Leonardo Tondello Martins

Com o presente trabalho, objetivou-se estudar a influência da somatotropina recombinante bovina (rbST) sobre a quantidade e qualidade de oócitos aspirados in vivo, produção embrionária e expressão gênica dos fatores de crescimento semelhantes à insulina (IGFs) tipos I e II em embriões produzidos in vitro de fêmeas bovinas da raça Nelore. Cinco vacas foram tratadas com duas administrações de 2mL de solução salina como placebo, com intervalo de catorze dias entre elas, sendo a primeira administração realizada dezenove e a segunda cinco dias antes das aspirações foliculares; decorridos trintas dias destas aspirações, em sistema crossover, o mesmo protocolo foi utilizado nesses cinco animais sendo, neste caso, a solução salina substituída por 500mg de rbST, com o intuito de efetuar-se comparações entre os tratamentos. A partir dos oócitos recuperados, realizou-se a produção in vitro de embriões (PIVE), sendo todas as etapas que envolvem este processo analisadas e com posterior realização de reações em cadeia da polimerase em tempo real (qPCRs) para expressões gênicas de IGF-I e IGF-II nos blastocistos produzidos. Observou-se que a rbST, ainda que numericamente tenha influenciado positivamente sobre os parâmetros estudados, não exerceu influência significativa sobre a quantidade e qualidade de oócitos aspirados in vivo, produção embrionária e expressão gênica de IGF-I e IGF-II em embriões produzidos in vitro de fêmeas bovinas da raça Nelore.

Platelet-rich plasma (PRP) has been considered a promising therapeutic alternative, since platelets are rich in growth factors that are used in the Regenerative Medicine field. However, fresh PRP cannot be stored for long periods. This study aimed to develop a protocol for obtaining lyophilized canine PRP capable of maintaining viability after its reconstitution. For that purpose, canine PRP extraction and lyophilization protocols were initially tested. Subsequently, assays were carried out to quantify the growth factors VEGF and TGF-β, before and after the lyophilization process, gelation test and the three-dimensional gel structure analysis of the reconstituted lyophilized PRP by electron microscopy, as well as in vitro cell proliferation test in lyophilized PRP gel. Additionally, the immunogenicity test was performed, using allogeneic samples of lyophilized PRP. The results showed that the lyophilized PRP had adequate therapeutic concentrations of growth factors VEGF and TGF-β (9.1pg/mL and 6161.6pg/mL, respectively). The reconstituted PRP gel after lyophilization showed an in vitro durability of 10 days. Its electron microscopy structure was similar to that of fresh PRP. In the cell proliferation test, an intense division process was verified in mesenchymal stem cells (MSCs) through the three-dimensional mesh structure of the lyophilized PRP gel. The immunogenicity test showed no evidence of an immune reaction. The findings were promising, suggesting the possibility of having a lyophilized canine PRP that can be marketed. New in vivo and in vitro studies must be carried out for therapeutic confirmation.

Oocyte competence plays a key role in the overall efficiency of reproductive biotechnologies. In cattle, FSH starvation following superovulation (coasting) improves oocyte competence, blastocyst yield and pregnancy outcome when used in ovum pickup-in vitro production programs. The aim of this study was to compare the effect of coasting after exogenous FSH stimulation on goat oocyte quality and competence to support in vitro maturation and in vivo embryo development following cloning procedures in goats. Donor and recipient preparation, cumulus-oocyte complex (COC) retrieval and selection, IVM, cloning by somatic cell nuclear transfer, embryo transfer, and pregnancy diagnosis (Days 23–26) were performed according to our established procedures [Martins et al. 2016 doi: 10.1089/cell.2015.0082]. Cumulus-oocyte complexes were obtained in vivo from 71 cycling FSH-stimulated mature Nubian-crossed goats, combined or not with FSH starvation (coasting period). Donor females were oestrous synchronized with a progesterone intravaginal insert (Day 0). On Day 10, a 0.75-mg D-cloprostenol dose was given IM, with the onset of the superovulation treatment, composed of five 20-mg FSH doses (Folltropin®, Bioniche Animal Health, Pullman, WA, USA), via IM at 12-h intervals. Donors were subjected to laparoscopic ovum pickup either 9 h (control group, n = 36) or 21 h (coasting group, n = 35) after the last FSH dose, respectively. Skin fibroblast cell cultures from a male neonate were co-transfected with a mammary gland expression vector with the human lactoferrin (hLF) coding sequence and with CRISPR/Cas9 system either for the PRNP prion gene or the Rosa26 locus. A bi-allelic hLF-PRNP and a mono-allelic hLF-Rosa26 cell colony were used for cloning. Data were compared by ANOVA or the ?2 test (P < 0.05). No differences were observed between control and coasting for number of follicles (18.7 ± 1.4 v. 21.2 ± 1.7), and retrieved (17.3 ± 1.2 v. 20.7 ± 1.9), viable (15.9 ± 1.1 v. 19.6 ± 1.8), Grade I (1.5 ± 0.3 v. 2.5 ± 0.5), and Grades III+IV (6.0 ± 0.6 v. 5.7 ± 0.7) COC, as well as for COC retrieval (92.4%, 574/621 v. 94.5%, 685/725) and fusion (62.8%, 273/435 v. 61.3%, 311/507) rates, respectively, irrespective of the cell lines. However, the coasting group rendered higher number of Grade II COC (11.3 ± 1.2 v. 8.4 ± 0.7), number and proportion of Grades I+II COC (13.9 ± 1.5 v. 9.9 ± 0.9, 70.8% v. 62.4%), and maturation rate (70.9% v. 65.4%) than the control group, respectively, for a lower proportion of Grades III+IV (29.2% v. 37.6%, respectively). A total of 213 and 233 Day-1 cloned embryos from the control and the coasting groups were transferred to 18 (96/9 hLF-PRNP and 117/9 hLF-Rosa26 cells) and 19 (128/11 hLF-PRNP and 105/8 hLF-Rosa26 cells) female recipients, respectively, resulting in 1/9 (11.1%) and 4/11 (36.4%) pregnancies from the hLF-PRNP cells, and 3/9 (33.3%) and 3/8 (37.5%) from the hLF-Rosa26 cells, for the control (4/18, 22.2%) and coasting (7/19, 36.8%) groups, respectively, for an overall pregnancy rate of 29.7% (11/37). In conclusion, the use of coasting improved oocyte quality and in vitro maturation rate, also appearing to increase pregnancy outcome after goat cloning.