Project description:Proliferative vitreoretinopathy (PVR) is a severe vision-threatening disorder characterized by the formation of cicatricial fibrous membranes leading to traction retinal detachment. As the pathophysiology remains unclear, there has been no effective therapeutic approach to date other than vitreoretinal surgery. In order to identify genes associated with the pathogenesis of PVR, we performed gene expression analyses in fibrous membrane in patients with PVR using DNA microarray technology. This study was approved by the Ethics Committee of the Kyushu University Hospital and Fukuoka University Chikushi Hospital, and the surgical specimens were handled in accordance with the ethical standards of the 1989 Declaration of Helsinki. All patients gave informed consent before inclusion in the study. Fibrousl membranes were surgically dissected from the retinal surface with horizontal scissors of patients with PVR undergoing pars plana vitrectomy. Total RNA were extracted from the fibrous membranes with three different PVR patients. RNA from human retina was obtained from Clontech (Palo Alto, CA).
Project description:Proliferative vitreoretinopathy (PVR) is a severe vision-threatening disorder characterized by the formation of cicatricial fibrous membranes leading to traction retinal detachment. As the pathophysiology remains unclear, there has been no effective therapeutic approach to date other than vitreoretinal surgery.
Project description:Single-cell RNA-sequencing reveals the heterogeneity of microglia in fibrous membrane derived from proliferative diabetic retinopathy and proliferative vitreoretinopathy
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Fibrous membrane (FM), the hallmark for proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR), can cause hemorrhages and retinal detachment, which may lead to blindness if not properly treated. However, little is known about the pathophysiology of FM. In this study, we successfully employed single-cell RNA sequencing on the small-sized vitreous FMs, and generated a comprehensive cell atlas of FMs derived from PVR and PDR. Distinct cell compositions were identified in the FMs, with microglia as the major cell population. Additionally, our analysis revealed a spectrum of microglia activation states with distinct molecular signatures and intercellular interactions in disease-specific microenvironment. This description of microglia phenotypes in the FM of PVR and PDR may offer insight into the activation of microglia in the FM pathogenesis, as well as potential signaling pathways amenable to disease-specific intervention.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.