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Patients with compromised respiratory function frequently require mechanical ventilation to survive. Unfortunately, non-uniform ventilation of injured lungs generates complex mechanical forces that lead to ventilator induced lung injury (VILI). Although investigators have developed lung-on-a-chip systems to simulate normal respiration, modeling the complex mechanics of VILI as well as the subsequent recovery phase is a challenge. Here we present a novel humanized in vitro ventilator-on-a-chip (VOC) model of the lung microenvironment that simulates the different types of injurious forces generated in the lung during mechanical ventilation. We used transepithelial/endothelial electrical impedance measurements to investigate how individual and simultaneous application of mechanical forces alters real-time changes in barrier integrity during and after injury. We find that compressive stress (i.e. barotrauma) does not significantly alter barrier integrity while over-distention (20% cyclic radial strain, volutrauma) results in decreased barrier integrity that quickly recovers upon removal of mechanical stress. Conversely, surface tension forces generated during airway reopening (atelectrauma), result in a rapid loss of barrier integrity with a delayed recovery relative to volutrauma. Simultaneous application of cyclic stretching (volutrauma) and airway reopening (atelectrauma), indicates that the surface tension forces associated with reopening fluid-occluded lung regions are the primary driver of barrier disruption. Thus, our novel VOC system can monitor the effects of different types of injurious forces on barrier disruption and recovery in real-time and can be used to interogate the biomechanical mechanisms of VILI. [ABSTRACT FROM AUTHOR]

Collagen deposition contributes to both high mammographic density and breast cancer progression. Low stromal PTEN expression has been observed in as many as half of breast tumors and is associated with increases in collagen deposition, however the mechanism connecting PTEN loss to increased collagen deposition remains unclear. Here, we demonstrate that Pten knockout in fibroblasts using an Fsp-Cre;PtenloxP/loxP mouse model increases collagen fiber number and fiber size within the mammary gland. Pten knockout additionally upregulated Sparc transcription in fibroblasts and promoted collagen shuttling out of the cell. Interestingly, SPARC mRNA expression was observed to be significantly elevated in the tumor stroma as compared to the normal breast in several patient cohorts. While SPARC knockdown via shRNA did not affect collagen shuttling, it notably decreased assembly of exogenous collagen. In addition, SPARC knockdown decreased fibronectin assembly and alignment of the extracellular matrix in an in vitro fibroblast-derived matrix model. Overall, these data indicate upregulation of SPARC is a mechanism by which PTEN regulates collagen deposition in the mammary gland stroma. [ABSTRACT FROM AUTHOR]

Mechanical ventilation generates injurious forces that exacerbate lung injury. These forces disrupt lung barrier integrity, trigger proinflammatory mediator release, and differentially regulate genes and non-coding oligonucleotides including microRNAs. In this study, we identify miR-146a as a mechanosensitive microRNA in alveolar macrophages that has therapeutic potential to mitigate lung injury during mechanical ventilation. We use humanized in-vitro systems, mouse models, and biospecimens from patients to elucidate the expression dynamics of miR-146a needed to decrease lung injury during mechanical ventilation. We find that the endogenous increase in miR-146a following injurious ventilation is not sufficient to prevent lung injury. However, when miR-146a is highly overexpressed using a nanoparticle delivery platform it is sufficient to prevent injury. These data indicate that the endogenous increase in microRNA-146a during mechanical ventilation is a compensatory response that partially limits injury and that nanoparticle delivery of miR-146a is an effective strategy for mitigating lung injury during mechanical ventilation. There are no targeted pharmacologic therapies to treat lung injury during mechanical ventilation (MV). Here the authors identify a mechanosensitive microRNA (miR-146a) in alveolar macrophages during MV and increase miR-146a to supraphysiological levels in these cells to mitigate ventilator induced lung injury. [ABSTRACT FROM AUTHOR]

Myeloid derived suppressor cells (MDSCs) have gained significant attention for their immunosuppressive role in cancer and their ability to contribute to tumor progression and metastasis. Understanding the role of MDSCs in driving cancer cell migration, a process fundamental to metastasis, is essential to fully comprehend and target MDSC‐tumor cell interactions. This study employs microfabricated platforms, which simulate the structural cues present in the tumor microenvironment (TME) to elucidate the effects of MDSCs on the migratory phenotype of cancer cells at the single cell level. The results indicate that the presence of MDSCs enhances the motility of cancer‐epithelial cells when directional cues (either topographical or spatial) are present. This behavior appears to be independent of cell–cell contact and driven by soluble byproducts from heterotypic interactions between MDSCs and cancer cells. Moreover, MDSC cell‐motility is also impacted by the presence of cancer cells and the cancer cell secretome in the presence of directional cues. Epithelial dedifferentiation is the likely mechanism for changes in cancer cell motility in response to MDSCs. These results highlight the biochemical and biostructural conditions under which MDSCs can support cancer cell migration, and could therefore provide new avenues of research and therapy aimed at stemming cancer progression. [ABSTRACT FROM AUTHOR]

Myeloid-derived suppressor cells (MDSCs) are immune cells that exert immunosuppression within the tumor, protecting cancer cells from the host's immune system and/or exogenous immunotherapies. While current research has been mostly focused in countering MDSC-driven immunosuppression, little is known about the mechanisms by which MDSCs disseminate/infiltrate cancerous tissue. This study looks into the use of microtextured surfaces, coupled with in vitro and in vivo cellular and molecular analysis tools, to videoscopically evaluate the dissemination patterns of MDSCs under structurally guided migration, at the single-cell level. MDSCs exhibited topographically driven migration, showing significant intra- and inter-population differences in motility, with velocities reaching ~40 μm h−1. Downstream analyses coupled with single-cell migration uncovered the presence of specific MDSC subpopulations with different degrees of tumor-infiltrating and anti-inflammatory capabilities. Granulocytic MDSCs showed a ~≥3-fold increase in maximum dissemination velocities and traveled distances, and a ~10-fold difference in the expression of pro- and anti-inflammatory markers. Prolonged culture also revealed that purified subpopulations of MDSCs exhibit remarkable plasticity, with homogeneous/sorted subpopulations giving rise to heterogenous cultures that represented the entire hierarchy of MDSC phenotypes within 7 days. These studies point towards the granulocytic subtype as a potential cellular target of interest given their superior dissemination ability and enhanced anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

The leading cause of neonatal mortality, pre-term birth, is often caused by pre-mature ripening/opening of the uterine cervix. Although cervical fibroblasts play an important role in modulating the cervix's extracellular matrix (ECM) and mechanical properties, it is not known how hormones, i.e., progesterone, and pro-inflammatory insults alter fibroblast mechanics, fibroblast-ECM interactions and the resulting changes in tissue mechanics. Here we investigate how progesterone and a pro-inflammatory cytokine, IL-1β, alter the biomechanical properties of human cervical fibroblasts and the fibroblast-ECM interactions that govern tissue-scale mechanics. Primary human fibroblasts were isolated from non-pregnant cervix and treated with estrogen/progesterone, IL-1β or both. The resulting changes in ECM gene expression, matrix remodeling, traction force generation, cell-ECM adhesion and tissue contractility were monitored. Results indicate that IL-1β induces a significant reduction in traction force and ECM adhesion independent of pre-treatment with progesterone. These cell level effects altered tissue-scale mechanics where IL-1β inhibited the contraction of a collagen gel over 6 days. Interestingly, progesterone treatment alone did not modulate traction forces or gel contraction but did result in a dramatic increase in cell-ECM adhesion. Therefore, the protective effect of progesterone may be due to altered adhesion dynamics as opposed to altered ECM remodeling. [ABSTRACT FROM AUTHOR]

Aqueous and alcoholic extracts of amalki (Emblica officinalis), spirulina and wheatgrass were prepared and analyzed for antioxidant vitamin content (vitamin C and E), total phenolic compounds. Antioxidant status, reducing power and effect on glutathione S-transferase (GST) activity were evaluated in vitro. Vitamin C content of crude amalaki powder was found to be 5.38 mg/g, while very less amount 0.22 mg/g was detected in wheat grass. Amalki was rich in vitamin E like activity, total phenolic content, reducing power and antioxidant activity. Total antioxidant activity of aqueous extract of amalki, spirulina and wheat grass at 1mg/ml concentration were 7.78, 1.33 and 0.278 mmol/l respectively. At similar concentrations the total antioxidant activity of alcoholic extract of amalaki, spirulina and wheat grass was 6.67, 1.73 and 0.380 mmol/l respectively. Amalki was also found to be rich source of phenolic compounds (241mg/g gallic acid equivalent). Alcoholic extract of wheat grass showed 50 % inhibition in FeCl2- ascorbic acid induced lipid peroxidation of rat liver homogenates in vitro. Both aqueous and alcoholic extracts of amalaki inhibited activity of rat liver glutathione S-transferase (GST) in vitro in dose dependant manner. Since GST acts as powerful drug metabolizing enzyme its inhibition by amalaki offers possibility of its use for lowering therapeutic dose of herbal preparations. The aqueous extracts of both amalki and spirulina also showed protection against t-BOOH induced cytotoxicity and production of ROS in cultured C6 glial cells. [ABSTRACT FROM AUTHOR]

The circulatory levels of two appetite regulatory hormones i.e. leptin and ghrelin were estimated in sojourners and acclimatized subjects to investigate their possible role in high altitude (HA) induced anorexia. A group of 30 lowlanders who had never visited HA were inducted to a height of 3600&ThickSpace;m by air and after 48&ThickSpace;h they were further taken to an altitude of 4300&ThickSpace;m by road. Blood samples were collected after 48&ThickSpace;h stay at 3600&ThickSpace;m and again after 48&ThickSpace;h and 7 days of stay at 4300&ThickSpace;m during 0700–0730&ThickSpace;h. There was a decrease in energy intake (850&ThickSpace;kcal/day) of sojourners, which resulted in loss of body weight by 2.12&ThickSpace;kg at HA. At an altitude of 4300&ThickSpace;m there was a significant increase in leptin over basal levels (54.9%, p <0.001) at 48&ThickSpace;h that persisted even after 7 days of stay at this altitude. Ghrelin levels of sojourners decreased by more than 30% in comparison to basal values at 48&ThickSpace;h of ascent to HA. Leptin levels of acclimatized lowlanders were also higher in comparison with control group (acclimatized group 7.6+0.6&ThickSpace;ng/ml vs. control 5.6+0.5&ThickSpace;ng/ml, p <0.01, n =50). [ABSTRACT FROM AUTHOR]

Background: A prominent strategy to engage private sector health providers in low- and middle-income countries is clinical social franchising, an organisational model that applies the principles of commercial franchising for socially beneficial goals. The Matrika programme, a multi-faceted social franchise model to improve maternal health, was implemented in three districts of Uttar Pradesh, India, between 2013 and 2016. Previous research indicates that the intervention was not effective in improving the quality and coverage of maternal health services at the population level. This paper reports findings from an independent external process evaluation, conducted alongside the impact evaluation, with the aim of explaining the impact findings. It focuses on the main component of the programme, the "Sky" social franchise.Methods: We first developed a theory of change, mapping the key mechanisms through which the programme was hypothesised to have impact. We then undertook a multi-methods study, drawing on both quantitative and qualitative primary data from a wide range of sources to assess the extent of implementation and to understand mechanisms of impact and the role of contextual factors. We analysed the quantitative data descriptively to generate indicators of implementation. We undertook a thematic analysis of the qualitative data before holding reflective meetings to triangulate across data sources, synthesise evidence, and identify the main findings. Finally, we used the framework provided by the theory of change to organise and interpret our findings.Results: We report six key findings. First, despite the franchisor achieving its recruitment targets, the competitive nature of the market for antenatal care meant social franchise providers achieved very low market share. Second, all Sky health providers were branded but community awareness of the franchise remained low. Third, using lower-level providers and community health volunteers to encourage women to attend franchised antenatal care services was ineffective. Fourth, referral linkages were not sufficiently strong between antenatal care providers in the franchise network and delivery care providers. Fifth, Sky health providers had better knowledge and self-reported practice than comparable health providers, but overall, the evidence pointed to poor quality of care across the board. Finally, telemedicine was perceived by clients as an attractive feature, but problems in the implementation of the technology meant its effect on quality of antenatal care was likely limited.Conclusions: These findings point towards the importance of designing programmes based on a strong theory of change, understanding market conditions and what patients value, and rigorously testing new technologies. The design of future social franchising programmes should take account of the challenges documented in this and other evaluations. [ABSTRACT FROM AUTHOR]