Fumiaki Kumase

AMPK-Activated Protein Kinase Suppresses Ccr2 Expression by Inhibiting the NF-κB Pathway in RAW264.7 Macrophages

C-C chemokine receptor 2 (Ccr2) is a key pro-inflammatory marker of classic (M1) macrophage activation. Although Ccr2 is known to be expressed both constitutively and inductively, the full regulatory mechanism of its expression remains unclear. AMP-activated protein kinase (AMPK) is not only a master regulator of energy homeostasis but also a central regulator of inflammation. In this study, we sought to assess AMPK’s role in regulating RAW264.7 macrophage Ccr2 protein levels in resting (M0) or LPS-induced M1 states. In both M0 and M1 RAW264.7 macrophages, knockdown of the AMPKα1 subunit by siRNA led to increased Ccr2 levels whereas pharmacologic (A769662) activation of AMPK, attenuated LPS-induced increases in Ccr2 expression in an AMPK dependent fashion. The increases in Ccr2 levels by AMPK downregulation were partially reversed by NF-κB inhibition whereas TNF-a inhibition had minimal effects. Our results indicate that AMPK is a negative regulator of Ccr2 expression in RAW264.7 macrophages, and that the mechanism of action of AMPK inhibition of Ccr2 is mediated, in part, through the NF-κB pathway.

Surgical outcome of idiopathic epiretinal membranes with intraretinal cystic spaces

Objective To investigate the occurrence ratio, localization, and surgical outcomes of intraretinal cystic spaces in idiopathic epiretinal membranes (ERMs). Methods We retrospectively reviewed the charts of 432 eyes of 398 consecutive patients with idiopathic ERM who underwent vitrectomy and ERM peeling from January 2012 to September 2015. We selected cases with intraretinal cystic space prior to surgery, detected by spectral-domain optical coherence tomography. We then evaluated the effects of ERM peeling on intraretinal cystic spaces, best corrected visual acuity, and central retinal thickness at 6 months after surgery. Results Twenty-four eyes (5.5%) showed intraretinal cystic spaces before surgery, present in the inner retinal layer (the inner group) in 9 eyes, in the outer retinal layer (the outer group) in 6 eyes, and in both the inner and the outer retinal layers (the combined group) in 9 eyes. Additionally, 30 eyes with ERM but without any presence of intraretinal cystic space were selected randomly and classified as the no cyst group. At 6 months after surgery, the disappearance rate of cystic spaces was significantly greater for the outer group than for the inner group (83.3% and 11.1%, respectively, P = 0.011). The mean best corrected visual acuity improved significantly after surgery in the inner group, the outer group, and the no cyst group (P < 0.05 for all three groups) but did not improve in the combined group (P = 0.58). The mean central retinal thickness decreased significantly after surgery in the inner group, the combined group, and the no cyst group (P < 0.05). Conclusions Intraretinal cystic spaces were observed in 5.5% of preoperative idiopathic ERM cases. Following surgery, the cystic spaces in the outer retinal layer disappeared at higher rates than those in the inner retinal layer, suggesting that the pathophysiologies of these cystic spaces are different.