RESUMEN

Oncogenic mutations are abundant in the tissues of healthy individuals, but rarely form tumours1-3. Yet, the underlying protection mechanisms are largely unknown. To resolve these mechanisms in mouse mammary tissue, we use lineage tracing to map the fate of wild-type and Brca1-/-;Trp53-/- cells, and find that both follow a similar pattern of loss and spread within ducts. Clonal analysis reveals that ducts consist of small repetitive units of self-renewing cells that give rise to short-lived descendants. This offers a first layer of protection as any descendants, including oncogenic mutant cells, are constantly lost, thereby limiting the spread of mutations to a single stem cell-descendant unit. Local tissue remodelling during consecutive oestrous cycles leads to the cooperative and stochastic loss and replacement of self-renewing cells. This process provides a second layer of protection, leading to the elimination of most mutant clones while enabling the minority that by chance survive to expand beyond the stem cell-descendant unit. This leads to fields of mutant cells spanning large parts of the epithelial network, predisposing it for transformation. Eventually, clone expansion becomes restrained by the geometry of the ducts, providing a third layer of protection. Together, these mechanisms act to eliminate most cells that acquire somatic mutations at the expense of driving the accelerated expansion of a minority of cells, which can colonize large areas, leading to field cancerization.

Asunto(s)

Proteína BRCA1 , Linaje de la Célula , Transformación Celular Neoplásica , Glándulas Mamarias Animales , Mutación , Proteína p53 Supresora de Tumor , Animales , Ratones , Femenino , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/patología , Glándulas Mamarias Animales/metabolismo , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Linaje de la Célula/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Transformación Celular Neoplásica/genética , Células Clonales/metabolismo , Células Clonales/citología , Carcinogénesis/genética , Carcinogénesis/patología , Autorrenovación de las Células/genética

RESUMEN

The dynamic interplay between intramammary IgG, formation of antigen-IgG complexes and effector immune cell function is essential for immune homeostasis within the bovine mammary gland. We explore how changes in the recognition and binding of anti-LPS IgG to the glycolipid "functional" core in milk from healthy or clinically diagnosed Escherichia coli (E. coli) mastitis cows' controls endotoxin function. In colostrum, we found a varied anti-LPS IgG repertoire and novel soluble LPS/IgG complexes with direct IgG binding to the LPS glycolipid core. These soluble complexes, absent in milk from healthy lactating cows, were evident in cows diagnosed with E. coli mastitis and correlated with endotoxin-driven inflammation. E. coli mastitis milk displayed a proportional reduction in anti-LPS glycolipid core IgG compared to colostrum. Milk IgG extracts showed that only colostrum IgG attenuated LPS induced endotoxin activity. Furthermore, LPS-stimulated reactive oxygen species (ROS) in milk granulocytes was only suppressed by colostrum IgG, while IgG extracts of neither colostrum nor E. coli mastitis milk influenced N-formylmethionine-leucyl-phenylalanine (fMLP)-stimulated ROS in LPS primed granulocytes. Our findings support bovine intramammary IgG diversity in health and in response to E. coli infection generate milk anti-LPS IgG repertoires that coordinate appropriate LPS innate-adaptive immune responses essential for animal health.

Asunto(s)

Calostro , Infecciones por Escherichia coli , Escherichia coli , Glucolípidos , Inmunoglobulina G , Lipopolisacáridos , Mastitis Bovina , Leche , Animales , Bovinos , Femenino , Calostro/inmunología , Calostro/metabolismo , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Mastitis Bovina/inmunología , Mastitis Bovina/microbiología , Escherichia coli/inmunología , Lipopolisacáridos/inmunología , Leche/inmunología , Glucolípidos/metabolismo , Glucolípidos/inmunología , Infecciones por Escherichia coli/inmunología , Endotoxinas/inmunología , Endotoxinas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Granulocitos/inmunología , Granulocitos/metabolismo , Unión Proteica , Glándulas Mamarias Animales/inmunología , Glándulas Mamarias Animales/metabolismo

RESUMEN

The prolactin (PRL) hormone is a major regulator of mammary gland development and lactation. However, it remains unclear whether and how PRL contributes to mammary epithelial cell proliferation and secretion. The Boer and Macheng black crossbred goats are superior in reproduction, meat, and milk, and are popular in Hubei province. To elucidate the mechanisms of PRL on mammary growth and lactation, to improve the local goat economic trade, we have performed studies on these crossbred goats during pregnancy and early lactation, and in goat mammary epithelial cells (GMECs). Here, we first found that the amino acid transporters of SNAT1 and SNAT2 expression in vivo and in vitro were closely associated with PRL levels, the proliferation and secretion of GMECs; knockdown and over-expression of SNAT1/2 demonstrated that PRL modulated the proliferation and lactation of GMECs through regulating SNAT1/2 expression. Transcriptome sequencing and qPCR assays demonstrated the effect of PRL on the transcriptional regulation of SNAT1 and SNAT2 in GMECs. Dual-luciferase reporter gene assays further verified that the binding of the potential PRL response element in the SNAT1/2 promoter regions activated SNAT1/2 transcription after PRL stimulation. Additionally, silencing of either PRLR or STAT5 nearly abolished PRL-stimulated SNAT1/2 promoter activity, suggesting PRLR-STAT5 signaling is involved in the regulation of PRL on the transcriptional activation of SNAT1/2. These results illustrated that PRL modulates the proliferation and secretion of GMECs via PRLR-STAT5-mediated regulation of the SNAT1/2 pathway. This study provides new insights into how PRL affects ruminant mammary development and lactation through regulation of amino acid transporters.

Asunto(s)

Proliferación Celular , Células Epiteliales , Cabras , Lactancia , Glándulas Mamarias Animales , Prolactina , Animales , Prolactina/metabolismo , Femenino , Células Epiteliales/metabolismo , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/crecimiento & desarrollo , Factor de Transcripción STAT5/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Embarazo , Regiones Promotoras Genéticas/genética

Asunto(s)

Neoplasias de la Mama , Glándulas Mamarias Animales , Animales , Femenino , Humanos , Ratones , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/fisiopatología , Transformación Celular Neoplásica/patología , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología

RESUMEN

Mastitis typically arises from bacterial invasion, where host cell apoptosis significantly contributes to the inflammatory response. Gram-positive bacteria predominantly utilize the virulence factor lipoteichoic acid (LTA), which frequently leads to chronic breast infections, thereby impacting dairy production and animal husbandry adversely. This study employed LTA to develop models of mastitis in cow mammary gland cells and mice. Transcriptomic analysis identified 120 mRNAs associated with endocytosis and apoptosis pathways that were enriched in the LTA-induced inflammation of the Mammary Alveolar Cells-large T antigen (MAC-T), with numerous differential proteins also concentrated in the endocytosis pathway. Notably, actin-related protein 2/3 complex subunit 3 (ARPC3), actin-related protein 2/3 complex subunit 4 (ARPC4), and the heat shock protein 70 (HSP70) are closely related. STRING analysis revealed interactions among ARPC3, ARPC4, and HSP70 with components of the apoptosis pathway. Histological and molecular biological assessments confirmed that ARPC3, ARPC4, and HSP70 were mainly localized to the cell membrane of mammary epithelial cells. ARPC3 and ARPC4 are implicated in the mechanisms of bacterial invasion and the initiation of inflammation. Compared to the control group, the expression levels of these proteins were markedly increased, alongside the significant upregulation of apoptosis-related factors. While HSP70 appears to inhibit apoptosis and alleviate inflammation, its upregulation presents novel research opportunities. In conclusion, we deduced the development mechanism of ARPC3, ARPC4, and HSP70 in breast inflammation, laying the foundation for further exploring the interaction mechanism between the actin-related protein 2/3 (ARP2/3) complex and HSP70.

Asunto(s)

Complejo 2-3 Proteico Relacionado con la Actina , Apoptosis , Proteínas HSP70 de Choque Térmico , Lipopolisacáridos , Ácidos Teicoicos , Ácidos Teicoicos/farmacología , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Animales , Lipopolisacáridos/farmacología , Femenino , Apoptosis/efectos de los fármacos , Ratones , Complejo 2-3 Proteico Relacionado con la Actina/metabolismo , Complejo 2-3 Proteico Relacionado con la Actina/genética , Bovinos , Mastitis/metabolismo , Mastitis/microbiología , Mastitis/patología , Inflamación/metabolismo , Inflamación/patología , Modelos Animales de Enfermedad , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología

RESUMEN

In this study, the expression profiles of miR-148a were constructed in eight different ovine tissues, including mammary gland tissue, during six different developmental periods. The effect of miR-148a on the viability, proliferation, and milk fat synthesis of ovine mammary epithelial cells (OMECs) was investigated, and the target relationship of miR-148a with two predicted target genes was verified. The expression of miR-148a exhibited obvious tissue-specific and temporal-specific patterns. miR-148a was expressed in all eight ovine tissues investigated, with the highest expression level in mammary gland tissue (p < 0.05). Additionally, miR-148a was expressed in ovine mammary gland tissue during each of the six developmental periods studied, with its highest level at peak lactation (p < 0.05). The overexpression of miR-148a increased the viability of OMECs, the number and percentage of Edu-labeled positive OMECs, and the expression levels of two cell-proliferation marker genes. miR-148a also increased the percentage of OMECs in the S phase. In contrast, transfection with an miR-148a inhibitor produced the opposite effect compared to the miR-148a mimic. These results indicate that miR-148a promotes the viability and proliferation of OMECs in Small-tailed Han sheep. The miR-148a mimic increased the triglyceride content by 37.78% (p < 0.01) and the expression levels of three milk fat synthesis marker genes in OMECs. However, the miR-148a inhibitor reduced the triglyceride level by 87.11% (p < 0.01). These results suggest that miR-148a promotes milk fat synthesis in OMECs. The dual-luciferase reporter assay showed that miR-148a reduced the luciferase activities of DNA methyltransferase 1 (DNMT1) and peroxisome proliferator-activated receptor gamma coactivator 1-A (PPARGC1A) in wild-type vectors, suggesting that they are target genes of miR-148a. The expression of miR-148a was highly negatively correlated with PPARGC1A (r = -0.789, p < 0.001) in ovine mammary gland tissue, while it had a moderate negative correlation with DNMT1 (r = -0.515, p = 0.029). This is the first study to reveal the molecular mechanisms of miR-148a underlying the viability, proliferation, and milk fat synthesis of OMECs in sheep.

Asunto(s)

Proliferación Celular , Supervivencia Celular , ADN (Citosina-5-)-Metiltransferasa 1 , Células Epiteliales , Glándulas Mamarias Animales , MicroARNs , Leche , Animales , MicroARNs/genética , MicroARNs/metabolismo , Células Epiteliales/metabolismo , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/citología , Femenino , Ovinos , Leche/metabolismo , ADN (Citosina-5-)-Metiltransferasa 1/metabolismo , ADN (Citosina-5-)-Metiltransferasa 1/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Lactancia/genética , Lactancia/metabolismo , Regulación de la Expresión Génica

RESUMEN

Selenomethionine (SeMet) is an important nutrient, but its role in milk synthesis and the GPCR related to SeMet sensing is still largely unknown. Here, we determined the dose-dependent role of SeMet on milk protein and fat synthesis and proliferation of mammary epithelial cells (MECs), and we also uncovered the GPCR-mediating SeMet function. At 24 h postdelivery, lactating mother mice were fed a maintenance diet supplemented with 0, 5, 10, 20, 40, and 80 mg/kg SeMet, and the feeding process lasted for 18 days. The 10 mg/kg group had the best increase in milk production, weight gain of offspring mice, and mammary gland weight and acinar size, whereas a higher concentration of SeMet gradually decreased the weight gain of the offspring mice and showed toxic effects. Transcriptome sequencing was performed to find the differentially expressed genes (DEGs) between the mammary gland tissues of mother mice in the 10 mg/kg SeMet treatment group and the control group. A total of 258 DEGs were screened out, including 82 highly expressed genes including GPR37 and 176 lowly expressed genes. SeMet increased milk protein and fat synthesis in HC11 cells and cell proliferation, mTOR and S6K1 phosphorylation, and expression of GPR37 in a dose-dependent manner. GPR37 knockdown decreased milk protein and fat synthesis in HC11 cells and cell proliferation and blocked SeMet stimulation on mTOR and S6K1 phosphorylation. Taken together, our data demonstrate that SeMet can promote milk protein and fat synthesis and proliferation of MECs and functions through the GPR37-mTOR-S6K1 signaling pathway.

Asunto(s)

Proliferación Celular , Células Epiteliales , Glándulas Mamarias Animales , Proteínas de la Leche , Receptores Acoplados a Proteínas G , Selenometionina , Transducción de Señal , Serina-Treonina Quinasas TOR , Animales , Serina-Treonina Quinasas TOR/metabolismo , Serina-Treonina Quinasas TOR/genética , Femenino , Ratones , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Selenometionina/farmacología , Transducción de Señal/efectos de los fármacos , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/efectos de los fármacos , Glándulas Mamarias Animales/citología , Proteínas de la Leche/metabolismo , Lactancia , Humanos , Proteínas Quinasas S6 Ribosómicas 90-kDa

RESUMEN

Antimicrobial-resistant bacteria have been an increasing problem in human medicine and animal husbandry since the introduction of antimicrobials on the market in the 1940s. Over the last decades, efforts to reduce antimicrobial usage in animal husbandry have been shown to limit the development of resistant bacteria. Despite this, antimicrobial-resistant bacteria are still commonly detected and isolated worldwide. In this study, we investigated the presence of antimicrobial-resistant bacteria in bovine milk samples using a multiple approach based on culturing and amplicon sequencing. We first enriched milk samples obtained aseptically from bovine udders in the presence of two antimicrobials commonly used to treat mastitis and then described the resistant microbiota by amplicon sequencing and isolate characterization. Our results show that several commensal species and mastitis pathogens harbor antimicrobial resistance and dominate the enriched microbiota in milk in presence of antimicrobial agents. The use of the two different antimicrobials selected for different bacterial taxa and affected the overall microbial composition. These results provide new information on how different antimicrobials can shape the microbiota which is able to survive and reestablish in the udder and point to the fact that antimicrobial resistance is widely spread also in commensal species.

Asunto(s)

Glándulas Mamarias Animales , Mastitis Bovina , Microbiota , Leche , Animales , Bovinos , Femenino , Microbiota/efectos de los fármacos , Glándulas Mamarias Animales/microbiología , Glándulas Mamarias Animales/efectos de los fármacos , Mastitis Bovina/microbiología , Mastitis Bovina/tratamiento farmacológico , Leche/microbiología , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Farmacorresistencia Bacteriana/efectos de los fármacos , Antiinfecciosos/farmacología , ARN Ribosómico 16S/genética

RESUMEN

Previous studies have demonstrated that gut microbiota dysbiosis promotes the development of mastitis. The interaction of the vagus nerve and gut microbiota endows host homeostasis and regulates disease development, but whether the vagus nerve participates in the pathogenesis of mastitis is unclear. Here, vagotomized mice exhibit disruption of the blood-milk barrier and mammary gland inflammation. Notably, mastitis and barrier damage caused by vagotomy are dependent on the gut microbiota, as evidenced by antibiotic treatment and fecal microbiota transplantation. Vagotomy significantly alters the gut microbial composition and tryptophan metabolism and reduces the 5-hydroxyindole acetic acid (5-HIAA) level. Supplementation with 5-HIAA alleviates vagotomy-induced mastitis, which is associated with the activation of the aryl hydrocarbon receptor (AhR) and subsequent inhibition of the NF-κB pathway. Collectively, our findings indicate the important role of the vagus-mediated gut-mammary axis in the pathogenesis of mastitis and imply a potential strategy for the treatment of mastitis by targeting the vagus-gut microbiota interaction.

Asunto(s)

Microbioma Gastrointestinal , Mastitis , Triptófano , Vagotomía , Animales , Triptófano/metabolismo , Femenino , Ratones , Mastitis/metabolismo , Mastitis/microbiología , Receptores de Hidrocarburo de Aril/metabolismo , Nervio Vago/metabolismo , FN-kappa B/metabolismo , Disbiosis/microbiología , Disbiosis/metabolismo , Ratones Endogámicos C57BL , Trasplante de Microbiota Fecal , Glándulas Mamarias Animales/microbiología , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología

RESUMEN

The unitary mammary gland is a synapomorphy of therian mammals and is thought to have evolved from the pilosebaceous organ in the mammalian stem lineage from which the lactogenic patch of monotremes is also derived. One of the key lines of evidence for the homology of the nipple and the lactogenic patch is that marsupials have retained a transient hair associated with developing mammary glands. However, these structures have not been documented since the early 20th-century drawings of Ernst Bresslau. In this study, we examine the developing mammary organs of Monodelphis domestica and document the presence of mammary hairs in 12-week-old females, as well as their absence after 18 weeks of age. Histochemical staining for cystine confirms the structures as keratinized hairs. Milk ducts of both juvenile and adult nipples show a division between KRT18+ luminal epithelium and KRT14+ ACTA2+ myoepithelium. These patterns match those in eutherians and suggest a conserved ductal morphology and mechanism of milk expulsion. Finally, PTHLH, a peptide hormone which promotes homeotic transformation of hairy skin into hairless nipples in the mouse, was detected in the Monodelphis milk duct during the mammary hair stage, suggesting that the mutual exclusivity of "hairless nipple" and "hair" organ identity is derived in eutherian mammals. These results reveal shared characteristics of the M. domestica nipple with both the eutherian nipple and the pilosebaceous organ, consistent with the evolutionary derivation of the mammary gland from an ancestral hair organ via developmental individualization of pilosebaceous and mammary identities.

Asunto(s)

Glándulas Mamarias Animales , Monodelphis , Animales , Femenino , Monodelphis/anatomía & histología , Glándulas Mamarias Animales/anatomía & histología , Glándulas Mamarias Animales/crecimiento & desarrollo , Cabello/anatomía & histología , Pezones/anatomía & histología , Evolución Biológica

RESUMEN

An outbreak of influenza A (H5N1) virus was detected in dairy cows in the United States. We detected influenza A virus sialic acid -α2,3/α2,6-galactose host receptors in bovine mammary glands by lectin histochemistry. Our results provide a rationale for the high levels of H5N1 virus in milk from infected cows.

Asunto(s)

Glándulas Mamarias Animales , Infecciones por Orthomyxoviridae , Receptores Virales , Animales , Bovinos , Glándulas Mamarias Animales/virología , Femenino , Receptores Virales/metabolismo , Humanos , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/veterinaria , Subtipo H5N1 del Virus de la Influenza A , Enfermedades de los Bovinos/virología , Gripe Humana/virología , Leche/virología , Receptores de Superficie Celular/metabolismo , Gripe Aviar/virología , Gripe Aviar/epidemiología , Aves/virología

RESUMEN

Postpartum breast cancer (PPBC) is a unique subset of breast cancer, accounting for nearly half of the women diagnosed during their postpartum years. Mammary gland involution is widely regarded as being a key orchestrator in the initiation and progression of PPBC due to its unique wound-healing inflammatory signature. Here, we provide dialogue suggestive that lactation may also facilitate neoplastic development as a result of sterile inflammation. Immune cells are involved in all stages of postnatal mammary development. It has been proposed that the functions of these immune cells are partially directed by mammary epithelial cells (MECs) and the cytokines they produce. This suggests that a more niche area of exploration aimed at assessing activation of innate immune pathways within MECs could provide insight into immune cell contributions to the developing mammary gland. Immune cell contribution to pubertal development and mammary gland involution has been extensively studied; however, investigations into pregnancy and lactation remain limited. During pregnancy, the mammary gland undergoes dramatic expansion to prepare for lactation. As a result, MECs are susceptible to replicative stress. During lactation, mitochondria are pushed to capacity to fulfill the high energetic demands of producing milk. This replicative and metabolic stress, if unresolved, can elicit activation of innate immune pathways within differentiating MECs. In this review, we broadly discuss postnatal mammary development and current knowledge of immune cell contribution to each developmental stage, while also emphasizing a more unique area of study that will be beneficial in the discovery of novel therapeutic biomarkers of PPBC.

Asunto(s)

Lactancia , Glándulas Mamarias Animales , Glándulas Mamarias Humanas , Femenino , Humanos , Glándulas Mamarias Humanas/crecimiento & desarrollo , Glándulas Mamarias Humanas/inmunología , Glándulas Mamarias Humanas/patología , Animales , Lactancia/inmunología , Embarazo , Glándulas Mamarias Animales/inmunología , Glándulas Mamarias Animales/crecimiento & desarrollo , Glándulas Mamarias Animales/patología , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Células Epiteliales/inmunología , Inmunidad Innata

RESUMEN

The genetic improvement of cattle is able to provide the highest economic efficiency. Animals with best external features often have the highest indicators of productivity and nonspecific resistance. In order to identify single nucleotide polymorphism (SNP) markers and genes, potentially responsible for conformation traits of Ayrshire cattle, we conducted a genome-wide association study (GWAS). Blood samples were collected from 495 first-calf Ayrshire heifers. For all animals, a linear assessment was carried out, which consisted of 17 conformation traits and 13 exterior flaws. Our study revealed a total of 43 SNPs on chromosomes BTA1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 16, 18, 19, 22, 25, 27, and 29 associated with conformation traits, four of which have met the significance threshold. Among these four significant SNPs, genes associated with exterior flaws such as tilted udder floor and weak loin and SNPs associated with weak back were identified. The markers and genes identified in the corresponding genomic regions are promising candidates for further investigation of the biological processes involved in cow exterior formation and function. The results obtained, including the MYO1B gene associated with weak loin, PEPD and ZFC3H1 genes related to tilted udder floor, and EDNRB gene associated with weak back can be effectively used as molecular markers in genomic selection programs.

Asunto(s)

Estudio de Asociación del Genoma Completo , Polimorfismo de Nucleótido Simple , Bovinos/genética , Animales , Femenino , Carácter Cuantitativo Heredable , Glándulas Mamarias Animales

RESUMEN

Mastitis, a serious threat to the health and milk production function of dairy cows decreases milk quality. Blood from three healthy cows and three mastitis cows were collected in this study and their transcriptome was sequenced using the Illumina HiSeq platform. Differentially expressed genes (DEGs) were screened according to the |log2FoldChange| > 1 and P-value < 0.05 criteria. Pathway enrichment and functional annotation were performed through KEGG and GO analyses. Finally, the mechanism of the AMP-activated protein kinase (AMPK) mediation of (-)-epigallocatechin-3-gallate (EGCG) to promote lipid metabolism in mastitis cows was analyzed in bovine mammary epithelial cells (BMECs). Transcriptome analysis revealed a total of 825 DEGs, with 474 genes showing increased expression and 351 genes showing decreased expression. The KEGG analysis of DEGs revealed that they were mainly linked to tumour necrosis factor, nuclear factor-κB signalling pathway, and lipid metabolism-related signalling pathway, whereas GO functional annotation found that DEGs were enriched in threonine and methionine kinase activity, cellular metabolic processes, and cytoplasm. AMPK expression, which is involved in several lipid metabolism pathways, was downregulated in mastitis cows. The results of in vitro experiments showed that the inhibition of AMPK promoted the expression of lipid synthesis genes in lipopolysaccharide-induced BMECs and that EGCG could promote lipid synthesis by decreasing the expression of AMPK and downregulating the expression of inflammatory factors in inflammatory BMECs. In conclusion, our study demonstrated that AMPK mediated EGCG to inhabit of inflammatory responses and promote of lipid synthesis in inflammatory BMECs.

Asunto(s)

Proteínas Quinasas Activadas por AMP , Catequina , Metabolismo de los Lípidos , Glándulas Mamarias Animales , Mastitis Bovina , Animales , Bovinos , Catequina/análogos & derivados , Catequina/farmacología , Femenino , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Mastitis Bovina/genética , Metabolismo de los Lípidos/efectos de los fármacos , Glándulas Mamarias Animales/efectos de los fármacos , Glándulas Mamarias Animales/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Perfilación de la Expresión Génica/veterinaria , Transcriptoma/efectos de los fármacos

RESUMEN

Branching morphogenesis is a characteristic feature of many essential organs, such as the lung and kidney, and most glands, and is the net result of two tissue behaviors: branch point initiation and elongation. Each branched organ has a distinct architecture customized to its physiological function, but how patterning occurs in these ramified tubular structures is a fundamental problem of development. Here, we use quantitative 3D morphometrics, time-lapse imaging, manipulation of ex vivo cultured mouse embryonic organs and mice deficient in the planar cell polarity component Vangl2 to address this question in the developing mammary gland. Our results show that the embryonic epithelial trees are highly complex in topology owing to the flexible use of two distinct modes of branch point initiation: lateral branching and tip bifurcation. This non-stereotypy was contrasted by the remarkably constant average branch frequency, indicating a ductal growth invariant, yet stochastic, propensity to branch. The probability of branching was malleable and could be tuned by manipulating the Fgf10 and Tgfß1 pathways. Finally, our in vivo data and ex vivo time-lapse imaging suggest the involvement of tissue rearrangements in mammary branch elongation.

Asunto(s)

Glándulas Mamarias Animales , Morfogénesis , Animales , Glándulas Mamarias Animales/embriología , Glándulas Mamarias Animales/crecimiento & desarrollo , Ratones , Femenino , Factor 10 de Crecimiento de Fibroblastos/metabolismo , Factor 10 de Crecimiento de Fibroblastos/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Factor de Crecimiento Transformador beta1/metabolismo , Imagen de Lapso de Tiempo , Polaridad Celular , Embrión de Mamíferos/metabolismo , Transducción de Señal

RESUMEN

The risk of acquiring new intramammary infections is high at the end of lactation, especially for the high milk-producing dairy animals. Resistance to bacterial infection increases following the completion of mammary gland involution after milking cessation. The serotonin precursor 5-hydroxytryptophan (5-HTP) could accelerate involution by increasing circulating serotonin levels, but ruminal microbes may degrade 5-HTP if orally administered to adult ruminants. It is unclear whether rumen-protected 5-HTP could effectively mediate circulating serotonin (5-hydroxytryptamine, 5-HT) and therefore accelerate mammary gland involution in ruminants. Goats were used as a model in the current study to investigate the effects of rumen-protected 5-HTP on behaviour, 5-HT metabolism, and mammary involution in ruminants. In the first experiment, 16 female Dazu black goats were assigned to one of four groups in a randomised block design. The treatments included a basal diet plus 0, 4, 20, or 100 mg/kg BW of rumen-protected 5-HTP. Serum was collected at 0, 3, 6, 12, and 24 h after offering the rumen-protected 5-HTP in the morning feed, and the behaviours were monitored. In the second experiment, 12 female Dazu black goats (Somatic cell count < 250 000) were randomly assigned to the control (basal diet) or rumen-protected 5-HTP group (basal diet plus 20 mg/kg BW). Milk or mammary secretions were manually collected aseptically on d -1, 1, 2, 3, 4, and 5 around weaning. The results depicted that rumen-protected 5-HTP supplementation elevated circulating 5-HTP and 5-hydroxyindole acetic acid concentrations, while 20 mg/kg BW of rumen-protected 5-HTP supplementation lowered the goats' locomotive activity. A high concentration of rumen-protected 5-HTP (100 mg/kg BW) increased serum alkaline phosphatase and gamma-glutamyl transpeptidase concentrations. Moreover, oral supplementation with 20 mg/kg BW of rumen-protected 5-HTP accelerated mammary gland involution and reduced feed intake in goats after weaning. These results demonstrate that oral supplementation with rumen-protected 5-HTP influences 5-HT metabolism and accelerates mammary gland involution after milking cessation in ruminants.

Asunto(s)

5-Hidroxitriptófano , Cabras , Lactancia , Glándulas Mamarias Animales , Rumen , Serotonina , Animales , Cabras/fisiología , Femenino , 5-Hidroxitriptófano/farmacología , 5-Hidroxitriptófano/administración & dosificación , Rumen/metabolismo , Rumen/efectos de los fármacos , Serotonina/sangre , Serotonina/metabolismo , Glándulas Mamarias Animales/efectos de los fármacos , Lactancia/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Suplementos Dietéticos/análisis , Leche/química , Leche/metabolismo , Dieta/veterinaria

RESUMEN

Cell death caused by severe Staphylococcus aureus (S. aureus) infection is a fatal threat to humans and animals. However, whether ferroptosis, an iron-dependent form of cell death, is involved in S. aureus-induced cell death and its role in S. aureus-induced diseases are unclear. Using a mouse mastitis model and mammary epithelial cells (MMECs), we investigated the role of ferroptosis in the pathogenesis of S. aureus infection. The results revealed that S. aureus-induced ferroptosis in vivo and in vitro as demonstrated by dose-dependent increases in cell death; the level of malondialdehyde (MDA), the final product of lipid peroxidation; and dose-dependent decrease the production of the antioxidant glutathione (GSH). Treatment with typical inhibitors of ferroptosis, including ferrostatin-1 (Fer-1) and deferiprone (DFO), significantly inhibited S. aureus-induced death in MMECs. Mechanistically, treatment with S. aureus activated the protein kinase RNA-like ER kinase (PERK)-eukaryotic initiation factor 2, α subunit (eIF2α)-activating transcription factor 4 (ATF4)-C/EBP homologous protein (CHOP) pathway, which subsequently upregulated autophagy and promoted S. aureus-induced ferroptosis. The activation of autophagy degraded ferritin, resulting in iron dysregulation and ferroptosis. In addition, we found that excessive reactive oxygen species (ROS) production induced ferroptosis and activated endoplasmic reticulum (ER) stress, manifesting as elevated p-PERK-p-eIF2α-ATF4-CHOP pathway protein levels. Collectively, our findings indicate that ferroptosis is involved in S. aureus-induced mastitis via ER stress-mediated autophagy activation, implying a potential strategy for the prevention of S. aureus-associated diseases by targeting ferroptosis. In conclusion, the ROS-ER stress-autophagy axis is involved in regulating S. aureus-induced ferroptosis in MMECs. These findings not only provide a new potential mechanism for mastitis induced by S. aureus but also provide a basis for the treatment of other ferroptotic-related diseases.

Asunto(s)

Autofagia , Estrés del Retículo Endoplásmico , Ferroptosis , Mastitis , Infecciones Estafilocócicas , Staphylococcus aureus , Animales , Ferroptosis/efectos de los fármacos , Mastitis/microbiología , Mastitis/metabolismo , Mastitis/patología , Femenino , Staphylococcus aureus/fisiología , Infecciones Estafilocócicas/inmunología , Ratones , Ratones Endogámicos BALB C , Células Epiteliales/metabolismo , Factor de Transcripción Activador 4/metabolismo , Factor de Transcripción Activador 4/genética , Glándulas Mamarias Animales/patología , Glándulas Mamarias Animales/microbiología , Factor de Transcripción CHOP/metabolismo , Humanos , Transducción de Señal , Especies Reactivas de Oxígeno/metabolismo , Células Cultivadas

RESUMEN

Background: Our previous studies have successfully reported the reprogramming of fibroblasts into induced mammary epithelial cells (iMECs). However, the regulatory relationships and functional roles of MicroRNAs (miRNAs) in the progression of fibroblasts achieving the cell fate of iMECs are insufficiently understood. Methods: First, we performed pre-and post-induction miRNAs sequencing analysis by using high-throughput sequencing. Following that, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment studies were used to determine the primary roles of the significantly distinct miRNAs and targeted genes. Finally, the effect of miR-222-3p on iMECs fate reprogramming in vitro by transfecting. Results: As a result goat ear fibroblasts (GEFs) reprogramming into iMECs activates a regulatory program, involving 79 differentially expressed miRNAs. Besides, the programming process involved changes in multiple signaling pathways such as adherens junction, TGF-ß signaling pathway, GnRH secretion and the prolactin signaling pathway, etc. Furthermore, it was discovered that the expression of miR-222-3p downregulation by miR-222-3p inhibitor significantly increase the reprogramming efficiency and promoted lipid accumulation of iMECs.

Asunto(s)

Reprogramación Celular , Células Epiteliales , Fibroblastos , Cabras , MicroARNs , MicroARNs/genética , MicroARNs/metabolismo , Animales , Fibroblastos/metabolismo , Células Epiteliales/metabolismo , Femenino , Reprogramación Celular/genética , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/metabolismo , Transducción de Señal , Células Cultivadas , Regulación hacia Abajo

RESUMEN

Myeloid cell leukemia-1 (MCL-1), which belongs to the anti-apoptotic B cell lymphoma-2 family protein, is overexpressed in various cancers and is associated with cell immortality, malignant transformation, chemoresistance, and poor prognosis in humans. However, the significance of MCL-1 in canine mammary gland tumors (MGTs) remains unknown. This study aimed to examine MCL-1 expression in normal canine mammary glands and tumors and to assess its correlation with clinical and histologic variables. In total, 111 samples were examined, including 12 normal mammary gland tissues, 51 benign MGTs, and 48 malignant MGTs. Immunohistochemistry revealed that 53% of benign tumors and 75% of malignant tumors exhibited high MCL-1 expression, whereas only 8% of normal mammary glands exhibited high MCL-1 expression. High MCL-1 expression correlated with tumor malignancy (p < 0.001), large tumor size (> 3 cm) (p = 0.005), high Ki-67 expression (p = 0.046), and metastasis (p = 0.027). Survival curve analysis of dogs with malignant MGTs demonstrated a significant association between high MCL-1 expression and shorter median overall survival (p = 0.027) and progression-free survival (p = 0.014). Our study identified MCL-1 as a prognostic factor and potential therapeutic target in canine MGTs.

Asunto(s)

Enfermedades de los Perros , Neoplasias Mamarias Animales , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Animales , Perros , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Femenino , Neoplasias Mamarias Animales/metabolismo , Neoplasias Mamarias Animales/patología , Pronóstico , Enfermedades de los Perros/metabolismo , Enfermedades de los Perros/patología , Biomarcadores de Tumor/metabolismo , Inmunohistoquímica , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/patología

RESUMEN

Macrophages have important roles in mammary gland development and tissue homeostasis, but the specific mechanisms that regulate macrophage function need further elucidation. We have identified C/EBPß as an important transcription factor expressed by multiple macrophage populations in the normal mammary gland. Mammary glands from mice with C/EBPß-deficient macrophages (Cebpb ΔM) show a significant decrease in alveolar budding during the diestrus stage of the reproductive cycle, whereas branching morphogenesis remains unchanged. Defects in alveolar budding were found to be the result of both systemic hormones and local macrophage-directed signals. RNA sequencing shows significant changes in PR-responsive genes and alterations in the Wnt landscape of mammary epithelial cells of Cebpb ΔM mice, which regulate stem cell expansion during diestrus. Cebpb ΔM macrophages demonstrate a shift from a pro-inflammatory to a tissue-reparative phenotype, and exhibit increased phagocytic capacity as compared to WT. Finally, Cebpb ΔM macrophages down-regulate Notch2 and Notch3, which normally promote stem cell expansion during alveolar budding. These results suggest that C/EBPß is an important macrophage factor that facilitates macrophage-epithelial crosstalk during a key stage of mammary gland tissue homeostasis.

Asunto(s)

Proteína beta Potenciadora de Unión a CCAAT , Ciclo Estral , Macrófagos , Glándulas Mamarias Animales , Animales , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Proteína beta Potenciadora de Unión a CCAAT/genética , Femenino , Ratones , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/citología , Glándulas Mamarias Animales/crecimiento & desarrollo , Macrófagos/metabolismo , Ciclo Estral/genética , Ratones Noqueados , Receptores Notch/metabolismo , Receptores Notch/genética , Células Epiteliales/metabolismo , Fagocitosis/genética , Ratones Endogámicos C57BL , Eliminación de Gen