Systemic inflammatory and regenerative milieu (SIRM) (SIRM)

The systemic inflammatory and regenerative milieu (SIRM) is a conceptual framework describing the collective state of circulating signaling molecules, immune cells, and extracellular factors that dictate the balance between tissue repair and chronic inflammation (Franceschi et al., 2018). It is not a single molecular target but rather a physiological environment influenced by age, disease, and metabolic status. In a healthy state, the milieu supports tissue regeneration through growth factors and controlled inflammatory signaling; however, in pathological conditions or aging, it shifts toward a pro-inflammatory profile—often referred to as inflammaging—which inhibits stem cell function and promotes systemic degeneration (Conboy et al., 2005). Therapeutic strategies often aim to modulate specific components of this milieu, such as neutralizing pro-inflammatory cytokines like IL-6 or TNF-alpha, to restore a more regenerative environment (Pradhan et al., 2001). Consequently, while the milieu itself is a broad physiological state, it serves as a critical context for understanding the efficacy of systemic therapies in chronic and age-related diseases.

Other names

Systemic environmentCirculating inflammatory milieuRegenerative environmentSystemic milieuCirculating milieu

Modulation of systemic signaling factors and circulating cytokines to shift the physiological state from pro-inflammatory to regenerative.