While the use of lipopolysaccharide (LPS) to induce inflammation has been well described in the horse, the object of this study was to evaluate the effect of repeated intra-articular LPS injections and determine whether this method may be of use to assess changes in gene expression related to inflammation. Six mixed breed horses were utilized for this study, with three horses aged 10-17 years (older group) and three horses aged 3 years (younger group). One milliliter of phosphate-buffered saline containing 3 μg of LPS from Escherichia coli O111:B4 was aseptically injected into either the radiocarpal or front fetlock joint a total of four times, with at least two weeks between each injection and a different joint injected each time. Serum for protein concentration quantification and whole blood for expression analysis of 20 different genes were collected before each injection, as well as at multiple times post-injection. Statistical analysis was performed using analysis of variance (one-way and two-way) (P < 0.05). All horses experienced minimal or non-weight bearing lameness at 4-6 hours post-LPS injection, which generally improved by 24 h and resolved by 48 h. Multiple genes exhibited significantly differential expression when compared to both the pre-injection and sham injection time points, including CD14, TLR4, MMP1, MMP9, IL-1β, IL1RN, IL-10, ALOX5AP, IL-8, TNFα, CCL8, IGF1, and PTGS2. Additionally, multiple genes exhibited increased expression in horses where the radiocarpal joint was injected when compared to the fetlock joint, as well as in younger horses compared to older horses. Serum concentrations of serum amyloid A (SAA) were negative prior to injection while all horses demonstrated an increase by 9 h post-injection, which often remained until at least 144 h. Attempts to measure in vivo serum cytokine levels using a multiplex assay were not successful and believed to be due to the lower limits of detection for the assays. The measurement of mRNA expression of pro- and anti-inflammatory genes provide sensitive and rapid information regarding the inflammatory response to an acute, localized stimulus, although care must be taken when selecting target joints or age groups of horses as the transcriptional response may vary based on these choices.

中文翻译：

---

响应于脂多糖诱导的滑膜炎的外周基因表达的变化，作为马炎症的模型。

虽然在马匹中已经很好地描述了使用脂多糖（LPS）诱导炎症，但本研究的目的是评估重复关节内LPS注射的效果并确定该方法是否可用于评估基因的变化与炎症有关的表达。本研究使用了六匹混种马，三匹年龄在10-17岁的马（大龄组）和三匹年龄在3岁的马（幼年组）。将一毫升含有3μg来自大肠杆菌O111：B4的LPS的磷酸盐缓冲盐水无菌注射至the骨或前额指关节四次，每次注射之间至少相隔两周，每次注射不同的关节。每次注射前以及注射后多次收集血清用于蛋白质浓度定量，并收集全血用于20种不同基因的表达分析。使用方差分析（单向和双向）进行统计分析（P <0.05）。所有马匹在注射LPS后4-6小时都经历了最小或不负重的la行，通常会改善24小时，并在48小时内消失。与注射前和假注射时间点相比，多个基因表现出显着差异表达，包括CD14，TLR4，MMP1，MMP9，IL-1β，IL1RN，IL-10，ALOX5AP，IL-8，TNFα，CCL8，IGF1和PTGS2。此外，与fetlock关节相比，在注射the腕关节的马中，多个基因表现出增加的表达，以及年纪较大的马匹。注射前血清淀粉样蛋白A（SAA）的血清浓度为阴性，而所有马匹在注射后9 h均表现出升高，通常一直持续到至少144 h。使用多重测定法测量体内血清细胞因子水平的尝试未成功，并且被认为是由于该测定法的检测限较低。对促炎和抗炎基因的mRNA表达的测量提供了有关对急性，局部刺激的炎性反应的敏感而快速的信息，尽管在选择目标关节或马匹的年龄段时必须小心，因为转录反应可能会有所不同。在这些选择上。注射前血清淀粉样蛋白A（SAA）的血清浓度为阴性，而所有马匹在注射后9 h均表现出升高，通常一直持续到至少144 h。使用多重测定法测量体内血清细胞因子水平的尝试未成功，并且被认为是由于该测定法的检测限较低。对促炎和抗炎基因的mRNA表达的测量提供了有关对急性，局部刺激的炎性反应的敏感而快速的信息，尽管在选择目标关节或马匹的年龄段时必须小心，因为转录反应可能会有所不同。在这些选择上。注射前血清淀粉样蛋白A（SAA）的血清浓度为阴性，而所有马匹在注射后9 h均表现出升高，通常一直持续到至少144 h。使用多重测定法测量体内血清细胞因子水平的尝试未成功，并且被认为是由于该测定法的检测限较低。对促炎和抗炎基因的mRNA表达的测量提供了有关对急性，局部刺激的炎性反应的敏感而快速的信息，尽管在选择目标关节或马匹的年龄段时必须小心，因为转录反应可能会有所不同。在这些选择上。使用多重测定法测量体内血清细胞因子水平的尝试未成功，并且被认为是由于该测定法的检测限较低。对促炎和抗炎基因的mRNA表达的测量提供了有关对急性，局部刺激的炎性反应的敏感而快速的信息，尽管在选择目标关节或马匹的年龄段时必须小心，因为转录反应可能会有所不同。在这些选择上。使用多重测定法测量体内血清细胞因子水平的尝试未成功，并且被认为是由于该测定法的检测限较低。对促炎和抗炎基因的mRNA表达的测量提供了有关对急性，局部刺激的炎性反应的敏感而快速的信息，尽管在选择目标关节或马匹的年龄段时必须小心，因为转录反应可能会有所不同。在这些选择上。