Pulmonary hypertension (PH) is a disease with a poor prognosis characterized by a vascular remodeling process and an increase in pulmonary vascular resistance. While a variety of reports demonstrated ...that exercise training exerts beneficial effects on exercise performance and quality of life in PH patients, it is not known how physical exercise affects vascular remodeling processes occurring in hypoxia-induced PH. Therefore, we investigated the effect of individualized exercise training on the development of hypoxia-induced PH in mice. Training effects were compared with pharmacological treatment with the phosphodiesterase 5 inhibitor Sildenafil or a combination of training plus Sildenafil. Trained mice who received Sildenafil showed a significantly improved walking distance (from 88.9 ± 8.1 to 146.4 ± 13.1 m) and maximum oxygen consumption (from 93.3 ± 2.9 to 105.5 ± 2.2% in combination with Sildenafil, to 102.2 ± 3.0% with placebo) compared with sedentary controls. Right ventricular systolic pressure, measured by telemetry, was at the level of healthy normoxic animals, whereas right heart hypertrophy did not benefit from training. Most interestingly, the increase in small pulmonary vessel muscularization was prevented by training. Respective counterregulatory processes were detected for the nitric oxide-soluble guanylate cyclase-phosphodiesterase system. We conclude that individualized daily exercise can prevent vascular remodeling in hypoxia-induced PH.
Club (Clara) cells are nonciliated secretory epithelial cells present in bronchioles of distal pulmonary airways. So far, no information is available on the postnatal differentiation of club cells by ...a combination of molecular biological, biochemical, and stereological approaches in the murine lung. Therefore, the present study was designed to investigate the changes in the club cell secretory proteins (CC10, surfactant proteins A, B and D) and club cell abundance within the epithelium of bronchioles of distal airways during the postnatal development of the mouse lung. Perfusion-fixed murine lungs of three developmental stages (newborn, 15-day-old and adult) were used. Frozen, unfixed lungs were used for cryosectioning and subsequent laser-assisted microdissection of bronchiolar epithelial cells and RT-PCR analyses. High resolution analyses of the three-dimensional structures and composition of lung airways were obtained by scanning electron microscopy. Finally, using design-based stereology, the total and average club cell volume and the volume of secretory granules were quantified by light and transmission electron microscopy. Our results reveal that murine club cells are immature at birth and differentiate postnatally. Further, increase of the club cell volume and number of intracellular granules are closely correlated to the total lung volume enlargement. However, secretory granule density was only increased within the first 15 days of postnatal development. The differentiation is accompanied by a decrease in glycogen content, and a close positive relationship between CC10 expression and secretory granule abundance. Taken together, our data are consistent with the concept that the morphological and functional differentiation of club cells is a postnatal phenomenon.
Mitochondrial biogenesis and adequate energy production in various organs of mammals are necessary for postnatal adaptation to extrauterine life in an environment with high oxygen content. Even ...though transgenic mice are frequently used as experimental models, to date, no combined detailed molecular and morphological analysis on the mitochondrial compartment in different lung cell types has been performed during postnatal mouse lung development. In our study, we revealed a significant upregulation of most mitochondrial respiratory complexes at protein and mRNA levels in the lungs of P15 and adult animals in comparison to newborns. The majority of adult animal samples showed the strongest increase, except for succinate dehydrogenase protein (SDHD). Likewise, an increase in mRNA expression for mtDNA transcription machinery genes (Polrmt, Tfam, Tfb1m, and Tfb2m), mitochondrially encoded RNA (mt-Rnr1 and mt-Rnr2), and the nuclear-encoded mitochondrial DNA polymerase (POLG) was observed. The biochemical and molecular results were corroborated by a parallel increase of mitochondrial number, size, cristae number, and complexity, exhibiting heterogeneous patterns in distinct bronchiolar and alveolar epithelial cells. Taken together, our results suggest a specific adaptation and differential maturation of the mitochondrial compartment according to the metabolic needs of individual cell types during postnatal development of the mouse lung.
The continuous development of ultra-fast high-power lasers (HPL) technology with the ability of working at unprecedented repetition rates, between 1 and 10 Hz, is raising the target needs for ...experiments in the different areas of interest to the HPL community. Many target designs can be conceived according to specific scientific issues, however to guarantee manufacturing abilities that enable large number production and still allow for versatility in the design is the main barrier in the exploitation of these high repetition rate facilities. Here, we have applied MEMS based manufacturing processes for this purpose. In particular, we have focused on the fabrication and characterization of submicrometric conductive membranes embedded in a silicon frame. These kinds of solid targets are used for laser-driven particle acceleration through the so-called Target Normal Sheath Acceleration mechanism (TNSA). They were obtained by top-down fabrication alternating pattern transfer, atomic layer deposition, and selective material etching. The adaptability of the approach is then analyzed and discussed by evaluating different properties of targets for use in laser-driven particle acceleration experiments. These characteristics include the surface properties of membranes after fabrication and the high density of the target array. Finally, we were able to show their efficiency for laser-driven proton acceleration in a series of experiments with a 3 TW table-top laser facility, achieving stable proton acceleration up to 2 MeV.
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and death worldwide. Peroxynitrite, formed from nitric oxide, which is derived from inducible nitric oxide synthase, and ...superoxide, has been implicated in the development of emphysema, but the source of the superoxide was hitherto not characterized. Here, we identify the non-phagocytic NADPH oxidase organizer 1 (NOXO1) as the superoxide source and an essential driver of smoke-induced emphysema and pulmonary hypertension development in mice. NOXO1 is consistently upregulated in two models of lung emphysema, Cybb (also known as NADPH oxidase 2, Nox2)-knockout mice and wild-type mice with tobacco-smoke-induced emphysema, and in human COPD. Noxo1-knockout mice are protected against tobacco-smoke-induced pulmonary hypertension and emphysema. Quantification of superoxide, nitrotyrosine and multiple NOXO1-dependent signalling pathways confirm that peroxynitrite formation from nitric oxide and superoxide is a driver of lung emphysema. Our results suggest that NOXO1 may have potential as a therapeutic target in emphysema.
Our previous findings demonstrated an increase in pulmonary mast cells (MCs) in idiopathic pulmonary arterial hypertension (IPAH). Also, literature suggests a potential role for MCs in chronic ...obstructive pulmonary disease (COPD). However, a comprehensive investigation of lungs from patients is still needed. We systematically investigated the presence/expression of MCs/MC chymase in the lungs of IPAH and COPD patients by (immuno)histochemistry and subsequent quantification. We found that total and perivascular chymase-positive MCs were significantly higher in IPAH patients than in donors. In addition, chymase-positive MCs were located in proximity to regions with prominent expression of big-endothelin-1 in the pulmonary vessels of IPAH patients. Total and perivascular MCs around resistant vessels were augmented and a significant majority of them were degranulated (activated) in COPD patients. While the total chymase-positive MC count tended to increase in COPD patients, the perivascular number was significantly enhanced in all vessel sizes analyzed. Surprisingly, MC and chymase-positive MC numbers positively correlated with better lung function in COPD. Our findings suggest that activated MCs, possibly by releasing chymase, may contribute to pulmonary vascular remodeling in IPAH. Pulmonary MCs/chymase may have compartment-specific (vascular vs. airway) functions in COPD. Future studies should elucidate the mechanisms of MC accumulation and the role of MC chymase in pathologies of these severe lung diseases.
Thin layer membranes with controllable features and material arrangements are often used as target materials for laser driven particle accelerators. Reduced cost, large scale fabrication of such ...membranes with high reproducibility, and good stability are central for the efficient production of proton beams. These characteristics are of growing importance in the context of advanced laser light sources where increased repetition rates boost the need for consumable targets with design and properties adjusted to study the different phenomena arising in ultra-intense laser-plasma interaction. We present the fabrication of sub-micrometric thin-layer gold or aluminum membranes in a silicon wafer frame by using nano/micro-electro-mechanical-system (N/MEMS) processing which are suitable for rapid patterning and machining of many samples at the same time and allowing for high-throughput production of targets for laser-driven acceleration. Obtained targets were tested for laser-proton acceleration through the Target Normal Sheath Acceleration mechanism (TNSA) in a series of experiments carried out on a purpose-made table-top Ti:Sa running at 3 TW peak power and 10 Hz diode pump rate with a contrast over ASE of 108.
Rationale Chronic obstructive pulmonary disease (COPD) is a widespread disease, with no curative therapies available. Recent findings suggest a key role of NO and sGC-cGMP signaling for the ...pathogenesis of the disease. Previous data suggest a downregulation/inactivation of the cGMP producing soluble guanylate cyclase, and sGC stimulation prevented cigarette smoke-induced emphysema and pulmonary hypertension (PH) in mice. We thus aimed to investigate if the inhibition of the cGMP degrading phosphodiesterase (PDE)5 has similar effects. Results were compared to the effects of a PDE 4 inhibitor (cAMP elevating) and a combination of both. Methods C57BL6/J mice were chronically exposed to cigarette smoke and in parallel either treated with Tadalafil (PDE5 inhibitor), Piclamilast (PDE4 inhibitor) or both. Functional measurements (lung compliance, hemodynamics) and structural investigations (alveolar and vascular morphometry) as well as the heart ratio were determined after 6 months of tobacco smoke exposure. In addition, the number of alveolar macrophages in the respective lungs was counted. Results Preventive treatment with Tadalafil, Piclamilast or a combination of both almost completely prevented the development of emphysema, the increase in lung compliance, tidal volume, structural remodeling of the lung vasculature, right ventricular systolic pressure, and right ventricular hypertrophy induced by cigarette smoke exposure. Single, but not combination treatment prevented or reduced smoke-induced increase in alveolar macrophages. Conclusion Cigarette smoke-induced emphysema and PH could be prevented by inhibition of the phosphodiesterases 4 and 5 in mice.
Pulmonary hypertension (PH) is a chronic, complex, and progressive disease that eventuates in fatality. Research efforts over the past decades have resulted in therapeutic options that improve ...quality of life and prolong survival of patients, but they do not offer a cure. We propose a philosophical model that a disturbed balance of yin and yang results in pulmonary vascular remodeling, the hallmark of PH pathology. The model may be useful in exploring the wisdom of traditional Chinese medicine and incorporating it into mainstream PH research. In this context, the medicinal plant Rhodiola can be of profound interest owing to its variety of health-friendly attributes. Rhodiola has been shown to be beneficial in high-altitude-related symptoms and acute exacerbation of PH; moreover, improvement of PH has been demonstrated experimentally in chronically hypoxic rats. The beneficial effects of Rhodiola in PH may be attributable to its potential targeting of the signaling pathways, such as endothelin-1, nitric oxide, vascular endothelial growth factor, angiotensin-converting enzyme, nuclear factor κ-B, tumor necrosis factor α, and interleukin-6. Alterations in these mediators are implicated in PH pathogenesis, the characteristics of which include chronic pulmonary vasoconstriction, vasoproliferation, and vascular inflammation. Salidroside, one of the compounds extracted from Rhodiola, has been found to provide therapeutic benefits in experimental PH. As the data are limited and the field is in its infancy, further studies including in-depth analysis of the therapeutic effects on various animal models of PH are desirable. We believe that future PH research should place an adequate and special emphasis on exploring and promoting the potential of traditional Chinese medicine, and to this end, the medicinal plant Rhodiola offers a promising field on which to embark.
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