Hyalocytes might be one of the critical components of ERM mediating its contractile property through the effect of TGF-beta2 in the vitreous fluid.

Neuroprotection can be achieved by preventing apoptotic death of postmitotic cells. Apoptotic death can occur by either a caspase-dependent mechanism, involving cytochrome c, apoptosis protease-activating factor-1 (Apaf-1), and caspase-9, or a caspase-independent mechanism, involving apoptosis-inducing factor (AIF). HIV protease inhibitors (PIs) avert apoptosis in part by preventing mitochondrial outer membrane permeabilization (MOMP), but the precise mechanism by which they work is not known. Here, we evaluated the impact of the PIs in a mouse model of retinal detachment (RD) in vivo and in murine primary retinal cell cultures in vitro. Oral administration of the PIs nelfinavir and ritonavir significantly inhibited photoreceptor apoptosis, while preventing the translocation of AIF from mitochondria to the nucleus as well as the activation of caspase-9. RD-induced photoreceptor apoptosis was similarly inhibited in mice carrying hypomorphic mutations of the genes encoding AIF or Apaf-1. Nelfinavir attenuated apoptosis as well as mitochondrial release of AIF and cytochrome c, and subsequent activation of caspase-9 in vitro, in photoreceptor cultures exposed to starvation or monocyte chemoattractant protein-1-stimulated (MCP-1-stimulated) macrophages. Our results suggest that the MOMP inhibition by PIs involved interruption of both caspase-dependent and caspase-independent apoptosis pathways and that PIs may be clinically useful for the treatment of diseases caused by excessive apoptosis.

Intravitreal injection of anti-VEGF-A Ab could inhibit leukocyte trafficking in the retina, suggesting that anti-VEGF-A therapy could serve as a treatment in retinal inflammation.

Recent clinical observations have indicated that vascular endothelial growth factor (VEGF) is a key factor that stimulates the development of preretinal pathological neovascularization (NV). However, it has not been established how intraretinal physiological revascularization of hypoxic avascular areas is regulated. Our earlier study on the gene expression profile of hypoxic retinas in a mouse model of oxygen-induced retinopathy (OIR) showed that macrophage inflammatory protein-1b (MIP-1b) was the most upregulated protein. The purpose of this study was to investigate the role played by MIP-1b in recruiting bone marrow-derived monocyte lineage cells (BM-MLCs) in a mouse model of OIR. Our results showed that MIP-1b was upregulated, and its receptor, CCR5, was expressed in BM-MLCs in the hypoxic inner retina. Neutralizing Ab against MIP-1b reduced the infiltration of BM-MLCs into the OIR retinas and increased the avascular area and preretinal neovascular tufts. A very strong significant correlation was found between the area of the preretinal neovascular tufts and the avascular area, regardless of the extent of BM-MLC infiltration into the OIR retinas. Additional treatment with VEGF-A-neutralizing Ab showed that the MIP-1b-regulated pathological NV strongly depended on VEGF-A, which was probably secreted by the hypoxic avascular retinas. These results indicate that MIP-1b is involved in the recruitment of BM-MLCs, which have a significant role in the physiological revascularization of hypoxic avascular retinas. Overall, these findings indicate that the MIP-1b induction of BM-MLCs might possibly be used to promote intraretinal revascularization and thus prevent the abnormal NV in ischemic vision-threatening retinal diseases. Tissue hypoxia is believed to be the common mechanism that initiates a series of events leading to compensatory angiogenesis. Hypoxia-induced retinal neovascularization (NV) is the main contributor to proliferative vascular diseases, such as diabetic retinopathy, retinopathy of prematurity, and retinal vein occlusion. These diseases can lead to irreversible damage to visual function.To determine the factors that are activated during retinal hypoxia, we performed a gene expression profile of hypoxic retinas obtained from a mouse model of oxygen-induced retinopathy (OIR) using gene microarray analyses. The results identified the functional set of genes that are related to the post-ischemic inflammation, neural and vascular development, and subsequent pathological NV. The most upregulated gene among the differentially expressed genes in hypoxic retinas was the macrophage inflammatory protein1b (MIP-1b) and not vascular endothelial growth factor A (VEGF-A) and other chemokines. 1 MIP-1b, also known as chemokine CC motif ligand 4, is a member of the CC chemokine family that are characterized by their ability to direct migration of leukocytes into inflamed tissues. 2 MIP-1b was first isolated from the culture medium of LPS-activated macrophages, 3 and it recruited macrophages/microglia to the sites of...