Wei Qiu, Zhang Zhenqiang, Luo Jing, Kong Jinliang, Ding Yudi, Chen Yiqiang, Wang Ke
Pulmonary and Critical Care Medicine Ward, The First Affiliated Hospital of Guangxi Medical University Nanning 530021, Guangxi, P. R. China.
Am J Transl Res. 2019 Jun 15;11(6):3261-3279. eCollection 2019.
Diabetes-related infections have become challenging and important public health problems in China and around the world. plays an important role in diabetic foot infections. As a gram-negative opportunistic pathogen, causes recurrent and refractory infections that are characterized by biofilm formation. Previous studies have demonstrated that biofilm-challenged wounds typically take longer to heal than non-biofilm-challenged normal wounds in diabetic mouse models. In the present study, we sought to explore the mechanism via which insulin treatment affects cyclic di-GMP signaling in -infected chronic wounds in db/db diabetic mice. We found that the wounds of diabetic mice healed more slowly than those of nondiabetic mice. Moreover, wound healing in diabetic mice treated with insulin exhibited a considerable delay. Peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH) was used to detect biofilms on -infected wound tissues. Increased intracellular c-di-GMP levels promoted biofilm formation in wound tissues from nondiabetic mice. Greater biofilm formation was observed in the wounds of insulin-treated diabetic mice than in the wounds of untreated diabetic mice or nondiabetic mice, in both the PAO1/p-- and PAO1-infected groups. Quantitative RT-PCR indicated that upon infection with PAO1/P- (the low c-di-GMP expression strain), the expression of IL-4 RNA was significantly higher in diabetic mice treated with insulin than in untreated diabetic mice or nondiabetic mice at each observation time point. Peak expression of IFN-γ occurred earlier in diabetic mice treated with insulin than in untreated diabetic mice with each of the experimental strains. Finally, harboring the plasmid pCdrA: was used as a reporter strain to monitor c-di-GMP levels. We found that insulin could promote biofilm formation by increasing intracellular c-di-GMP levels in vitro. Taken together, these data demonstrate that insulin treatment increases intracellular c-di-GMP levels, promotes biofilm formation and prolongs the inflammation period during the healing of infected wounds, resulting in delayed wound healing.
糖尿病相关感染已成为中国乃至全球具有挑战性的重要公共卫生问题。（此处原文有缺失信息）在糖尿病足感染中起重要作用。作为一种革兰氏阴性机会性病原体，（此处原文有缺失信息）会引发以生物膜形成为特征的复发性和难治性感染。先前的研究表明，在糖尿病小鼠模型中，受生物膜挑战的伤口通常比未受生物膜挑战的正常伤口愈合时间更长。在本研究中，我们试图探索胰岛素治疗影响db/db糖尿病小鼠（此处原文有缺失信息）感染的慢性伤口中环状二鸟苷单磷酸（c-di-GMP）信号传导的机制。我们发现糖尿病小鼠的伤口比非糖尿病小鼠愈合得更慢。此外，接受胰岛素治疗的糖尿病小鼠伤口愈合出现了相当大的延迟。肽核酸荧光原位杂交（PNA-FISH）用于检测（此处原文有缺失信息）感染的伤口组织上的生物膜。细胞内c-di-GMP水平升高促进了非糖尿病小鼠伤口组织中的生物膜形成。在PAO1/p--和PAO1感染组中，胰岛素治疗的糖尿病小鼠伤口中的生物膜形成均比未治疗的糖尿病小鼠或非糖尿病小鼠伤口中更明显。定量逆转录聚合酶链反应（qRT-PCR）表明，在用PAO-1/P-（低c-di-GMP表达菌株）感染后，在每个观察时间点，接受胰岛素治疗的糖尿病小鼠中白细胞介素-4（IL-4）RNA的表达均显著高于未治疗的糖尿病小鼠或非糖尿病小鼠。在用每种实验菌株处理时，接受胰岛素治疗的糖尿病小鼠中γ干扰素（IFN-γ）的峰值表达比未治疗糖尿病小鼠出现得更早。最后，携带质粒pCdrA的（此处原文有缺失信息）用作报告菌株来监测c-di-GMP水平。我们发现胰岛素在体外可通过增加细胞内c-di-GMP水平促进生物膜形成。综上所述，这些数据表明胰岛素治疗会增加细胞内c-di-GMP水平，促进生物膜形成并延长感染伤口愈合期间的炎症期，从而导致伤口愈合延迟。
