Breastmilk is a novel source of stem cells with multilineage differentiation potential

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.

The Effect of Breast Milk from Different Lactation Stages on in Vitro Wound Healing

Objective: Wound healing is a complex and dynamic process essential for restoring tissue integrity and homeostasis. It is thought that breast milk contributes positively to the wound healing process, thanks to the components it contains. The aim of this study is to compare the effects of breast milk on the wound healing process at different lactation stages and to evaluate the underlying mechanism(s). Materials and Methods: The effects of breast milk from different lactation stages (colostrum, transitional, and mature milk) on wound healing were determined by in vitro scratch assay in L929 fibroblast cells. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), total oxidant, and antioxidant capacity were used to confirm antioxidant effects. The effect of breast milk on netrin-1 levels in L929 cells was elucidated by ELISA. Results: Breast milk at different lactation stages promoted wound healing. While the wound closure percentage was determined as 48.7% in the control group, this rate was determined to be the highest at 81.6% in the mature milk group (p:0.0002). The free radical scavenging capacity of colostrum, transitional, and mature milk with DPPH was determined as 49.69%, 60.64%, and 80.85%, respectively, depending on the lactation stages. Netrin-1 levels detected by ELISA were determined as 490.1 ± 6.5 pg/mL in the control group, while the lowest level was determined as 376.6 ± 4.5 pg/mL in mature milk (p:0.0003). Conclusions: Breast milk, especially mature milk, promoted wound healing on L929 cells by suppressing netrin-1 levels and scavenging free radicals.

Potential of Milk-Derived Extracellular Vesicles as Carriers for Oral Delivery of Active Phytoconstituents

Extracellular vesicles (EVs) play a crucial role in intercellular communication and have the potential to serve as in vivo carriers for delivering active molecules. The biocompatibility advantages of EVs over artificial nanocarriers create new frontiers for delivering modern active molecules. Milk is a favorable source of EVs because of its high bioavailability, low immunogenicity, and commercial producibility. In this review, we analyzed the advantages of milk-derived EVs in the oral delivery of active molecules, discussed their research progress in delivering active phytoconstituents, and summarized the necessary technologies and critical unit operations required for the development of an oral delivery system based on EVs. The review aims to provide innovative ideas and fundamental quality control guidelines for developing the next-generation oral drug delivery system based on milk-derived EVs.

Point-of-care human milk concentration by passive osmosis: comprehensive analysis of fresh human milk samples

OBJECTIVE

Preterm infants need enrichment of human milk (HM) for optimal growth. This study evaluated a novel, point-of-care human milk concentration (HMC) process for water removal from fresh HM samples by passive osmotic concentration.

STUDY DESIGN

Nineteen fresh HM samples were concentrated by incubation with the HMC devices for 3 h at 4 °C. Pre- and post-concentration HM samples were compared by HM properties for: pH, osmolality, macronutrients, enzyme activity, bioactive, and total cell viability.

RESULTS

Passive osmotic concentration reduced HM volume by an average of 16.3% ± 3.8% without a significant effect on pH or cell viability. Ten of the 41 HM components did not differ significantly (p > 0.05) between pre- and post-concentration samples. Twenty-three increased within the expected range by volume reduction. Six increased more than expected, two less than expected, and none decreased significantly.

CONCLUSION

Passive osmotic concentration of fresh HM can concentrate HM components by selective removal of water. HM osmolality and pH remained within neonatal feeding parameters.

Diabetes-induced male infertility: potential mechanisms and treatment options

Male infertility is a physiological phenomenon in which a man is unable to impregnate a fertile woman during a 12-month period of continuous, unprotected sexual intercourse. A growing body of clinical and epidemiological evidence indicates that the increasing incidence of male reproductive problems, especially infertility, shows a very similar trend to the incidence of diabetes within the same age range. In addition, a large number of previous in vivo and in vitro experiments have also suggested that the complex pathophysiological changes caused by diabetes may induce male infertility in multiple aspects, including hypothalamic-pituitary-gonadal axis dysfunction, spermatogenesis and maturation disorders, testicular interstitial cell damage erectile dysfunction. Based on the above related mechanisms, a large number of studies have focused on the potential therapeutic association between diabetes progression and infertility in patients with diabetes and infertility, providing important clues for the treatment of this population. In this paper, we summarized the research results of the effects of diabetes on male reproductive function in recent 5 years, elaborated the potential pathophysiological mechanisms of male infertility induced by diabetes, and reviewed and prospected the therapeutic measures.

Effect of milk and whey on proliferation and differentiation of placental stromal cells

Fetal bovine serum (FBS), which is widely used in cell culture media, has the potential to cause medical and ethical problems. Here, an experimental study using milk or whey proteins containing essential nutrients and growth factors is presented to limit the use of FBS in cell culture media produced for cell and tissue regeneration. Study groups were formed by culturing human placenta mesenchymal stem cells, known to have high proliferation and differentiation capacity, with milk or whey solution at increasing concentrations, alone or in combination with FBS. Osteogenic and adipogenic differentiation capacities of proliferating cells were observed in FBS, milk or whey groups. Milk, whey or FBS groups obtained in P3 and after differentiation were separately analyzed for protein mRNA expression by reverse transcriptase-polymerase chain reaction (RT-qPCR). Fibroblast Growth Factor 2 (FGF2), Octamer-binding Transcription Factor 4 (OCT4), Bone Morphogenetic Protein 6 (BMP6), and adipogenic differentiation marker Peroxisome Proliferator-Activated Receptor Gamma (PPARG) were analysed by RT-qPCR. Proliferation was more pronounced in FBS alone and in its combinations with milk-whey compared to the groups in which only milk and whey were used. OCT4 mRNA and FGF2 mRNA expression decreased in differentiated cells. BMP6 mRNA expression increased with osteogenic and adipogenic stimuli. As expected, PPRG expression also increased with adipogenic stimulation. With this experimental study, evidence has been obtained that milk or whey can provide nutritional support to the culture media of repair cells and preserve the functional capacity of the cells, with a slightly more limited capacity than FBS.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-023-00585-z.

Immunomodulatory Effect of Infectious Disease of a Breastfed Child on the Cellular Composition of Breast Milk

Recent studies suggest that the content of immune components in milk is influenced by the mother's health and also by the infant she feeds. We aimed to evaluate the effect of a child's respiratory tract infection on the cellular composition of breast milk (neutrophils, monocytes, eosinophils, lymphocytes, and their subpopulations). Twenty-six breastfeeding mothers whose children were hospitalized for respiratory tract infections were enrolled in the study. The control group consisted of 23 mothers of healthy children. Regarding the children, baseline laboratory blood tests were performed, and nasal swabs were taken for the presence of RS virus. In the next step, milk samples were collected from the mothers to assess the cellular composition of the milk, including neutrophils, monocytes, eosinophils, lymphocytes, and their subpopulations. Significantly higher percentages of T lymphocytes (helper and cytotoxic lymphocytes) were observed in the milk of the studied mothers. There was a significantly higher percentage of milk lymphocytes in the group of affected children with confirmed RSV etiology than in children with excluded RSV etiology. A significant positive correlation was observed between the duration of infection and the percentage of milk NK cells and between milk CD19 lymphocytes and the child's serum leukocytosis. This study may provide evidence of a link between cells in breast milk and disease in the breastfed infant. The severity of the infection, its duration, and the etiological agent of the infection may affect the cellular composition of milk.

Breast Milk Mesenchymal Stem Cells and/or Derived Exosomes Mitigated Adenine-Induced Nephropathy via Modulating Renal Autophagy and Fibrotic Signaling Pathways and Their Epigenetic Regulations

Chronic kidney disease (CKD), a global health concern, is highly prevalent among adults. Presently, there are limited therapeutic options to restore kidney function. This study aimed to investigate the therapeutic potential of breast milk mesenchymal stem cells (Br-MSCs) and their derived exosomes in CKD. Eighty adult male Sprague Dawley rats were randomly assigned to one of six groups, including control, nephropathy, nephropathy + conditioned media (CM), nephropathy + Br-MSCs, nephropathy + Br-MSCs derived exosomes (Br-MSCs-EXOs), and nephropathy + Br-MSCs + Br-MSCs-EXOs. Before administration, Br-MSCs and Br-MSCs-EXOs were isolated, identified, and labeled with PKH-26. SOX2, Nanog, and OCT3/4 expression levels in Br-MSCs and miR-29b, miR-181, and Let-7b in both Br-MSCs and Br-MSCs-EXOs were assayed. Twelve weeks after transplantation, renal function tests, oxidative stress, expression of the long non-coding RNA SNHG-7, autophagy, fibrosis, and expression of profibrotic miR-34a and antifibrotic miR-29b, miR-181, and Let-7b were measured in renal tissues. Immunohistochemical analysis for renal Beclin-1, LC3-II, and P62, Masson trichome staining, and histopathological examination of kidney tissues were also performed. The results showed that Br-MSCs expressed SOX2, Nanog, and OCT3/4, while both Br-MSCs and Br-MSCs-EXOs expressed antifibrotic miR-181, miR-29b, and Let-7b, with higher expression levels in exosomes than in Br-MSCs. Interestingly, the administration of Br-MSCs + EXOs, EXOs, and Br-MSCs improved renal function tests, reduced renal oxidative stress, upregulated the renal expression of SNHG-7, AMPK, ULK-1, Beclin-1, LC3, miR-29b, miR-181, Let-7b, and Smad-7, downregulated the renal expression of miR-34a, AKT, mTOR, P62, TGF-β, Smad-3, and Coli-1, and ameliorated renal pathology. Thus, Br-MSCs and/or their derived exosomes appear to reduce adenine-induced renal damage by secreting antifibrotic microRNAs and potentiate renal autophagy by modulating SNHG-7 expression.

Milk Transmission of Mammalian Retroviruses

The transmission of viruses from one host to another typically occurs through horizontal or vertical pathways. The horizontal pathways include transmission amongst individuals, usually through bodily fluids or excretions, while vertical transmission transpires from mother to their offspring, either during pregnancy, childbirth, or breastfeeding. While there are more than 200 human pathogenic viruses to date, only a small number of them are known to be transmitted via breast milk, including cytomegalovirus (CMV), human immunodeficiency virus type 1 (HIV-1), and human T cell lymphotropic virus type 1 (HTLV-1), the latter two belonging to the family Retroviridae. Breast milk transmission is a common characteristic among mammalian retroviruses, but there is a lack of reports summarizing our knowledge regarding this route of transmission of mammalian retroviruses. Here, we provide an overview of the transmission of mammalian exogenous retroviruses with a focus on Orthoretrovirinae, and we highlight whether they have been described or suspected to be transmitted through breast milk, covering various species. We also elaborate on the production and composition of breast milk and discuss potential entry sites of exogenous mammalian retroviruses during oral transmission.

Advantages of mesenchymal stem cell over the other stem cells

A stem cell is a particular group of cells that has the extraordinary potential to convert within the body into particular cell types. They are used to regenerate tissues and cells in the body that have been damaged or destroyed by the disease. Stem cells come in three different varieties: adult stem cells, embryonic stem cells and induced pluripotent stem cells (iPSCs). Embryonic stem cells have a high chance of immune rejection and also have ethical dilemmas and iPSCs have genetic instability. Adult stem cells are difficult to analyze and extract for research since they are frequently insufficient in native tissues. However, mesenchymal stem cells (MSC) one of the categories of adult stem cells are stromal cells with a variety of potentials that can differentiate into a wide range of cell types. MSCs can be transplanted into a variety of people without worrying about rejection because they have demonstrated the ability to prevent an adverse reaction from the immune system. These transplants have powerful anti-inflammatory and immunosuppressive effects and greatly enhance the body's inherent healing capacity. While MSCs do not offer treatment for illnesses, the idea behind them is to enable the body to recover sufficiently for a protracted reduction in symptoms. In many cases, this is sufficient to significantly enhance the patient's well-being. Inspite of several advantages some potential long-term concerns connected to MSC therapy are maldifferentiation, immunosuppression and cancerous tumor growth. In this review, we will compare the mesenchymal stem cells with other stem cells with respect to the source of origin, their properties and therapeutic applications, and discuss the MSC's disadvantages.

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.

Comparison of SOX2 and POU5F1 Gene Expression in Leukapheresis-Derived CD34+ Cells before and during Cell Culture

Bone marrow is an abundant source of both hematopoietic as well as non-hematopoietic stem cells. Embryonic, fetal and stem cells located in tissues (adipose tissue, skin, myocardium and dental pulp) express core transcription factors, including the SOX2, POU5F1 and NANOG gene responsible for regeneration, proliferation and differentiation into daughter cells. The aim of the study was to examine the expression of SOX2 and POU5F1 genes in CD34-positive peripheral blood stem cells (CD34+ PBSCs) and to analyze the influence of cell culture on the expression of SOX2 and POU5F1 genes. The study material consisted of bone marrow-derived stem cells isolated by using leukapheresis from 40 hematooncology patients. Cells obtained in this process were subject to cytometric analysis to determine the content of CD34+ cells. CD34-positive cell separation was conducted using MACS separation. Cell cultures were set, and RNA was isolated. Real-time PCR was conducted in order to evaluate the expression of SOX2 and POU5F1 genes and the obtained data were subject to statistical analysis. We identified the expression of SOX2 and POU5F1 genes in the examined cells and demonstrated a statistically significant (p < 0.05) change in their expression in cell cultures. Short-term cell cultures (<6 days) were associated with an increase in the expression of SOX2 and POU5F1 genes. Thus, short-term cultivation of transplanted stem cells could be used to induce pluripotency, leading to better therapeutic effects.

Influence of Perinatal Factors on Gene Expression of IAPs Family and Main Factors of Pluripotency: OCT4 and SOX2 in Human Breast Milk Stem Cells-A Preliminary Report

Due to their therapeutic potential, mesenchymal stem cells are the subject of intensive research on the use of their potential in the treatment of, among others, neurodegenerative diseases or immunological diseases. They are among the newest in the field of medicine. The presented study aimed to evaluate the expression of eight genes from the IAP family and the gene regulating IAP-XAF1-in stem cells derived from human milk, using the qPCR method. The relationships between the expression of genes under study and clinical data, such as maternal age, maternal BMI, week of pregnancy in which the delivery took place, bodyweight of the newborn, the number of pregnancies and deliveries, and the time elapsed since delivery, were also analyzed. The research was carried out on samples of human milk collected from 42 patients hospitalized in The Clinic of Obstetrics and Perinatology of the Independent Public Clinical Hospital No. 4, in Lublin. The conducted research confirmed the expression of the following genes in the tested material: NAIP, BIRC2, BIRC3, BIRC5, BIRC6, BIRC8, XIAP, XAF1, OCT4 and SOX2. Moreover, several dependencies of the expression of individual genes on the maternal BMI (BIRC5, XAF1 and NAIP), the time since childbirth (BIRC5, BIRC6, XAF1 and NAIP), the number of pregnancies and deliveries (BIRC2, BIRC5, BIRC6 and XAF1), the manner of delivery (XAF1 and OCT4), preterm labor (BIRC6 and NAIP) were demonstrated. Additionally, we found positive relationships between gene expression of BIRC7, BIRC8 and XAF1 and the main factors of pluripotency: SOX2 and OCT4. This work is the first to investigate the expression of genes from the IAPs family in mother's milk stem cells.

Exploring cell surface markers and cell-cell interactions of human breast milk stem cells

Background

Breakthrough studies have shown that pluripotent stem cells are present in human breast milk. The expression of pluripotency markers by breast milk cells is heterogeneous, relating to cellular hierarchy, from early-stage multi-lineage stem cells to fully differentiated mammary epithelial cells, as well as weeks of gestation and days of lactation.

Design and methods

Here, we qualitatively analyze cell marker expression in freshly isolated human breast milk cells, without any manipulation that could influence protein expression. Moreover, we use electron microscopy to investigate cell-cell networks in breast milk for the first time, providing evidence of active intercellular communication between cells expressing different cellular markers.

Results

The immunocytochemistry results of human breast milk cells showed positive staining in all samples for CD44, CD45, CD133, and Ki67 markers. Variable positivity was present with P63, Tβ4 and CK14 markers. No immunostaining was detected for Wt1, nestin, Nanog, OCT4, SOX2, CK5, and CD34 markers. Cells isolated from human breast milk form intercellular connections, which together create a cell-to-cell communication network.

Conclusions

Cells freshly isolated form human breast milk, without particular manipulations, show heterogeneous expression of stemness markers. The studied milk staminal cells show "pluripotency" at different stages of differentiation, and are present as single cells or grouped cells. The adjacent cell interactions are evidenced by electron microscopy, which showed the formation of intercellular connections, numerous contact regions, and thin pseudopods.

Dilemmas in initiation of very preterm infant enteral feeds-when, what, how?

With limited clinical evidence available to guide common nutritional decisions, significant variation exists in approaches to enteral feeding for very preterm infants, specifically when feedings are initiated, what is fed, and the method used for feedings. Preclinical studies have highlighted the benefits associated with avoiding nil per os and providing early-stage mother's own milk or colostrum. However, these recommended approaches are often mutually exclusive due to the delays in lactation associated with very preterm delivery, resulting in uncertainty regarding which approach should be prioritized. Few studies have evaluated feeding frequency in preterm infants, with limited generalizability to extremely preterm infants. Therefore, even evidence-based approaches to very preterm infant feed initiation can differ. Future research is needed to identify optimal strategies for enteral nutrition in very preterm infants, but, until then, evidence-informed approaches may vary depending on each neonatal intensive care unit's assessment of risk and benefit.

Are active efflux transporters contributing to infant drug exposure via breastmilk? A longitudinal study

Although most drugs are considered safe and compatible with breastfeeding, cases of toxic drug exposure have been reported. Active efflux transporters have been implicated as a mechanism in the transfer of drugs from mother to baby via breastmilk. Using breastmilk as a source of human mammary epithelial cells, this novel longitudinal study investigated the expression of four active transporters, namely, MDR1, MRP1, MRP2 and BCRP in the lactating human breast. BCRP gene was found to be strongly overexpressed with levels peaking at 5 months postpartum, potentially indicating a time where a breastfed infant may be at risk of inadvertent exposure to BCRP substrates. Serum albumin, a major component of human breastmilk was increasingly downregulated as lactation progresses. Xanthine oxidase/dehydrogenase, an enzyme in breastmilk attributed to a reduced risk of gastroenteritis caused by Escherichia coli and Salmonella enteritides, was downregulated. Lysozyme and fatty acid synthase are progressively upregulated. This study also shows that breastmilk-derived epithelial cells, when propagated in culture, exhibit characteristics significantly different to those derived directly from breastmilk. This serves to warn that in vitro studies are not a true representation of in vivo processes in the lactating breast; hence, application of in vitro data should be conducted with caution.

The Effect of Infant Gastric Digestion on Human Maternal Milk Cells

SCOPE

Human breast milk contains a variety of cell types that have potential roles in infant immunity and development. One challenge associates with defining the purpose(s) of milk cells in the infant is a poor understanding of the effect of digestion on cell fate.

METHODS AND RESULTS

This study first demonstrates that milk cell death occurs after gastric digestion in mice. Then flow cytometry and RT-PCR are used to understand the mechanism of human milk cell death and quantify live cell types before and after simulated gastric digestion. This study finds that digestion in simulated gastric fluid for 30 min reduces cell viability from 72% to 27%, with most cell death is caused by the acidic pH. The primary mechanism of cell death is caspase-mediated apoptosis. The non-cellular components of milk offer only mild protection against cell death from stomach acid.

CONCLUSIONS

Gastric digestion does not select for a specific resilient cell population to survive-most cell types die in equal proportions in the gastric environment. Taken together, these results provide a foundation with which to understand the fate of human breast milk cells in the infant's intestine and beyond.

Evaluation of the Impact of Pregnancy-Associated Factors on the Quality of Wharton's Jelly-Derived Stem Cells Using SOX2 Gene Expression as a Marker

SOX2 is a recognized pluripotent transcription factor involved in stem cell homeostasis, self-renewal and reprogramming. It belongs to, one of the SRY-related HMG-box (SOX) family of transcription factors, taking part in the regulation of embryonic development and determination of cell fate. Among other functions, SOX2 promotes proliferation, survival, invasion, metastasis, cancer stemness, and drug resistance. SOX2 interacts with other transcription factors in multiple signaling pathways to control growth and survival. The aim of the study was to determine the effect of a parturient’s age, umbilical cord blood pH and length of pregnancy on the quality of stem cells derived from Wharton’s jelly (WJSC) by looking at birth weight and using SOX2 gene expression as a marker. Using qPCR the authors, evaluated the expression of SOX2 in WJSC acquired from the umbilical cords of 30 women right after the delivery. The results showed a significant correlation between the birth weight and the expression of SOX2 in WJSC in relation to maternal age, umbilical cord blood pH, and the length of pregnancy. The authors observed that the younger the woman and the lower the umbilical cord blood pH, the earlier the delivery occurs, the lower the birth weight and the higher SOX2 gene expression in WJSC. In research studies and clinical applications of regenerative medicine utilizing mesenchymal stem cells derived from Wharton’s Jelly of the umbilical cord, assessment of maternal and embryonic factors influencing the quality of cells is critical.

Profiling of mature-stage human breast milk cells identifies six unique lactocyte subpopulations

Breast milk is chock-full of nutrients, immunological factors, and cells that aid infant development. Maternal cells are the least studied breast milk component, and their unique properties are difficult to identify using traditional techniques. Here, we characterized the cells in mature-stage breast milk from healthy donors at the protein, gene, and transcriptome levels. Holistic analysis of flow cytometry, quantitative polymerase chain reaction, and single-cell RNA sequencing data identified the predominant cell population as epithelial with smaller populations of macrophages and T cells. Two percent of epithelial cells expressed four stem cell markers: SOX2, TRA-1-60, NANOG, and SSEA4. Furthermore, milk contained six distinct epithelial lactocyte subpopulations, including three previously unidentified subpopulations programmed toward mucosal defense and intestinal development. Pseudotime analysis delineated the differentiation pathways of epithelial progenitors. Together, these data define healthy human maternal breast milk cells and provide a basis for their application in maternal and infant medicine.

Gestational Diabetes Mellitus Changes Human Colostrum Immune Composition

Breast milk is considered a complete food for babies. Up to 7 days postpartum, it is known as colostrum, rich in immunological compounds, responsible for providing nutrition and ensuring immune protection. However, some maternal factors, such as gestational diabetes mellitus (GDM), can change the concentration of bioactive compounds present in the colostrum and may affect the development of the newborn’s immune system. The effect of GDM on colostrum cytokine, chemokine, and growth factors is not well described. Thus, the present study evaluated whether the occurrence of GDM changes the concentration of biomarkers in the colostrum. A cross-sectional study was carried out on postpartum women who had healthy pregnancies and women who had been diagnosed with GDM. A sample of colostrum was collected for Luminex analysis. Our results showed that GDM mothers had higher secretion of cytokines and chemokines in the colostrum, with a higher concentration of IFN-g, IL-6, and IL-15, and a lower concentration of IL-1ra. Among growth factors, we identified a decreased concentration of GM-CSF in the colostrum of GDM mothers. Thus, the data obtained support the idea that the disease leads to immune alterations in the colostrum.

Cellular and transcriptional diversity over the course of human lactation

Human breast milk (hBM) is a dynamic fluid that contains millions of cells, but their identities and phenotypic properties are poorly understood. We generated and analyzed single-cell RNA-sequencing (scRNA-seq) data to characterize the transcriptomes of cells from hBM across lactational time from 3 to 632 d postpartum in 15 donors. We found that the majority of cells in hBM are lactocytes, a specialized epithelial subset, and that cell-type frequencies shift over the course of lactation, yielding greater epithelial diversity at later points. Analysis of lactocytes reveals a continuum of cell states characterized by transcriptional changes in hormone-, growth factor-, and milk production-related pathways. Generalized additive models suggest that one subcluster, LC1 epithelial cells, increases as a function of time postpartum, daycare attendance, and the use of hormonal birth control. We identify several subclusters of macrophages in hBM that are enriched for tolerogenic functions, possibly playing a role in protecting the mammary gland during lactation. Our description of the cellular components of breast milk, their association with maternal–infant dyad metadata, and our quantification of alterations at the gene and pathway levels provide a detailed longitudinal picture of hBM cells across lactational time. This work paves the way for future investigations of how a potential division of cellular labor and differential hormone regulation might be leveraged therapeutically to support healthy lactation and potentially aid in milk production.

Safety and Feasibility of Using Cell-Enriched Human Milk in the Treatment of Early Necrotizing Enterocolitis

Background: Necrotizing enterocolitis (NEC) is a severe intestinal disease that often occurs in preterm infants, and there currently is a lack of specific and effective therapy. Human milk is rich in cells that may become a potential NEC treatment. Research Aim: To evaluate the safety and feasibility of cell-enriched fresh human milk treatment for premature infants with stage I NEC. Materials and Methods: Infants born at <1,500 g birth weight who developed stage I NEC were enrolled. Along with routine treatment for these infants, those in the intervention group were treated with cell-enriched fresh mother's milk (1 mL/kg) once per day for seven consecutive days. The intervention feasibility and safety were monitored and evaluated as primary outcomes. Short-term outcomes, including the duration of antibiotics, days to full enteral feeding and prognosis, were investigated as secondary outcomes. Results: Forty infants were enrolled, and 20 infants were included in each group. The demographic characteristics of the two groups of infants were comparable. All infants in the intervention group completed cell-enriched fresh mother's milk feeding for 7 days without any adverse clinical issues. The infants' vital signs were within the normal range during and after the intervention. None of the enrolled patients progressed to stage II NEC or above. The time interval from milk pumping to feeding was 3.7 ± 0.5 hours. Conclusions: Using cell-enriched fresh mother's milk to treat premature infants with stage I NEC was safe and feasible.

Human milk: From complex tailored nutrition to bioactive impact on child cognition and behavior

Human milk is a highly complex liquid food tailor-made to match an infant's needs. Beyond documented positive effects of breastfeeding on infant and maternal health, there is increasing evidence that milk constituents also impact child neurodevelopment. Non-nutrient milk bioactives would contribute to the (long-term) development of child cognition and behavior, a process termed 'Lactocrine Programming'. In this review we discuss the current state of the field on human milk composition and its links with child cognitive and behavioral development. To promote state-of-the-art methodologies and designs that facilitate data pooling and meta-analytic endeavors, we present detailed recommendations and best practices for future studies. Finally, we determine important scientific gaps that need to be filled to advance the field, and discuss innovative directions for future research. Unveiling the mechanisms underlying the links between human milk and child cognition and behavior will deepen our understanding of the broad functions of this complex liquid food, as well as provide necessary information for designing future interventions.

[Generating pancreatic islets organoids: Langerhanoids]

The extension of islet transplantation to a wider number of Type 1 diabetic patients is compromised by the scarcity of donors, the reduced ex vivo survival of pancreatic islets and the use of immunosuppressive treatments. Islets of Langerhans isolated from brain-dead donors are currently the only cell source for transplantation. Thus, it is crucial to find an alternative and an abundant source of functional insulin secreting cells not only for clinical use but also for the development of research dedicated to the screening of drugs and to the development of new therapeutic targets. Several groups around the world, including ours, develop 3D culture models as Langerhanoids that closely mimick human pancreatic islets physiology. In this review, we describe recent advances to mimic the pancreatic niche (extracellular matrix, vascularization, microfluidics) allowing better functionality of Langerhanoids.

Role, molecular mechanism and the potential target of breast cancer stem cells in breast cancer development

Breast cancer (BC) is one of the most common malignant tumors in women globally, and its occurrence has surpassed lung cancer and become the biggest threat for women. At present, breast cancer treatment includes surgical resection or postoperative chemotherapy and radiotherapy. However, tumor relapse and metastasis usually lead to current therapy failure thanks to breast cancer stem cells (BCSCs)-mediated tumorigenicity and drug resistance. Drug resistance is mainly due to the long-term quiescent G0 phase, strong DNA repairability, and high expression of ABC transporter, and the tumorigenicity is reflected in the activation of various proliferation pathways related to BCSCs. Therefore, understanding the characteristics of BCSCs and their intracellular and extracellular molecular mechanisms is crucial for the development of targeted drugs for BCSCs. To this end, we discussed the latest developments in BCSCs research, focusing on the analysis of specific markers, critical signaling pathways that maintain the stemness of BCSCs，such as NOTCH, Wnt/β-catenin, STAT3, Hedgehog, and Hippo-YAP signaling, immunomicroenviroment and summarizes targeting therapy strategies for stemness maintenance and differentiation, which provides a theoretical basis for further exploration of treating breast cancer and preventing relapse derived from BCSCs.

Functional and Molecular Characters of Cancer Stem Cells Through Development to Establishment

Cancer stem cells (CSCs) are small subpopulation sharing similar properties like normal stem such as self-renewal and differentiation potential to direct tumor growth. Last few years, scientists considered CSCs as the cause of phenotypic heterogeneity in diverse cancer types. Also, CSCs contribute to cancer metastasis and recurrence. The cellular and molecular regulators influence on the CSCs' phenotype changing their behaviors in different stages of cancer progression. CSC markers play significance roles in cancer diagnosis and characterization. We delineate the cross-talks between CSCs and the tumor microenvironment that supports their intrinsic properties including survival, stemness, quiescence and their cellular and molecular adaptation. An insight into the markers of CSCs specific to organs is described.

Impacts of Enriched Human Milk Cells on Fecal Metabolome and Gut Microbiome of Premature Infants with Stage I Necrotizing Enterocolitis: A Pilot Study

SCOPE

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants, occurring more often in formula-fed infants than in breastfed infants. Recent animal studies have shown that cells in fresh breast milk survive in the newborns' digestive tract. However, no clinical studies have been conducted on the effects of human milk cells, and their biological roles in the infants' intestines remain unexplored.

METHODS AND RESULTS

Twenty premature infants are enrolled. Cells from fresh milk of their own mothers are enriched and fed to infants with Bell's Stage I NEC once a day for 7 days since the onset of NEC. Fecal samples are collected at enrollment and 2 weeks later. Fecal sphingolipids are observed to be enriched in NEC patients and positively correlated with calprotectin levels. After intervention with enriched human milk cells, inflammation-associated sphingolipids and microbiome profiles are altered and resembled those of the controls.

CONCLUSION

These preliminary findings reveal the potential impacts of enriched human milk cells on premature infants with Bell's Stage I NEC and provide insight into the roles of fecal sphingolipid metabolism in the neonates' intestinal inflammation. However, the limited sample size of the study indicates the need for further investigation.

25 Years of Research in Human Lactation: From Discovery to Translation

Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation.

Breast milk MSCs upregulated β-cells PDX1, Ngn3, and PCNA expression via remodeling ER stress /inflammatory /apoptotic signaling pathways in type 1 diabetic rats

Type 1 diabetes mellitus (T1DM) is one of the autoimmune diseases characterized by beta-cell dysfunction with serious health complications. Br-MSCs represent a novel valid candidate in regenerative medicine disciplines. Yet, the full potential of Br-MSCs in managing type 1 diabetes remains elusive. Indeed, this study was designed to explore a novel approach investigating the possible regenerative capacity of Br-MSCs in type1 diabetic islet on the level of the cellular mRNA expression of different molecular pathways involved in pancreatic beta-cell dysfunction. Sixty adult male Sprague-Dawley rats were randomly assigned into 3 groups (20 rats each); the control group, type1 diabetic group, and the type 1 diabetic Br-MSCs treated group. And, for the first time, our results revealed that intraperitoneally transplanted Br-MSCs homed to the diabetic islet and improved fasting blood glucose, serum insulin level, pancreatic oxidative stress, upregulated pancreatic mRNA expression for: regenerative markers (Pdx1, Ngn3, PCNA), INS, beta-cell receptors (IRS1, IRβ, PPARγ), pancreatic growth factors (IGF-1, VEGFβ1, FGFβ), anti-inflammatory cytokine (IL10) and anti-apoptotic marker (BCL2) too, Br-MSCs downregulated pancreatic mRNA expression for: inflammatory markers (NFKβ, TNFα, IL1β, IL6, IL8, MCP1), apoptotic markers for both intrinsic and extrinsic pathways (FAS, FAS-L, P53, P38, BAX, Caspase3), ER stress markers (ATF6, ATF3, ATF4, BIP, CHOP, JNK, XBP1) and autophagy inhibitor (mTOR). In conclusion, Br-MSCs could be considered as a new insight in beta cell regenerative therapy improving the deteriorated diabetic islet microenvironment via modulating; ER stress, inflammatory, and apoptotic signaling pathways besides, switching on the cellular quality control system (autophagy) thus enhancing beta-cell function.

The effect of risk at birth on breastfeeding duration and exclusivity: A cohort study at a Brazilian referral center for high-risk neonates and infants

Background and aim

Both breastfeeding and the use of human milk are strategies that provide better conformation to health throughout an individual’s life and bring countless short- and long- term benefits, which are well established in the scientific literature. For at-risk newborns (NBs), these strategies are crucial interventions to enable neonatal survival with better quality of life due to the distinctive and complex composition of human milk, which serves as personalized food-medicine-protection. However, there is limited knowledge about breastfeeding practices in high-risk NBs. The aim was to estimate the duration of EBF and to investigate the effect of risk at birth on EBF discontinuity in the first six months of life’.

Methods

This cohort study included 1,003 NBs from a high-risk referral center, followed up from birth to the sixth month of life, between 2017 and 2018. Correspondence and cluster analysis was used to identify neonatal risk clusters as the main exposure. The object of interest was the time until EBF discontinuity. The Kaplan-Meier methods and the Cox proportional hazards model were used to estimate the hazard ratio and 95% confidence intervals.

Results

The prevalence and median duration of EBF decreased proportionally in the three groups. The multiple model revealed a gradient in EBF discontinuity, which was 40% higher in risk group 1 and 111% higher in risk group 2 compared to healthy full-term NBs. Additionally, EBF during hospitalization predicted a longer median duration of this practice for high-risk NBs.

Conclusion

This study confirms a high proportion of high-risk NBs who have EBF discontinued before six months of life. The risk of EBF discontinuity is higher in risk groups, with a gradual effect even when adjusted by several factors. Effective interventions are needed to promote, protect, and support breastfeeding in different profiles of risk-at-birth groups.

Transdifferentiation of goat ear fibroblasts into lactating mammary epithelial cells induced by small molecule compounds

Mammary epithelial cells are the only cells in the mammary glands that are capable of lactation and they are ideal for studying cellular and molecular biology mechanisms during growth, development and lactation of the mammary glands. The limiting factors in most of the currently available mammary epithelial cells are low cell viability, transgenerational efficiency and lactation function that renders them unsuitable for subsequent studies on mammary gland's cellular and lactation mechanisms and utilizing them as bioreactors. Hence, new methods are required to obtain mammary epithelial cells with high transgenerational efficiency and lactation function. In this study, transdifferentiation of goat ear fibroblasts (GEFs) into goat mammary epithelial cells (CiMECs) was induced in only eight days by five small molecule compounds, including 500 μg/mL VPA, 10 μM Tranylcypromine, 10 μM Forskolin, 1 μM TTNPB, 10 μM RepSox. Morphological observation, marker genes comparison, specific antigen expression and comparison of gene expression levels by transcriptome sequencing between the two types of cells that led to the primary deduction that CiMECs have similar biological properties to goat mammary epithelial cells (GMECs) and comparatively more lactation capacity. Therefore, we establish a novel reprogramming route to convert fibroblasts into CiMECs under fully chemically conditions. This study is expected to provide an in vitro platform for understanding cellular mechanisms such as mammary epithelial cells' fate determination and developmental differentiation, and also to find a new way to obtain a large number of functional mammary epithelial cells in vitro.

Breastfeeding in the First Days of Life Is Associated With Lower Blood Pressure at 3 Years of Age

Background

Breastfeeding in infancy is associated with lower cardiovascular disease risk in adulthood; however, the amount of breastfeeding required to achieve this benefit is unknown.

Methods and Results

In the CHILD (Canadian Healthy Infant Longitudinal Development) Cohort Study, we analyzed 2382 children with complete data on early life feeding and blood pressure. Infant feeding was documented from hospital records in the first few days of life and reported by mothers throughout infancy. Blood pressure was measured at 3 years of age. Analyses controlled for birth weight, gestational age, socioeconomic status, maternal body mass index, and other potential confounders. We found that nearly all children (2333/2382; 97.9%) were ever breastfed, of whom 98 (4.2%) only briefly received breast milk during their birth hospitalization (“early limited breastfeeding”). At 3 years of age, blood pressure was higher in children who were never breastfed (mean systolic/diastolic 103/60 mm Hg) compared with those who were ever breastfed (99/58 mm Hg), including those who received only early limited breastfeeding (99/57 mm Hg). These differences in systolic blood pressure persisted in adjusted models (ever breastfed: −3.47 mm Hg, 95% CI, −6.14 to −0.80; early limited breastfeeding: −4.24 mm Hg, 95% CI, −7.45 to −1.04). Among breastfed children, there was no significant dose‐response association according to the duration or exclusivity of breastfeeding. Associations were not mediated by child body mass index.

Conclusions

Although the benefits of sustained and exclusive breastfeeding are indisputable, this study indicates any breastfeeding, regardless of duration or exclusivity, is associated with lower blood pressure at 3 years of age. Further research examining the bioactive components of early breast milk, underlying mechanisms, and long‐term associations is warranted.

Immunomodulatory Effects of Human Colostrum and Milk

The immune system is not fully developed in human neonates and infants; breastfeeding is important in this stage as the bioactive components of human breast milk are known to have anti-microbial, anti-inflammatory, and immunomodulatory effects, and can therefore contribute to an infant's immunity against allergies, asthma, autoimmune diseases, and inflammatory bowel disease. Herein, the positive effect on the immune system by human colostrum and milk are reviewed.

Comparison of the Characteristics of Breast Milk-derived Stem Cells with the Stem Cells Derived from the Other Sources: A Comparative Review

Breast milk (BrM) not only supplies nutrition, but it also contains a diverse population of cells. It has been estimated that up to 6% of the cells in human milk possess the characteristics of mesenchymal stem cells (MSC). Available data also indicate that these cells are multipotent and capable of self-renewal and differentiation with other cells. In this review, we have compared different characteristics, such as CD markers, differentiation capacity, and morphology of stem cells, derived from human breast milk (hBr-MSC) with human bone marrow (hBMSC), Wharton's jelly (WJMSC), and human adipose tissue (hADMSC). Through the literature review, it was revealed that human breast milk-derived stem cells specifically express a group of cell surface markers, including CD14, CD31, CD45, and CD86. Importantly, a group of markers, CD13, CD29, CD44, CD105, CD106, CD146, and CD166, were identified, which were common in the four sources of stem cells. WJMSC, hBMSC, hADMSC, and hBr-MSC are potently able to differentiate into the mesoderm, ectoderm, and endoderm cell lineages. The ability of hBr-MSCs todifferentiate into the neural stem cells, neurons, adipocyte, hepatocyte, chondrocyte, osteocyte, and cardiomyocytes has made these cells a promising source of stem cells in regenerative medicine, while isolation of stem cells from the commonly used sources, such as bone marrow, requires invasive procedures. Although autologous breast milk-derived stem cells are an accessible source for women who are in the lactation period, breast milk can be considered as a source of stem cells with high differentiation potential without any ethical concern.

Breast milk stem cells: Are they magic bullets in neonatology?

Each mammal produces milk specific to its newborn that meets all nutritional needs. Breast milk is not only a secretory product but is also a complex liquid containing several components that provide enteral nutrition. The stage of lactation, the fullness of the breast, the feeding of the baby, and the health of the mother during the breastfeeding period cause differences in the composition of breast milk. Although the positive effects of breast milk on the physical and intellectual development of a child in the short and long term have been known for centuries, its mechanism has not been elucidated. Stem cells are defined as the cells that possess specific markers and have not undergone differentiation. Under suitable conditions and stimuli, they can differentiate into desired cells. The detection of stem cells, whose exact origin is not known, in breast milk and their demonstration in the baby's body have prompted the necessity of exploring the possible role of stem cells in the treatment of diseases. In this review, breast milk-derived stem cells and their possible role in neonatology are discussed.

Human Breast Milk: Bioactive Components, from Stem Cells to Health Outcomes

PURPOSE OF REVIEW

Breast milk (BM) is a peculiar fluid owing unique properties and resulting the ideal food during early neonatal period. As widely known, it can improve the outcome of both neonate and lactating mother, influencing their whole life. BM is characterized by several beneficial components; among these, a great role is played by BM own and specific microbiome, deeply investigated in many studies. Moreover, the use of metabolomics in BM analysis allowed a better characterization of its metabolic pathways that vary according to lactation stage and neonatal gestational age. The aim of this review is to describe growth factors, cytokines, immunity mediators, and stem cells (SCs) contained in BM and investigate their functions and effects on neonatal outcome, especially focusing on immuno- and neurodevelopment.

RECENT FINDINGS

We evaluated recent and updated literature on this field. The article that we analyzed to write this review have been found in MEDLINE using breast milk-derived stem cells, biofactors, growth factors, breastfeeding-related outcomes, neurodevelopment, and neonatal immunological system as keywords. Discovering and characterizing BM components could result very useful to clarify the pathophysiology of their influence on neonatal growth and even to improve artificial formulations' composition. Moreover, since SCs abilities and their involvement in the development of several diseases, they could help to discover specific targets for new therapies. It could be useful to characterize BM-derived SC markers, properties, and variations during lactation stages, to understand their potential role in therapeutic applications, since they could be noninvasively isolated from BM. More studies will help to describe more in detail the characteristics of mother-to-child communication through breastfeeding and its potential role in the next future.

Proteomic analysis of hypoxia and non-hypoxia secretome mesenchymal stem-like cells from human breastmilk

Introduction

Breastmilk contains proteins and cells which have stem cell properties. The human breastmilk stem cell mimick mesenchymal stem cells and expresses pluripotency genes. The protein level of breastmilk is high in colostrum and gradually subsides in the first year of lactation. The mesenchymal stem cells from breastmilk can be an alternative source of stem cells that can potentially affect cardiovascular therapy. This study aimed to identify the proteomic analysis of secretome mesenchymal stem-like cells under hypoxia compared to non-hypoxia from human breastmilk stem cells.

Material and methods

The human breastmilk was collected from six healthy breastfeeding women and transported to the laboratory under aseptic conditions. The breastmilk cells were isolated then cultured. After 72 h, the human breastmilk stem cells reached confluence then cleaned up and isolated in serum-free media (spheroid) to allow serial passaging every 48 h. The acquisition stem cell was made with flow cytometry. The cells were divided into hBSC secretomes under hypoxia (A) and non-hypoxia (B) and analyzed for LC-MS to identify the peptide structure.

Results

The human breastmilk cells contained several mesenchymal stem-like cells in density 2.4 × 10⁶ cell/mL for hypoxia and 2 × 10⁶ cell/mL for non-hypoxia conditions. The human breastmilk stem cell surface markers derived from the third cell passage process were 93.77% for CD44, 98.69% for CD73, 88.45% for CD90, and 96.30% for CD105. The protein level of secretome mesenchymal stem -like cells under hypoxia was measured at 5.56 μg/mL and 4.28 μg/mL for non-hypoxia. The liquid chromatography-mass spectrometry analysis identified 130 and 59 peptides from hypoxia and non-hypoxia of the human breastmilk stem cell secretome sequentially. Some important proteomics structures were found in the hypoxic human breastmilk stem cell secretome, such as transforming growth factor-β, VE-cadherin, and caspase.

Conclusion

The human breastmilk cells contain mesenchymal stem-like cells and a high concentration of CD44, CD73, CD90, and CD105 as surface markers at third passage culture. The hypoxic hBSC secretome produces a higher protein level compare to non-hypoxia. The transforming growth factor -β was found in the hypoxic hBSC secretome as a modulator of VEGF-mediated angiogenesis.

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.

How Knowledge about Stem Cells Influences Attitudes towards Breastfeeding: Case Study of Polish Women

Maternal breastfeeding is associated with multiple health benefits, both for the child and the mother. Since breastfeeding rates are declining, finding new, future-oriented strategies to strengthen and support mothers’ positive attitudes towards breastfeeding need to be developed. In this paper, we describe how information about the presence of stem cells in breast milk can influence the willingness to breastfeed in the population of Polish pregnant women. A cross-sectional study involving a group of 150 pregnant women was conducted to assess the correlation between their knowledge about stem cells and their attitude towards breastfeeding. Among the respondents, only 6% claimed that they did not know anything about stem cells, but general knowledge about stem cells in the research group was poor. The survey results indicated that city residence, university degree, maternal experience and advanced pregnancy correlated with higher general knowledge regarding stem cells. Most respondents (77.3%) had no knowledge regarding the presence of stem cells in breast milk. Approximately two-thirds of mothers with earlier negative breastfeeding experience declared that information about the presence of stem cells in breast milk could have influenced the decision to continue and extend the time of breastfeeding. Hence highlighting the presence of stem cells in breast milk can be used to encourage breastfeeding as a unique activity.

The Gut‒Breast Axis: Programming Health for Life

The gut is a pivotal organ in health and disease. The events that take place in the gut during early life contribute to the programming, shaping and tuning of distant organs, having lifelong consequences. In this context, the maternal gut plays a quintessence in programming the mammary gland to face the nutritional, microbiological, immunological, and neuroendocrine requirements of the growing infant. Subsequently, human colostrum and milk provides the infant with an impressive array of nutrients and bioactive components, including microbes, immune cells, and stem cells. Therefore, the axis linking the maternal gut, the breast, and the infant gut seems crucial for a correct infant growth and development. The aim of this article is not to perform a systematic review of the human milk components but to provide an insight of their extremely complex interactions, which render human milk a unique functional food and explain why this biological fluid still truly remains as a scientific enigma.

The Revolution of Breast Milk: The Multiple Role of Human Milk Banking between Evidence and Experience-A Narrative Review

The review recalls the importance of breast milk and deepens the theme of human milk banking, a virtuous reality that is expanding all over the world but is still little known. In the last 15 years, modern biological technologies have crystallized the concept of uniqueness and irreproducibility of human milk, by establishing three new principles: first: human milk: a "life-saving" drug; second: human milk: the best food for preterm infants; and third: human milk: the main component of premature infant care. Our experience teaches us that human milk banking plays many roles that need to be known and shared.

Racial and socioeconomic disparities in breast milk feedings in US neonatal intensive care units

Very low birth weight (VLBW; <1500 g birth weight) infants are substantially more likely to be born to black than to non-black mothers, predisposing them to potentially preventable morbidities that increase the risk for costly lifelong health problems. Mothers' own milk (MOM) may be considered the ultimate "personalized medicine" since milk composition and bioactive components vary among mothers and multiple milk constituents provide specific protection based on shared exposures between mother and infant. MOM feedings reduce the risks and associated costs of prematurity-associated morbidities, with the greatest reduction afforded by MOM through to NICU discharge. Although black and non-black mothers have similar lactation goals and initiation rates, black VLBW infants are half as likely to receive MOM at NICU discharge in the United States. Black mothers are significantly more likely to be low-income, single heads of household and have more children in the home, increasing the burden of MOM provision. Although rarely considered, the out-of-pocket and opportunity costs associated with providing MOM for VLBW infants are especially onerous for black mothers. When MOM is not available, the NICU assumes the costs of inferior substitutes for MOM, contributing further to disparate outcomes. Novel strategies to mitigate these disparities are urgently needed. IMPACT: Mother's own milk exemplifies personalized medicine through its unique biologic activity. Hospital factors and social determinants of health are associated with mother's own milk feedings for very low-birth-weight infants in the neonatal intensive care unit. Notably, out-of-pocket and opportunity costs associated with providing mother's own milk are borne by mothers. Conceptualizing mother's own milk feedings as an integral part of NICU care requires consideration of who bears the costs of MOM provision-the mother or the NICU?

Predictors of maternal-origin microchimerism in young women in the Philippines

OBJECTIVES

Microchimerism is the presence of a small quantity of cells or DNA from a genetically distinct individual. This phenomenon occurs with bidirectional maternal-fetal exchange during pregnancy. Microchimerism can persist for decades after delivery and have long-term health implications. However, little is known about why microchimerism is detectable at varying levels in different individuals. We examine the variability and the following potential determinants of maternal-origin microchimerism (MMc) in young women in the Philippines: gestational duration (in utero exposure to MMc), history of being breastfed (postpartum exposure to MMc), maternal telomere length (maternal cells' ability to replicate and persist), and participant's pregnancies in young adulthood (effect of adding fetal-origin microchimerism to preexisting MMc).

MATERIALS AND METHODS

Data are from the Cebu Longitudinal Health and Nutrition Survey, a population-based study of infant feeding practices and long-term health outcomes. We quantified MMc using quantitative PCR (qPCR) in 89 female participants, ages 20-22, and analyzed these data using negative binomial regression.

RESULTS

In a multivariate model including all predictors, being breastfed substantially predicted decreased MMc (detection rate ratio = 0.15, p = 0.007), and there was a trend of decreasing MMc in participants who had experienced more pregnancies (detection rate ratio = 0.55, p = 0.057).

DISCUSSION

These results might be explained by breastfeeding having lasting impact on immune regulatory networks, thus reducing MMc persistence. MMc may also decrease in response to the introduction of fetal-origin microchimerism with pregnancies experienced in adulthood.

The Effects and Underlying Mechanisms of Cell Therapy on Blood-Brain Barrier Integrity After Ischemic Stroke

Ischemic stroke is one of the main causes of mortality and disability worldwide. However, efficient therapeutic strategies are still lacking. Stem/progenitor cell-based therapy, with its vigorous advantages, has emerged as a promising tool for the treatment of ischemic stroke. The mechanisms involve new neural cells and neuronal circuitry formation, antioxidation, inflammation alleviation, angiogenesis, and neurogenesis promotion. In the past decades, in-depth studies have suggested that cell therapy could promote vascular stabilization and decrease blood-brain barrier (BBB) leakage after ischemic stroke. However, the effects and underlying mechanisms on BBB integrity induced by the engrafted cells in ischemic stroke have not been reviewed yet. Herein, we will update the progress in research on the effects of cell therapy on BBB integrity after ischemic stroke and review the underlying mechanisms. First, we will present an overview of BBB dysfunction under the ischemic condition and cells engraftment for ischemic treatment. Then, we will summarize and discuss the current knowledge about the effects and underlying mechanisms of cell therapy on BBB integrity after ischemic stroke. In particular, we will review the most recent studies in regard to the relationship between cell therapy and BBB in tissue plasminogen activator (t-PA)-mediated therapy and diabetic stroke.

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.

Epigenetic Programming Through Breast Milk and Its Impact on Milk-Siblings Mating

Background

The epigenetic effects of transmission of certain regulatory molecules, such as miRNAs, through maternal milk on future generations, are still unknown and have not been fully understood yet. We hypothesized that breastfeeding regularly by adoptive-mother may cause transmission of miRNAs as epigenetic regulating factors to the infant, and the marriage of milk-siblings may cause various pathologies in the future generations.

Results

A cross-fostering model using a/a and A^vy/a mice had been established. F2 milk-sibling and F2 control groups were obtained from mating of milk-siblings or unrelated mice. Randomized selected animals in the both F2 groups were sacrificed for miRNA expression studies and the remainings were followed for phenotypic changes (coat color, obesity, hyperglycemia, liver pathology, and life span). The lifespan in the F2 milk-sibling group was shorter than the control group (387 vs 590 days, p = 0.011) and they were more obese during the aging period. Histopathological examination of liver tissues revealed abnormal findings in F2 milk-sibling group. In order to understand the epigenetic mechanisms leading to these phenotypic changes, we analyzed miRNA expression differences between offspring of milk-sibling and control matings and focused on the signaling pathways regulating lifespan and metabolism. Bioinformatic analysis demonstrated that differentially expressed miRNAs were associated with pathways regulating metabolism, survival, and cancer development such as the PI3K-Akt, ErbB, mTOR, and MAPK, insulin signaling pathways. We further analyzed the expression patterns of miR-186-5p, miR-141-3p, miR-345-5p, and miR-34c-5p and their candidate target genes Mapk8, Gsk3b, and Ppargc1a in ovarian and liver tissues.

Conclusion

Our findings support for the first time that the factors modifying the epigenetic mechanisms may be transmitted by breast milk and these epigenetic interactions may be transferred transgenerationally. Results also suggested hereditary epigenetic effects of cross-fostering on future generations and the impact of mother-infant dyad on epigenetic programming.

The CD133+ Stem/Progenitor-Like Cell Subset Is Increased in Human Milk and Peripheral Blood of HIV-Positive Women

Human milk is a significant source of different CD133⁺ and/or CD34⁺ stem/progenitor-like cell subsets in healthy women but their cell distribution and percentages in this compartment of HIV-positive women have not been explored. To date, a decrease of CD34⁺ hematopoietic stem and progenitor cell frequencies in peripheral blood and bone marrow of HIV-positive patients has been reported. Herein, human milk and peripheral blood samples were collected between day 2–15 post-partum from HIV-positive and HIV-negative women, and cells were stained with stem cell markers and analyzed by flow cytometry. We report that the median percentage of CD45^+/highCD34⁻CD133⁺ cell subset from milk and blood was significantly higher in HIV-positive than in HIV-negative women. The percentage of CD45^dimCD34⁻CD133⁺ cell subset from blood was significantly higher in HIV-positive than HIV-negative women. Moreover, percentages of CD45^dimCD34⁺, CD45^dimCD34⁺CD133⁻, and CD45^+highCD34⁺CD133⁻ cell subsets from blood were significantly lower in HIV-positive than HIV-negative women. The CD133⁺ stem/progenitor-like cell subsets are increased in early human milk and blood of HIV-positive women and are differentially distributed to CD34⁺ cell subset frequencies which are decreased in blood.

Fetal and neonatal allo-immune response

The components of the immune system may be present in early stages of embryonic and then fetal, then they reach maturity at different stages of pregnancy. Just as the growth and development of the components of the embryonic and then fetal immune system progressively mature, functions are acquired sequentially during the course of pregnancy, both the ability to mount a cell-mediated or antibody-mediated immune response and the tolerance towards a certain group of antigens. The fetus is immunocompetent because during this development, it acquires the ability to generate an immune response. As development takes place, the fetus also generates specific tolerance as it is exposed to genetically foreign and non-inherited maternal antigens. Nonetheless, the fetal immune system does not attack nor harm maternal tissues. At birth, the immune system, although developed, is not mature enough yet. Furthermore, passive transfer of maternal antibodies creates a unique scenario of compatibility that cannot be seen in children or adults. Recent advances in knowledge of fetal and neonatal immunology make it possible to recognize the risks associated with transfusion and how to resolve them.

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.