SMALL MOLECULE INHIBITORS OF CARIOGENIC BIOFILMS

描述(申请人提供)：龋齿(龋齿)是困扰美国公众的最常见的传染病。生物膜的形成在致龋菌变形链球菌引起的龋病发病机制中起着关键作用。变形链球菌已经适应了生物膜的生活方式。生物被膜中的细菌对传统抗生素具有极强的抗药性(100-1000倍以上)，因此开发能够抑制变形链球菌生物被膜形成的新型抗生物被膜试剂对于治疗和预防龋病是必要的和关键的。具有抗生物被膜特性的最有效和最通用的一类分子是那些来自Melander小组从天然海洋产品中发现的2-氨基咪唑(2-AI)支架的分子。2-AI衍生物能够抑制和分散由革兰氏阴性和革兰氏阳性细菌形成的各种生物膜。鉴于这种2-AI衍生物的成功，我们已经对设计、筛选和表征其衍生物感兴趣，这些衍生物将抑制和分散变形链球菌的生物被膜，但警告说，小分子化合物不会影响共生链球菌生物被膜的形成。我们将使用血链球菌和戈登链球菌作为共生链球菌的模型，因为这两种链球菌都是牙齿表面的主要定殖者，在健康口腔中数量占主导地位。我们的初步研究表明，2-AI的修饰可以提高2-AI衍生物的选择性，我们已经得到了一个对变形链球菌具有中等选择性的2-AI类似物。我们目前提议的目标是开发新的基于小分子的疗法。我们假设2-AI衍生物可以作为支架来设计先进的类似物：对变形链球菌具有更高的选择性和更强的抑制作用。为实现这一目标提出了三个具体目标：具体目标1：合成和筛选不同的2-AI衍生物文库，以鉴定具有选择性抗龋性生物被膜活性的化合物。具体目标2：在龋齿动物模型中测定铅小分子的疗效。具体目标3：识别和表征有效小分子的分子靶标，并确定抗龋性生物膜活性的潜在机制。为了实现这一研究目标，一个由化学家、动物模型专家、微生物学家和牙医科学家组成的多学科研究团队已经成立。与抗生物膜合成化学的先驱Christian Melander博士开发2-AI衍生物的密切合作，龋齿研究的领导者Sue Michalek博士，以及牙科科学家Noel Childers博士将促进新的抗龋性生物膜化合物的开发。这项研究将对公众的口腔健康产生直接影响，因为这些活性化合物可以很容易地发展成一种有效的治疗方法，可以被公众常规使用。

DESCRIPTION (provided by applicant): Dental caries (tooth decay) is the most prevalent infectious disease afflicting American Public. Biofilm formation is crucial for the pathogenesis of dental caries caused by cariogenic bacterium Streptococcus mutans. S. mutans has adapted to the biofilm lifestyle. Bacteria within a biofilm are extremely (100-1000 fold more) resistant to traditional antibiotics; therefore development of new classes of anti-biofilm reagents with the ability to inhibit biofilm formation by S. mutans is necessary and critical for the treatment and prevention of dental caries. The most potent and versatile class of molecules with anti-biofilm properties are those derived from the 2-aminoimidazole (2-AI) scaffold discovered by the Melander group from natural marine products. The 2-AI derivative is capable of inhibiting and dispersing diverse biofilms formed by Gram-negative and Gram-positive bacteria. Given the success of this 2-AI derivative, we have become interested in designing, screening and characterizing its derivatives that will both inhibit and disperse S. mutans biofilms with the caveat that the small molecule compounds will not affect biofilm formation by commensal streptococci. We will use Streptococcus sanguinis and Streptococcus gordonii as model commensal streptococci as both are primary colonizers of the tooth surface and numerically dominated in the healthy oral cavity. Our preliminary studies have shown that modification of 2-AI can enhance selectivity of the 2-AI derivatives, and we have derived a 2-AI analogue that exhibits moderate selectivity towards inhibiting S. mutans. The goal of our current proposal is to develop new small molecule-based therapeutics. We hypothesize that 2-AI derivative can be used as a scaffold to design advanced analogues that: are more selective and potent towards inhibiting S. mutans. Three specific aims are proposed to achieve the goal: Specific Aim 1: Synthesize and screen diverse libraries of 2-AI derivatives to identify compounds with selective anticariogenic biofilm activity. Specific Aim 2: Determine efficacy of the lead small molecules in an animal model of dental caries. Specific Aim 3: Identify and characterize molecular targets of the potent small molecules and determine the underlying mechanism of the anticariogenic biofilm activity. A multidisciplinary research team among chemists, animal model experts, microbiologists and dentist scientists has been established to achieve the research goal. The close collaboration with Dr. Christian Melander, a pioneer in anti-biofilm synthetic chemistry to develop 2-AI derivatives, Dr. Sue Michalek, a leader in the caries research, and Dr. Noel Childers, a dentist scientist will facilitate the development of new anticariogenic biofilm compounds. This study will have a direct impact on the oral health of the public since the active compounds can be readily developed into an effective therapy that can be used routinely by the public.