Project description:To investigate the expression of circRNAs, miRNAs, and related co-expression and competitive endogenous RNA (ceRNA) in diabetic chronic refractory wounds
Project description:To investigate the expression of circRNAs, miRNAs, and related co-expression and competitive endogenous RNA (ceRNA) in diabetic chronic refractory wounds
Project description:Circular RNA (circRNA) microarray analysis was performed to examine the expression profiles of circRNAs in diabetic foot ulcers (DFU) and in human excisional skin wounds 7 days after injury.
Project description:Circular RNAs (circRNAs) have been found to play critical roles in the development and progression of human diseases. However, the role of circRNAs in regulating MSCs (mesenchymal stromal cells) to repair diabetic wounds remains unclear. Here, we showed that MSCs subjected to high glucose stress showed an obvious decrease in circARHGAP12, while circARHGAP12-mediated autophagy inhibited high glucose-induced apoptosis of MSCs. Mechanistically, circARHGAP12 could directly interact with miR-301b-3p, and subsequently act as a miRNA sponge to regulate the expression of the miR-301b-3p target genes ATG16L1 and ULK2 and the downstream signaling pathway. Furthermore, circARHGAP12 led to a decrease in apoptosis of MSCs in wounds and promoted wound healing. Taken together, these data indicated that circARHGAP12/ miR-301b-3p/ATG16L1 and ULK2 regulatory networks may be a potential therapeutic target for MSCs in repairing diabetic wounds.
Project description:Dysregulation of macrophage populations at the wound site is responsible for the non-healing state of chronic wounds. The molecular mechanisms underlying macrophage dysfunction and its control in diabetes are largely unexplored on an epigenetic level. Here, we report that acetyl histone-H3 (Lys27), an epigenetic mark regulating the macrophage transcriptome, is lost in the hostile tissue microenvironment in diabetes. The diabetic microenvironment, profoundly suppresses the acetylation of histone by activating HDACs-dependent deacetylation pathways. This, in consequence, suppress the STAT1 signaling in macrophages maintained in diabetic conditions. Interestingly, the HDAC inhibitor butyrate - via restoring the acetyl histone-H3 (Lys27)-dependent transcriptome - effectively rescues macrophage functions in a diabetic microenvironment. Butyrate reinstalls the STAT1 mediated transcription program and consequently macrophage activity depicting a unique fingerprint of tissue regeneration and inflammation control even in a hostile diabetic microenvironment. Most interesting, butyrate breaks the vicious cycle of inflammation in diabetic wounds. Our study offers novel pathogenic insight and the unique opportunity to reverse perturbed macrophage function thus holding promise to successfully treat diabetic and other chronic wounds and conditions of unrestrained inflammation.
Project description:Diabetic wound infections have poor healing outcomes due to the presence of numerous pathogens in addition to an impaired immune response. Group B Streptococcus (GBS) is one of the most commonly isolated bacteria from diabetic wound infections, but virulence mechanisms GBS uses during these infections have not been investigated. Here, we developed a new murine model of GBS diabetic wound infection to determine how GBS establishes infection and persists in the wound environment. Using dual RNA sequencing, we demonstrate that GBS infection of diabetic wounds triggers an inflammatory response, leading to increased transcript levels of inflammatory cytokines and chemokines as well as markers of neutrophil degranulation such as myeloperoxidase, calprotectin, and elastase. We then confirm that diabetic wounds infected with GBS have significantly higher abundance of Il-1b, KC (CXCL1), myeloperoxidase, calprotectin and elastase in wound tissues than uninfected controls . When examining how GBS adapts to this hyper-inflammatory environment we find that GBS upregulates numerous virulence factors including the surface plasminogen-binding protein pbsP, the nuclease nucA, the cyl operon which is responsible for hemolysin production and pigmentation as well as numerous effectors of type VII secretion. In addition, we recovered multiple hyper-pigmented/hemolytic GBS colonies from the murine diabetic wound environment which encode mutations in the two-component system covRS. We then go on to demonstrate that a mutant in cylE, which is repressed by CovR, is attenuated in diabetic wound infection. Finally, we examine the most highly upregulated gene pbsP in diabetic wound infection and find that PbsP is necessary for diabetic wound infection via adherence to the skin and promotion of inflammation.