Paolo Fantinati

Heat shock protein 70, heat shock protein 32, and vascular endothelial growth factor production and their effects on lipopolysaccharide-induced apoptosis in porcine aortic endothelial cells

Abstract Lipopolysaccharide (LPS) is a highly proactive molecule that causes in vivo a systemic inflammatory response syndrome and activates in vitro the inflammatory pathway in different cellular types, including endothelial cells (EC). Because the proinflammatory status could lead to EC injury and apoptosis, the expression of proinflammatory genes must be finely regulated through the induction of protective genes. This study aimed at determining whether an LPS exposure is effective in inducing apoptosis in primary cultures of porcine aortic endothelial cells and in stimulating heat shock protein (Hsp)70 and Hsp32 production as well as vascular endothelial growth factor (VEGF) secretion. Cells between third and eighth passage were exposed to 10 μg/mL LPS for 1, 7, 15, and 24 hours (time-course experiments) or to 1, 10, and 100 μg/mL LPS for 7 and 15 hours (dose-response experiments). Apoptosis was not affected by 1 μg/mL LPS but significantly increased in a dose-dependent manner with the highest LPS doses. Furthermore, apoptosis rate increased only till 15 hours of LPS exposure. LPS stimulated VEGF secretion in a dose-dependent manner; its effect became significant after 7 hours and reached a plateau after 15 hours. Both Hsp70 and Hsp32 expressions were induced by LPS in a dose-dependent manner after 7 hours. Subsequent studies were addressed to evaluate the protective role of Hsp32, Hsp70, and VEGF. Hemin, an Hsp32 inducer (5, 20, 50 μM), and recombinant VEGF (100 and 200 ng/mL), were added to the culture 2 hours before LPS (10 μg/mL for 24 hours); to induce Hsp70 expression, cells were heat shocked (42°C for 1 hour) 15 hours before LPS (10 μg/mL for 24 hours). Hemin exposure upregulated Hsp32 expression in a dose-dependent manner and protected cells against LPS-induced apoptosis. Heat shock (HS) stimulated Hsp70 expression but failed to reduce LPS-induced apoptosis; VEGF addition did not protect cells against LPS-induced apoptosis at any dose tested. Nevertheless, when treatments were associated, a reduction of LPS-induced apoptosis was always observed; the reduction was maximal when all the treatments (HS + Hemin + VEGF) were associated. In conclusion, this study demonstrates that LPS is effective in evoking “the heat shock response” with an increase of nonspecific protective molecules (namely Hsp70 and Hsp32) and of VEGF, a specific EC growth factor. The protective role of Hsp32 was also demonstrated. Further investigations are required to clarify the synergic effect of Hsp32, Hsp70, and VEGF, thus elucidating the possible interaction between these molecules.

Sperm-mediated gene transfer-treated spermatozoa maintain good quality parameters and in vitro fertilization ability in swine.

A simple and efficient method for producing multitransgenic animals is required for medical and veterinary applications. Sperm-mediated gene transfer (SMGT) is an effective method for introducing multiple genes into pigs (Sus, Sus scrofa). The major benefits of this technique are the high efficiency, low cost, and ease of use compared with that of other methods: Sperm-mediated gene transfer does not require embryo handling or expensive equipment. The aim of this study was to investigate the influence of SMGT treatment and exogenous DNA uptake on sperm quality. Even after a coincubation with a 20-fold larger amount (100 microg/mL) of DNA than usual (5 microg/mL), sperm quality parameters were not significantly affected, confirming the hypothesis that the SMGT protocol itself or the amount of bound DNA do not compromise the possibility of an extended employment of SMGT. More importantly, we found that semen used for in vitro fertilization 24h after DNA uptake gave good cleavage (60% vs. 58%, treated vs. control) and developmental rates definitely positive (41% vs. 48%, treated vs. control). These good results are connected to a competitive efficiency of transformation (62%) due to the numerous improvements in SMGT technique. We demonstrate that SMGT-treated spermatozoa retain good quality and fertilization potential for at least 24h, expanding the possibility to apply transgenesis in field conditions in swine, where the greatest hurdles are fertilization timing and plain procedure.

Evaluation of swine fertilisation medium (SFM) efficiency in preserving spermatozoa quality during long-term storage in comparison to four commercial swine extenders.

In pig production, artificial insemination is widely carried out and the use of fresh diluted semen is predominant. For this reason, there are increasing interests in developing new extenders and in establishing the optimal storage conditions for diluted spermatozoa. In the last few decades, we utilised a homemade diluent (swine fertilisation medium (SFM)) for spermatozoa manipulation and biotechnological application as the production of transgenic pigs utilising the sperm-mediated gene transfer technique. The purpose of the present study is therefore to analyse the ability of SFM, in comparison to four commercial extenders, in preserving the quality of diluted boar semen stored at 16.5°C till 15 days. We utilised some of the main predictive tests as objectively measured motility, acrosome and sperm membrane integrity, high mitochondrial membrane potential and pH. Based on our in vitro study, SFM could be declared as a good long-term extender, able to preserve spermatozoa quality as well as Androhep Enduraguard for up to 6 to 9 days and more.

Alteration of constitutive heat shock protein 70 (HSC70) production by in vitro culture of porcine preimplanted embryos.

C. Bernardini, P. Fantinati, G. Castellani, M. Forni, A. Zannoni, E. Seren and M.L. Bacci Department of Veterinary Morphophysiology and Animal Production, University of Bologna, Ozzano Emilia, Italy *Correspondence: Dipartimento di Morfofisiologia Veterinaria e Produzioni Animali, Facoltà di Medicina Veterinaria, via T olara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy E-mail: cbernardini@vet.unibo.it

Paternal chromatin remodelling in mouse oocytes following fertilization.

The oocyte is characterized by particular functional properties that drive the fusion of the parental genomes and set up the embryonic development. Among these functions, the ability to accept the sperm’s DNA, to transform it into somatic DNA and finally to reprogramme it in a coordinated manner with the maternal DNA probably represents the most complex and sophisticated contribution of the oocyte. During the final phases of spermatogenesis, the histones are substituted by protamines. These proteins confer the optimal dimensions and rigidity for fertilization to the chromatin, at the same time giving noteworthy resilience to the spermatic DNA. The sperm DNA so packed is inactive for transcription. Therefore, at fertilization the parental DNAs present in the ooplasm are characterized by different architectures and the oocyte must intervene in a selective way on the paternal component, rearranging the sperm DNA and transforming it into somatic DNA (Nonchev and Tzanev, 1990). The oocyte acquires this ability only at the end of the maturation period (McLay and Clarke, 1997). In order to better define the concept of properly matured oocytes, we have followed the time course of the introduction of histone H2B and acetylated H4 in paternal chromatin following fertilization of mouse oocytes matured under different conditions, using immunofluorescence.

Semen evaluation and in vivo fertility in a Northern Italian pig farm: Can advanced statistical approaches compensate for low sample size? An observational study

The evaluation of sperm functionality and morphology allows discerning between high and low quality ejaculates, but does not give detailed predictive information regarding in vivo fertility. The current developments in statistical modeling have helped in carrying out reproductive studies, but their biggest limitation is in the size of the dataset to be used. The aim of the present observational study was to evaluate whether advanced statistical approaches, such as mixed effects regression models and bootstrap resampling, can help in assessing the predictive ability of semen parameters in terms of in vivo fertility (farrowing rate and litter size), on a small/medium farm with a limited number of animals. Data regarding 33 ejaculates, including viability, subjective motility and acrosome reaction, were collected. Two hundred and thirty-five sows were inseminated with an outcome of 167 deliveries and 1734 newborn piglets. In order to evaluate the relationships among the parameters measured and fertility, mixed effects regression statistical models were used. Once the covariates to be included in the final models were identified, non-parametric bootstrapping was used. The results showed that the farrowing rate was highly associated with the total number of spermatozoa and subjective motility, while litter size was associated with percentage of acrosome reaction. In conclusion, the proposed statistical approach seemed to be suitable for studies regarding reproduction and fertility, even for relatively small sample sizes. Nonetheless, larger data sets are still preferable and required in order to achieve higher reliability.