Bitto Alessandra, Altavilla Domenica, Pizzino Gabriele, Irrera Natasha, Pallio Giovanni, Colonna Michele R, Squadrito Francesco
Department of Clinical and Experimental Medicine, Section of Pharmacology, Medical School, University of Messina, Messina, Italy.
Br J Pharmacol. 2014 May;171(9):2300-7. doi: 10.1111/bph.12557.
Type 2 diabetes impairs the healing process because of an exaggerated and persistent inflammatory response, and an altered expression pattern of angiogenic molecules. We investigated the effects of inflammasome blockade in diabetes-related wound-healings defects, in genetically diabetic mice.
An incisional skin wound model was produced on the back of female diabetic C57BL/KsJ-m +/+ Lept(db) mice (db⁺ /db⁺) and their normal littermates (db⁺ /m⁺). Animals were treated daily with two inflammasome blocking agents, BAY 11-7082 (20 mg·kg⁻¹ i.p.), or Brilliant Blue G (BBG, 45.5 mg·kg⁻¹ i.p.), or vehicle. Mice were killed on 3, 6 and 12 days after skin injury to measure expression of the NOD-like receptor NLRP3, caspase-1, VEGF, the inflammasome adapter protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and the chemokine CXCL12. Wound levels of IL-1β and IL-18 were also measured, along with histological assessments of wound tissue and the time to complete wound closure.
During healing, the diabetic mice exhibited increased activation of NLRP3, caspase-1, ASC, IL-1β and IL-18. They also showed a reduced expression of VEGF and CXCL12.Treatment with BAY 11-7082 or BBG, to block activation of the inflammasome, decreased the levels of pro-inflammatory molecules. Histological evaluation indicated that inflammasome blockade improved the impaired healing pattern, at day 12 in diabetic mice, along with a decreased time to complete skin healing.
These data strongly suggest that activation of the NLRP3 inflammasome is one of the key contributors to the delayed healing of wounds in diabetic mice.
2型糖尿病会因过度且持续的炎症反应以及血管生成分子表达模式的改变而损害愈合过程。我们在遗传性糖尿病小鼠中研究了炎性小体阻断对糖尿病相关伤口愈合缺陷的影响。
在雌性糖尿病C57BL/KsJ-m +/+ Lept(db)小鼠（db⁺ /db⁺）及其正常同窝小鼠（db⁺ /m⁺）的背部制作切开皮肤伤口模型。动物每天用两种炎性小体阻断剂进行处理，即BAY 11-7082（20 mg·kg⁻¹腹腔注射）或亮蓝G（BBG，45.5 mg·kg⁻¹腹腔注射），或赋形剂。在皮肤损伤后3天、6天和12天处死小鼠，以测量NOD样受体NLRP3、半胱天冬酶-1、血管内皮生长因子（VEGF）、炎性小体衔接蛋白含半胱天冬酶募集结构域的凋亡相关斑点样蛋白（ASC）和趋化因子CXCL12的表达。还测量了伤口处白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）的水平，以及伤口组织的组织学评估和伤口完全闭合的时间。
在愈合过程中，糖尿病小鼠的NLRP3、半胱天冬酶-1、ASC、IL-1β和IL-18的激活增加。它们还表现出VEGF和CXCL12的表达降低。用BAY 11-7082或BBG处理以阻断炎性小体的激活，可降低促炎分子的水平。组织学评估表明，炎性小体阻断改善了糖尿病小鼠在第12天时受损的愈合模式，同时缩短了皮肤愈合的时间。
这些数据有力地表明，NLRP3炎性小体的激活是糖尿病小鼠伤口愈合延迟的关键因素之一。
