Wound healing is a carefully coordinated process. In the early stage, inflammation is necessary. It helps the body clear damaged tissue, dead cells, and invading microorganisms from the wound. After this initial response, inflammation should gradually subside, and the wound should progress toward repair and tissue remodeling. Complications arise when this transition fails to occur. If inflammation persists too long, immune cells remain active and can cause further tissue damage. As a result, the wound’s transition to the repair stage may be delayed. This prolonged inflammatory state is characteristic of many chronic wounds, including diabetic wounds, where persistent macrophage activation can interfere with the transition from inflammation to tissue repair.
Are We Dealing with Wounds the Right Way?
For many years, researchers have tried to control chronic inflammation by targeting inflammatory molecules such as TNF-α, IL-1β, and IL-6. These molecules are important in chronic wound inflammation, but targeting them individually has not been enough to restore normal healing. The reason is that chronic wounds are complex. More than one process is usually affected at the same time. Inflammation, immune responses, and tissue repair can all become disturbed. Macrophages are an important part of this process. They respond to signals from damaged tissue, microbes, oxidative stress, and other factors in the wound environment. These signals can activate pathways such as Toll-like receptors, NF-κB, and MAPKs. When these pathways remain active for too long, macrophages may continue to produce inflammatory responses rather than shift toward functions that support tissue repair. This raises an important question: instead of blocking inflammatory molecules after they are produced; can we control the signaling pathways that drive macrophages to produce them in the first place?
A New Way to Think About Wound Healing
The aim is not to stop inflammation altogether. Some inflammation is needed at the beginning of wound healing to clear damaged tissue and harmful microorganisms and to prepare the wound for repair. The problem arises when this response continues for too long. Macrophages are important in this process because the signals they receive can determine whether they continue to promote inflammation or begin supporting tissue repair. Treatment could also be delivered directly to the affected area. Hydrogels, nanoparticles, biomaterials, and controlled-release systems could be used to deliver compounds that modulate macrophage signaling at the wound site while reducing their effects elsewhere in the body.
Adaptor Proteins: The Signals Behind Inflammation
Adaptor proteins are key components of cell signaling. They link activated receptors to other proteins inside the cell and help relay signals from one part of the cell to another. One example is Toll/interleukin-1 receptor domain-containing adaptor protein, or TIRAP. TIRAP helps transmit signals from Toll-like receptors and can influence pathways including NF-κB, AP-1, STAT1, and IRF3. TIRAP has been studied extensively in immune responses, but we still know relatively little about its role in macrophages during wound healing. This potential role of TIRAP-mediated signaling in macrophage responses provides a rationale for exploring whether modulation of this pathway could influence wound repair. Our recent work with the novel sulfonamide-based compound DRZ-V provides one example of this approach. In our study, DRZ-V was associated with modulation of inflammatory responses in macrophages and enhanced wound repair, with the findings implicating TIRAP-mediated signaling in this response. This work suggests that altering macrophage signaling may help reduce prolonged inflammation and allow the wound to progress toward repair.
Moving from Inflammation to Healing
The therapeutic challenge is not to eliminate inflammation, but to restore its appropriate timing and resolution. Macrophages are central to this transition, and understanding the signaling mechanisms that regulate their inflammatory and reparative functions may provide new opportunities to influence chronic wound healing. Our findings with DRZ-V provide an example of this approach, with modulation of TIRAP-mediated signaling associated with changes in macrophage inflammatory responses and wound repair.
