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Upregulation of genes detected at mRNA level highlights a potential increase of fatty acid oxidation. Red boxes indicate upregulated genes. Blue and green boxes represent the nucleus, and mitochondria, respectively. Carnitine O-palmitoyltrasferase 1 (CPT1A) encodes carnitine O-palmitin Opalmitoyltranferase 1, Mitochondrial Carnitine/Acylcarnitine Carrier Protein (SLC25A20) and Solute Carrier Family 25 Member 34 (SLC25A34) are two members of the solute carrier family 25. Steroid Hormone Receptor ERR1 (ESRRA) and Pyruvate Dehydrogenase Acetyl-Transferring Kinase Isozyme 4 (PDK4) encode a steroid hormone receptor and a pyruvate dehydrogenase, respectively.
Source publication
The objective is to study the effects of nutrient restrictions, which induce a metabolic imbalance on the inflammatory response of the mammary gland in early lactation cows. The aim is to decipher the molecular mechanisms involved, by comparing a control, with a restriction group, a transcriptome and proteome, after an intra-mammary lipopolysacchar...
Contexts in source publication
Context 1
... is supposed to act in a similar way, but its exact function still is not known totally [39]. MG seems to spare glucose (downregulating glycolysis) and promote FAs as an energy source (upregulating β-oxidation; Figure 4) in order to adapt to underfeeding. The mammary expression of genes involved in lipid metabolism is also modified in comparison with NEB (induced by caloric restriction) and the positive energy balance of cows after the peak in lactation [40]. ...
Context 2
... is supposed to act in a similar way, but its exact function still is not known totally [39]. MG seems to spare glucose (downregulating glycolysis) and promote FAs as an energy source (upregulating β-oxidation; Figure 4) in order to adapt to underfeeding. The mammary expression of genes involved in lipid metabolism is also modified in comparison with NEB (induced by caloric restriction) and the positive energy balance of cows after the peak in lactation [40]. ...
Citations
... CPT1A is a key gene related to fatty acid oxidation and play important roles on lipid metabolism in dairy cattle [84]. A previous study identified upregulated expression of CPT1A in response to intra-mammary lipopolysaccharide challenge [85], which agrees with its upregulation in milk somatic cells during S. aureus subclinical mastitis in this study. The strong negative correlation between this pro-GE-dMHB and the expression of CPT1A further strengthens the association of this epigenetic signature with S. aureus subclinical mastitis. ...
Background
DNA methylation has been documented to play vital roles in diseases and biological processes. In bovine, little is known about the regulatory roles of DNA methylation alterations on production and health traits, including mastitis.
Results
Here, we employed whole-genome DNA methylation sequencing to profile the DNA methylation patterns of milk somatic cells from sixteen cows with naturally occurring Staphylococcus aureus (S. aureus) subclinical mastitis and ten healthy control cows. We observed abundant DNA methylation alterations, including 3,356,456 differentially methylated cytosines and 153,783 differential methylation haplotype blocks (dMHBs). The DNA methylation in regulatory regions, including promoters, first exons and first introns, showed global significant negative correlations with gene expression status. We identified 6435 dMHBs located in the regulatory regions of differentially expressed genes and significantly correlated with their corresponding genes, revealing their potential effects on transcriptional activities. Genes harboring DNA methylation alterations were significantly enriched in multiple immune- and disease-related pathways, suggesting the involvement of DNA methylation in regulating host responses to S. aureus subclinical mastitis. In addition, we found nine discriminant signatures (differentiates cows with S. aureus subclinical mastitis from healthy cows) representing the majority of the DNA methylation variations related to S. aureus subclinical mastitis. Validation of seven dMHBs in 200 cows indicated significant associations with mammary gland health (SCC and SCS) and milk production performance (milk yield).
Conclusions
In conclusion, our findings revealed abundant DNA methylation alterations in milk somatic cells that may be involved in regulating mammary gland defense against S. aureus infection. Particularly noteworthy is the identification of seven dMHBs showing significant associations with mammary gland health, underscoring their potential as promising epigenetic biomarkers. Overall, our findings on DNA methylation alterations offer novel insights into the regulatory mechanisms of bovine subclinical mastitis, providing further avenues for the development of effective control measures.
Graphical Abstract
... Research has demonstrated the involvement of this gene in the increase in lipid and triglyceride levels in the blood [25]. Pawłowski et al. investigated mammary gland transcriptome and proteome in early lactation of Holstein cows and found involvement of PPP2CA in the following processes: protein catabolic process, regulation of inflammatory response, and RNA splicing [26]. ...
... Pawlowski et al. studied differences in miRNA expression between mammary epithelial cells and milk fat globules and showed that miR-141-3p and miR-204 were detected in the mammary tissue and mammary epithelial cells [26]. These miRNAs can regulate lactation via the expression of STAT5 protein, which plays a crucial role in the mammary gland by influencing various pathways that fall under the influence of lactogenic and galactopoietic hormones [34]. ...
Dairy milk production is a quantitative trait that is controlled by many biological and environmental factors. This study employs a network-driven systems approach and clustering algorithm to uncover deeper insights into its genetic associations. We analyzed the GSE33680 dataset from the GEO database to understand the biological importance of milk production through gene expression and modules. In this study, we employed CytoNCA and ClusterONE plugins within Cytoscape for network analysis. Moreover, miRWalk software was utilized to detect miRNAs, and DAVID was employed to identify gene ontology and pathways. The results revealed 140 up-regulated genes and 312 down-regulated genes. In addition, we have identified 91 influential genes and 47 miRNAs that are closely associated with milk production. Through our examination of the network connecting these genes, we have found significant involvement in important biological processes such as calcium ion transit across cell membranes, the BMP signaling pathway, and the regulation of MAPK cascade. The conclusive network analysis further reveals that GAPDH, KDR, CSF1, PYGM, RET, PPP2CA, GUSB, and PRKCA are closely linked to key pathways essential for governing milk production. Various mechanisms can control these genes, making them valuable for breeding programs aiming to enhance selection indexes.
... casein) takes place. Protein synthesis has been reported to be negatively regulated in the mammary gland of nutritionally restricted Holstein cows [24]. Altogether, these relations suggest that acetate is a good indicator of less energy dense diets, which are negatively related with mammary gland tissue development and milk protein synthesis, that are maintained in Majorera goats, well adapted to SWL. ...
... In a third study carried out in this tissue, the authors investigated the impact of nutrient restriction and its consequences on an inflammatory challenge given by the administration of lipopolysaccharide. In this experimental setting, dietary restriction had a profound impact on the beta-oxidation process, which may affect the response to inflammation [7]. This paper offers a perspective on the way that nutritional status may condition other cellular processes such as inflammation by changes in the gene expression of the enzymes involved in lipid metabolism. ...
This Special Issue is devoted to nutrition genomics, which is the characterization of the whole genome response to nutrients, in an effort to gather all the available pertinent information and to establish the foundation for a future encyclopedia of genomic responses driven by diets or nutrients [...]
... To confirm the differential expression of genes revealed by RNA-Seq, 11 DEGs were studied by RT-qPCR using the same RNA samples used for the RNA-Seq analysis (the primers are listed in Supplemental Table S1). RT-qPCR was performed as previously described (Pawlowski et al., 2019). The genes UXT1, PPIA, and EIF3K were used as housekeeping genes (Bonnet et al., 2013). ...
Adipose tissue is the energy storage organ providing energy to other tissues, including mammary gland, that supports the achievement of successive lactation cycles. Our objective was to investigate the ability of goats to restore body fat reserves by comparing lipogenic enzyme activities and by transcriptomic RNA-Seq data at two different physiological stages, mid- and post-lactation.
Key lipogenic enzyme activities were higher in goat omental adipose tissue during mid-lactation (74 days in milk) than during the post-lactation period (300 days postpartum). RNA-Sequencing analysis revealed 19,271 expressed genes in the omental adipose tissue. The comparison between adipose transcriptome analysis from mid- and post-lactation goats highlighted 252 differentially expressed genes (padj < 0.05) between these two physiological stages. The differential expression of 11 genes was confirmed by RT-qPCR. Functional genomic analysis revealed that 31% were involved in metabolic processes among which 38% in lipid metabolism. Most of the genes involved in lipid synthesis and those in lipid transport and storage were upregulated in adipose tissue of mid- compared to post-lactation goats. In addition, adipose tissue plasticity was emphasized by genes involved in cellular signaling and tissue integrity. Network analyses also highlighted three key regulators of lipid metabolism (LEP, APOE and HNF4A) and a key target gene (VCAM1).
The greatest lipogenic enzyme activities with the upregulation of genes involved in lipid metabolism highlighted a higher recovery of lipid reserves after the lactation peak than 4 months post-lactation. This study contributes to a better understanding of the molecular mechanisms controlling the body lipid reserves management during the successive lactations.
... The transcriptome was altered in bovine MG during the negative energy balance period [172][173][174]. Thus, feed restriction (at 60% of calculated net energy for lactation requirements) for 5 days resulted in 278 [172] and during 6 days in 374 [174] (Figure 3) differentially expressed genes in the MG of mid-lactation Holstein cows. ...
... The downregulation of ACSL1, FABP3, and LPIN1 in mammary tissue of dairy cows [174] is in line with the decrease in their expression during the natural negative energy balance period of early lactation (day 15 of lactation) compared to mid-lactation (day 60 of lactation), which is associated with a lower fat yield [165]. Similar results were shown in the MG of early lactation Holstein cows in response to undernutrition after an intramammary 24-h lipopolysaccharide (LPS) challenge [173]. Indeed, microarray analyses identified 33 differentially expressed genes in response to diet dilution (at 48% barley straw and dry matter basis) for 4 days compared to control cows: 19 genes were upregulated and 6 were downregulated. ...
... The effects of feed restriction on MG were recently extended to proteome studies [158,173,180]. Proteomic analyses showed that a feed restriction (at 48% barley straw and dry matter basis) during 4 days after an intramammary 24-h LPS challenge resulted in 53 differentially expressed proteins in the MG of early lactation Holstein cows [173]. ...
In mammals, milk is essential for the growth, development, and health. Milk quantity and quality are dependent on mammary development, strongly influenced by nutrition. This review provides an overview of the data on nutritional regulations of mammary development and gene expression involved in milk component synthesis. Mammary development is described related to rodents, rabbits, and pigs, common models in mammary biology. Molecular mechanisms of the nutritional regulation of milk synthesis are reported in ruminants regarding the importance of ruminant milk in human health. The effects of dietary quantitative and qualitative alterations are described considering the dietary composition and in regard to the periods of nutritional susceptibly. During lactation, the effects of lipid supplementation and feed restriction or deprivation are discussed regarding gene expression involved in milk biosynthesis, in ruminants. Moreover, nutrigenomic studies underline the role of the mammary structure and the potential influence of microRNAs. Knowledge from three lactating and three dairy livestock species contribute to understanding the variety of phenotypes reported in this review and highlight (1) the importance of critical physiological stages, such as puberty gestation and early lactation and (2) the relative importance of the various nutrients besides the total energetic value and their interaction.
... proposed that FA oxidation in mammary cells during periods of lipomobilization would increase oxidative stress, requiring upregulation of the pentose phosphate pathway to generate reducing potential to neutralize reactive oxygen species. Mammary gland gene expression shows a shift toward increased reliance on β-oxidation for energy and sparing of glucose in underfed early-lactation cows (Pawłowski et al., 2019). Oxidative stress may have occurred in our study, inducing a gradual depletion of glucose-6-phosphate and isocitrate on d 5 and 6 of restriction. ...
Durant la lactation et plus particulièrement en son début les vaches peuvent subir un déficit énergétique conduisant à un déséquilibre métabolique. Ce dernier modifie la production et de la composition du lait. A l’heure de l’élevage de précision, identifier des molécules faciles d’accès pour détecter précocement les animaux en bilan énergétique négatif est un point important. Le lait est un fluide qui contient un grand nombre de molécules parmi lesquelles les métabolites et les microARN; petits ARN non-codants connus pour réguler de nombreux processus biologiques y compris dans la glande mammaire, ont été récemment détectés. L’objectif de mon travail de thèse est d’identifier des biomarqueurs du statut nutritionnel et de caractériser l’impact d’une restriction alimentaire sur le miRNome de la glande mammaire chez la vache laitière. Pour ce faire, dix-neuf vaches en milieu de lactation (9 Holstein et 10 Montbéliarde) ont été restreintes pendant 6 jours à 50% de leurs besoins énergétiques. Les effets de cette restriction sur la production et la composition fine du lait ont été déterminés. Son impact sur le fonctionnement de la glande mammaire a été étudié par des approches de nutrigénomique. Les données de production laitière et les métabolites sanguins ont confirmé le déficit énergétique des vaches. Les teneurs de certains métabolites du lait (glucose, glutamate, glucose-6P, isocitrate, β-hydroxybutyrate, acide urique et acide aminé libre) et les profils en acide gras ont été modifiés par la restriction alimentaire. L’étude de leurs corrélations avec le bilan énergétique nous ont conduits à proposer le glucose et le glutamate comme potentiels biomarqueurs non invasifs dans le lait. D’éventuelles différences entre races et des seuils critiques devront être définis sur un plus grand nombre d’animaux, et au cours de différents stades de lactation avant que ces métabolites ne soient utilisés en élevage.La comparaison des miRNomes mammaires entre les vaches Holstein et Montbéliarde a identifié 22 miARN différentiellement exprimés entre les deux races. Des analyses bioinformatiques ont mis en évidence un rôle potentiel de ces miARN dans le développement mammaire, et l’étude approfondie des 6 miARN les plus exprimés parmi les 22 a révélé leur potentiel rôle dans la synthèse lipidique. Ces deux résultats peuvent en partie expliquer les différences de production observées entre ces races.La restriction alimentaire a affecté l’expression de 27 miARN et 374 ARNm chez les vaches Holstein. Cependant aucun effet n’a été détecté sur les vaches Montbéliarde. L’analyse des positions génomiques des 27 miARN et l’analyse bibliographique des 8 miARN les plus exprimés révèlent une forte implication de ces miARN dans la synthèse lipidique et la prolifération cellulaire. L’intersection des 374 ARNm différentiels avec la liste des ARNm potentiellement cibles des 8 miARN les plus exprimés a mis en évidence 59 mARN communs majoritairement impliqués dans la synthèse lipidique et le développement cellulaire. Ces résultats suggèrent un rôle des miARN via la régulation des ARNm, dans les changements de profil d’acides gras ainsi que les pertes de production observées au cours d’une restriction alimentaire.Les perspectives de ce travail à court terme, sont de valider ces résultats sur une population plus large et d’étudier les profils en miARNs dans les globules gras du lait A plus long terme il faudra s’attacher à mettre en place des méthodes de dosages applicables en ferme afin de permettre à l’éleveur de piloter les rations et les animaux de manière précoce.
... Lipopolysaccharide (LPS) is the pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria, and lipoteichoic acid (LTA) and peptidoglycan (PGN) are those of Gram-positive bacteria [2]. Previous studies have reported the effects of LPS, PGN, LTA, and PGN + LTA on the gene expression profiles of bovine mammary epithelial cells (BMECs) and mainly focused on their proinflammatory activity [12][13][14][15][16][17][18][19]. However, the additive effects of LPS, PGN, and LTA on the gene expression profiles of BMECs are still unclear. ...
Mastitis is usually caused by a variety of pathogenic bacteria that include both Gram-positive and Gram-negative bacteria. Lipopolysaccharide (LPS) is the pathogen-associated molecular pattern (PAMP) of Gram-negative bacteria, and peptidoglycan (PGN) and lipoteichoic acid (LTA) are those of Gram-positive bacteria. The effects of LPS, PGN and/or LTA on inflammatory response and lactation in bovine mammary epithelial cells (BMECs) are well studied, but the epigenetic mechanisms of their effects received less attention. Furthermore, since the three PAMPs are often simultaneously present in the udder of cows with mastitis, it has implications in practice to study their additive effects. The results show that co-stimulation of bovine mammary epithelial cells with PGN, LTA, and LPS induced a higher number of differentially expressed genes (DEGs) and greater expressions of inflammatory factors including interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α (TNF-α), chemokine (C-X-C motif) ligand (CXCL)1, and CXCL6. In addition, co-stimulation further increased DNA hypomethylation compared with sole LPS stimulation. Co-stimulation greatly decreased casein expression but did not further decrease histone acetylation levels and affect the activity of histone acetyltransferase (HAT) and histone deacetylase (HDAC), compared with sole LPS stimulation. Collectively, this study demonstrated that PGN, LTA, and LPS had an additive effect on inducing transcriptome changes and inflammatory responses in BMECs, probably through inducing a greater decrease in DNA methylation. Co-stimulation with PGN, LTA, and LPS decreased casein expression to a greater degree, but it might not be linked to histone acetylation and HAT and HDAC activity.
... Zachut et al. (2016) proposed that FA oxidation in mammary cells during periods of lipomobilization would increase oxidative stress, requiring upregulation of the pentose phosphate pathway to generate reducing potential to neutralize reactive oxygen species. Mammary gland gene expression shows a shift toward increased reliance on β-oxidation for energy and sparing of glucose in underfed early-lactation cows (Pawłowski et al., 2019). Oxidative stress may have occurred in our study, inducing a gradual depletion of glucose-6-phosphate and isocitrate on d 5 and 6 of restriction. ...
The objective was to investigate the effects of feed restriction on concentrations of selected milk metabo-lites in mid-lactation Holstein and Montbéliarde cows and to explore their correlations with energy balance and classic plasma and milk indicators of nutritional status. Eight Holstein and 10 Montbéliarde cows (165 ± 21 d in milk) underwent 6 d of feed restriction during which feed allowance was reduced to meet 50% of their net energy for lactation (NE L) requirements. The experiment was divided in 4 periods: control (CON; d −3 to −1), restriction (RES; d 1 to 6), wk 1 (W1; d 7 to 13), and wk 2 (W2; d 14 to 18) after refeeding at ad libitum intake. Intake, milk production, energy balance and plasma metabolites were used to validate the feed restriction model. Concentrations of 7 milk me-tabolites: β-hydroxybutyrate (BHB), glucose, glucose-6-phosphate, isocitrate, glutamate, uric acid, and free amino groups were measured in morning milk samples, and fatty acids were measured in pooled p.m. and a.m. samples. Feed restriction induced a negative energy balance (−42.5 ± 4.4 MJ/d), increased plasma non-esterified fatty acids and BHB, and decreased plasma glucose concentrations. Feed restriction increased milk glucose-6-phosphate and isocitrate (+38% and +39%, respectively) and decreased milk BHB, glucose, gluta-mate, uric acid and free amino group concentrations (−20%, −57%, −65%, −42%, and −14%, respectively), compared with pre-restriction. Milk concentrations of medium-chain fatty acids (e.g., sum of C10 to C15) decreased and those of long chain (e.g., 18:0, cis-9 18:1) increased during restriction. Breed differences were not detected for the majority of variables. All studied milk metabolites were significantly correlated with energy balance (Spearman correlation = 0.48, 0.63, −0.31, −0.45, and 0.61 for BHB, glucose, glucose-6-phosphate, isocitrate, and glutamate, respectively). Milk glucose and glutamate showed the strongest correlations with plasma metabolites and milk FA associated with lipo-mobilization. These results suggest that milk metabo-lites may be used as noninvasive indicators of negative energy balance and metabolic status of dairy cows.
Mastitis is an inflammatory disease in dairy cows, causing economic losses and reducing animal welfare. In order to contribute for the discovery of early and noninvasive indicators, our objective was to determine the effects of a lipopolysaccharide (LPS) challenge on the microRNA profile (miRNome) of milk fat, using microarray analyses in cows. Cows were fed a lactation diet at ad libitum intake (n = 6). At 27 ± 3 days in milk, cows were injected with 50 µg of LPS Escherichia coli in one healthy rear mammary quarter. Milk samples were collected just before LPS challenge (LPS−) and 6.5 h after LPS challenge (LPS +) from the same cows. Microarray analysis was performed using customized 8 × 60 K ruminant miRNA microarrays to compare LPS− to LPS + miRNome. In silico functional analyses were performed using OmicsNet and Mienturnet software. MiRNome comparison between LPS− and LPS + identified 37 differentially abundant miRNAs (q-value ≤ 0.05). The predicted target genes of the 37 differentially abundant miRNAs are mostly involved in cell life including apoptosis, cell cycle, proliferation and differentiation and in gene expression processes. MiRNome analyses suggest that miRNAs profile is related to the inflammation response of the mammary gland. In conclusion, we demonstrated that milk fat might be an easy and rapid source of miRNAs that are potential indicators of early mastitis in cows.
Supplementary Information
The online version contains supplementary material available at 10.1186/s13567-023-01231-4.
