Project description:Influenza virus transmission between mothers and nursing-infants has not been investigated although mothers and infants often develop severe disease. Ferrets are considered the most appropriate model for influenza studies. We investigated influenza transmission in infant and nursing-mother ferrets. Influenza infected infants transmitted virus to mother mammary glands leading to live virus excretion in milk and influenza virus positive mammary gland epithelial cells. Global gene expression analysis showed down-regulation of milk production and induction of breast involution and oncogenesis pathways. Our results provide insight into influenza transmission between mothers and infants which may impact fields of infectious disease, maternal/infant health and neoplasm etiology.
Project description:Influenza virus transmission between mothers and nursing-infants has not been investigated although mothers and infants often develop severe disease. Ferrets are considered the most appropriate model for influenza studies. We investigated influenza transmission in infant and nursing-mother ferrets. Influenza infected infants transmitted virus to mother mammary glands leading to live virus excretion in milk and influenza virus positive mammary gland epithelial cells. Global gene expression analysis showed down-regulation of milk production and induction of breast involution and oncogenesis pathways. Our results provide insight into influenza transmission between mothers and infants which may impact fields of infectious disease, maternal/infant health and neoplasm etiology.
Project description:Influenza virus transmission between mothers and nursing-infants has not been investigated although mothers and infants often develop severe disease. Ferrets are considered the most appropriate model for influenza studies. We investigated influenza transmission in infant and nursing-mother ferrets. Influenza infected infants transmitted virus to mother mammary glands leading to live virus excretion in milk and influenza virus positive mammary gland epithelial cells. Global gene expression analysis showed down-regulation of milk production and induction of breast involution and oncogenesis pathways. Our results provide insight into influenza transmission between mothers and infants which may impact fields of infectious disease, maternal/infant health and neoplasm etiology. Total RNA was obtained from nursing mother ferret mammary glands at days 3/4 and 6/7 post-intranasal kit infection with 10^5 EID50 A/California/07/2009 (H1N1). Total RNA was also collected from uninfected control nursing mother mammary gland tissues (n = 3). Changes in gene expression relative to uninfected tissue controls were then investigated.
Project description:Influenza virus transmission between mothers and nursing-infants has not been investigated although mothers and infants often develop severe disease. Ferrets are considered the most appropriate model for influenza studies. We investigated influenza transmission in infant and nursing-mother ferrets. Influenza infected infants transmitted virus to mother mammary glands leading to live virus excretion in milk and influenza virus positive mammary gland epithelial cells. Global gene expression analysis showed down-regulation of milk production and induction of breast involution and oncogenesis pathways. Our results provide insight into influenza transmission between mothers and infants which may impact fields of infectious disease, maternal/infant health and neoplasm etiology. Total RNA was obtained from ferret lungs at days 3 and 6 post-intranasal infection with 10^5 EID50 A/California/07/2009 (H1N1) (n = 3/time-point). Total RNA was also collected from uninfected control lung tissues (n = 3). Changes in gene expression relative to uninfected tissue controls were then investigated.
Project description:Arthropod-borne viruses (arboviruses), such as Zika virus, chikungunya virus, and West Nile virus (WNV), pose continuous threats to emerge and cause large epidemics. Often, these events are associated with novel virus variants optimized for local transmission that first arise as minorities within a host. Thus, the conditions that regulate the frequency of intrahost variants are important determinants of emergence. Here, we describe the dynamics of WNV genetic diversity during its transmission cycle. By temporally sampling saliva from individual mosquitoes, we demonstrate that virus populations expectorated by mosquitoes are highly diverse and unique to each feeding episode. After transmission to birds, however, most genetic diversity is removed by strong purifying selection. Further, transmission of potentially mosquito-adaptive WNV variants is strongly influenced by genetic drift in mosquitoes. These results highlight the complex evolutionary forces a novel virus variant must overcome to alter infection phenotypes at the population level.
Project description:Postnatal dietary modulation of microRNAs (miRNAs) and effects on miRNA-mRNA interactions in tissues remain unknown. This study aimed to investigate whether dietary factors (formula vs. breastfeeding) affect mammary miRNA expression and to determine if these changes are concurrent with developmental alterations of the mammary gland in neonatal piglets. Female Yorkshire/Duroc piglets were fed sow's milk or cow's milk- or soy-based infant formula (from postnatal day 2 to day 21; n=6/group). Differentially expressed miRNAs were determined using mammary miRNA profiling, followed by miRNA and mRNA expressions characterized by quantitative reverse-transcription polymerase chain reaction. Milk and soy formulas reduced expressions of miR-1, -128, -133a, -193b, -206 and -27a; miRNA down-regulation altered mRNA expressions of genes (e.g., Ccnd1, Tgfb3, Igf1r and Tbx3) that were consistent with enhanced cell proliferation and suppressed apoptotic processes in the developing mammary gland. Interestingly, down-regulation of miR-1, -128 and -27a also correlated with increased mRNA genes such as Hmgcs and Hmgcr encoding cholesterol synthesis in the mammary glands in response to lower circulating cholesterol levels. Infant formula feeding affected mammary miRNA profiles in neonatal piglets, concurrent with increased expression of cell proliferation and cholesterol synthesis genes, suggesting early nutritional modulation of miRNAs may contribute to regulation of proliferative status and cholesterol homeostasis of developing mammary glands during infancy.
Project description:Zika virus (ZIKV) belongs to the large category of arboviruses. Surprisingly, several human-to-human transmissions of ZIKV have been notified, either following sexual intercourse or from the mother to fetus during pregnancy. Importantly, high viral loads have been detected in the human breast milk of infected mothers, and the existence of breastfeeding as a new mode of mother-to-child transmission of ZIKV was recently hypothesized. However, the maternal origin of infectious particles in breast milk is currently unknown. Here, we show that ZIKV disseminates to the mammary glands of infected mice after both systemic and local exposure with differential kinetics. Ex vivo, we demonstrate that primary human mammary epithelial cells were sensitive and permissive to ZIKV infection in this study. Moreover, by using in vitro models, we prove that mammary luminal- and myoepithelial-phenotype cell lines are both able to produce important virus progeny after ZIKV exposure. Our data suggest that the dissemination of ZIKV to the mammary glands and subsequent infection of the mammary epithelium could be one mechanism of viral excretion in human breast milk.
Project description:BACKGROUND:Few studies have examined the role of maternal emotions in breastfeeding outcomes. RESEARCH AIM:We aimed to determine the extent to which positive maternal emotions during human milk feeding at 2 months were associated with time to any and exclusive human milk feeding cessation and overall breastfeeding experience. METHODS:A sample of 192 women intending to breastfeed for at least 2 months was followed from the third trimester until 12 months postpartum. Positive emotions during infant feeding at 2 months were measured using the modified Differential Emotions Scale. Cox proportional hazards regression was used to estimate adjusted hazard ratios (aHR) for time to any and exclusive human milk feeding cessation associated with a 1-point increase in positive emotions. Linear regression was used to estimate the association between positive emotions and maternal breastfeeding experience reported at 12 months. RESULTS:Among those human milk feeding at 2 months, positive emotions during feeding were not associated with human milk feeding cessation by 12 months (aHR = 0.94, 95% CI [0.64, 1.31]). However, among women exclusively human milk feeding at 2 months, a 1-point increase in positive emotions was associated with a 35% lower hazard of introducing formula or solid foods by 6 months (aHR = 0.65, 95% CI [0.46, 0.92]). Positive emotions were associated with a significantly more favorable maternal report of breastfeeding experience at 12 months. Results were similar in sensitivity analyses using maternal feelings about breastfeeding in the first week as the exposure. CONCLUSIONS:A positive maternal emotional experience of feeding is associated with breastfeeding outcomes.
Project description:BackgroundSoy infant formula contains isoflavones, which are able to bind to and activate estrogen receptor (ER) pathways. The mammary gland is sensitive to estrogens, raising concern that the use of soy formulas may promote premature development.ObjectiveWe aimed to determine if soy formula feeding increases mammary gland proliferation and differentiation in comparison to other infant postnatal diets.MethodsWhite-Dutch Landrace piglets aged 2 d received either sow milk (Sow), or were provided milk formula (Milk), soy formula (Soy), milk formula supplemented with 17-beta-estradiol (2 mg/(kg·d); M + E2), or milk formula supplemented with genistein (84 mg/L of diet; M + G) until day 21. Mammary gland proliferation and differentiation was assessed by histology, and real-time RT-PCR confirmation of differentially expressed genes identified by microarray analysis.ResultsMammary terminal end bud numbers were 19-31% greater in the Milk, Soy, and M + G groups relative to the Sow and M + E2, P <0.05. Microarray analysis identified differentially expressed genes between each formula-fed group relative to the Sow (±1.7-fold, P <0.05). Real-time RT-PCR confirmed 2- to 4-fold increases in mRNA transcripts of genes involved in cell proliferation, insulin-like growth factor 1 (IGF1), fibroblast growth factor 10 (FGF10), and fibroblast growth factor 18 (FGF18), in all groups relative to the Sow, P <0.05. In contrast, genes involved in cell differentiation and ductal morphogenesis, angiotensin II receptor type 2 (AGTR2), microtubule associated protein 1b (MAP1B), and kinesin family member 26b (KIF26B), were significantly upregulated by 2-, 4-, and 13-fold, respectively, in the M + E2 group. Additionally, mRNA expression of ER-specific gene targets, progesterone receptor (PGR), was increased by 12-fold, and amphiregulin (AREG) and Ras-like estrogen regulated growth inhibitor (RERG) expression by 1.5-fold in the M + E2 group, P <0.05. In the soy and M + G groups, mRNA expressions of fatty acid synthesis genes were increased 2- to 4-fold.ConclusionsOur data indicate soy formula feeding does not promote ER-signaling in the piglet mammary gland. Infant formula feeding (milk- or soy-based) may initiate proliferative pathways independently of estrogenic signaling.