Zongliang Jiang

Chronic wound care seeks natural biomimetic materials to improve the regeneration of functional tissues while reversing the damage-induced state that impairs healing. This study proposes a bovine placental-derived natural bio-ink for 3D printing, composed of droplets encapsulating placental collagen type I (COL 1) and amniotic fluid-derived extracellular vesicles (AF-EVs). It hypothesizes that COL 1 from bovine placenta can better replicate human tissue environments, leveraging placenta’s rich regenerative and biochemical properties. Amniotic fluid is a rich source of EVs, which have demonstrated anti-inflammatory, angiogenic, regenerative and anti-senescent properties. A bioink combining these components provides both structural support and the potential to reprogram the wound microenvironment of chronic wounds. Here, it is shown that bovine placental collagen exhibits high purity and enhanced biocompatibility compared to commercial collagen, while AF-EVs improve wound closure and reduce markers of cellular senescence. Together, these findings support the use of a placental-derived bioink for promoting regeneration and restoring function in chronic wounds.

The derivation of authentic embryonic stem cells (ESCs) across mammalian species remains a major challenge. Here, we report the development of a defined, serum-free culture system, termed 6iL/E4, that enables the derivation and long-term self-renewal of ESCs across diverse mammalian species. Through systematic dissection of signaling pathways, we identified conserved regulatory modules involving GSK3α, WNT, STAT3, PDGFR, and MEK/ERK signaling. The optimized 6iL/E4 conditions support stable derivation and expansion of ESCs from mouse, rat, rabbit, and bovine embryos. For rabbit, ESC derivation required supplementation with the LATS inhibitor TDI-011536 (TDI), and 6iL/TDI-cultured rabbit ESCs exhibited chimera-forming capability. In bovine ESCs, inducible expression of Klf2 and Nanog reinforced pluripotency and promoted in vivo chimeric contribution. Importantly, we demonstrated that 6iL robustly establishes and maintains human pluripotent stem cells in a naïve-like state. These findings reveal conserved principles underlying ESC self-renewal across divergent mammalian species and provide a universal platform for cross-species stem cell research, disease modeling, and biotechnological applications.

Cannabis (marijuana) is the most widely used recreational drug in the USA accounting for about 62 million users in 2024. Among cannabis users, 26% are of prime reproductive age (18-25 years). Delta-9 tetrahydrocannabinol (THC) is the principal psychoactive component of cannabis and has been detected in human seminal fluids. Although abundant evidence indicates adverse effects of THC exposure on spermatogenesis in different species, acute effects of THC on postejaculatory sperm including fertilization potential and subsequent carryover effects on embryo development are largely unknown. The present study was designed to provide missing information on structural and mechanistic effects of THC exposure to postejaculatory sperm function by evaluating sperm indices often overlooked or masked during clinical evaluation. A bovine embryo continuum model was employed to determine effects of THC on sperm structure, kinematics, bioenergetics, and binding mechanisms. Effects of THC on the sperm genomic and epigenomic landscape were determined, complemented by paternal carry over effects on embryo development as a human translational model to elucidate paternal effects on future development, and to mirror sperm exposure during transport within the female reproductive tract. Cryopreserved bovine sperm from three bulls were independently exposed to physiologically relevant concentrations of THC (0 and 32nM, n = 2 individual replicates/bull) for 24 h under non-capacitating conditions at 25°C followed by quantification of sperm kinematics at 37°C. Samples of THC-exposed sperm and vehicle-control (0.1% DMSO) were collected in replicate following immediate addition of THC (0 h) and again at 24 h. DNA damage, acrosome integrity, bioenergetics, changes to DNA methylation and embryo development were quantified. Data were analyzed by logistic regression with a generalized linear mixed effect model. Computer-assisted sperm assessment revealed a reduction in progressive motility of THC-exposed sperm after 24 h while other parameters were not affected. Acrosome integrity as determined by flowcytometric analysis with FITC-PSA was severely compromised in THC-exposed sperm (P ≤ 0.05), despite no detectable difference in capacitation status using merocyanine staining. Similarly, DNA integrity as determined by TUNEL assay was significantly impaired after 24 h of THC exposure (P ≤ 0.05). Mechanistic effects of THC were explored through characterization of the transmembrane G-protein coupled cannabinoid 1 receptor (CB1). CB1 is expressed in the post-acrosomal region and its abundance decreased as compared to unexposed sperm. Alterations to the methylation landscape of sperm were then determined after 24 h of THC exposure through whole-genome Enzymatic Methyl Sequencing. PCA analysis indicated that sperm from different males formed distinct clusters, implying individual differences among bulls, while the effects of THC exposure produced tighter clusters. Paternal carryover effects on embryos derived by in vitro fertilization from THC exposed sperm had reduced 2-cell cleavage, 8-16 cell morula development, and reduced blastocyst development compared to unexposed sperm (46% vs. 33%). In conclusion, post-ejaculatory mammalian sperm exposure to THC compromises acrosome integrity, induces DNA damage, changes the sperm methylome, and reduces developmental potential. Collectively, these data implicate new considerations for recreational and clinical use of cannabis that impact cellular and molecular mechanisms important for sperm function with detrimental consequences for gamete interaction and embryo development.

Recent advances in technologies that replicate specific aspects of embryogenesis in vitro by using stem cells have opened new frontiers in our understanding of the earliest steps of mammalian development and creation of promising novel assisted reproductive technologies (ARTs). We begin by summarizing the widely used ARTs in improving animal reproduction. We then explore current progress in deriving embryo-based stem cells from livestock species and highlight the latest breakthroughs in blastoid generation. Furthermore, we examine the potential applications of blastoids in domestic livestock and discuss key challenges and future directions for advancing blastoid models that closely mimic natural embryonic development.

The rapid emergence of stem cell-based embryo models, such as blastocyst-like structures, or blastoids, leverages the remarkable self-organizing capabilities of cultured stem cells to generate structured, multicellular assemblies that replicate specific aspects of embryogenesis. This breakthrough opens new frontiers for our understanding of the earliest steps of embryogenesis and creation of promising innovative ARTs aimed at enhancing reproductive efficiency in cattle. This review begins by summarizing the bovine pluripotent stem cells including embryo-derived stem cells and induced pluripotency. Then the current progresses in generating bovine stem cell-derived embryos, blastoids, are explored. Finally, the potential application of bovine blastoid technology for in vitro breeding, and the key challenges and future directions are discussed.

Translational regulation plays a pivotal role during pre-implantation development. However, the mechanisms by which messenger RNAs (mRNAs) are selectively regulated over time, along with their dynamic utilization and fate during this period, remain largely unknown. Here, we performed fraction-resolved polysome profiling and characterized translational dynamics across oocytes and early embryo development. This approach allowed us to examine the changes in translation during pre-implantation development in high resolution and uncover previously unrecognized modes of translational selectivity. We observed a stage-specific delay in translation, characterized by the postponed recruitment of stored mRNAs-either unbound or associated with light ribosomal fractions-into actively translating polysomes (heavy fraction). Comparative analysis of translatome with proteomics, RNA N6-methyladenosine modifications, and mRNA features further revealed both coordinated and distinct regulatory mechanisms during pre-implantation development. Furthermore, we identified a eukaryotic initiation factor 1A domain containing 3, Eif1ad3, which is exclusively translated at the two-cell stage and is essential for embryonic development by regulating ribosome biogenesis and protein synthesis. Collectively, our study provides a valuable resource of spatiotemporal translational regulation in mammalian pre-implantation development and highlights a previously uncharacterized translation initiation factor critical for early embryos.

RNA N ⁶ -methyladenosine (m ⁶ A) plays a crucial role in regulating gene expression during early embryonic development. However, the m ⁶ A dynamics at single-nucleotide resolution in preimplantation development remain uncharacterized, and the functional significance of site specific m ⁶ A modifications in key developmental regulators is largely unknown. Here, using SAC-seq, a single-base resolution, antibody-independent m ⁶ A profiling method, we generate the first comprehensive m ⁶ A landscape in bovine oocytes and preimplantation embryos. We identify a previously uncharacterized m ⁶ A site in RPL12 transcript that is essential for embryonic development. Loss of m ⁶ A at this site leads to reduced protein synthesis, disrupted expression of translation-related genes, and impaired zygotic genome activation and blastocyst formation. Notably, supplementation with wild-type RPL12 mRNA fails to rescue the developmental arrest, indicating that m ⁶ A regulation extends beyond transcript abundance. Our findings provide a valuable resource of m ⁶ A at single-nucleotide resolution in mammalian embryogenesis and uncover a critical mechanism by which precise, site-specific m ⁶ A regulates translation and developmental competence in early embryos.

The derivation of authentic embryonic stem cells (ESCs) from diverse mammalian species offers valuable opportunities for advancing regenerative medicine, studying developmental biology, and enabling species conservation. Here, we report the development of a robust, serum-free culture system, termed 6iL/E4 that enables the derivation and long-term self-renewal of ESCs from multiple mammalian species, including mouse, rat, bovine, rabbit, and human. Using systematic signaling pathway analysis, we identified key regulators—including GSK3α, STAT3, PDGFR, BRAF, and LATS—critical for ESC maintenance across species. Additionally, inducible expression of KLF2 and NANOG enhances the naive pluripotency and chimeric potential of bovine ESCs. The E4 medium also supports stable ESC growth while minimizing lineage bias. These findings reveal conserved principles underlying ESC self-renewal across divergent mammalian species and provide a universal platform for cross-species stem cell research, disease modeling, and biotechnology applications. In Brief Wang et al. developed 6iL/E4, a serum-free system sustaining ESCs from mouse, rat, bovine, rabbit, and human. These findings reveal conserved fundamental mechanisms governing ESC self-renewal across diverse mammalian species. Highlights Developed 6iL/E4 system for ESC derivation across five mammalian species. PDGFR signaling inhibition as critical for ESC derivation across species. E4 medium improves ESC maintenance and avoids neural bias of traditional N2B27. Inducible KLF2/NANOG enhances naive pluripotency and chimera formation in bovine.