Vertical Transmission of Respiratory Syncytial Virus Modulates Pre- and Postnatal Innervation and Reactivity of Rat Airways

Background

Environmental exposure to respiratory syncytial virus (RSV) is a leading cause of respiratory infections in infants, but it remains unknown whether this infection is transmitted transplacentally from the lungs of infected mothers to the offspring. We sought to test the hypothesis that RSV travels from the respiratory tract during pregnancy, crosses the placenta to the fetus, persists in the lung tissues of the offspring, and modulates pre- and postnatal expression of growth factors, thereby predisposing to airway hyperreactivity.

Methodology

Pregnant rats were inoculated intratracheally at midterm using recombinant RSV expressing red fluorescent protein (RFP). Viral RNA was amplified by RT-PCR and confirmed by sequencing. RFP expression was analyzed by flow cytometry and viral culture. Developmental and pathophysiologic implications of prenatal infection were determined by analyzing the expression of genes encoding critical growth factors, particularly neurotrophic factors and receptors. We also measured the expression of key neurotransmitters and postnatal bronchial reactivity in vertically infected lungs, and assessed their dependence on neurotrophic signaling using selective biological or chemical inhibition.

Principal Findings

RSV genome was found in 30% of fetuses, as well as in the lungs of 40% of newborns and 25% of adults. RFP expression was also shown by flow cytometry and replicating virus was cultured from exposed fetuses. Nerve growth factor and its TrkA receptor were upregulated in RSV- infected fetal lungs and co-localized with increased cholinergic innervation. Acetylcholine expression and smooth muscle response to cholinergic stimulation increased in lungs exposed to RSV in utero and reinfected after birth, and blocking TrkA signaling inhibited both effects.

Conclusions/Significance

Our data show transplacental transmission of RSV from mother to offspring and persistence of vertically transmitted virus in lungs after birth. Exposure to RSV in utero is followed by dysregulation of neurotrophic pathways predisposing to postnatal airway hyperreactivity upon reinfection with the virus.     

Multivariate Models of Adult Pacific Salmon Returns

Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding of the processes affecting variability in survival. Better methods and data for predicting the abundance of returning adults are therefore required to effectively manage the species. We combined 31 distinct indicators of the marine environment collected over an 11-year period into a multivariate analysis to summarize and predict adult spring Chinook salmon returns to the Columbia River in 2012. In addition to forecasts, this tool quantifies the strength of the relationship between various ecological indicators and salmon returns, allowing interpretation of ecosystem processes. The relative importance of indicators varied, but a few trends emerged. Adult returns of spring Chinook salmon were best described using indicators of bottom-up ecological processes such as composition and abundance of zooplankton and fish prey as well as measures of individual fish, such as growth and condition. Local indicators of temperature or coastal upwelling did not contribute as much as large-scale indicators of temperature variability, matching the spatial scale over which salmon spend the majority of their ocean residence. Results suggest that effective management of Pacific salmon requires multiple types of data and that no single indicator can represent the complex early-ocean ecology of salmon.     

Aerobic exercise alone results in clinically significant weight loss for men and women: Midwest exercise trial 2

Exercise is recommended by public health agencies for weight management; however, the role of exercise is generally considered secondary to energy restriction. Few studies exist that have verified completion of exercise, measured the energy expenditure of exercise, and prescribed exercise with equivalent energy expenditure across individuals and genders.

Objective:

The objective of this study was to evaluate aerobic exercise, without energy restriction, on weight loss in sedentary overweight and obese men and women.

Design and Methods:

This investigation was a randomized, controlled, efficacy trial in 141 overweight and obese participants (body mass index, 31.0 ± 4.6 kg/m²; age 22.6 ± 3.9 years). Participants were randomized (2:2:1 ratio) to exercise at either 400 kcal/session or 600 kcal/session or to a nonexercise control. Exercise was supervised, 5 days/week, for 10 months. All participants were instructed to maintain usual ad libitum diets. Because of the efficacy design, completion of ≥90% of exercise sessions was an a priori definition of per protocol, and these participants were included in the analysis.

Results:

Weight loss from baseline to 10 months for the 400 and 600 kcal/session groups was 3.9 ± 4.9 kg (4.3%) and 5.2 ± 5.6 kg (5.7%), respectively, compared with weight gain for controls of 0.5 ± 3.5 kg (0.5%) (P < 0.05). Differences for weight loss from baseline to 10 months between the exercise groups and differences between men and women within groups were not statistically significant.

Conclusions:

Supervised exercise, with equivalent energy expenditure, results in clinically significant weight loss with no significant difference between men and women.     

Explaining Disparities in Use of Skilled Birth Attendants in Developing Countries: A Conceptual Framework

Despite World Health Organization recommendations that all women deliver with a skilled birth attendant (SBA), research continues to demonstrate large disparities in use of SBAs by socioeconomic status (SES). Yet few quantitative studies empirically examine the factors underlying these disparities, due in part to the fact that current models do not provide clear pathways—with measurable mediators—for how distal factors like SES may affect maternal health-seeking behaviors like delivering with SBAs. We propose the Disparities in Skilled Birth Attendance (DiSBA) framework for examining the determinants of use of SBAs. We posit that three proximal factors directly affect use of SBAs: perceived need, perceived accessibility of maternal health services, and perceived quality of care. Distal factors like SES affect use of SBAs indirectly through these proximal factors, and the effects can be measured. We test the assumptions of the DiSBA framework using data from the Ghana Maternal Health Survey. The analytic techniques we use include logistic regression with mediation analysis to examine the intervening effects. We find that our proxies for perceived access, perceived need, and perceived quality of care account for approximately 23% of the difference between women with no education and those with primary school education, and about 55% of the difference between women in the lowest wealth quintile and those in the middle wealth quintiles. This study suggests that proximal factors are worthy of increased attention in terms of measurement, data collection, analysis, programmatic efforts, and policy interventions, as these factors are potentially more amenable to change than the distal factors. The effects of proximal factors are also likely context specific, thus sufficient understanding in different contexts is essential to developing appropriate interventions.     

Valproic acid stimulates proliferation of glial precursors during cortical gliogenesis in developing rat

Valproic acid (VPA) is a neurotherapeutic drug prescribed for seizures, bipolar disorder, and migraine, including women of reproductive age. VPA is a well‐known teratogen that produces congenital malformations in many organs including the nervous system, as well as later neurodevelopmental disorders, including mental retardation and autism. In developing brain, few studies have examined VPA effects on glial cells, particularly astrocytes. To investigate effects on primary glial precursors, we developed new cell culture and in vivo models using frontal cerebral cortex of postnatal day (P2) rat. In vitro, VPA exposure elicited dose‐dependent, biphasic effects on DNA synthesis and proliferation. In vivo VPA (300 mg/kg) exposure from P2 to P4 increased both DNA synthesis and cell proliferation, affecting primarily astrocyte precursors, as >75% of mitotic cells expressed brain lipid‐binding protein. Significantly, the consequence of early VPA exposure was increased astrocytes, as both S100‐β+ cells and glial fibrillary acidic protein were increased in adolescent brain. Molecularly, VPA served as an HDAC inhibitor in vitro and in vivo as enhanced proliferation was accompanied by increased histone acetylation, whereas it elicited changes in culture in cell‐cycle regulators, including cyclin D1 and E, and cyclin‐dependent kinase (CDK) inhibitors, p21 and p27. Collectively, these data suggest clinically relevant VPA exposures stimulate glial precursor proliferation, though at higher doses can elicit inhibition through differential regulation of CDK inhibitors. Because changes in glial cell functions are proposed as mechanisms contributing to neuropsychiatric disorders, these observations suggest that VPA teratogenic actions may be mediated through changes in astrocyte generation during development. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 780–798, 2016     

Babesia divergens builds a complex population structure composed of specific ratios of infected cells to ensure a prompt response to changing environmental conditions

Babesia parasites cause a malaria‐like febrile illness by infection of red blood cells (RBCs). Despite the growing importance of this tick‐borne infection, its basic biology has been neglected. Using novel synchronization tools, the sequence of intra‐erythrocytic events was followed from invasion through development and differentiation to egress. The dynamics of the parasite population were studied in culture, revealing for the first time, the complete array of morphological forms in a precursor–product relationship. Important chronological constants including Babesia's highly unusual variable intra‐erythrocytic life cycle, the life span of each population of infected cells and the time required for the genesis of the different parasite stages were elucidated. Importantly, the maintenance of specific ratios of the infected RBC populations was shown to be responsible for the parasites' choice of developmental pathways, enabling swift responses to changing environmental conditions like availability of RBCs and nutrition. These results could impact the control of parasite proliferation and therefore disease.     

Molecular mechanisms regulating formation,trafficking and processing of annular gap junctions

Internalization of gap junction plaques results in the formation of annular gap junction vesicles. The factors that regulate the coordinated internalization of the gap junction plaques to form annular gap junction vesicles, and the subsequent events involved in annular gap junction processing have only relatively recently been investigated in detail. However it is becoming clear that while annular gap junction vesicles have been demonstrated to be degraded by autophagosomal and endo-lysosomal pathways, they undergo a number of additional processing events. Here, we characterize the morphology of the annular gap junction vesicle and review the current knowledge of the processes involved in their formation, fission, fusion, and degradation. In addition, we address the possibility for connexin protein recycling back to the plasma membrane to contribute to gap junction formation and intercellular communication. Information on gap junction plaque removal from the plasma membrane and the subsequent processing of annular gap junction vesicles is critical to our understanding of cell-cell communication as it relates to events regulating development, cell homeostasis, unstable proliferation of cancer cells, wound healing, changes in the ischemic heart, and many other physiological and pathological cellular phenomena.     

Anti‐human CD9 antibody Fab fragment impairs the internalization of extracellular vesicles and the nuclear transfer of their cargo proteins

The intercellular communication mediated by extracellular vesicles (EVs) has gained international interest during the last decade. Interfering with the mechanisms regulating this cellular process might find application particularly in oncology where cancer cell‐derived EVs play a role in tumour microenvironment transformation. Although several mechanisms were ascribed to explain the internalization of EVs, little is our knowledge about the fate of their cargos, which are crucial to mediate their function. We recently demonstrated a new intracellular pathway in which a fraction of endocytosed EV‐associated proteins is transported into the nucleoplasm of the host cell via a subpopulation of late endosomes penetrating into the nucleoplasmic reticulum. Silencing tetraspanin CD9 both in EVs and recipient cells strongly decreased the endocytosis of EVs and abolished the nuclear transfer of their cargos. Here, we investigated whether monovalent Fab fragments derived from 5H9 anti‐CD9 monoclonal antibody (referred hereafter as CD9 Fab) interfered with these cellular processes. To monitor the intracellular transport of proteins, we used fluorescent EVs containing CD9‐green fluorescent protein fusion protein and various melanoma cell lines and bone marrow‐derived mesenchymal stromal cells as recipient cells. Interestingly, CD9 Fab considerably reduced EV uptake and the nuclear transfer of their proteins in all examined cells. In contrast, the divalent CD9 antibody stimulated both events. By impeding intercellular communication in the tumour microenvironment, CD9 Fab‐mediated inhibition of EV uptake, combined with direct targeting of cancerous cells could lead to the development of novel anti‐melanoma therapeutic strategies.     

Tumor-infiltrating lymphocytes: Streamlining a complex manufacturing process

Adoptive cell therapy of tumor-infiltrating lymphocytes has shown promise for treatment of refractory melanoma and other solid malignancies; however, challenges to manufacturing have limited its widespread use. Traditional manufacturing efforts were lengthy, cumbersome and used open culture systems. We describe changes in testing and manufacturing that decreased the process cycle time, enhanced the robustness of critical quality attribute testing and facilitated a functionally closed system. These changes have enabled export of the manufacturing process to support multi-center clinical trials.