干细胞外泌体培养的巨噬细胞和外泌体促进韧带愈合的作用差异

2021/3/19 11:21:19 本站原创 佚名 【字体:

编译     廖联明

 

每年韧带损伤使成千上万的运动员和普通市民无法参加活动。恢复是一个漫长而痛苦的过程,有时由于疤痕的形成而无法完全恢复功能,这是韧带损伤容易进一步受损的一个因素。在《干细胞杂志》中发表的一项新的外泌体研究可能会在未来产生一个受欢迎的解决方案。

这项研究展示了胞外体(体内细胞膜的囊泡,在细胞之间传递蛋白质和遗传信息)和外泌体培养的巨噬细胞(EEM)能促进韧带愈合,减少疤痕。巨噬细胞是典型的杀死微生物和清除死细胞的白细胞,但也能刺激其他免疫系统细胞的活动。

去年,完成这项研究的团队,威斯康星大学麦迪逊分校(UW Madison)的研究人员发布了另一项研究(同样发表在《干细胞》杂志上),该研究展示了用EEMs治疗跟腱是如何减少炎症和提高肌腱强度的。将CD14+巨噬细胞和间充质干细胞(MSC)来源的外泌体一起培养就可产生EEMs

“我们之前的研究是在一个小鼠模型上进行的,”雷范德比博士说,他是威斯康辛大学麦迪逊分校的整形外科和康复教授。虽然结果优于MSCs治疗,但外泌体对韧带的生物功能和机械功能的促进作用不如EEMs明显。这使我们进一步研究以达到目前的研究目标。”

首先,研究人员想在一种不同的啮齿类动物模型中重现EEMs的愈合效果——大鼠内侧副韧带(MCL),这是一种沿着膝盖边缘延伸的韧带。”我们假设EEM治疗可以减少炎症,加速韧带愈合,这与我们之前的肌腱结果相似,”Vanderby博士说。

其次,他们想研究外泌体治疗对大鼠MCL损伤的影响,假设MSC来源的外泌体也可以促进韧带愈合和减少瘢痕形成。结果支持了研究小组的推测,即EEMs确实改善了大鼠MCL功能,并降低了M1/M2巨噬细胞比率。(M1巨噬细胞保护机体抵抗细菌和病毒,而M2巨噬细胞专注于伤口愈合和组织修复。)

外泌体也引起了生物反应,最显著的是,胶原蛋白增加了而疤痕却减少了。”在肌腱愈合模型中,外泌体减少瘢痕形成和上调胶原表达的能力已被证明,但据我们所知,这是第一个在韧带中发现这一点的研究。

Jan Nolta博士说:“这项研究是MSC衍生外显体领域的一项令人兴奋的进展,《干细胞》主编:“这个优秀的研究小组证明,体外培养的巨噬细胞可以在肌腱和韧带的愈合中发挥如此重要的作用,这对于改善人类运动损伤的愈合轨迹具有令人兴奋的潜力。”

Hematti博士指出:“EEM和外泌体在治疗方面都有很吸引人的特点。”作为一种细胞疗法,EEMs不会增殖或分化成不需要的细胞类型,这是许多干细胞疗法关注的问题。此外,利用现成的外显体可以从患者自身的单核细胞生成EEM,与自体MSCs相比,产生EEM的过程更快、更容易。另一方面,外泌子体疗法可以是一种稳定的无细胞产品,可以提供生物活性成分。”

 

-----原文

Exosome educated macrophages and exosomes differentially improve ligament healing

 

Each year ligament injuries sideline thousands of athletes and regular citizens. Recovery is long and painful, and sometimes a return to full function is never realized due to scar formation - a factor that makes ligament injuries prone to further damage. A new exosomes study released in STEM CELLS may lead to a welcomed solution in the future.

This study demonstrates how exosomes, sacs of cell membrane in the body that shuttle proteins and genetic information between cells, and exosome-educated macrophages (EEMs), a type of white blood cell that typically kills microorganisms and removes dead cells, but also could stimulate the action of other immune system cells, can promote ligament healing and reduce scarring.

Last year the team behind this study, researchers at the University of Wisconsin-Madison (UW-Madison), released another study (also published in STEM CELLS) that showed how treating an Achilles tendon with EEMs reduces inflammation and improves tendon strength. The EEMs were generated by exposing CD14+ macrophages to mesenchymal stromal cell (MSC) derived exosomes.

"Our previous study was done on a mouse model," said Ray Vanderby, Ph.D., professor of orthopedics and rehabilitation at UW-Madison.  "While the results were superior when compared to treatment with MSCs, the functional/mechanical benefit of the exosomes was not as obvious as with the EEMs. This led us to our current study goals."

First, the researchers wanted to reproduce the healing effects of EEMs in a different rodent model - a rat medial collateral ligament (MCL), which is a ligament that runs along the edge of the knee. "We hypothesized the EEM treatment would reduce inflammation and accelerate ligament healing, similar to our previous tendon results," Dr. Vanderby said.

Secondly, they wanted to study the effects of exosome therapy on the rats' MCL injuries, hypothesizing that MSC-derived exosomes could also improve ligament healing and reduce scar formation.

When the results came in, they supported the team's speculation that EEMs did, indeed, improve rat MCL function and reduced the M1/M2 macrophage ratio, too. (M1 macrophages protect against bacteria and viruses, while M2 macrophages focus on wound healing and tissue repair.)

The exosomes also elicited a biological response - most notably, an increase in collagen and a reduction in scarring. "The ability of exosomes to reduce scar formation and upregulate collagen type expression has been documented in tendon healing models, but to our knowledge this is the first study to report this in ligaments," Dr. Vanderby said.

"This study is an exciting advance in the field of MSC-derived exosomes," said Dr. Jan Nolta, Editor-in-Chief of STEM CELLS "the demonstration by this excellent group that exosome-educated macrophages can play such a major role in both tendon and ligament healing has exciting potential for improving the trajectory of healing of human athletic injuries."

"EEMs and exosomes each have attractive characteristics as therapeutics," Dr. Hematti noted. "As a cell therapy, EEMs will not proliferate or differentiate to undesirable cell types, which remains a concern for many stem cell therapies. Moreover, EEMs could be generated from a patient's own monocytes using off-the-shelf exosomes, resulting in a faster and more facile process compared to autologous MSCs. Alternatively, exosome therapy could be a cell free, shelf-stable therapeutic to deliver biologically active components."

 

Journal Reference:

Chamberlain CS, Kink JA, Wildenauer LA, McCaughey M, Henry K, Spiker AM, Halanski MA, Hematti P, Vanderby R. Exosome-educated macrophages and exosomes differentially improve ligament healing. Stem Cells. 2020 Nov 3. doi: 10.1002/stem.3291.

 

相关阅读: