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Microorganisms May 2024The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal... (Review)
Review
The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that the lactating mammary gland houses a warm and nutrient-rich environment and is in contact with the external environment, it may be expected that the lactating mammary gland would contain a high biomass microbiome. This discrepancy raises the question of whether the bacteria in milk come from true microbial colonization in the mammary gland ("residents") or are merely the result of constant influx from other bacterial sources ("tourists"). By drawing together data from animal, in vitro, and human studies, this review will examine the question of whether the lactating mammary gland is colonized by a residential microbiome.
PubMed: 38792838
DOI: 10.3390/microorganisms12051009 -
Animals : An Open Access Journal From... May 2024Additional Affiliation(s) [...].
Correction: Geldsetzer-Mendoza, C.; Riveros, J.L. Morphophysiological Responses of the Goat Mammary Gland to Water Scarcity in Arid and Semi-Arid Environments: Are They Enough to Generate Adaptation to New Climatic Challenges? 2023, , 3825.
Additional Affiliation(s) [...].
PubMed: 38791731
DOI: 10.3390/ani14101445 -
Animals : An Open Access Journal From... May 2024Compared to the number of studies on the neoplasms of laboratory rodents, fewer studies have focused on spontaneous neoplasms in pet rodents. Notably, the mouse mammary...
Compared to the number of studies on the neoplasms of laboratory rodents, fewer studies have focused on spontaneous neoplasms in pet rodents. Notably, the mouse mammary tumor virus (MMTV) is associated with mammary tumors in rodents. In this study, 77 tumors and tumor-like lesions of biopsy samples were collected from 70 pet rodents, including hamsters (n = 47), guinea pigs (n = 16), unknown species (n = 4), rats (n = 2), and a gerbil. Fifty tumors were collected from 47 hamsters, in which the most common tumors were mammary tumors (13/50), followed by fibrosarcoma (9/50), mast cell tumors (4/50), and squamous cell carcinoma (4/50). The collected subtypes of mammary tumors in hamsters included tubular carcinoma (n = 5), tubular adenoma (n = 4), carcinoma and malignant myoepithelioma (n = 1), simple tubular carcinoma (n = 1), adenosquamous carcinoma (n = 1), and tubulopapillary adenoma (n = 1). In addition, twenty tumors were collected from guinea pigs, in which the most common tumor was lipoma (6/20), followed by adenocarcinoma of the mammary gland (4/20), trichofolliculoma (2/20), and collagenous hamartomas (2/20). In guinea pigs, the subtypes of mammary gland tumors were tubular carcinoma (n = 2), tubular and solid carcinoma (n = 1), and tubulopapillary carcinoma (n = 1). In 20 cases of mammary tumors, MMTV was not detected, implicating no evidence of MMTV infection in mammary oncogenesis in pet rodents in Taiwan.
PubMed: 38791685
DOI: 10.3390/ani14101469 -
Journal of Dairy Science May 2024The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 years ago. To provide evidences that one or more...
The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 years ago. To provide evidences that one or more autocrine factor(s) exists, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked while the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples was infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and then quarter milking was resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. RNA was extracted from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 were upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established.
PubMed: 38788842
DOI: 10.3168/jds.2023-24603 -
Pathogens (Basel, Switzerland) May 2024Mastitis is a common mammary gland disease of dairy cattle caused by a wide range of organisms including bacteria, fungi and algae. Mastitis contributes to economic...
Mastitis is a common mammary gland disease of dairy cattle caused by a wide range of organisms including bacteria, fungi and algae. Mastitis contributes to economic losses of dairy farms due to reduced yield and poor quality of milk. Since the correct identification of pathogens responsible for the development of mastitis is crucial to the success of treatment, it is necessary to develop a quick and accurate test to distinguish the main pathogens causing this disease. In this paper, we describe the development of a test based on the multiplex polymerase chain reaction (PCR) method allowing for the identification of , , and When creating our test, we relied on the results from new generation sequencing (NGS) for accurate determination of species affiliation. The multiplex PCR test was verified on 100 strains including veterinary samples, ATCC and Polish Collection of Microorganisms (PCM) reference strains. The obtained results indicate that this test is accurate and displays high specificity. It may serve as a valuable molecular tool for the detection of major mastitis pathogens.
PubMed: 38787275
DOI: 10.3390/pathogens13050423 -
Tomography (Ann Arbor, Mich.) May 2024The aim of this study was to show for the first time that low-frequency 3D-transmitted ultrasound tomography (3D UT, volography) can differentiate breast tissue types...
The aim of this study was to show for the first time that low-frequency 3D-transmitted ultrasound tomography (3D UT, volography) can differentiate breast tissue types using tissue properties, accurately measure glandular and ductal volumes in vivo, and measure variation over time. Data were collected for 400 QT breast scans on 24 women (ages 18-71), including four (4) postmenopausal subjects, 6-10 times over 2+ months of observation. The date of onset of menopause was noted, and the cases were further subdivided into three (3) classes: pre-, post-, and peri-menopausal. The ducts and glands were segmented using breast speed of sound, attenuation, and reflectivity images and followed over several menstrual cycles. The coefficient of variation (CoV) for in premenopausal women was significantly larger than for postmenopausal women, whereas this is not true for the CoV. The glandular standard deviation (SD) is significantly larger in premenopausal women vs. postmenopausal women, whereas this is not true for ductal tissue. We conclude that ducts do not appreciably change over the menstrual cycle in either pre- or post-menopausal subjects, whereas glands change significantly over the cycle in pre-menopausal women, and 3D UT can differentiate ducts from glands in vivo.
Topics: Humans; Female; Adult; Menstrual Cycle; Middle Aged; Aged; Breast; Young Adult; Ultrasonography, Mammary; Imaging, Three-Dimensional; Adolescent; Mammary Glands, Human
PubMed: 38787020
DOI: 10.3390/tomography10050060 -
Cells May 2024Breast cancer develops upon sequential acquisition of driver mutations in mammary epithelial cells; however, how these mutations collaborate to transform normal cells...
Breast cancer develops upon sequential acquisition of driver mutations in mammary epithelial cells; however, how these mutations collaborate to transform normal cells remains unclear in most cases. We aimed to reconstitute this process in a particular case. To this end, we combined the activated form of the PI 3-kinase harboring the H1047R mutation with the inactivation of the histone lysine methyl-transferase KMT2D in the non-tumorigenic human mammary epithelial cell line MCF10A. We found that PI 3-kinase activation promoted cell-cycle progression, especially when growth signals were limiting, as well as cell migration, both in a collective monolayer and as single cells. Furthermore, we showed that KMT2D inactivation had relatively little influence on these processes, except for single-cell migration, which KMT2D inactivation promoted in synergy with PI 3-kinase activation. The combination of these two genetic alterations induced expression of the gene that encodes a subunit of the Arp2/3 complex. ARPC5L depletion fully abolished the enhanced migration persistence exhibited by double-mutant cells. Our reconstitution approach in MCF10A has thus revealed both the cell function and the single-cell migration, and the underlying Arp2/3-dependent mechanism, which are synergistically regulated when KMT2D inactivation is combined with the activation of the PI 3-kinase.
Topics: Humans; Cell Movement; Epithelial Cells; Phosphatidylinositol 3-Kinases; Histone-Lysine N-Methyltransferase; Actin-Related Protein 2-3 Complex; Female; Mammary Glands, Human; DNA-Binding Proteins; Neoplasm Proteins; Mutation; Cell Line
PubMed: 38786098
DOI: 10.3390/cells13100876 -
Current Issues in Molecular Biology May 2024This review systematizes information about the metabolic features of breast cancer directly related to oxidative stress. It has been shown those redox changes occur at... (Review)
Review
This review systematizes information about the metabolic features of breast cancer directly related to oxidative stress. It has been shown those redox changes occur at all levels and affect many regulatory systems in the human body. The features of the biochemical processes occurring in breast cancer are described, ranging from nonspecific, at first glance, and strictly biochemical to hormone-induced reactions, genetic and epigenetic regulation, which allows for a broader and deeper understanding of the principles of oncogenesis, as well as maintaining the viability of cancer cells in the mammary gland. Specific pathways of the activation of oxidative stress have been studied as a response to the overproduction of stress hormones and estrogens, and specific ways to reduce its negative impact have been described. The diversity of participants that trigger redox reactions from different sides is considered more fully: glycolytic activity in breast cancer, and the nature of consumption of amino acids and metals. The role of metals in oxidative stress is discussed in detail. They can act as both co-factors and direct participants in oxidative stress, since they are either a trigger mechanism for lipid peroxidation or capable of activating signaling pathways that affect tumorigenesis. Special attention has been paid to the genetic and epigenetic regulation of breast tumors. A complex cascade of mechanisms of epigenetic regulation is explained, which made it possible to reconsider the existing opinion about the triggers and pathways for launching the oncological process, the survival of cancer cells and their ability to localize.
PubMed: 38785550
DOI: 10.3390/cimb46050282 -
MSystems Jun 2024In low-microbial biomass samples such as bovine milk, contaminants can outnumber endogenous bacteria. Because of this, milk microbiome research suffers from a critical...
In low-microbial biomass samples such as bovine milk, contaminants can outnumber endogenous bacteria. Because of this, milk microbiome research suffers from a critical knowledge gap, namely, does non-mastitis bovine milk contain a native microbiome? In this study, we sampled external and internal mammary epithelia and stripped and cisternal milk and used numerous negative controls, including air and sampling controls and extraction and library preparation blanks, to identify the potential sources of contamination. Two algorithms were used to mathematically remove contaminants and track the potential movement of microbes among samples. Results suggest that the majority (i.e., >75%) of sequence data generated from bovine milk and mammary epithelium samples represents contaminating DNA. Contaminants in milk samples were primarily sourced from DNA extraction kits and the internal and external skin of the teat, while teat canal and apex samples were mainly contaminated during the sampling process. After decontamination, the milk microbiome displayed a more dispersed, less diverse, and compositionally distinct bacterial profile compared with epithelial samples. Similar microbial compositions were observed between cisternal and stripped milk samples, as well as between teat apex and canal samples. and were the predominant genera detected in milk sample sequences, and bacterial culture showed growth of and spp. in 50% (7/14) of stripped milk samples and growth of spp. in 7% (1/14) of cisternal milk samples. Our study suggests that microbiome data generated from milk samples obtained from clinically healthy bovine udders may be heavily biased by contaminants that enter the sample during sample collection and processing workflows.IMPORTANCEObtaining a non-contaminated sample of bovine milk is challenging due to the nature of the sampling environment and the route by which milk is typically extracted from the mammary gland. Furthermore, the very low bacterial biomass of bovine milk exacerbates the impacts of contaminant sequences in downstream analyses, which can lead to severe biases. Our finding showed that bovine milk contains very low bacterial biomass and each contamination event (including sampling procedure and DNA extraction process) introduces bacteria and/or DNA fragments that easily outnumber the native bacterial cells. This finding has important implications for our ability to draw robust conclusions from milk microbiome data, especially if the data have not been subjected to rigorous decontamination procedures. Based on these findings, we strongly urge researchers to include numerous negative controls into their sampling and sample processing workflows and to utilize several complementary methods for identifying potential contaminants within the resulting sequence data. These measures will improve the accuracy, reliability, reproducibility, and interpretability of milk microbiome data and research.
Topics: Animals; Cattle; Milk; Microbiota; Female; DNA, Bacterial; Bacteria; Mammary Glands, Animal; Specimen Handling; RNA, Ribosomal, 16S
PubMed: 38785438
DOI: 10.1128/msystems.01158-23 -
BMC Veterinary Research May 2024Mammary Pathogenic Escherichia coli (MPEC) is an important pathogen that can escape the attack of the host immune system through biofilm formation and proliferate in the...
BACKGROUND
Mammary Pathogenic Escherichia coli (MPEC) is an important pathogen that can escape the attack of the host immune system through biofilm formation and proliferate in the mammary gland continuously, resulting in mastitis in cows and causing enormous economic losses. As an effector of AI-2 quorum sensing, LsrR extensively affects the expression levels of hundreds of genes related to multiple biological processes in model E. coli strain. However, the regulatory role of LsrR in MPEC and whether it is involved in pathogenesis has been seldom reported.
RESULTS
In this study, the function of LsrR in strain MPEC5, obtained from a milk sample in dairy cows with mastitis, was investigated by performing high-throughput sequencing (RNA-seq) assays. The results revealed that LsrR down-regulated the transcript levels of fimAICDFGH (encoding Type 1 pili), which have been reported to be associated with biofilm formation process. Biofilm assays confirmed that deletion of lsrR resulted in a significant increase in biofilm formation in vitro. In addition, electrophoretic mobility shift assay (EMSA) provided evidence that LsrR protein could directly bind to the promoter regions of fimAICDFGH in a dose-dependent manner.
CONCLUSIONS
These results indicate that LsrR protein inhibits the biofilm formation ability of MPEC5 by directly binding to the fimAICDFGH promoter region. This study presents a novel clue for further exploration of the prevention and treatment of MPEC.
Topics: Biofilms; Animals; Escherichia coli Proteins; Escherichia coli; Cattle; Female; Escherichia coli Infections; Mastitis, Bovine; Gene Expression Regulation, Bacterial; Mammary Glands, Animal; Repressor Proteins
PubMed: 38783285
DOI: 10.1186/s12917-024-04086-9