研究揭示干细胞如何用于治疗肺病

坤明

2014年9月11日讯 /生物谷BIOON/--在2014年9月9日，欧洲呼吸学会国际会议上公布的一项新研究揭示了干细胞是如何作用改善肺功能急性呼吸窘迫综合征（ARDS）的。 4 z" K7 B/ f% Q3 O3 P
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以往的研究表明，干细胞可以减轻肺部炎症，恢复急性呼吸窘迫综合征中的某些肺功能，但专家们不知道是如何发生这种情况的。这项新的研究发现使得我们更接近了一步了解干细胞在受伤肺内的作用机制。 0 b& s: o1 q# b, T' J

: a9 N! Q, v! P急性呼吸窘迫综合征是一种危及生命的疾病，肺部的效率严重降低。肺ARDS的特征在于过度和失调的炎症，患者需要机械通气(mechanical ventilation)，以便进行呼吸。
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虽然炎症通常是身体对付感染的方式，但炎症失调可导致严重的伤害。目前已知的是，免疫细胞中的巨噬细胞可以通过驱动或抑制炎症来协调炎症反应。研究人员调查了干细胞是否会影响巨噬细胞，推动巨噬细胞来抑制炎症。他们在动物模型中，使用人骨髓间充质干细胞进行测试。小鼠感染活的细菌，诱发急性肺炎和ARDS模型。% K0 e6 l2 U. }5 b# o* `

) g& e+ f8 U* l$ ?) {/ F" _该结果表明，干细胞治疗能导致肺损伤、炎症显著减少，细菌清除得到改进。重要的是，当干细胞给予人为去除巨噬细胞的动物后，干细胞保护作用就消失了。这表明，巨噬细胞是干细胞发挥有益效果的一个重要组成部分。 1 H+ Y2 I1 f) D' p( P( r

; p2 K3 \+ z- D0 g这些结果被另一项实验结果进一步支持，即干细胞给予来源于急性呼吸窘迫综合征患者的人类巨噬细胞后，干细胞能够再次促进人巨噬细胞细胞抗炎状态。研究人员已经确定了由干细胞分泌的几个蛋白质是负责干细胞有益效果的关键。! |: J/ Y1 M' y) o' Q* F
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贝尔法斯特女王大学的Anna Krasnodembskaya医生说：这是第一次有研究分析干细胞如何能够改变人类和小鼠模型中巨噬细胞的功能特性，结果强调了干细胞治疗的优势，因为干细胞可以积极应对局部微环境和施加多种有益的效果。我们相信，现在急需要临床试验检验干细胞是否是治疗ARDS患者的一种有效策略。
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Study sheds light on how stem cells can be used to treat lung disease
# k  T. j5 B: o  J4 h+ HA new study has revealed how stem cells work to improve lung function in acute respiratory distress syndrome (ARDS).9 Q8 S2 {' P! }  J) [/ b9 l8 \9 {
Previous studies have shown that stem cells can reduce lung inflammation and restore some function in ARDS, but experts are not sure how this occurs. The new study, which was presented at the European Respiratory Society's International Congress today (09 September 2014), brings us a step closer to understanding the mechanisms that occur within an injured lung.7 l# U& l: N! x9 T. o, V7 J( n- A- @
ARDS is a life-threatening condition in which the efficiency of the lungs is severely reduced. It is caused by damage to the capillary wall either from illness or a physical injury, such as major trauma. ARDS is characterised by excessive and dysregulated inflammation in the lung and patients require mechanical ventilation in order to breathe.$ j- e/ ~  T( [! I! ^) e
Although inflammation is usually a method by which the body heals and copes with an infection, when the inflammation is dysregulated it can lead to severe damage. Immune cells known as macrophages can coordinate the inflammatory response by driving or suppressing inflammation, depending on the stimulation.- @( ~! ~5 X% q% R
The researchers investigated whether stem cells can affect the stimulation of the macrophages and promote the state in which they will suppress the inflammation.
2 O' S& Y1 `6 j$ @7 NThey tested this in an animal model using human bone marrow-derived stem cells. Mice were infected with live bacteria to induce acute pneumonia and model the condition of ARDS. The results showed that treatment with stem cells led to significant reductions in lung injury, inflammation and improved bacterial clearance. Importantly, when stem cells were given to animals that had their macrophages artificially removed, the protective effect was gone. This suggests that the macrophages are an important part of the beneficial effects of stem cells seen in this model of ARDS.
' I' }1 J- W+ T' g& C- n' {These results were further supported by experiments where stem cells were applied to human macrophages in samples of fluid taken from lungs of patients with ARDS. Again, the stem cells were able to promote the anti-inflammatory state in the human macrophage cells. The authors have identified several proteins, secreted by the stem cells, that would be responsible for this effect.2 a, z( ^6 _; J1 j, {: [! U
Dr Anna Krasnodembskaya, lead author of the study from the Queens University Belfast, said: "This is the first study to our knowledge that has looked at how stem cells can change the functional properties of the macrophages in both humans and a mouse model. The findings highlight the advantages of stem cell treatment, as they can actively respond to the local micro-environment and exert multiple beneficial effects. We believe that clinical trials are now needed to test whether this can be an effective treatment for people suffering from ARDS."
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( m1 D# Z' |/ TMore information: Abstract: "Human mesenchymal stem cells (MSC) modulate alveolar macrophage polarization in vivo and in vitro." Tuesday,09 September from 10:45 to 12:45
* s, M' H6 R4 S0 {) y0 LProvided by European Lung Foundation  . U' ?& }5 X) G8 K4 K* }. ]! z7 d' H
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http://medicalxpress.com/news/20 ... s-lung-disease.html4 T2 Y/ z! r( x9 t7 I2 b( e