scholarly journals In silico Characterization of the Structure of Genes and Proteins related to β-carotene Degradation in Musa acuminata ‘DH-Pahang’ and Musa balbisiana ‘Pisang Klutuk Wulung’

2021 ◽  
Vol 44 (2) ◽  
Author(s):  
Fenny Martha Dwivany ◽  
Nisrina Sukriandi ◽  
Karlia Meitha ◽  
Tatas H. P. Brotosudarmo
Keyword(s):  
Phylogenetic Trees ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Musa Acuminata ◽  
Sequence Length ◽  
Future Research ◽  
Carotenoid Cleavage Dioxygenase ◽  
Musa Balbisiana ◽  
Β Carotene ◽  
Carotene Degradation

β-carotene is an important nutritious content in banana. However, its lifetime depends on the enzymes controlling its conversion into strigolactone. To understand the involved enzymes’ activity, which are β-carotene isomerase (D27), carotenoid cleavage dioxygenase 7 (CCD7), and CCD8, would be the key to manipulate the rate of β-carotene degradation. In this research, we characterized the structure of genes and proteins of the D27, CCD7, and CCD8 from Musa acuminata ‘DH-Pahang’ and Musa balbisiana ‘Pisang Klutuk Wulung’ (PKW). We aligned the corresponding sequence of genes from both species to determine similarity and intron/exon positions. We also identified domains and motifs in the sequences of putative proteins of D27, CCD7, and CCD8. We found that D27, CCD7, and CCD8 genes in DH-Pahang and PKW comprise of various nucleotide sequence length, putative proteins, and numbers and length of exons and introns. However, the putative proteins possess the same domains: DUF4033 (domain of unknown function) in D27 and RPE65 (retinal pigment epithelium) in CCD7 and CCD8. Phylogenetic trees showed that D27, CCD7, and CCD8 proteins from DH-Pahang and PKW are conserved and clustered in the same clades with the same proteins of monocot plants. Hence, the results could be useful for future research in optimizing β-carotene content in banana.

scholarly journals Evolution of the visual cycle: the role of retinoid-binding proteins

2002 ◽  
Vol 175 (1) ◽  
pp. 75-88 ◽  
Author(s):  
F Gonzalez-Fernandez
Keyword(s):  
Binding Proteins ◽  
Binding Protein ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Future Research ◽  
Visual Cycle ◽  
Hormone Binding ◽  
Evolutionary Context ◽  
And Function

The trafficking of retinoids in the retina represents a model to study soluble hormone-binding proteins in a complex system subject to profound evolutionary adaptations. Although a remarkable illustration of convergent evolution, all visual systems detect light in the same way, that is through the photoisomerization of an 11-cis retinoid to a corresponding trans isomer. What is strikingly different between the systems, is the mechanism by which the 11-cis chromophore is reformed and visual pigment regenerated in a process known as the visual cycle. The variations of the cycle address a problem inherent to retinoids themselves. That is, the properties that make these molecules suited for light detection also account for their susceptibility to oxidative and isomeric degradation, and cellular toxicity. The cycle therefore provides an opportunity to examine the role of soluble hormone-binding proteins within an integrative and evolutionary context. The present review focuses on interphotoreceptor retinoid-binding protein (IRBP), a controversial glycolipoprotein that recruits a protein fold common to Cterminal-processing proteases and the crotonase family. This unorthodox retinoid-binding protein is entrapped in the subretinal compartment of those eyes that translocate visual cycle retinoids between the photoreceptors and the retinal pigment epithelium. Recent studies suggest that we should look beyond a strictly carrier function if we are to appreciate the role of IRBP in the visual cycle. Here we draw lessons from other soluble hormone-binding proteins to anticipate avenues of future research likely to provide insight into the structure and function of IRBP in vision.

scholarly journals Cell Therapy for Retinal Dystrophies: From Cell Suspension Formulation to Complex Retinal Tissue Bioengineering

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Karim Ben M’Barek ◽  
Christelle Monville
Keyword(s):  
Cell Therapy ◽  
Current Knowledge ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Future Research ◽  
Therapeutic Effects ◽  
Primary Defect ◽  
Retinal Tissue ◽  
Age Related

Retinal degeneration is an irreversible phenomenon caused by various disease conditions including age-related macular degeneration (AMD) and retinitis pigmentosa (RP). During the course of these diseases, photoreceptors (PRs) are susceptible to degeneration due to their malfunctions or to a primary dysfunction of the retinal pigment epithelium (RPE). Once lost, these cells could not be endogenously regenerated in humans, and cell therapy to replace the lost cells is one of the promising strategies to recover vision. Depending on the nature of the primary defect and the stage of the disease, RPE cells, PRs, or both might be transplanted to achieve therapeutic effects. We describe in this review the current knowledge and recent progress to develop such approaches. The different cell sources proposed for cell therapy including human pluripotent stem cells are presented with their advantages and limits. Another critical aspect described herein is the pharmaceutical formulation of the end product to be delivered into the eye of patients. Finally, we also outline the future research directions in order to develop a complex multilayered retinal tissue for end-stage patients.

scholarly journals Aqueous humour concentrations of PEDF and Erythropoietin are not influenced by subthreshold micropulse laser treatment of diabetic macular edema

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Edoardo Midena ◽  
Silvia Bini ◽  
Luisa Frizziero ◽  
Elisabetta Pilotto ◽  
Graziana Esposito ◽  
...  
Keyword(s):  
Macular Edema ◽  
Diabetic Macular Edema ◽  
Aqueous Humour ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Future Research ◽  
Micropulse Laser ◽  
Subthreshold Micropulse Laser ◽  
Treatment Naïve ◽  
Glass Chip

Abstract Purpose: To determine if aqueous humour (AH) concentrations of Retinal Pigment Epithelium (RPE)’s biomarkers are modified after subthreshold micropulse laser (SMPL) treatment of diabetic macular edema (DME). Methods: Naïve DME and healthy subjects were enrolled. All DME patients received SMPL treatments (577-nm yellow light, 5% duty cycle of 0.2 s, power 250 mW), according to study protocol. AH of DME eyes was sampled at baseline and periodically after first SMPL treatment. Control eyes were sampled before cataract surgery. Pigment Epithelium Derived Factor (PEDF) and Erythropoietin (EPO) were quantified with glass-chip protein array. Results: Eighteen DME patients (central retinal thickness ≤ 400 μm on Spectral Domain Optical Coherence Tomography (SD-OCT)) and ten controls were enrolled. The main exclusion criteria were high refractive error, proliferative diabetic retinopathy, glaucoma and neurodegenerative disorders. PEDF concentration was decreased in DME patients at baseline versus controls (P=0.012), while EPO was increased (P=0.029). Both molecules’ concentrations remained stable during follow-up after treatments, compared with DME-baseline. Conclusions: The AH concentrations of RPE biomarkers were significantly different in DME treatment-naïve eyes versus controls. The expression of PEDF and EPO remained unchanged after treatments with SMPL in DME eyes. These data are relevant for future research and applications of SMPL.

Cloning and Characterization of a Human β,β-Carotene-15, 15′-Dioxygenase That Is Highly Expressed in the Retinal Pigment Epithelium

Genomics ◽  
2001 ◽  
Vol 72 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Weiming Yan ◽  
Geeng-Fu Jang ◽  
Françoise Haeseleer ◽  
Noriko Esumi ◽  
Jinghua Chang ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Β Carotene

scholarly journals Cell Type-specific Expression of β-Carotene 9', 10'-Monooxygenase in Human Tissues

2005 ◽  
Vol 53 (11) ◽  
pp. 1403-1412 ◽  
Author(s):  
Annika Lindqvist ◽  
Yu-Guang He ◽  
Stefan Andersson
Keyword(s):  
Small Intestine ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Physiological Role ◽  
Cell Types ◽  
Human Tissues ◽  
Specific Expression ◽  
Β Carotene

The symmetrically cleaving β-carotene 15, 15'-monooxygenase (BCO1) catalyzes the first step in the conversion of provitamin A carotenoids to vitamin A in the mucosa of the small intestine. This enzyme is also expressed in epithelia in a variety of extraintestinal tissues. The newly discovered β-carotene 9', 10'-monooxygenase (BCO2) catalyzes asymmetric cleavage of carotenoids. To gain some insight into the physiological role of BCO2, we determined the expression pattern of BCO2 mRNA and protein in human tissues. By immunohistochemical analysis it was revealed that BCO2 was detected in cell types that are known to express BCO1, such as epithelial cells in the mucosa of small intestine and stomach, parenchymal cells in liver, Leydig and Sertoli cells in testis, kidney tubules, adrenal gland, exocrine pancreas, and retinal pigment epithelium and ciliary body pigment epithelia in the eye. BCO2 was uniquely detected in cardiac and skeletal muscle cells, prostate and endometrial connective tissue, and endocrine pancreas. The finding that the BCO2 enzyme was expressed in some tissues and cell types that are not sensitive to vitamin A deficiency and where no BCO1 has been detected suggests that BCO2 may also be involved in biological processes other than vitamin A synthesis.

High-resolution scanning electron microscopy (HRSEM) of mitochondria from various rat tissues

1988 ◽  
Vol 46 ◽  
pp. 14-15
Author(s):  
P.J. Lea ◽  
M.J. Hollenberg
Keyword(s):  
Electron Microscopy ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Rat Hepatocytes ◽  
Three Dimensions ◽  
Objective Lens ◽  
Rat Tissues ◽  
Thin Sections ◽  
Reconstruction Methods ◽  
Scanning Electron

Our current understanding of mitochondrial ultrastructure has been derived primarily from thin sections using transmission electron microscopy (TEM). This information has been extrapolated into three dimensions by artist's impressions (1) or serial sectioning techniques in combination with computer processing (2). The resolution of serial reconstruction methods is limited by section thickness whereas artist's impressions have obvious disadvantages.In contrast, the new techniques of HRSEM used in this study (3) offer the opportunity to view simultaneously both the internal and external structure of mitochondria directly in three dimensions and in detail.The tridimensional ultrastructure of mitochondria from rat hepatocytes, retinal (retinal pigment epithelium), renal (proximal convoluted tubule) and adrenal cortex cells were studied by HRSEM. The specimens were prepared by aldehyde-osmium fixation in combination with freeze cleavage followed by partial extraction of cytosol with a weak solution of osmium tetroxide (4). The specimens were examined with a Hitachi S-570 scanning electron microscope, resolution better than 30 nm, where the secondary electron detector is located in the column directly above the specimen inserted within the objective lens.

Ultrastructural Changes of Smoooth Endoplasmic Reticulum in the Retinal Pigment Epithelium by Choline Chloride

1972 ◽  
Vol 30 ◽  
pp. 58-59
Author(s):  
Kazushige Hirosawa ◽  
Eichi Yamada
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cell ◽  
Smooth Endoplasmic Reticulum ◽  
Pigment Epithelium ◽  
Choline Chloride ◽  
Retinal Pigment ◽  
Ultrastructural Changes ◽  
Lower Vertebrate ◽  
Visual Cells ◽  
Pigment Epithelial

The pigment epithelium is located between the choriocapillary and the visual cells. The pigment epithelial cell is characterized by a large amount of the smooth endoplasmic reticulum (SER) in its cytoplasm. In addition, the pigment epithelial cell of some lower vertebrate has myeloid body as a specialized form of the SER. Generally, SER is supposed to work in the lipid metabolism. However, the functions of abundant SER and myeloid body in the pigment epithelial cell are still in question. This paper reports an attempt, to depict the functions of these organelles in the frog retina by administering one of phospholipid precursors.

High-voltage electron microscopy of subretinal scar formation

1992 ◽  
Vol 50 (1) ◽  
pp. 486-487
Author(s):  
G.E. Korte ◽  
M. Marko ◽  
G. Hageman
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibody ◽  
Retinal Pigment Epithelium ◽  
Glial Cells ◽  
High Voltage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Sodium Iodate ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron

Sodium iodate iv. damages the retinal pigment epithelium (RPE) in rabbits. Where RPE does not regenerate (e.g., 1,2) Muller glial cells (MC) forma subretinal scar that replaces RPE. The MC response was studied by HVEM in 3D computer reconstructions of serial thick sections, made using the STEREC0N program (3), and the HVEM at the NYS Dept. of Health in Albany, NY. Tissue was processed for HVEM or immunofluorescence localization of a monoclonal antibody recognizing MG microvilli (4).

The photoreceptor cytoskeleton visualized

1992 ◽  
Vol 50 (1) ◽  
pp. 480-481
Author(s):  
Beth Burnside
Keyword(s):  
Outer Segment ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Polarization ◽  
Synaptic Proteins ◽  
Cell Functions ◽  
Vertebrate Photoreceptor ◽  
Numerous Cell ◽  
Turn Over

The vertebrate photoreceptor provides a drammatic example of cell polarization. Specialized to carry out phototransduction at its distal end and to synapse with retinal interneurons at its proximal end, this long slender cell has a uniquely polarized morphology which is reflected in a similarly polarized cytoskeleton. Membranes bearing photopigment are localized in the outer segment, a modified sensory cilium. Sodium pumps which maintain the dark current critical to photosensory transduction are anchored along the inner segment plasma membrane between the outer segment and the nucleus.Proximal to the nucleus is a slender axon terminating in specialized invaginating synapses with other neurons of the retina. Though photoreceptor diameter is only 3-8u, its length from the tip of the outer segment to the synapse may be as great as 200μ. This peculiar linear cell morphology poses special logistical problems and has evoked interesting solutions for numerous cell functions. For example, the outer segment membranes turn over by means of a unique mechanism in which new disks are continuously added at the proximal base of the outer segment, while effete disks are discarded at the tip and phagocytosed by the retinal pigment epithelium. Outer segment proteins are synthesized in the Golgi near the nucleus and must be transported north through the inner segment to their sites of assembly into the outer segment, while synaptic proteins must be transported south through the axon to the synapse.The role of the cytoskeleton in photoreceptor motile processes is being intensely investigated in several laboratories.

Sign in / Sign up

Export Citation Format

Share Document