National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Acta Biomater. 2024 Oct 15;188:358-373. doi: 10.1016/j.actbio.2024.09.026. Epub 2024 Sep 19.
Matrix metalloproteinases (MMPs) are involved in the breakdown of lung extracellular matrix and the consequent release of Mycobacterium tuberculosis into the airways. Recent studies indicate that kallikrein-related peptidase 12 (KLK12) regulate MMP-1 and MMP-9, suggesting that targeting the KLK12 gene could be a promising tuberculosis (TB) treatment. To maximise therapeutic potential, this strategy of silencing KLK12 needs to be delivered to the pathogenic cell population while preserving the immunoprotective and tissue homeostatic functions of other lung macrophages. Our research found that KLK12 is highly expressed in M2 macrophages, leading us to design mannose-based bovine serum albumin nanoparticles (MBNPs) for delivering siRNA to silence KLK12 in these cells. The results of in vitro experiments showed that MBNPs could accurately enter M2 macrophages and sustainably release KLK12-siRNA with the help of mannose and mannose receptor targeting. The results of the in vivo experiments showed that MBNPs could reach the lungs within 1 h after intraperitoneal injection and peaked at 6 h. MBNPs increased collagen fibre content in the lungs by decreasing the levels of KLK12/MMPs thereby limiting the progression of TB. Importantly, MBNPs provided greater alleviation of pulmonary TB symptoms and reduced bacterial load in both TB and drug-resistant TB models. These findings provide an alternative and effective option for the treatment of TB, especially when drug resistance occurs. STATEMENT OF SIGNIFICANCE: RNA interference using small interfering RNA (siRNA) can target various genes and has potential for treating diseases such as tuberculosis (TB). However, siRNAs are unstable in the blood and within cells. This study presents bovine serum albumin nanoparticles encapsulating KLK12-siRNA (BNPs) synthesized via desolvation. A mannose layer was added (MBNPs) to target mannose receptors on M2 macrophages, facilitating endocytosis. The low pH-responsive MBNPs enhance lysosomal escape for siRNA delivery, downregulating the KLK12 pathway. Tests confirmed that MBNPs effectively inhibited Mycobacterium bovis proliferation, reduced granulomas, and decreased inflammation in a mouse model. This research aims to reduce antibiotic use, shorten treatment duration, and provide a novel TB treatment option.
基质金属蛋白酶（MMPs）参与肺细胞外基质的分解，导致结核分枝杆菌进入气道。最近的研究表明，激肽释放酶相关肽酶 12（KLK12）调节 MMP-1 和 MMP-9，这表明靶向 KLK12 基因可能是一种有前途的结核病（TB）治疗方法。为了最大限度地发挥治疗潜力，这种沉默 KLK12 的策略需要递送到致病细胞群体，同时保留其他肺巨噬细胞的免疫保护和组织稳态功能。我们的研究发现 KLK12 在 M2 巨噬细胞中高度表达，这促使我们设计基于甘露糖的牛血清白蛋白纳米颗粒（MBNPs），以便将 siRNA 递送到这些细胞中沉默 KLK12。体外实验结果表明，MBNPs 可以在甘露糖和甘露糖受体靶向的帮助下准确进入 M2 巨噬细胞并持续释放 KLK12-siRNA。体内实验结果表明，MBNPs 经腹腔注射后 1 小时内即可到达肺部，并在 6 小时时达到峰值。MBNPs 通过降低 KLK12/MMPs 的水平增加肺部胶原纤维含量，从而限制 TB 的进展。重要的是，MBNPs 在 TB 和耐药性 TB 模型中均提供了更大程度的缓解肺部 TB 症状和减少细菌负荷。这些发现为治疗 TB 提供了一种替代且有效的选择，特别是在发生耐药性时。意义声明：使用小干扰 RNA（siRNA）的 RNA 干扰可以靶向各种基因，具有治疗结核病（TB）等疾病的潜力。然而，siRNA 在血液中和细胞内不稳定。本研究提出了通过去溶剂化合成的包封 KLK12-siRNA 的牛血清白蛋白纳米颗粒（BNPs）。添加了一层甘露糖（MBNPs）以靶向 M2 巨噬细胞上的甘露糖受体，促进内吞作用。低 pH 响应性 MBNPs 增强了 siRNA 递送的溶酶体逃逸，下调了 KLK12 途径。测试证实，MBNPs 有效抑制了牛分枝杆菌的增殖，减少了肉芽肿，并降低了小鼠模型中的炎症。这项研究旨在减少抗生素的使用，缩短治疗时间，并提供一种新的 TB 治疗选择。
