Profilin 1 knockdown prevents ischemic brain damage by promoting M2 microglial polarization associated with the RhoA/ROCK pathway

Abstract

Microglial polarization to the anti-inflammatory M2 phenotype is essential in resolving neuroinflammation, making it a promising therapeutic strategy for stroke intervention. The actin cytoskeleton is known to be important for the physiological functions of microglia, including migration and phagocytosis. Profilin 1 (PFN1), an actin-binding protein, is involved in the dynamic transformation and reorganization of actin. However, the role of PFN1 in microglial polarization and ischemia/reperfusion injury is unclear. The role of PFN1 on microglial polarization was examined in vitro in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGDR) and in vivo in male mice after transient middle cerebral artery occlusion (MCAO). Knockdown of PFN1 inhibited M1 microglial polarization and promoted M2 microglia polarization 48 hr after OGDR stimulation in BV2 cells and 7 days after MCAO-induced injury in male mice. RhoA/ROCK pathway was involved in the regulation of PFN1 during microglial polarization. Knockdown of PFN1 also significantly attenuated brain infarcts and edema, improved cerebral blood flow and neurological deficits in MCAO-injured mice. Inhibition of PFN1 effectively protected the brain against ischemia/reperfusion injuries by promoting M2 microglial polarization in vitro and in vivo.

A CRISPRi/a platform in iPSC-derived microglia uncovers regulators of disease states

“…This process could disturb orchestrated actin polymerization at the membrane and thus decrease phagocytosis. In addition to direct effects on the actin cytoskeleton, PFN1 knockdown has also been reported to result in anti-inflammatory changes 57 . Indeed, we observed transcriptional changes in immune-related genes and AD risk genes upon PFN1 overexpression in iTF-Microglia (Fig.…”

“…We observed that PFN1 overexpression disrupts the actin cytoskeleton in iTF-Microglia with higher levels of F-actin. Recently, a study has shown that PFN1 is also involved in microglia activation, since knockdown of PFN1 inhibited M1 proinflammatory microglial polarization and promoted anti-inflammatory M2 microglia polarization after oxygen and glucose deprivation 61 . Introducing the ALS-associated mutations in the PFN1 gene in iPSCs will shed light on the impact of these specific mutations on the function of different relevant cell types, such as iPSC-derived neurons and microglia.…”

Tanshinone IIA Protects Against Cerebral Ischemia Reperfusion Injury by Regulating Microglial Activation and Polarization via NF-κB Pathway

“…), transforming growth factor β (TGF-β), brain-derived neurotrophic factor (BDNF) (Boche et al, 2013;Hu et al, 2015), and help restore the homeostasis of the central nervous system (Gogoleva et al, 2019). Therefore, promoting microglia conversion to M2 type is considered a therapeutic strategy for cerebral ischemic injury (Lu et al, 2020).…”

Annexin A1 protects against cerebral ischemia–reperfusion injury by modulating microglia/macrophage polarization via FPR2/ALX-dependent AMPK-mTOR pathway

“…They were incubated at 37 °C in a humidified 5% carbon dioxide atmosphere, with medium changed every 2 days. To mimic cerebral I/R injury in vitro , cells were exposed to OGD/R as previously reported [ 25 ]. Briefly, the medium was replaced with D-glucose-free DMEM (Corning), and incubated at 37 °C in a hypoxic incubator (94% nitrogen and 5% carbon dioxide) for 2 h to simulate OGD damage.…”