Development of decellularization protocols for female cat reproductive organs.

Decellularization is an innovative method to create natural scaffolds by removing all cellular materials while preserving the composition and three-dimensional ultrastructure of the extracellular matrix (ECM). The obtention of decellularized reproductive organs in cats might facilitate the development of assisted reproductive techniques not only in this species but also in other felids. The aim was to compare the efficiency of three decellularization protocols on reproductive organs (ovary, oviduct, and uterine horn) in domestic cats. The decellularization protocol involved 0.1% sodium dodecyl sulfate and 1%Triton X-100. Protocol 1 (P1) entailed 2-cycles of decellularization using these detergents. Protocol 2 (P2) was like P1 but included 3-cycles. Protocol 3 (P3) was similar to P2, with the addition of deoxyribonuclease incubation. Reproductive organs from nine cats were separated into two sides. One side served as the control (non-decellularized organ) while the contralateral side was the treated group (decellularized organ). The treated organs were subdivided into 3 groups (n = 3 per group) for each protocol. Both control and treated samples were analyzed for DNA content, histology (nuclear and ECM (collagen, elastin, and glycosaminoglycans (GAGs)) density), ultrastructure by electron microscopy, and cytotoxicity. The results of the study showed that P3 was the only protocol that displayed no nucleus residue and significantly reduced DNA content in decellularized samples (in all the studied organs) compared to the control (P < 0.05). The ECM content in the ovaries remained similar across all protocols compared with controls (P > 0.05). However, elastic fibers and GAGs decreased in decellularized oviducts (P < 0.05), while collagen levels remained unchanged (P > 0.05). Regarding the uterus, the ECM content decreased in decellularized uterine horns from P3 (P < 0.05). Electron microscopy revealed that the microarchitecture of the decellularized samples was maintained compared to controls. The decellularized tissues, upon being washed for 24 h, showed cytocompatibility following co-incubation with sperm. In conclusion, when comparing different decellularization methods, P3 proved to be the most efficient in removing nuclear material from reproductive organs compared to P1 and P2. P3 demonstrated its success in decellularizing ovarian samples by significantly decreasing DNA content while maintaining ECM components and tissue microarchitecture. However, P3 was less effective in maintaining ECM contents in decellularized oviducts and uterine horns.

Expression of IZUMO1 and JUNO in the gonads of domestic cats (Felis catus).

Because of the time-consuming nature of surgical neutering and the rapid rate of reproduction among domestic cats, it is crucial to investigate alternative, nonsurgical methods of contraception for this species. Sperm protein IZUMO1 and its oocyte receptor JUNO have been proposed as potential targets for nonsurgical contraceptives. This study aimed to demonstrate (1) the protein coding sequence of feline IZUMO1 and JUNO, (2) gene expression in specific organs by measuring mRNA levels in different visceral tissues, and (3) the expression of IZUMO1 and JUNO during sperm maturation and folliculogenesis, respectively. Amplification for sequencing of feline IZUMO1 and JUNO was performed using the RT-PCR method. Levels of gene expression in different tissues were evaluated using real-time PCR. In situ hybridization was performed to localize JUNO mRNA in ovarian tissues. The complete coding sequences of IZUMO1 and JUNO were obtained and analyzed. A comparison between protein orthologs demonstrated the conservation of IZUMO1 and JUNO in Felidae. The real-time PCR results from various visceral organs indicated that IZUMO1 was significantly higher in the testis than in other organs, whereas JUNO was significantly higher in the ovary than in other organs. Expression of IZUMO1 was found to be higher in the testes than in the caput, corpus, and cauda of epididymides. In situ hybridization revealed that JUNO mRNA was in the ooplasm and nucleus of the primordial, primary, secondary, and antral follicles. Importantly, this was the first study to demonstrate the IZUMO1 and JUNO genes in the testis and ovary of cats. The results are useful for future research related to these genes and for developing contraceptives against these targets.