F&S science最新文献

Objective: To study the protective effects of bioactive peptides derived from whiteleg shrimp (Litopenaeus vannamei) by-products on testicular function in a rat model of nonalcoholic fatty liver disease (NAFLD).

Design: Experimental study.

Setting: Urmia University, Urmia, Iran.

Animals: Twenty-four adults male Wistar rats (8 weeks old, average weight 230.2 ± 23 g).

Exposure: Rats were divided into four groups (n=6): control (standard chow), high-fat diet (HFD), HFD + 20 mg peptide/kg body weight (BW), and HFD + 300 mg peptide/kg BW. Peptides were enzymatically hydrolyzed at 40-60°C, yielding 60-70% low molecular weight peptides (<500 Da), and administered via oral gavage for 10 weeks.

Main outcome measures: Spermatogenic indices (tubule diameter, Sertoli/Leydig cell counts, tubular differentiation index [TDI], spermiogenesis index [SPI]), oxidative stress markers (malondialdehyde [MDA], reduced glutathione [GSH], oxidized glutathione [GSSG], total antioxidant capacity [TAC]), autophagy-related gene expression (Beclin-1, Atg7, LC3-I, p62), and glucose/lactate transporter expression (GLUT1/3, MCT1/4) assessed via quantitative PCR and immunohistochemistry.

Results: HFD significantly reduced tubule diameter, Sertoli/Leydig cell numbers, TDI, and SPI while increasing MDA (11.7 ± 2.9 vs. 8.3 ± 1.0 nmol/mL, P < 0.05) and disrupting GSH/GSSG ratio (78.6 ± 8.7 vs. 48.2 ± 9.3, P < 0.05). Autophagy genes were upregulated, and GLUT/MCT expression decreased at mRNA and protein levels. Peptide supplementation, particularly at 300 mg/kg BW, dose-dependently reversed these effects by preserving tubular structure, normalizing oxidative markers (MDA: 8.8 ± 0.55 nmol/mL; GSH/GSSG: 51.5 ± 3.0), reducing autophagy gene expression, and enhancing GLUT/MCT expression in germ and Sertoli cells (P < 0.05), with superior efficacy at the higher dose.

Conclusions: Shrimp-derived bioactive peptides mitigate NAFLD-induced testicular dysfunction by modulating oxidative stress, autophagy pathways, and energy metabolism. They are promising natural therapeutics for preserving male fertility under metabolic stress and warrant clinical investigation.

Objective: To characterize the redistribution patterns of zinc and calcium ions during human sperm capacitation and to investigate their roles in sperm maturation and fertilization.

Design: In vitro experimental study using synchrotron-based x-ray fluorescence microscopy and complementary immunohistochemistry to assess elemental changes during different capacitation stages at nanometric spatial resolution.

Subjects: Semen samples collected from healthy donors, evaluated according to World Health Organization guidelines.

Exposure: None.

Main outcome measures: Nanometric distribution and quantification of zinc and calcium in different sperm region (head, midpiece, tail, and centriole) during different stages of capacitation.

Results: The x-ray fluorescence mapping allowed to evaluate the nanometric redistribution of zinc and calcium in human sperm during capacitation. Distinct "zinc signatures" were observed during different capacitation stages, with zinc initially abundant throughout the cell, later concentrating in the midpiece after capacitation, and further decreasing during acrosomal exocytosis. A persistent presence of zinc-rich areas at the centriole was also observed, which likely helps maintain the integrity of the head and midpiece. Concurrently, increased calcium levels in the flagellum during capacitation suggest potentially linked dynamics between zinc efflux and calcium influx. These findings provide new insight into elemental dynamics underlying sperm maturation and fertilization potential.

Conclusion: A deeper understanding of male fertility may be achieved by elucidating the multifaceted role of zinc in sperm function, particularly its interaction with calcium signaling pathways. By considering both the biochemical and ionic mechanisms alongside the physical aspects of sperm activity, a more precise assessment of sperm functionality becomes possible.

Objective: To investigate the effect of angiotensin II (Ang II) on proliferation and extracellular matrix (ECM) deposition in human uterine leiomyoma cells and normal myometrial cells.

Design: Experimental in vitro study using immortalized human leiomyoma (HuLM) cells, immortalized human uterine smooth muscle (UTSM) cells, and patient-derived primary fibroid and myometrial cells.

Subjects: Women with uterine fibroids who underwent hysterectomy.

Exposure: Administration of physiological and supraphysiological levels of Ang II (to mimic essential hypertension) to cultured HuLM, UTSM, primary fibroid, and myometrial cells to assess effects on cellular proliferation and ECM deposition.

Main outcome measures: We evaluated HuLM, UTSM, primary fibroid, and UTSM cells for the presence of the Ang II type 1 receptor. Angiotensin II-induced proliferation and ECM deposition was assessed through MTS assay, Western blot analysis, immunofluorescence, and real-time polymerase chain reaction.

Results: Immortalized and primary leiomyoma and myometrial cells expressed Ang II type 1 receptor. Leiomyoma cells responded to Ang II with increased cellular proliferation measured by MTS assay, proliferating cell nuclear antigen protein levels, and Ki67 staining. The Ang II treatment of fibroid cells showed increased expression of Collagen 1A1, the predominant fibroid and myometrial collagen. Integrin β1, an upstream regulator of fibrosis, also showed an increase in protein and messenger ribonucleic acid expression in fibroid cells treated with Ang II. No difference in proliferation or ECM production was observed in myometrial cell controls.

Conclusion: Angiotensin II promoted growth and matrix accumulation in fibroid cells, highlighting a potential link between fibroids and cardiovascular disease.

Objective: To study the levels of oxidant and antioxidant parameters, including total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI), in the follicular fluid of patients with diminished ovarian reserve (DOR) or unexplained infertility (UEI), to compare these groups, and to analyze the relationship between these parameters and antimüllerian hormone (AMH) levels.

Design: The study was planned and completed as a prospective cohort study.

Subjects: A total of 90 patients (n [DOR] = 45 and n [UEI] = 45) aged 23-38 years, who applied to undergo in vitro fertilization treatment between February 2024 and August 2024 and were diagnosed with DOR or UEI, were included in the study. Total oxidant status and TAS levels were determined in follicle fluid obtained during oocyte retrieval via double-antibody sandwich enzyme-linked immunosorbent assay.

Exposure: Patients categorized as having DOR or UEI.

Main outcome measures: Oocyte retrieval was performed on all patients, and follicular fluid was obtained simultaneously. Total antioxidant status and TOS values were measured in the follicular fluid, and the OSI value was calculated. Total antioxidant status, TOS, and OSI values were compared between the groups. The relationship between the three parameters and AMH levels was analyzed separately in each group. To analyze the relationship between low OSI values and AMH levels, mean OSI values within the group were determined. The AMH levels of the populations above and below the mean OSI value within the same group were compared.

Results: No significant differences in TAS, TOS, and OSI values were observed between groups. A significant positive correlation was found between TOS values and AMH levels in the DOR group. A statistically significant difference was found between AMH levels of the populations with OSI values above or below the mean in the UEI group. Antimüllerian hormone levels of the population with lower OSI values were higher. A high TOS value may not indicate that the AMH level is negatively affected. The AMH level may be negatively affected at high OSI values, indicating increased oxidative stress levels.

Conclusion: In evaluating the relationship between the oxidant-antioxidant system and infertility, it may not be appropriate to comment on the TOS or TAS value alone. The OSI value may significantly influence the AMH level.

Objective: To study the maternal contribution to early human embryogenesis by describing the transcriptional dynamics and regulatory roles of maternal effect genes (MEGs) and transcription factors (TFs) throughout the first four cell cycles. This will be achieved using parthenogenotes, such as the human uniparental bioconstruct model.

Design: Descriptive observational study based on single-cell transcriptomic analysis.

Subjects: A total of 19 single human parthenocytes were derived from six parthenogenotes at the first (n = 2), third (n = 2), and fourth (n = 2) cell cycles.

Exposure: Transcriptomic changes occurring during early embryonic development in the absence of paternal genomic input.

Main outcome measures: Transcript abundance of MEGs, expression levels of key TFs, number and identity of differentially expressed genes (DEGs), pathway enrichment associated with DEGs, transcriptional complexity, temporal patterns of MEG transcript decay and persistence and timing of embryonic genome activation (EGA).

Results: Transcriptomic analysis revealed progressive increases in transcriptional complexity, with major shifts between the third and fourth cell cycles coinciding with EGA. A total of 212 and 1,515 DEGs were identified in the third and fourth cycles, respectively (fold change ≥|2| vs. first cycle), predominantly involved in ribonucleic acid biosynthesis and cell proliferation pathways. Principal component and hierarchical clustering analyses showed distinct transcriptomic profiles by cell cycle and oocyte origin. Key TFs (DUXA, DUX4, Elk-1, E2F-1, Sp1) were implicated in cell cycle regulation. The MEG analysis revealed decay of transcripts associated with messenger ribonucleic acid clearance, alongside sustained expression of MEGs linked to cell cycle progression and spindle assembly, suggesting a nonrandom, structured maternal regulatory program.

Conclusion: This study provides the first comprehensive single-cell transcriptomic characterization of early human parthenogenotes, suggesting a structured, genome-driven maternal program that governs early embryonic development in the absence of paternal input. The identification of key TFs and MEG signature highlights the pivotal regulatory role of the maternal genome before EGA and may inform strategies to improve outcomes in assisted reproductive technologies.

Objective: To evaluate the feasibility of using endometrial stromal cells (EmSCs) and bone marrow-derived mesenchymal stem cells (BM-MSCs) as alternative sources of donor nuclei for somatic cell haploidization.

Design: To perform somatic cell haploidization, mouse metaphase II oocytes were enucleated and injected with the nucleus of cumulus cells (CCs), EmSCs or BM-MSCs. Intact metaphase II oocytes served as controls. Oocytes after haploidization and controls were inseminated and cultured up to 96 hours in a time-lapse incubator to assess embryo development and morphokinesis. Blastocysts were either cryopreserved for future genetic analysis or transferred to surrogate pseudo-pregnant mice.

Subjects: Female B2D2F1 mice (ooplasm donor), male B6-EGFP mice (spermatozoa donor), CD-1 female mice (surrogate) EXPOSURE: Enucleated oocytes underwent somatic cell nuclear transfer using the nucleus of CCs, EmSCs or BM-MSCs to generate functional oocytes. These oocytes are fertilized to generate conceptuses.

Main outcome measures: The primary outcome compared embryo development in the experimental groups vs. control. The secondary outcome was embryo morphokinetics evaluated with time-lapse microscopy.

Results: A total of 811 oocytes were enucleated, with a survival rate of 97.5%. Somatic cell nuclear transfer (SCNT) was performed using CCs (n = 90), EmSCs (n = 394), or BM-MSCs (n = 327), resulting in comparable somatic cell fusion rates of 95.2%, 96.0%, and 96.5%, respectively. Comparing the different SCNT groups, the CC cohort had a higher fertilization rate (45.6%) than the EmSC (30.8%) and BM-MSC (26.5%) cohorts. However, subsequent embryo development showed significant attrition in the CC cohort, where only 14.4% of CC embryos developed into blastocysts compared with 25.6% of EmSC embryos and 19.6% of BM-MSC embryos. In terms of embryo morphokinetics, all SCNT groups had slower embryo progression than the control group. However, EmSC and BM-MSC embryo development was faster than CC embryos from syngamy to the 8-cell stage (48.8 vs. 48.5 vs. 58.5 hours, respectively). All EmSC embryos and eight out of nine BM-MSC embryos displayed heterozygosity, confirming biparental contribution from the somatic cell and sperm genome. In the EmSC cohort, 42 blastocysts were transferred, yielding three healthy mouse pups (2 male, 1 female). All three pups displayed biparental inheritance, grew to adulthood and produced three healthy first-generation litters.

Conclusion: Somatic cell haploidization of EmSCs and BM-MSCs generated oocytes capable of full preimplantation development and yielded healthy offspring. The utilization of genotyped donor nuclei for neogametogenesis may represent a feasible fertility treatment option for individuals with complete absence of oocytes.