Gene expression and genome-wide association studies analysis to select heavy pigs for protected designation of origin cured meats production

The high quality of protected designation of origin (PDO) dry-cured pork products depends largely on the chemical and physical parameters of the fresh meat and their variation during the production process of the final product. The discovery of the mechanisms that regulate the variability of these parameters was aided by the reference genome of swine adjuvant to genetic analysis methods. This thesis can contribute to the discovery of genetic mechanisms that regulate the variability of some quality parameters of fresh meat for PDO dry-cured pork production. The first study is of gene expression and showed that between low and high glycolytic potential (GP) samples of Semimembranosus muscle of Italian Large White (ILW) pigs in early postmortem, the differentially expressed genes were all but one over expressed in low GP. These were involved in ATP biosynthesis processes, calcium homeostasis, and lipid metabolism including the potential master regulator gene Peroxisome Proliferator-Activated Receptor Alpha (PPARA). The second is a study in commercial hybrid pigs to evaluate correlations between carcass and fresh ham traits, including carcass and fresh ham lean meat percentages, the former, a potential predictor of the latter. In addition, a genome-wide association study allowed the identification of chromosome-wide associations with phenotypic traits for 19 SNPs, and genome-wide associations for 14 SNPs for ferrochelatase activity. The latter could be a determinant for color variation in nitrite-free dry-cured ham. The third study showed gene expression differences in the Longissimus thoracis muscle of ILW pigs by feeding diets with extruded linseed (source of polyunsaturated fatty acids) and vitamin E and selenium (diet three) or natural (diet four) antioxidants. The diet three promoted a more rapid and massive immune system response possibly determined by improvement in muscle tissue function, while the diet four promoted oxidative stability and increased the anti-inflammatory potential of muscle tissue.

Influence of cultivar choice, sowing date and abiotic stresses on tocopherol content and composition in Camelina sativa (L.) Crantz

In Europe, the current demand for vegetable oils and the need to find alternative crops for the regions most affected by climate change (i.e., Mediterranean basin) may be a launchpad for camelina [Camelina sativa (L.) Crantz] to be steadily introduced in European cropping systems. Camelina is mainly known for the unique composition of its oil, with a fatty acids profile including more than 50% content of essential linoleic and linolenic fatty acids, and a high tocopherol content. Being tocopherols part of the vitamin E family of antioxidants, the added value of growing camelina in harsh environments could be the enhancement of tocopherol content in camelina oil, thus having a more stable and nutritionally valuable product. With the final purpose of fully valorize camelina as a tolerant, valuable-oil producing crop for the Mediterranean basin, the main aim of this study was to investigate whether and how sowing date, cultivar choice, and abiotic stresses can affect tocopherol content and composition in camelina oil. The results showed that cultivar choice and growing conditions influenced total tocopherol, γ-tocopherol, and α-tocopherol contents. Moreover, heat stress trial revealed that high temperature increased α-tocopherol content, while no effect was observed in total tocopherols and in γ-tocopherol content. Finally, drought increased total tocopherols in camelina, and in drought-sensitive lines an increase in α-tocopherol was observed. This study allowed to acquire awareness on camelina resistance to abiotic stresses, coupled with a better knowledge on tocopherol content and composition in relation to cultivar, sowing date, and abiotic stresses. This will have an impact for the introduction of camelina as an alternative crop in harsher environments, such as the Mediterranean basin, to produce an oil suitable for food, feed, and industrial applications.

Nutritional strategies to modulate metabolism and heat stress resilience in dairy cattle

Physiological and environmental stressors can disrupt barrier integrity at epithelial interfaces (e.g., uterine, mammary, intestinal, and lung), which are constantly exposed to pathogens that can lead to the activation of the immune system. Unresolved inflammation can result in the emergence of metabolic and infectious diseases. Maintaining cow health and performance during periods of immune activation such as in the peripartum or under heat stress represents a significant obstacle to the dairy industry. Feeding microencapsulated organic acids and pure botanicals (OAPB) has shown to improve intestinal health in monogastric species and prevent systemic inflammation via the gut-liver axis. Feeding unsaturated fatty acids (FA) such as oleic acid (OA) and very-long-chain omega-3 (VLC n-3) FA are of interest in dairy cow nutrition because of their potential to improve health, fertility, and milk production. In the first study, we evaluated the effects of heat stress (HS) conditions and dietary OAPB supplementation on gut permeability and milk production. In parallel with an improved milk performance and N metabolism, cows supplemented with OAPB also had an enhanced hepatic methyl donor status and greater inflammatory and oxidative stress status compared to the HS control group. In a second study, we evaluated the relative bioavailability of VLC n-3 in cows fed a bolus of rumen-protected (RP) fish oil (FO). In a third study, we proved the interaction between RPFO and RP choline to promote the synthesis of phosphatydilcholines. Lipid forms that support hepatic triglyceride export and can prevent steatosis in dairy cows. The last study, demonstrated that algae oil outperforms against a toxin challenge compared to FO and that feeding RPOA modulates energy partitioning relative to n-3 FA-containing oils. Overall, this thesis confirms the need and the effectiveness of different strategies that aimed to improve dairy cows’ health and performance under heat stress, inflammation or metabolic disease.

Role of CARM1 (PRMT4) in high grade serous ovarian cancer metabolism and function of PRMT5 in ARID1A- deficient endometrial cancer invasion

The arginine methyltransferase CARM1 (PRMT4) is amplified and overexpressed in ~20% of high-grade serous ovarian cancer (HGSOC) and correlates with a poor survival. Therapeutic approaches based on CARM1 expression remain to be an unmet need. Here we show that fatty acid metabolism represents a metabolic vulnerability for HGSOC in a CARM1 expression status dependent manner. CARM1 promotes the de novo synthesis of fatty acids and monounsaturated fatty acids (MUFAs). The disruption of MUFAs synthesis by inhibition of SCD1 results in excessive accumulation of cytotoxic saturated fatty acids and it is synthetic lethal with CARM1 expression. Collectively, our data show that the pharmacological inhibition of MUFAs synthesis via SCD1 inhibition represents a therapeutic strategy for CARM1-high HGSOC. Another arginine methyltransferase, PRMT5, has been identified by our CRISPR screening analysis as a promising candidate for invasive ARID1A-deficient endometrial cancer. Endometrial Cancer frequently harbor somatic inactivating mutation of ARID1A that can promote an invasive phenotype. Our in vitro approach validated the CRISPR screening showing that both PRTM5 knock down and its pharmaceutical inhibition specifically hamper the invasion of ARID1A inactivated cells. Mechanistically, PRMT5 directly regulates the epithelia to mesenchymal transition pathway genes interacting with the SWI/SNF complexes. Moreover, in vivo experiments showed that PRMT5 inhibition contrasted the myometrium invasion highlighting PRMT5 inhibition as promising therapeutic strategy for ARID1A- inactivated aggressive endometrial cancer.