Project description:Inflammation and autoimmunity are known as central processes in many skin diseases, including psoriasis. It is therefore important to develop pre-clinical models that describe disease-related aspects to enable testing of pharmaceutical drug candidates and formulations to essentially develop safe and effective treatments. A widely accepted pre-clinical model of psoriasis is the imiquimod (IMQ)-induced skin inflammation mouse model. It is primarily used to assess safety and efficacy of drug candidates for treatment of psoriasis but can also be used to evaluate the performance of drug delivery systems. In this model, topically applied IMQ provokes local skin inflammation, which is characterized by elevated levels of cytokines and chemokines, cellular infiltration, and increased epidermal thickness. In this study, we investigated the abundance of a subset of matrix metalloproteinases (MMPs) in skin from mice with IMQ-induced skin inflammation and skin from naïve mice using targeted proteomics. Our findings revealed a significant increase in the abundance of MMP-2, MMP-7, MMP-8, and MMP-13 after treatment with IMQ compared to the control skin, while MMP-3, MMP-9, and MMP-10 were exclusively detected in the IMQ-treated skin. The increased abundance and broader representation of MMPs in the IMQ-treated skin provide valuable insight into the pathophysiology of skin inflammation in the IMQ model. Specifically, the changes in the MMP profiles observed in the IMQ-treated skin resemble the MMP patterns found in skin lesions of individuals with psoriasis. Ultimately, the differences in MMP abundance under IMQ-induced inflammation as compared to non-inflamed control skin can be exploited as a model to investigate drug efficacy or performance of drug delivery systems.
Project description:This program aims at identifying a skin gene signature associated with inflammation pain in rat CGN model The profiling data was analyzed by identifying genes that were up- and down-regulated at selected p value and fold change in the skin of rats treated with CGN (to induce pain) compared to the corresponding non-treated controls.
Project description:Inflammation plays a role in neuropathic pain conditions as well as in pain induced solely by an inflammatory stimulus. Robust mechanical hyperalgesia and allodynia can be induced by locally inflaming the L5 dorsal root ganglion (DRG) in rat. This model allows investigation of the contribution of inflammation per se to chronic pain conditions. Most previous microarray studies of DRG gene expression have investigated neuropathic pain models involving axon transection. To examine the role of inflammation, we used microarray methods to examine gene expression 3 days after local inflammation of the L5 DRG in rat. We observed significant regulation in a large number of genes (23% of observed transcripts), and examined 221 (3%) with a fold-change of 1.5-fold or more in more detail. Immune-related genes were the largest category in this group and included members of the complement system as well as several pro-inflammatory cytokines. However, these upregulated cytokines had no prior links to peripheral pain in the literature other than through microarray studies, though most had previously described roles in CNS (especially neuroinflammatory conditions) as well as in immune responses. The L5 dorsal root ganglion (DRG) was locally inflamed with zymosan/Incomplete Freund's Adjuvant. DRG were isolated 3 days later. Each sample was RNA extracted from a single DRG. 6 samples from rats with local DRG inflammation were compared with 6 samples from sham-operated rats.