, were transferred into the oviducts of 30 donor pseudopregnant C57BL/6 female mice via IVF-ET; and the embryonic tissue was collected on day 7 of implantation. After successful modeling and intervention completion, the general conditions of mice in each group were observed, and the estrous cycle disorder rate was compared among the groups. After intervention completion, the numbers of oocyte, ovarian wet weight and ovarian index were recorded in each group; the levels of anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) in the serum were measured using ELISA; and ovarian morphology and mitochondrial ultrastructure were examined using HE staining and transmission electron microscopy. The transcriptome sequencing technology was employed to identify differentially expressed genes (DEGs) in early embryos of each group, followed by bioinformatics analysis; and the reversed DEGs with significant difference were verified using quantitative real-time PCR (qRT-PCR). RESULTS: After intervention, compared with the blank group, the mice in the model group presented poor spirits and declined water and food intake, reduced activity, the higher rate of estrous cycle disorder (P< 0.01); the decrease of the numbers of oocyte, ovarian wet weight, and ovarian index (P<0.01), reduced AMH and E2 in the serum (P<0.01), elevated FSH and LH in the serum (P<0.01); more atresia follicles in ovarian tissue, disorganized granulosa cells, reduced the numbers of mitochondria, vacuoles appeared and cristae breakage. When compared with the model group, in the acupuncture group, the spirits of mice, food intake and activity were improved, the rate of estrous cycle disorder was reduced (P<0.01); the numbers of oocyte, ovarian wet weight, and ovarian index were higher (P<0.01, P<0.05), the levels of AMH and E2 in the serum increased (P<0.01), the levels of FSH and LH in the serum decreased (P<0.01); the atresia follicles were reduced, the numbers of follicle increased at all levels, the numbers of mitochondria got higher, vacuoles and cristae breakage were declined. In comparison between the blank group and the model group, and between the model group and the acupuncture group, a total of 258 intersecting DEGs were identified, and 194 DEGs of them exhibited a trend of reversion before and after intervention. The top 5 reversed DEGs with significant difference included dexamethasone-induced Ras-related protein 1 (Rasd1), gene regulated by estrogen in breast cancer 1 (Greb1), leucine-rich repeat-containing G protein-coupled receptor 6 (Lgr6), Fraser syndrome 1 (Fras1), and apolipoprotein D (Apod). Compared with the blank group, the mRNA expression of Rasd1, Greb1, Lgr6, Fras1 and Apod in embryonic tissues decreased in the model group (P<0.01, P<0.05); and when compared with the model group, the mRNA expression of Rasd1, Greb1, Lgr6, Fras1 and Apod in embryonic tissues increased in the acupuncture group (P<0.05, P<0.01). These findings were consistent with the DEGs screening results. Gene ontology (GO) analysis revealed that the reversed genes of co-expression were primarily participated in the biological processes such as myoblast differentiation, endocardial cushion development, and cardiac morphogenesis. Kyoto encyclopedia of genes and genomes (KEGG) analysis indicated that the reversed genes of co-expression are enriched in the Wnt signaling pathway, and they were associated with various types of cardiac diseases. CONCLUSION The "Zhibian" (BL54)-to-"Shuidao" (ST28) needling technique may ameliorate the decline of ovarian response in mice with POR, promote normal follicle development and ovulation, thereby improve embryo quality and reduce the risk of developmental defects and deformity in the organs such as the embryonic heart. The underlying mechanism may be related to the regulation of the expression pattern of embryonic key genes through the Wnt signaling pathway.
Animals ; Female ; Mice ; Mice, Inbred C57BL ; Acupuncture Therapy ; Ovary/physiopathology* ; Humans ; Fertilization in Vitro ; Transcriptome ; Embryo Transfer ; Infertility, Female/physiopathology*

BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry

Collagen-based materials, renowned for their biocompatibility and minimal immunogenicity, serve as exemplary substrates in a myriad of biomedical applications. Collagen-based micro/nanogels, in particular, are valued for their increased surface area, tunable degradation rates, and ability to facilitate targeted drug delivery, making them instrumental in advanced therapeutics and tissue engineering endeavors. Although extensive reviews on micro/nanogels exist, they tend to cover a wide range of biomaterials and lack a specific focus on collagen-based materials. The current review offers an in-depth look into the manufacturing technologies, drug release mechanisms, and biomedical applications of collagen-based micro/nanogels to address this gap. First, we provide an overview of the synthetic strategies that allow the precise control of the size, shape, and mechanical strength of these collagen-based micro/nanogels by controlling the degree of cross-linking of the materials. These properties are crucial for their performance in biomedical applications. We then highlight the environmental responsiveness of these collagen-based micro/nanogels, particularly their sensitivity to enzymes and pH, which enables controlled drug release under various pathological conditions. The discussion then expands to include their applications in cancer therapy, antimicrobial treatments, bone tissue repair, and imaging diagnosis, emphasizing their versatility and potential in these critical areas. The challenges and future perspectives of collagen-based micro/nanogels in the field are discussed at the end of the review, with an emphasis on the translation to clinical practice. This comprehensive review serves as a valuable resource for researchers, clinicians, and scientists alike, providing insights into the current state and future directions of collagen-based micro/nanogel research and development.
Collagen/chemistry* ; Drug Delivery Systems/methods* ; Humans ; Tissue Engineering/methods* ; Animals ; Biocompatible Materials/chemistry*

Diterpenoid ferruginol is a key intermediate in biosynthesis of active ingredients such as tanshinone and carnosic acid.However, the traditional process of obtaining ferruginol from plants is often cumbersome and inefficient. In recent years, the increasingly developing gene editing technology has been gradually applied to the heterologous production of natural products, but the production of ferruginol in microbe is still very low, which has become an obstacle to the efficient biosynthesis of downstream chemicals, such as tanshinone. In this study, miltiradiene was produced by integrating the shortened diterpene synthase fusion protein,and the key genes in the MVA pathway were overexpressed to improve the yield of miltiradiene. Under the shake flask fermentation condition, the yield of miltiradiene reached about(113. 12±17. 4)mg·L~(-1). Subsequently, this study integrated the ferruginol synthase Sm CYP76AH1 and Sm CPR1 to reconstruct the ferruginol pathway and thereby realized the heterologous synthesis of ferruginol in Saccharomyces cerevisiae. The study selected the best ferruginol synthase(Il CYP76AH46) from different plants and optimized the expression of pathway genes through redox partner engineering to increase the yield of ferruginol. By increasing the copy number of diterpene synthase, CYP450, and CPR, the yield of ferruginol reached(370. 39± 21. 65) mg·L~(-1) in the shake flask, which was increased by 21. 57-fold compared with that when the initial ferruginol strain JMLT05 was used. Finally, 1 083. 51 mg·L~(-1) ferruginol was obtained by fed-batch fermentation, which is the highest yield of ferruginol from biosynthesis so far. This study provides not only research ideas for other metabolic engineering but also a platform for the construction of cell factories for downstream products.
Saccharomyces cerevisiae/genetics* ; Diterpenes/metabolism* ; Metabolic Engineering ; Fermentation ; Abietanes

Callicarpa is an important medicinal plant in China, which has hemostatic, antibacterial, and antioxidant pharmacological effects, and the efficacy of astringing and arresting bleeding, clearing heat and detoxification, activating blood, and resolving stasis is outstanding. At the same time, Callicarpa can be used as an ornamental plant because of its gorgeous flowers and fruits. Callicarpa has good market development prospects, but the long seed reproduction cycle directly limits the large demand for seedlings in its industrial development. Asexual reproduction technology is the basis for the industrialization development of Callicarpa, which is helpful in producing high-quality seedlings and medicinal materials. Although Chinese and foreign scholars have achieved remarkable results in the study of asexual reproduction of Callicarpa, there is no report on the large-scale production of seedlings of Callicarpa. Integrating and improving its asexual reproduction technology can promote the development and utilization of Callicarpa, improve its medicinal value, and create significant economic benefits. Therefore, the authors reviewed the effects of cutting, season, plant growth regulators, substrates, environment, and management measures on the cutting of Callicarpa and the research progress of tissue culture propagation affected by explants, basic media, exogenous additives, subculture cycles, culture conditions, and transplanting substrates. The mechanism of adventitious root formation was reviewed at the cellular, physiological, and biochemical levels, so as to put forward the problems and corresponding solutions in the study of asexual propagation technology and regulatory mechanism of Callicarpa and point out the future research directions. The study aims to provide a reference for in-depth research on the asexual propagation technology of Callicarpa and the commercial production of its high-quality seedlings.
Reproduction, Asexual ; Plants, Medicinal/physiology* ; Seedlings/growth & development* ; Tissue Culture Techniques

In this study, Saccharomyces cerevisiae R0 was used as the chassis cell to synthesize oleanolic acid from scratch through the heterologous expression of β-amyrin synthase(β-AS) from Glycyrrhiza uralensis, cytochrome P450 enzyme CYP716A154 from Catharanthus roseus, and cytochrome P450 reductase AtCPR from Arabidopsis thaliana. The engineered strain R1 achieved shake flask titres of 5.19 mg·L~(-1). By overexpressing enzymes in the pentose phosphate pathway(PPP)(ZWF1, GND1, TKL1, and TAL), the NADH kinase gene in the mitochondrial matrix(POS5), truncated 3-hydroxy-3-methylglutaryl-CoA reductase(tPgHMGR1) from Panax ginseng, and farnesyl diphosphate synthase gene(SmFPS) from Salvia miltiorrhiza, the precursor supply and intracellular reduced nicotinamide adenine dinucleotide phosphate(NADPH) supply were enhanced, resulting in an 11.4-fold increase in squalene yield and a 3.6-fold increase in oleanolic acid yield. Subsequently, increasing the copy number of the heterologous genes tPgHMGR1, β-AS, CYP716A154, and AtCPR promoted the metabolic flow towards the final product, oleanolic acid, and increased the yield by three times. Shake flask fermentation data showed that, by increasing the copy number, precursor supply, and intracellular NADPH supply, the final engineered strain R3 could achieve an oleanolic acid yield of 53.96 mg·L~(-1), which was 10 times higher than that of the control strain R1. This study not only laid the foundation for the green biosynthesis of oleanolic acid but also provided a reference for metabolic engineering research on other pentacyclic triterpenoids in S. cerevisiae.
Oleanolic Acid/biosynthesis* ; Saccharomyces cerevisiae/metabolism* ; Industrial Microbiology ; Microorganisms, Genetically-Modified/metabolism* ; Plants/enzymology* ; Fermentation ; Metabolic Engineering

Many triterpenoid compounds have been successfully heterologously synthesized in Saccharomyces cerevisiae. To increase the yield of triterpenoids, various metabolic engineering strategies have been developed. One commonly applied strategy is to enhance the supply of precursors, which has been widely used by researchers. Squalene, as a precursor to triterpenoid biosynthesis, plays a crucial role in the synthesis of these compounds. This study primarily investigates the effect of different squalene levels in chassis strains on the synthesis of triterpenoids(oleanolic acid and ursolic acid), and the underlying mechanisms are further explored using real-time quantitative PCR(qPCR) analysis. The results demonstrate that the chassis strain CB-9-5, which produces high levels of squalene, inhibits the synthesis of oleanolic acid and ursolic acid. In contrast, chassis strains with moderate to low squalene production, such as Y8-1 and CNPK, are more conducive to the synthesis of oleanolic acid and ursolic acid. The qPCR analysis reveals that the expression levels of ERG1, βAS, and CrCYP716A154 in the oleanolic acid-producing strain CB-OA are significantly lower than those in the control strains C-OA and Y-OA, suggesting that high squalene production in the chassis strains suppresses the transcription of certain genes, leading to a reduced yield of triterpenoids. Our findings indicate that when constructing S. cerevisiae strains for triterpenoid production, chassis strains with high squalene content may suppress the expression of certain genes, ultimately lowering their production, whereas chassis strains with moderate squalene levels are more favorable for triterpenoid biosynthesis.
Squalene/analysis* ; Saccharomyces cerevisiae/genetics* ; Triterpenes/metabolism* ; Metabolic Engineering ; Oleanolic Acid/biosynthesis* ; Ursolic Acid

As a high-quality moxibustion material, Artemisia stolonifera has high economic value and research prospects. However, due to difficulties in seed germination, its wild germplasm resources are sparsely distributed in China. This study used young stem segments grown in the current year to investigate the effects of explant sterilization, different combinations and concentrations of plant growth regulators on the proliferation and rooting of adventitious shoots, with the aim of constructing an in vitro rapid propagation technology system for A. stolonifera. The results showed that the lowest contamination rate of 25.83% was achieved when sterilizing the stem segments by rinsing with running water for 30 min, soaking in 75% ethanol for 30 s, followed by a 5 min treatment with 0.1% HgCl_2, 10 min with 8% NaClO, and 10 min with 0.6% phytosaniline. There was no browning of the stem segments, and surface sterilization of the A. stolonifera stem segments was successfully achieved. In the induction culture phase, when the concentration of kinetin(KT) was 0.05 mg·L~(-1) and 6-benzylaminopurine(6-BA) was 0.05 mg·L~(-1), the adventitious shoot proliferation coefficient was 2.02, effectively promoting the proliferation and growth of A. stolonifera. In the rooting culture phase, 0.1 mg·L~(-1) 1-naphthaleneacetic acid(NAA) effectively induced A. stolonifera test-tube seedlings to root within a short period, achieving a rooting rate of 100%. The addition of a small amount of activated charcoal also promoted rooting and strengthened seedling growth. The survival rate of A. stolonifera seedlings transplanted into a substrate consisting of 90% nutrient soil and 10% perlite was 100%. This study established an efficient in vitro rapid propagation system for A. stolonifera, overcoming difficulties with seed germination, shortening the breeding cycle, and reducing production and planting costs. It provides technical support for the introduction, domestication, seedling propagation, germplasm conservation, and industrial development of A. stolonifera.
Artemisia/drug effects* ; Tissue Culture Techniques/methods* ; Plant Growth Regulators/pharmacology* ; Plant Stems/drug effects* ; Plant Shoots/drug effects*