Laboratory of Amphibian Diversity Investigation, College of Ecology, Lishui University, Lishui, 323000, China.
College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou , Zhejiang, 311121, China.
BMC Vet Res. 2024 Aug 2;20(1):343. doi: 10.1186/s12917-024-04202-9.
Cathelicidins are vital antimicrobial peptides expressed in diverse vertebrates, crucial for immunity. Despite being a new field, amphibian cathelicidin research holds promise.
We isolated the cDNA sequence of the cathelicidin (Ll-CATH) gene from the liver transcriptome of the Chong'an Moustache Toad (Leptobrachium liui). We confirmed the authenticity of the cDNA sequence by rapid amplification of cDNA ends and reverse transcription PCR, and obtained the Ll-CATH amino acid sequence using the Open Reading Frame Finder, an online bioinformatics tool. Its translated protein contained a cathelin domain, signal peptide, and mature peptide, confirmed by amino acid sequence. The comparative analysis showed that the mature peptides were variable between the amphibian species, while the cathelin domain was conserved. The concentration of Ll-CATH protein and the expression of its gene varied in the tissues, with the spleen showing the highest levels. The expression levels of Ll-CATH in different tissues of toads was significantly increased post infection with Aeromonas hydrophila. Chemically synthesized Ll-CATH effectively combated Proteus mirabilis, Staphylococcus epidermidis, Vibrio harveyi, V. parahaemolyticus, and V. vulnificus; disrupted the membrane of V. harveyi, hydrolyzed its DNA. Ll-CATH induced chemotaxis and modulated the expression of pro-inflammatory cytokine genes in RAW264.7 macrophages.
This study unveiled the antibacterial and immunomodulatory potential of amphibian cathelicidin, implying its efficacy against infections. Ll-CATH characterization expands our knowledge, emphasizing its in a bacterial infection therapy.
抗菌肽 cathelicidins 是在各种脊椎动物中表达的重要抗菌肽，对免疫至关重要。尽管是一个新领域，但两栖动物抗菌肽的研究具有很大的潜力。
我们从 Chong'an Moustache Toad（Leptobrachium liui）的肝转录组中分离出 cathelicidin（Ll-CATH）基因的 cDNA 序列。我们通过快速扩增 cDNA 末端和反转录 PCR 确认了 cDNA 序列的真实性，并使用在线生物信息学工具 Open Reading Frame Finder 获得了 Ll-CATH 氨基酸序列。其翻译的蛋白质包含一个 cathelin 结构域、信号肽和成熟肽，这通过氨基酸序列得到了证实。比较分析表明，两栖动物物种之间的成熟肽是可变的，而 cathelin 结构域是保守的。Ll-CATH 蛋白的浓度和基因的表达在组织中存在差异，脾脏的表达水平最高。在感染嗜水气单胞菌后，Ll-CATH 在蟾蜍不同组织中的表达水平显著增加。化学合成的 Ll-CATH 有效地对抗了奇异变形杆菌、表皮葡萄球菌、哈维氏弧菌、副溶血性弧菌和创伤弧菌；破坏了哈维氏弧菌的膜，并水解了其 DNA。Ll-CATH 诱导 RAW264.7 巨噬细胞的趋化作用，并调节促炎细胞因子基因的表达。
本研究揭示了两栖动物抗菌肽的抗菌和免疫调节潜力，表明其对感染的疗效。Ll-CATH 的特征描述扩展了我们的知识，强调了其在细菌感染治疗中的应用。
