This study aims to investigate the effects of polystyrene microplastics (PS-MPs) on the entire female reproductive cycle and to elucidate the molecular mechanisms underlying their adverse impact on female ovaries. Additionally, it develops an in vitro follicle culture system as a novel methodological approach to evaluate reproductive toxicity, mimicking in vivo reproductive outcomes. First, PS-MPs were characterized using FTIR spectroscopy, TEM, and fluorescence microscopy. To assess reproductive toxicity, female mice were exposed to polystyrene microplastics (PS-MPs) at a dose of 30 mg/kg with an average particle size of 1 μm for 35 days. As a result, PS-MPs accumulated in the ovaries, leading to increased follicular atresia and apoptosis of granulosa cells. TEM revealed abnormal mitochondrial morphology in granulosa cells. Post-superovulation treatment, significant differences were noted in the number of ovulated metaphase II (MII) oocytes, spindle chromosome integrity, mitochondrial patterns, and ROS levels compared to controls. Mating with PS-MPs-exposed females led to fewer offspring. The in vitro follicle culture system proved promising for assessing PS-MPs reproductive toxicity. Immunohistochemistry showed increased Cleaved Caspase 3 and decreased Bcl2 levels in PS-MPs-treated groups, indicating apoptosis in granulosa cells. PS-MPs activate JNK and ERK pathways to mediate cell death, while impairing AKT signaling, reducing granulosa cell survival and ovarian function. This study highlights PS-MPs adverse reproductive effects and aids in developing strategies to protect female reproductive health.

This study aimed to derive mature oocytes from murine preantral follicles cultured in a biomimetic ovary with a porcine scaffold using decellularization technology. We evaluated the DNA content and the presence of cell and extracellular matrix (ECM) components, including collagen, elastin, and glycosaminoglycans (GAGs), in decellularized (decell) porcine ovaries. The DNA content inthe decell ovarian tissues was approximately 94 % less than that in native tissues (66 ± 9.8 ng/mg vs. 1139 ± 269 ng/mg). Furthermore, the ECM component integrity was maintained in the decell ovarian tissue. The soluble collagen concentration of native ovarian tissue (native) was 195.34 ± 15.13 μg/mg (dry wt.), which was less than 878.6 ± 8.24 μg/mg for the decell ovarian tissue due to the loss of cellular mass. Hydrogels derived from decell porcine ovaries were prepared to develop an in vitro biomimetic ovary with appropriate ECM concentration (2−6 mg/mL). Scanning electron microscope (SEM) imagining revealed that the complex fiber network and porous structure were maintained in all groups treated with varying ECM concentration (2–6 mg/mL). Furthermore, rheometer analysis indicated that mechanical strength increased with ECM concentration in a dose-dependently. The preantral follicles cultured with 4 mg/mL ECM showed high rates of antral follicle (66 %) and mature oocyte (metaphase II) development (47 %). The preantral follicles cultured in a biomimetic ovary with a decell porcine scaffold showed a higher rate of antral follicle and mature oocytes than those cultured in other biomaterials such as collagen and Matrigel. In mature oocytes derived from antral follicles, meiotic spindles and nuclei were stained using a tubulin antibody and Hoechst, respectively. Two-cell embryos were developed from MII oocytes following parthenogenetic activation. Preantral follicles were cultured in a biomimetic ovary derived from the ECM of a decell porcine ovary, and embryos were generated from MII oocytes. This biomimetic ovary could contribute to restoring fertility in infertile women with reduced ovarian function, benefit mating efforts for endangered species, and maintain animals with valuable genetic traits.

When ejaculated sperm travels through the vagina to the uterus, mucus secreted by the cervical canal generally filters out sperm having low motility and poor morphology. To investigate this selection principle in vivo, we developed a microfluidic sperm-sorting chip with a viscous medium (polyvinylpyrrolidone: PVP) to imitate the biophysical environment mimic system of the human cervical canal. The material property of the PVP solution was tuned to the range of viscosities of cervical mucus using micro-viscometry. The selection of high-quality human sperm was experimentally evaluated in vitro and theoretically analyzed by the convection-diffusion mechanism. The convection flow is shown to be dominant at low viscosity of the medium used in the sperm-sorting chip when seeded with raw semen; hence, the raw semen containing sperm and debris convectively flow together with suppressed relative dispersions. Also, it was observed that the sperm selected via the chip not only had high motilities but also normal morphologies and high DNA integrity. Therefore, the biomimetic sperm-sorting chip with PVP medium is expected to improve male fertility by enabling the selection of high-quality sperm as well as uncovering pathways and regulatory mechanisms involved in sperm transport through the female reproductive tract for egg fertilization.

Organoids are mini-organs generated through in vitro 3-dimensional culture that mimic some of the structural and physiological functions of real organs. In recent research, various organoids have been derived from pluripotent stem cells or multipotent organ-specific adult stem cells in vitro and have been used in regenerative medicine, disease modeling, precision medicine, toxicology studies, and drug discovery. However, research on reproduction-related organoids has not been comprehensive, and some limitations need to be addressed for culturing these organoids. In this review, we discuss the historical advances, major recent developments, limitations, and potential of organoid culture, including human reproductive organoids.

Cancer stem cells (CSCs) are a tumor cell subpopulation that drives tumor progression and metastasis, leading to a poor overall survival of patients. In colorectal cancer (CRC), the hyper-activation of Wnt/β-catenin signaling by a mutation of both adenomatous polyposis coli (APC) and K-Ras increases the size of the CSC population. We previously showed that CPD0857 inactivates Wnt/β-catenin signaling by promoting the ubiquitin-dependent proteasomal degradation of β-catenin and Ras proteins, thereby decreasing proliferation and increasing the apoptosis of CRC lines. CPD0857 also decreased the growth and invasiveness of CRC cells harboring mutant K-Ras resistant to EGFR mAb therapy. Here, we show that CPD0857 treatment decreases proliferation and increases the neuronal differentiation of neural progenitor cells (NPCs). CDP0857 effectively reduced the expression of CSC markers and suppressed self-renewal capacity. CPD0857 treatment also inhibited the proliferation and expression of CSC markers in D-K-Ras MT cells carrying K-Ras, APC and PI3K mutations, indicating the inhibition of PI3K/AKT signaling. Moreover, CPD0857-treated xenograft mice showed a regression of tumor growth and decreased numbers of CSCs in tumors. We conclude that CPD0857 could serve as the basis of a drug development strategy targeting CSCs activated through Wnt/β-catenin-Ras MAPK-PI3K/AKT signaling in CRCs.