3.2 Immune macrophages
As an important cell of the innate immune system, macrophages can show
different phenotypes and functions when stimulated by external factors,
and they are widely distributed in various tissues and organs of the
body. Among them, M1 macrophages (classically activated macrophages) are
activated and secreted proinflammatory cytokines, which play a central
role in the host’s defense against infection, while M2 macrophages
(alternatively activated macrophages) are involved in the body’s
anti-inflammatory response and tissue remodeling response by secreting
inhibitory cytokines [29]. Hypoxia-inducible
factor-1 in sepsis α、 Abnormal changes in substances such as
5-adenosine monophosphate-activated protein kinase (AMPK) and succinate
dehydrogenase can regulate the metabolism of immune macrophages, and
then directly affect the prognosis of sepsis [30].
A recent study by Kong [31] et al. Showed that the
aerobic glycolysis of macrophages could be regulated by targeting GAPDH
(a rate-limiting enzyme that regulates the rate of aerobic glycolysis),
thereby inhibiting the activation of inflammatory macrophages to play an
anti-inflammatory role, and significantly reducing the mortality of
septic rats. In addition, inhibiting the abnormal activation of
macrophages can regulate the polarization phenotype of macrophages,
promote tissue repair and angiogenesis, inhibit pro-inflammatory immune
response, and reduce tissue and organ damage. There is evidence that[32], macrophages regulate tissue damage and
affect the inflammatory response in the microenvironment, which is
related to the release of lipid bilayer-blocking structure (EV). In
addition, damaged tissue cells can release ev to activate local
macrophages to promote tissue repair.