Comparative phenotypic characterization of human colostrum and breast milk-derived stem cells

Evaluation puramatrix as a 3D microenvironment for neural differentiation of human breastmilk stem cells

The extracellular matrix is recognized as an efficient and determining component in the growth, proliferation, and differentiation of cells due to its ability to perceive and respond to environmental signals. Applying three-dimensional scaffolds can create conditions similar to the extracellular matrix and provide an opportunity to investigate cell fate. In this study, we employed the PuraMatrix hydrogel scaffold as an advanced cell culture platform for the neural differentiation of stem cells derived from human breastmilk to design an opportune model for tissue engineering. Isolated stem cells from breastmilk were cultured and differentiated into neural-like cells on PuraMatrix peptide hydrogel and in the two-dimensional system. The compatibility of breastmilk-derived stem cells with PuraMatrix and cell viability was evaluated by scanning electron microscopy and MTT assay, respectively. Induction of differentiation was achieved by exposing cells to the neurogenic medium. After 21 days of the initial differentiation process, the expression levels of glial fibrillary acidic protein (GFAP), microtubule-associated protein (MAP2), β-tubulin III, and neuronal nuclear antigen (NeuN) were analyzed using the immunostaining technique. The results illustrated a notable expression of MAP2, β-tubulin-III, and NeuN in the three-dimensional cell culture in comparison to the two-dimensional system, indicating the beneficial effect of PuraMatrix scaffolds in the process of differentiating breastmilk-derived stem cells into neural-like cells. In view of the obtained results, the combination of breastmilk-derived stem cells and PuraMatrix hydrogel scaffold could be an advisable preference for neural tissue regeneration and cell therapy.

Mesenchymal stem cells (MSCs) from the mouse bone marrow show differential expression of interferon regulatory factors IRF-1 and IRF-2

BACKGROUND

Interferon regulatory factors (IRF-1 and IRF-2) are transcription factors widely implicated in various cellular processes, including regulation of inflammatory responses to pathogens, cell proliferation, oncogenesis, differentiation, autophagy, and apoptosis.

METHODS

We have studied the expression of IRF-1, IRF-2 mRNAs by RT-PCR, cellular localization of the proteins by immunofluorescence, and expression of mRNAs of genes regulated by IRF-1, IRF-2 by RT-PCR in mouse bone marrow cells (BMCs) and mesenchymal stem cells (MSCs).

RESULTS

Higher level of IRF-1 mRNA was observed in BMCs and MSCs compared to that of IRF-2. Similarly, differential expression of IRF-1 and IRF-2 proteins was observed in BMCs and MSCs. IRF-1 was predominantly localized in the cytoplasm, whereas IRF-2 was localized in the nuclei of BMCs. MSCs showed nucleo-cytoplasmic distribution of IRF-1 and nuclear localization of IRF-2. Constitutive expression of IRF-1 and IRF-2 target genes: monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9), and caspase-1 was observed in both BMCs and MSCs. MSCs showed constitutive expression of the pluripotency-associated factors, Oct3/4 and Sox-2. Lipopolysaccharide (LPS)-treatment of MSCs induced prominent cellular localization of IRF-1 and IRF-2.

CONCLUSIONS

Our results suggest that IRF-1 and IRF-2 exhibit differential expression of their mRNAs and subcellular localization of the proteins in BMCs and MSCs. These cells also show differential levels of constitutive expression of IRF-1 and IRF-2 target genes. This may regulate immune-responsive properties of BMCs and MSCs through IRF-1, IRF-2-dependent gene expression and protein-protein interaction. Regulating IRF-1 and IRF-2 may be helpful for immunomodulatory functions of MSCs for cell therapy and regenerative medicine.

Nutritional and health effects of bovine colostrum in neonates

High concentrations of immunoglobulins, bioactive peptides, and growth factors are found in bovine colostrum (BC), the milk produced by cows in the first few days after parturition. Various biological functions make it increasingly used to provide nutritional support and immune protection to the offspring of many species, including humans. These biological functions include cell growth stimulation, anti-infection, and immunomodulation. The primary components and biological functions of colostrum were reviewed in the literature, and the authors also looked at its latent effects on the growth and development of neonates as well as on conditions such as infections, necrotizing enterocolitis, short bowel syndrome, and feeding intolerance. The importance of BC in neonatal nutrition, immune support, growth and development, and gut health has been demonstrated in a number of experimental and animal studies. BC has also been shown to be safe at low doses without adverse effects in newborns. BC supplementation has been shown to be efficient in preventing several disorders, including rotavirus diarrhea, necrotizing enterocolitis, and sepsis in animal models of prematurity and some newborn studies. Therefore, BC supplementation should be considered in cases where maternal milk is insufficient or donor milk is unavailable. The optimal age, timing, dosage, and form of BC administration still require further investigation.

Ecologies, synergies, and biological systems shaping human milk composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 2

Human milk is universally recognized as the preferred food for infants during the first 6 mo of life because it provides not only essential and conditionally essential nutrients in necessary amounts but also other biologically active components that are instrumental in protecting, communicating important information to support, and promoting optimal development and growth in infants. Despite decades of research, however, the multifaceted impacts of human milk consumption on infant health are far from understood on a biological or physiological basis. Reasons for this lack of comprehensive knowledge of human milk functions are numerous, including the fact that milk components tend to be studied in isolation, although there is reason to believe that they interact. In addition, milk composition can vary greatly within an individual as well as within and among populations. The objective of this working group within the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project was to provide an overview of human milk composition, factors impacting its variation, and how its components may function to coordinately nourish, protect, and communicate complex information to the recipient infant. Moreover, we discuss the ways whereby milk components might interact such that the benefits of an intact milk matrix are greater than the sum of its parts. We then apply several examples to illustrate how milk is better thought of as a biological system rather than a more simplistic "mixture" of independent components to synergistically support optimal infant health.

Parental factors that impact the ecology of human mammary development, milk secretion, and milk composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 1

The goal of Working Group 1 in the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project was to outline factors influencing biological processes governing human milk secretion and to evaluate our current knowledge of these processes. Many factors regulate mammary gland development in utero, during puberty, in pregnancy, through secretory activation, and at weaning. These factors include breast anatomy, breast vasculature, diet, and the lactating parent's hormonal milieu including estrogen, progesterone, placental lactogen, cortisol, prolactin, and growth hormone. We examine the effects of time of day and postpartum interval on milk secretion, along with the role and mechanisms of lactating parent-infant interactions on milk secretion and bonding, with particular attention to the actions of oxytocin on the mammary gland and the pleasure systems in the brain. We then consider the potential effects of clinical conditions including infection, pre-eclampsia, preterm birth, cardiovascular health, inflammatory states, mastitis, and particularly, gestational diabetes and obesity. Although we know a great deal about the transporter systems by which zinc and calcium pass from the blood stream into milk, the interactions and cellular localization of transporters that carry substrates such as glucose, amino acids, copper, and the many other trace metals present in human milk across plasma and intracellular membranes require more research. We pose the question of how cultured mammary alveolar cells and animal models can help answer lingering questions about the mechanisms and regulation of human milk secretion. We raise questions about the role of the lactating parent and the infant microbiome and the immune system during breast development, secretion of immune molecules into milk, and protection of the breast from pathogens. Finally, we consider the effect of medications, recreational and illicit drugs, pesticides, and endocrine-disrupting chemicals on milk secretion and composition, emphasizing that this area needs much more research attention.

Dynamic change, influencing factors, and clinical impact of cellular components in human breast milk

BACKGROUND

Numerous cellular components have been well demonstrated in human breast milk. However, little is known about their dynamic change, influencing factors, and potential clinical impacts on infants.

METHODS

Sixty and forty-five healthy mother-infant pairs were enrolled in the colostrum group and mature milk group, respectively. Participants' demographic and clinical information were collected by questionnaires, and the infants were followed up until 6 months after birth through telephone interview. Colostrum and mature milk were collected, and the percentage of various cell components were determined by flow cytometric analysis.

RESULTS

The results showed that, the total cell numbers, and the percentages of some stem cells, including CD34+, CD117+, CD133+, CD90+, CD105+, and CD146+ cells, were different in colostrum and mature milk. Besides, participants' characteristics had influence on the cellular components. Finally, high-CD34+ cells in colostrum, as well as the high-CD133+ cells and low-CD105+ cells in mature milk were associated with a significantly increased risk of infantile eczema within their first 3 months after birth.

CONCLUSIONS

Our data showed a dynamic change of cellular components, identified some of their influencing factors and their potential clinical impacts on infantile eczema, which helps to better understand the cellular components in human breast milk.

IMPACT

Some stem cell markers were dynamically changed in human colostrum and mature milk. Different cellular components were shown to be influenced by different participants' characteristics. High percentage of CD34+ cells in colostrum, as well as high percentage of CD133+ cells and low percentage of CD105+ cells in mature milk, were associated with a significantly increased risk of infantile eczema within their first 3 months after birth. To our knowledge, this is the first study on the clinical impacts of stem cells on infantile diseases, which helps to give a better understanding of human breast milk.

Stem cells in neonatal diseases: An overview

Preterm birth and its common complications are major causes of infant mortality and long-term morbidity. Despite great advances in understanding the pathogenesis of neonatal diseases and improvements in neonatal intensive care, effective therapies for the prevention or treatment for these conditions are still lacking. Stem cell (SC) therapy is rapidly emerging as a novel therapeutic tool for several diseases of the newborn with encouraging pre-clinical results that hold promise for translation to the bedside. The utility of different types of SCs in neonatal diseases is being explored. SC therapeutic efficacy is closely associated with its secretome-conditioned media and SC-derived extracellular vesicles, and a subsequent paracrine action in response to tissue injuries. In the current review, we summarize the pre-clinical and clinical studies of SCs and its secretome in diverse preterm and term birth-related diseases, thereby providing new insights for future therapies in neonatal medicine.

Potential Benefits of Bovine Colostrum in Pediatric Nutrition and Health

Bovine colostrum (BC), the first milk produced from cows after parturition, is increasingly used as a nutritional supplement to promote gut function and health in other species, including humans. The high levels of whey and casein proteins, immunoglobulins (Igs), and other milk bioactives in BC are adapted to meet the needs of newborn calves. However, BC supplementation may improve health outcomes across other species, especially when immune and gut functions are immature in early life. We provide a review of BC composition and its effects in infants and children in health and selected diseases (diarrhea, infection, growth-failure, preterm birth, necrotizing enterocolitis (NEC), short-bowel syndrome, and mucositis). Human trials and animal studies (mainly in piglets) are reviewed to assess the scientific evidence of whether BC is a safe and effective antimicrobial and immunomodulatory nutritional supplement that reduces clinical complications related to preterm birth, infections, and gut disorders. Studies in infants and animals suggest that BC should be supplemented at an optimal age, time, and level to be both safe and effective. Exclusive BC feeding is not recommended for infants because of nutritional imbalances relative to human milk. On the other hand, adverse effects, including allergies and intolerance, appear unlikely when BC is provided as a supplement within normal nutrition guidelines for infants and children. Larger clinical trials in infant populations are needed to provide more evidence of health benefits when patients are supplemented with BC in addition to human milk or formula. Igs and other bioactive factors in BC may work in synergy, making it critical to preserve bioactivity with gentle processing and pasteurization methods. BC has the potential to become a safe and effective nutritional supplement for several pediatric subpopulations.

Maternal Microbiota, Early Life Colonization and Breast Milk Drive Immune Development in the Newborn

The innate immune system is the oldest protection strategy that is conserved across all organisms. Although having an unspecific action, it is the first and fastest defense mechanism against pathogens. Development of predominantly the adaptive immune system takes place after birth. However, some key components of the innate immune system evolve during the prenatal period of life, which endows the newborn with the ability to mount an immune response against pathogenic invaders directly after birth. Undoubtedly, the crosstalk between maternal immune cells, antibodies, dietary antigens, and microbial metabolites originating from the maternal microbiota are the key players in preparing the neonate’s immunity to the outer world. Birth represents the biggest substantial environmental change in life, where the newborn leaves the protective amniotic sac and is exposed for the first time to a countless variety of microbes. Colonization of all body surfaces commences, including skin, lung, and gastrointestinal tract, leading to the establishment of the commensal microbiota and the maturation of the newborn immune system, and hence lifelong health. Pregnancy, birth, and the consumption of breast milk shape the immune development in coordination with maternal and newborn microbiota. Discrepancies in these fine-tuned microbiota interactions during each developmental stage can have long-term effects on disease susceptibility, such as metabolic syndrome, childhood asthma, or autoimmune type 1 diabetes. In this review, we will give an overview of the recent studies by discussing the multifaceted emergence of the newborn innate immune development in line with the importance of maternal and early life microbiota exposure and breast milk intake.

Resolving Human Lactation Heterogeneity Using Single Milk-Derived Cells, a Resource at the Ready

Single cell RNA sequencing (scRNAseq) of human milk-derived cells (HMDCs) makes highly detailed analyses of the biology of human lactation possible. We explore this powerful application as an exciting tool to inspect the cellular composition of human milk. We point out some important challenges unique to this approach and highlight the importance of collaborations between biologists and well-trained bioinformaticians to utilize these data to their maximum potential. We extend this focus by discussing the first two such studies that describe HMDCs via scRNAseq and a variety of important questions in the field that warrant attention through further research. The stage is set to apply scRNAseq in human lactation biology, potentially leading to new insights regarding the molecular and cellular diversity of human secretory mammary epithelial cells.

Single Cell RNA Sequencing of Human Milk-Derived Cells Reveals Sub-Populations of Mammary Epithelial Cells with Molecular Signatures of Progenitor and Mature States: a Novel, Non-invasive Framework for Investigating Human Lactation Physiology

Cells in human milk are an untapped source, as potential "liquid breast biopsies", of material for investigating lactation physiology in a non-invasive manner. We used single cell RNA sequencing (scRNA-seq) to identify milk-derived mammary epithelial cells (MECs) and their transcriptional signatures in women with diet-controlled gestational diabetes (GDM) with normal lactation. Methodology is described for coordinating milk collections with single cell capture and library preparation via cryopreservation, in addition to scRNA-seq data processing and analyses of MEC transcriptional signatures. We comprehensively characterized 3740 cells from milk samples from two mothers at two weeks postpartum. Most cells (>90%) were luminal MECs (luMECs) expressing lactalbumin alpha and casein beta and positive for keratin 8 and keratin 18. Few cells were keratin 14⁺ basal MECs and a small immune cell population was present (<10%). Analysis of differential gene expression among clusters identified six potentially distinct luMEC subpopulation signatures, suggesting the potential for subtle functional differences among luMECs, and included one cluster that was positive for both progenitor markers and mature milk transcripts. No expression of pluripotency markers POU class 5 homeobox 1 (POU5F1, encoding OCT4) SRY-box transcription factor 2 (SOX2) or nanog homeobox (NANOG), was observed. These observations were supported by flow cytometric analysis of MECs from mature milk samples from three women with diet-controlled GDM (2-8 mo postpartum), indicating a negligible basal/stem cell population (epithelial cell adhesion molecule (EPCAM)^-/integrin subunit alpha 6 (CD49f)⁺, 0.07%) and a small progenitor population (EPCAM⁺/CD49f⁺, 1.1%). We provide a computational framework for others and future studies, as well as report the first milk-derived cells to be analyzed by scRNA-seq. We discuss the clinical potential and current limitations of using milk-derived cells as material for characterizing human mammary physiology.

Amniotic fluid and breast milk: a rationale for breast milk stem cell therapy in neonatal diseases

Amniotic fluid and breast milk play important roles in structural development throughout fetal growth and infancy. Given their significance in physical maturation, many studies have investigated the therapeutic and protective roles of amniotic fluid and breast milk in neonatal diseases. Of particular interest to researchers are stem cells found in the two fluids. These stem cells have been investigated due to their ability to self-replicate, differentiate, reduce tissue damage, and their expression of pluripotent markers. While amniotic fluid stem cells have received some attention regarding their ability to treat neonatal diseases, breast milk stem cells have not been investigated to the same extent given the recency of their discovery. The purpose of this review is to compare the functions of amniotic fluid, breast milk, and their stem cells to provide a rationale for the use of breast milk stem cells as a therapy for neonatal diseases. Breast milk stem cells present as an important tool for treating neonatal diseases given their ability to reduce inflammation and tissue damage, as well as their multilineage differentiation potential, easy accessibility, and ability to be used in disease modelling.