Yim Sunghan, Dhawan Puneet, Ragunath Chandran, Christakos Sylvia, Diamond Gill
Department of Oral Biology, UMDNJ-New Jersey Dental School, 185 South Orange Ave., Newark, NJ 07103, USA.
J Cyst Fibros. 2007 Nov 30;6(6):403-10. doi: 10.1016/j.jcf.2007.03.003. Epub 2007 Apr 27.
Antimicrobial peptides (AMPs) such as cathelicidins contribute to initial defense of the airway against inhaled pathogens. Recent studies have shown that the hormonally active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) up-regulates AMP gene expression in several established cell lines. Furthermore, serum levels of vitamin D are often deficient in cystic fibrosis (CF) patients.
We investigated the effect of 1,25(OH)(2)D(3) on AMP mRNA levels in primary cultures of normal human bronchial epithelial (NHBE) cells by real-time PCR, and protein levels by Western blot. Antimicrobial activity of airway surface fluid from these cells was measured by in vitro assay against laboratory strains of bacteria.
Treatment of NHBE cells with 1,25(OH)(2)D(3) (10(-8)M), resulted in a 10-fold up-regulation of cathelicidin mRNA levels after 12 h, which was augmented 2-fold with co-incubation of 1 mM Calcium. Moreover, 1,25(OH)(2)D(3) induced antimicrobial activity against the airway pathogens Bordetella bronchiseptica and Pseudomonas aeruginosa. 1,25(OH)(2)D(3) induced cathelicidin mRNA expression equally in both normal and CF bronchial epithelial cells.
Elucidation of the effect of 1,25(OH)(2)D(3) on cathelicidin expression in NHBE cells and CF bronchial epithelial cells will aid in the development of novel therapeutic agents for treatment of airway infections in CF.
抗菌肽（如cathelicidins）有助于气道对吸入病原体的初始防御。最近的研究表明，维生素D(3)的激素活性形式1,25-二羟基维生素D(3)（1,25(OH)(2)D(3)）可上调几种成熟细胞系中的抗菌肽基因表达。此外，囊性纤维化（CF）患者的血清维生素D水平常常不足。
我们通过实时PCR研究了1,25(OH)(2)D(3)对正常人支气管上皮（NHBE）细胞原代培养物中抗菌肽mRNA水平的影响，并通过蛋白质印迹法研究了其对蛋白质水平的影响。通过针对实验室细菌菌株的体外测定来测量这些细胞气道表面液体的抗菌活性。
用1,25(OH)(2)D(3)（10^(-8)M）处理NHBE细胞，12小时后cathelicidin mRNA水平上调了10倍，在与1 mM钙共同孵育时增加了2倍。此外，1,25(OH)(2)D(3)诱导了对气道病原体支气管败血博德特氏菌和铜绿假单胞菌的抗菌活性。1,25(OH)(2)D(3)在正常和CF支气管上皮细胞中均同等程度地诱导cathelicidin mRNA表达。
阐明1,25(OH)(2)D(3)对NHBE细胞和CF支气管上皮细胞中cathelicidin表达的影响将有助于开发用于治疗CF气道感染的新型治疗药物。
