Search Results (917)

In goats, the influence of microRNAs on the post-transcriptional regulation of genes involved in mammary development and remodeling and milk secretion has not been fully elucidated yet. In this study, we have obtained mammary biopsies from five lactating and four dry Murciano-Granadina goats and, subsequently, small RNA has been purified and sequenced, obtaining, on average, 11 million reads per sample with an 85% alignment rate. Bioinformatic analysis of the sequencing data revealed the expression of 342 unique microRNAs in the goat mammary gland, among which 32 were novel miRNAs. Moreover, we have determined that as many as 93 mature microRNAs are differentially expressed (fold-change ≥ 2.7, q-value = 0.05) in lactating vs. dry goats. Of these, 49 and 44 were upregulated and downregulated in lactating goats, respectively, including 13 novel miRNAs. For each one of these differentially expressed miRNAs, we have made a search of scientific literature to find out whether their functional role in lactation has been elucidated, and, if so, we have contrasted the expected (based on function) vs. the observed (inferred from the differential expression analysis) change in gene expression to determine their degree of concordance. About 82% of the miRNAs with functional information that were differentially expressed in lactating vs. dry goats showed concordance between the observed and expected directions of the change in gene expression. By integrating differential expression analysis and functional data generated by others, we have identified a set of 17 miRNAs with converging evidence of being involved in the physiological transformations associated with lactation and mammary involution. Full article

Multidrug-resistant hypervirulent Klebsiella pneumoniae caused by the improper use of antibiotics has become a major threat to the dairy industry and public health, posing a major challenge to the treatment of bovine mastitis. The resurgence of phage (and its lysozyme therapy) provides a novel strategy to combat such infections. In this study, bovine Klebsiella pneumoniae phage vB_Kpn_B01 nucleic acid was used as a template to successfully achieve the prokaryotic expression of its endolysin. The results of protein gene annotation and prediction showed that Lysin K had the function of lyase, and was designated Lysin K. After optimizing the production conditions, Lysin K could be produced in a soluble form after induction with 0.25 mmol/L IPTG at 37 °C for 16 h, and the concentration was 100 μg/mL after purification. The stability test confirmed that Lysin K can maintain stable antibacterial activity over a wide temperature and pH range. The minimum inhibitory concentration (MIC) of Lysin K was 0.01 μg/mL and remained stable in milk. The Lysin K showed strong lysis activity in vitro and could effectively lyse three types of multidrug-resistant hypervirulent Klebsiella pneumoniae. In the mouse mastitis model induced by Klebsiella pneumoniae KP18 (10⁸ CFU/mL), the intervention of Lysin K can significantly reduce the bacterial load, alleviate the inflammatory response, and restore the normal functional structure of the target mammary gland. In summary, Lysin K has valuable application prospect in the prevention and treatment of bovine mastitis caused by drug-resistant Klebsiella pneumoniae and the development of phage lysin preparations. Full article

Mammary gland inflammation, clinically expressed as mastitis in dairy ruminants and lactating women, arises from a self-amplifying loop of pathogen sensing, oxidative stress and innate immune activation, and remains a leading driver of antibiotic use, milk-quality loss and morbidity. Mounting pressure to reduce antimicrobial dependence has refocused attention on flavonoids—structurally diverse plant polyphenols with multi-target bioactivity, derived mainly from in vitro and rodent mastitis models. This review integrates contemporary evidence on the six principal flavonoid subclasses within a unifying molecular framework. Across subclasses, flavonoids converge on shared targets: the TLR4–MyD88–NF-κB axis, MAPK cascades, the Keap1–Nrf2–ARE antioxidant pathway, the NLRP3 inflammasome and tight-junction proteins of the blood–milk barrier. Less canonical mechanisms—m⁶A epitranscriptomic regulation, ferroptosis suppression, AhR signalling, anti-virulence binding to bacterial enzymes such as IGPD, and gut-microbiota-driven remodelling of the gut–mammary axis—expand the pharmacological landscape. We additionally appraise the subclasses comparatively, identifying flavanones and the flavone baicalin as carrying the strongest translational evidence, and examine the conflicting findings, model limitations, and delivery, residue and regulatory barriers that currently separate mechanistic promise from on-farm application. We outline structure–activity considerations and translational priorities, and position flavonoids as mechanism-rich, antibiotic-sparing candidates for the prevention and adjunctive management of mammary gland inflammation in dairy ruminants. Full article

Mammary gland development during puberty requires tightly coordinated epithelial proliferation, lineage specification, and branching morphogenesis, processes critically regulated by growth factor signaling. While epidermal growth factor receptor (EGFR) signaling is essential for ductal development, how its activity is quantitatively controlled within mammary epithelial cells (MECs) remains incompletely understood. Here, we identify Rasgrp1, a Ras guanine nucleotide exchange factor, as a key modulator of EGFR signaling in the mammary epithelium. Using Rasgrp1-deficient mice, primary MEC assays, and organoid models, we demonstrate that loss of Rasgrp1 leads to elevated EGFR–Ras–PI3K–AKT and mTORC1-S6 signaling, resulting in enhanced proliferative capacity and aberrant EGF-driven branching. Transcriptomic analysis of organoids reveals that EGF signaling suppresses Wnt/R-spondin-dependent stem-cell gene programs, suggesting that excessive EGFR activity disrupts stem cell maintenance. In vivo, Rasgrp1 deficiency causes impaired ductal elongation, persistent terminal end buds, and increased epithelial proliferation, indicating a breakdown in the spatial and temporal coordination of mammary morphogenesis. Together, our findings establish Rasgrp1 as a signaling rheostat that dampens EGFR pathway activity to support coordinated mammary gland development. These results highlight the importance of precise signaling calibration in epithelial development and suggest broader implications for Ras pathway regulation in tissue homeostasis and disease. Full article

Yak is a distinctive domestic animal adapted to the Qinghai–Tibet Plateau, and its lactation performance is restricted by extreme high-altitude conditions. Despite the growing recognition of circRNAs as important regulators of mammary gland development in other species, no study has yet systematically investigated the stage-specific circRNA expression landscapes in yak mammary glands across gestation, lactation, and non-pregnant periods, or the potential ceRNA networks through which these circRNA may participate in regulating milk synthesis and mammary cell proliferation under high-altitude conditions. This study aimed to characterize circRNA expression features and lactation regulation in yak mammary glands at the gestation, lactation, and non-pregnant stages. Total RNA sequencing was performed on mammary specimens, followed by differential screening, functional enrichment, ceRNA network construction, and qPCR verification. Numerous stage-biased circRNAs were identified, among which circNFATC2, circTRPS1 and circTAF3 were highlighted as hub candidates potentially involved in mammary cell differentiation, milk synthesis, and energy metabolism, with qPCR validating sequencing outcomes. Our results provide a comprehensive circRNA expression atlas and candidate molecular markers for understanding lactation regulation in high-altitude yaks, offering a valuable foundation for the future genetic improvement of milk production traits. Full article

Fluoroquinolones are broad-spectrum, bactericidal antibacterial agents used in both human and veterinary medicine. Some human-approved drugs are used off label in veterinary medicine while veterinary-approved drugs are not used in humans. Veterinary-approved fluoroquinolones are used on both food and companion animals and against a wide range of clinical indications including infections of the urinary tract, respiratory tract, skin and skin structure, mammary gland and others. Not all veterinary-approved fluoroquinolones have the same clinical indication and it is important to understand these important differences. A recently approved for food animals agent called pradofloxacin is characterized as being dual targeting in that it simultaneously inhibits DNA gyrase (topoisomerase II) and Topoisomerase IV—two enzymes critical for DNA replication. Simultaneous targeting of two enzymes is argued to reduce the likelihood for resistance selection. This article reviews veterinary-approved fluoroquinolones including an overview of the drugs, in vitro activity including bactericidal properties, pharmacokinetic/pharmacodynamics, antimicrobial resistance, anti-inflammatory properties and clinical trial results. Appropriate use of this important class of antimicrobial agents is essential for clinical success and long-term viability of these compounds. Full article

Porcine epidemic diarrhea virus (PEDV) remains one of the most critical enteric coronaviruses affecting the global swine industry. PEDV causes severe diarrhea, dehydration, and high mortality in neonatal piglets. Despite the widespread use of commercial vaccines, persistent PEDV outbreaks worldwide indicate that current vaccination strategies provide suboptimal protection. Increasing evidence suggests that the limited effectiveness of current control strategies is primarily attributable to two interrelated factors: continuous antigenic variation among circulating PEDV strains and inadequate induction of maternal mucosal immunity. Unlike systemic viral infections, effective protection against PEDV in neonatal piglets predominantly depends on lactational immunity mediated by the gut–mammary gland–secretory IgA (sIgA) axis. However, most currently available vaccines predominantly induce systemic IgG responses and fail to effectively stimulate intestinal immune imprinting or sustain sIgA secretion in colostrum and milk. In this review, we summarize the mechanisms underlying PEDV evolution and maternal mucosal immunity, with particular emphasis on the gut–mammary gland–sIgA axis. We further discuss the recent advances in and limitations of current vaccine platforms and propose an integrated framework for broadly protective PEDV vaccines based on structural antigen optimization, mucosal-targeted immunization, and sIgA-oriented evaluation systems. This framework may provide new insights into the rational design of more effective maternal vaccines against PEDV and other enteric coronaviruses affecting pigs. Full article

Yaks have long inhabited the Qinghai-Tibetan Plateau. This region features low-oxygen, frigid temperatures and pronounced seasonal variation in nutrient availability. They have evolved adaptive phenotypes centered on energy metabolism reprogramming, tissue structure remodeling, and stress homeostasis maintenance. In recent years, non-coding RNAs (ncRNAs) have been confirmed as an important component of the yak’s post-transcriptional regulatory network. They play a key bridging role between environmental stress perception and phenotypic output through mechanisms such as influencing RNA splicing, stability, translation activity, and constructing competitive endogenous RNA (ceRNA) networks. This article systematically reviews the biogenesis pathways and core regulatory patterns of circular RNAs (circRNAs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). It focuses on summarizing the expression profile characteristics and dynamic spatiotemporal changes of these three types of ncRNAs in physiological contexts such as muscle and fat deposition, mammary gland lactation, testicular development, and hypoxia response in the heart, lungs, and vascular system of yaks. Current research evidence indicates that the regulatory network of yaks ncRNAs shows significant convergence on multiple key signaling pathways, mainly concentrating on lipid metabolism (PPAR/AMPK), nutrition and growth signals (PI3K-Akt/MAPK/mTOR), extracellular matrix remodeling (ECM-receptor interaction, Wnt/TGF-β), and cell stress fate determination (apoptosis, oxidative stress/ferroptosis) modules. Among them, some core circRNA and lncRNA-miRNA-mRNA regulatory axes have been functionally validated in vitro. Despite the phased progress, current research on ncRNA in yaks still faces bottlenecks: the multi-omics molecular atlases (encompassing genomics, transcriptomics, proteomics, and metabolomics) of key high-altitude adaptive organs remain incomplete, analysis processes lack sufficient standardization, and most studies stay at the association network level with limited causal mechanism validation. To address these limitations, future research should focus on building a standardized evidence chain, integrating multi-omics and single-cell/spatial transcriptome technologies, and conducting mechanism verification for traits in independent populations, thereby providing a solid theoretical basis for understanding the extreme environmental adaptation mechanisms of yaks and molecular breeding improvement. Full article

In dairy cows, teat keratinization occurs where keratinized tissue rings form around teat tips (opening). Manifesting as skin damage in mechanically milked dairy cows, keratinization presents as dry, rough, pale, or milky-white keratinous protrusions around teat orifices and progresses via the combined effects of mechanical stress, management practices, host genetics, environmental influences, and nutritional metabolism. The teat hole is the first physiological barrier protecting the mammary glands from external pathogen invasion. Most mastitis cases are caused by pathogens invading the mammary tissues from the teat end, thereby significantly impacting mammary gland health. Thus, there are no safe, effective, economical, and standardized treatment protocols for terminal teat hyperkeratosis in dairy cows. To address this, we treated keratinization lesions using pharmacological interventions and evaluated their efficacy in 91 cows at a large commercial dairy farm in Heilongjiang Province. Urea ointment, salicylic acid ointment, and 5% azelaic acid acne cream exerted therapeutic or alleviating effects toward teat keratosis, whereas retinoic acid ointment demonstrated poor therapeutic efficacy. In a three-daily application regimen, the optimal treating dose was 0.3 g. These findings provide a scientific basis for the clinical management of hyperkeratosis in large-scale dairy farms and the development of related veterinary therapeutics. Full article

One of the major obstacles in early cancer detection in dogs is the limited sensitivity in detecting circulating tumor DNAs (ctDNAs) with low abundances. Standard next-generation sequencing (NGS) without error correction typically achieves detection limits around ~1% mutant allele frequency (MAF). We sought to improve the detection sensitivity using a sequential CRISPR-EspCas9 enrichment strategy in which iterative in vitro cleavage (IVC) was combined with PCR amplification to selectively deplete wild-type DNA and enrich rare tumor mutations. Applying the strategy to genomic DNA and cell-free DNA mimics from canine mammary gland tumor cell lines demonstrated that IVC enrichment enabled the detection of cancer-associated PIK3CA H1047R mutations that were undetectable by conventional Sanger sequencing. To evaluate detection sensitivity, we characterized enrichment using synthetic templates for PIK3CA H1047R and other cancer-related mutations, BRAF V596E, and KRAS G12C. We observed that three iterations of sequential IVC achieved ~160, ~15, and ~2.2-fold enrichment for PIK3CA H1047R, BRAF V596E, and KRAS G12C, respectively. Under the present synthetic-template conditions, the analytical LOD reached 0.001% MAF for PIK3CA and 0.01% MAF for BRAF, whereas KRAS showed only modest enrichment and remained practically limited under the current guide design. Together, the results show that the CRISPR-EspCas9 IVC strategy enables selective enrichment of low-frequency single-nucleotide mutant alleles. We anticipate that the finding could be utilized to develop a highly sensitive veterinary liquid biopsy application with further optimization and validation using canine plasma cfDNA. Full article

Some dairy cows develop postpartum hypocalcemia because they cannot adapt to the drastic loss of blood calcium during the periparturient period. Parathyroid hormone (PTH) maintains calcium homeostasis by regulating bone calcium mobilization, gastric and intestinal calcium absorption, and renal calcium reabsorption. Traditionally, dysregulation of PTH has been considered the main cause of this disorder. Recent studies have confirmed that parathyroid hormone-related protein (PTHrP) secreted by the mammary gland is also involved in calcium homeostasis by promoting bone resorption. Based on existing research evidence and cross-species comparisons, this paper analyzes the effects of differences in mammary calcium output and compensatory mechanisms among various mammals on the risk of postpartum hypocalcemia, with a particular focus on processes related to bone resorption and bone formation. It further explains the pathogenesis of postpartum hypocalcemia in dairy cows by examining the roles of the mammary–brain–bone axis, PTH, and PTHrP in bone resorption and bone formation in these animals. Full article

The mammary gland is a heterogeneous organ that modulates ductal morphogenesis and alveolar differentiation. Obesity is a significant risk factor for several cancers, including postmenopausal breast cancer. We and others have described an association between obesity and increased breast cancer growth. However, the effects of obesity on the mammary fat pad microenvironment (MFPME) remain understudied. Here, we investigated the effect of the Western Diet (WD) on immunocompetent female mice and on their MFPME. Our data suggest that the WD increased body, liver, and perigonadal white adipose tissue (pWAT) weight, as well as myeloid cell infiltration into these tissues. Interestingly, we did not find any significant change in CD4⁺ and CD8⁺ T cells in the liver, blood, and pWAT. NanoString data demonstrates that various cellular processes, including the complement system, innate immune system, phagocytic activity, immune metabolism, and NOD-like receptor (NLR) signaling, were upregulated in the MFPME of obese mice. RNA-Seq data suggest that WD significantly modulated MFPME physiology through regulation of gene expression, cellular processes, and signaling pathways. Further investigation is necessary to determine how WD-mediated changes in MFPME modulate breast cancer biology. Full article

Bovine mastitis is a persistent and challenging illness in dairy industry, bringing about devastating economic losses to the sector. The longstanding over-reliance on antibiotic therapy has raised severe public health concerns, highlighting the critical need to develop safe and effective alternative regimens. Pulsatilla saponin B4 (PSB4), a plant-derived triterpenoid saponin, has been shown to regulate inflammation. However, the effect of PSB4 on mastitis in lactating cows has not been elucidated. The aim of this study was to explore the anti-inflammatory property and the molecular mechanisms of PSB4 in bovine mammary epithelial cells (BMECs) and mouse mastitis model. In cultured cells, PSB4 alleviated LPS-induced inflammatory reaction by suppressing the expression of pro-inflammatory mediators in BMECs. Notably, RNA-seq analysis indicated that the anti-inflammatory effect of PSB4 was correlated with IL-17RA and NF-κB signaling, with subsequent Western blot validation. Moreover, BMECs were stimulated with recombinant interleukin-17A (rIL-17A) to induce inflammation and challenged with Taltz to specifically inhibit IL-17RA signaling. The results showed that PSB4 reversed the rIL-17A-induced upregulation of elements within the IL-17RA pathway and its downstream MAPK/NF-κB cascade, including their downstream effectors. Furthermore, Taltz blocked the efficacy of PSB4 in protecting against LPS-induced inflammation. In vivo, PSB4 alleviated the inflammatory damage of mammary gland, pro-inflammatory mediator levels in mammary gland tissue and se-rum, while blocking the activation of IL-17RA signal along with downstream MAPK/NF-κB signal in LPS-induced mouse mastitis model. Taken together, studies in both BMECs and mice demonstrated that PSB4 alleviates mastitis by inhibiting IL-17RA signaling and downstream MAPK/NF-κB pathway, which may be a new strategy and a target for the management of mastitis. Full article

Bovine mastitis remains a major impediment to optimal dairy production. Somatic cell count (SCC) is commonly used as an indicator of mammary gland inflammation, while milk microbiota may also reflect mastitis-related changes. Here, we employed Oxford Nanopore full-length transcript sequencing to delineate the peripheral blood transcriptomic landscape of Xinjiang Brown cattle stratified by high (SCC ≥ 1,000,000 cells mL⁻¹) and low (SCC ≤ 200,000 cells mL⁻¹) SCCs, with the objective of identifying candidate genes underpinning mastitis resistance. We identified 226 differentially expressed genes and 441 differentially expressed transcripts. Genes in the high-SCC group were prominently enriched in immune response pathways and chemokine signalling cascades. Protein–protein interaction network analysis further delineated a core module of ten immune-related genes, including CCL4, IL1B and CXCL2. Integrative analysis with complementary second-generation sequencing data pinpointed CXCL2 as a high-priority candidate. Subsequent RT–qPCR and enzyme-linked immunosorbent assay (ELISA) validation revealed that CXCL2 expression was significantly elevated both in high-SCC individuals and in an LPS-induced bovine mammary epithelial cell inflammation model. Collectively, these findings establish CXCL2 as a putative molecular marker for mastitis resistance breeding and provide a foundational resource for deciphering the molecular mechanisms governing mammary health. Full article

Although human mammary glands were traditionally considered sterile, accumulating evidence has established the presence of distinct microbial communities that may have colonized breast tissue primarily via retrograde nipple flow or via hematogenous or lymphatic translocation from other body sites. Comparative studies reveal differences in the microbiota of healthy and diseased breast tissues, with variations in microbial signatures across breast cancer subtypes and in comparison with adjacent normal tissues. This review synthesizes current evidence on the composition of the breast microbiome, the factors shaping its development, and alterations it undergoes in inflammatory and malignant breast diseases. Furthermore, the article discusses mechanistic insights, methodological challenges, and future therapeutic perspectives based on published studies employing culture-independent approaches, such as 16S rRNA gene sequencing and metagenomic analyses. Key host-related factors influencing breast-associated microbial communities, including hormonal regulation, environmental exposure, diet, and therapeutic interventions, are explored. The existing literature is assessed to identify key associations between the breast microbiome and host signaling pathways, as well as the significant challenges that remain unresolved, including low biomass contamination, inter-study variability, limited longitudinal data, and an incomplete understanding of causality. Addressing these limitations is critical for advancing microbiome-based diagnostic and therapeutic strategies for breast disease. Full article