1
|
Hoyek S, Wu F, Berrocal AM, Patel NA. Induction of Posterior Vitreous Detachment Using Perfluorooctane Dissection in a Pediatric Patient. Ophthalmic Surg Lasers Imaging Retina 2023; 54:543-546. [PMID: 37708224 DOI: 10.3928/23258160-20230823-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
BACKGROUND AND OBJECTIVE Inducing a posterior vitreous detachment (PVD) may be challenging, especially in pediatric patients with firm vitreo-retinal adherence. This case report will present an alternative method of PVD induction using adjunctive perfluorooctane (PFO). MATERIALS AND METHODS An 11-year-old boy underwent scleral buckle placement and 23-gauge pars plana vitrectomy for macula-off retinal detachment. Triamcinolone acetonide was used for vitreous staining. A flexible loop was used to peel the hyaloid membrane from attached retina nasal to the optic nerve. A small hole was created in the posterior hyaloid, and a small PFO bubble was injected under the detached vitreous to further dissect it from the retina and propagate the vitreous detachment anteriorly. The vitrector was used to lift and complete the PVD peripherally. RESULTS PVD induction was obtained with no iatrogenic retinal breaks or postoperative complications. CONCLUSION PVD induction using a stepwise PFO approach is a safe and effective alternative to conventional techniques. [Ophthalmic Surg Lasers Imaging Retina 2023;54:543-546.].
Collapse
|
2
|
Aziz IA, Hussein MM, Fouad YA. Perfluorocarbon liquid-assisted vitreo-dissection in eyes with firmly adherent posterior hyaloid. BMC Ophthalmol 2022; 22:475. [PMID: 36476333 PMCID: PMC9727894 DOI: 10.1186/s12886-022-02715-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Induction of posterior vitreous detachment (PVD) is a critical step during pars plana vitrectomy. Multiple techniques and utilities have been proposed for assistance with this step with no consensus on the safest and most effective means, especially in eyes with firmly adherent posterior hyaloid. Viscodissection or the utilization of perfluorocarbon liquid (PFCL) can be used to dissect the posterior hyaloid and widely adherent epiretinal membranes. METHODS A technique of PFCL dissection of the posterior hyaloid in eyes with abnormal adhesion of the posterior hyaloid. After core vitrectomy, breaking into the posterior hyaloid face is made via active aspiration and cutting or a sharp dissection. This is followed by active and slow injection of PFCL into the potential space between the posterior cortical vitreous and the neurosensory retina. A wave of PFCL propagates anteriorly causing "vitreo-dissection" of the peripheral cortical vitreous. RESULTS The technique was effective and safe in 8 successive cases, 4 cases with vitreoretinal traction syndrome and 4 with diabetic tractional membranes. CONCLUSION The technique can be considered in cases with abnormal firmly adherent posterior hyaloid when induction of PVD proves difficult.
Collapse
Affiliation(s)
- Ihab Abdel Aziz
- Al Mashreq Eye Center, Cairo, Egypt ,The Memorial Institute for Ophthalmic Research, Cairo, Egypt
| | - Moaaz M. Hussein
- Al Mashreq Eye Center, Cairo, Egypt ,Department of Ophthalmology, Electricity Hospital, Cairo, Egypt
| | - Yousef A. Fouad
- Al Mashreq Eye Center, Cairo, Egypt ,grid.7269.a0000 0004 0621 1570Department of Ophthalmology, Ain Shams University Hospitals, Cairo, Egypt
| |
Collapse
|
3
|
Bianchi L, Altera A, Barone V, Bonente D, Bacci T, De Benedetto E, Bini L, Tosi GM, Galvagni F, Bertelli E. Untangling the Extracellular Matrix of Idiopathic Epiretinal Membrane: A Path Winding among Structure, Interactomics and Translational Medicine. Cells 2022; 11:cells11162531. [PMID: 36010606 PMCID: PMC9406781 DOI: 10.3390/cells11162531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 12/16/2022] Open
Abstract
Idiopathic epiretinal membranes (iERMs) are fibrocellular sheets of tissue that develop at the vitreoretinal interface. The iERMs consist of cells and an extracellular matrix (ECM) formed by a complex array of structural proteins and a large number of proteins that regulate cell–matrix interaction, matrix deposition and remodelling. Many components of the ECM tend to produce a layered pattern that can influence the tractional properties of the membranes. We applied a bioinformatics approach on a list of proteins previously identified with an MS-based proteomic analysis on samples of iERM to report the interactome of some key proteins. The performed pathway analysis highlights interactions occurring among ECM molecules, their cell receptors and intra- or extracellular proteins that may play a role in matrix biology in this special context. In particular, integrin β1, cathepsin B, epidermal growth factor receptor, protein-glutamine gamma-glutamyltransferase 2 and prolow-density lipoprotein receptor-related protein 1 are key hubs in the outlined protein–protein cross-talks. A section on the biomarkers that can be found in the vitreous humor of patients affected by iERM and that can modulate matrix deposition is also presented. Finally, translational medicine in iERM treatment has been summed up taking stock of the techniques that have been proposed for pharmacologic vitreolysis.
Collapse
Affiliation(s)
- Laura Bianchi
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Annalisa Altera
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy
| | - Virginia Barone
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy
| | - Denise Bonente
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy
| | - Tommaso Bacci
- Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, Italy
| | - Elena De Benedetto
- Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, Italy
| | - Luca Bini
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Gian Marco Tosi
- Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, Italy
| | - Federico Galvagni
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Eugenio Bertelli
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy
- Correspondence:
| |
Collapse
|
4
|
Santra M, Liu YC, Jhanji V, Yam GHF. Human SMILE-Derived Stromal Lenticule Scaffold for Regenerative Therapy: Review and Perspectives. Int J Mol Sci 2022; 23:ijms23147967. [PMID: 35887309 PMCID: PMC9315730 DOI: 10.3390/ijms23147967] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/10/2022] [Accepted: 07/18/2022] [Indexed: 12/13/2022] Open
Abstract
A transparent cornea is paramount for vision. Corneal opacity is one of the leading causes of blindness. Although conventional corneal transplantation has been successful in recovering patients’ vision, the outcomes are challenged by a global lack of donor tissue availability. Bioengineered corneal tissues are gaining momentum as a new source for corneal wound healing and scar management. Extracellular matrix (ECM)-scaffold-based engineering offers a new perspective on corneal regenerative medicine. Ultrathin stromal laminar tissues obtained from lenticule-based refractive correction procedures, such as SMall Incision Lenticule Extraction (SMILE), are an accessible and novel source of collagen-rich ECM scaffolds with high mechanical strength, biocompatibility, and transparency. After customization (including decellularization), these lenticules can serve as an acellular scaffold niche to repopulate cells, including stromal keratocytes and stem cells, with functional phenotypes. The intrastromal transplantation of these cell/tissue composites can regenerate native-like corneal stromal tissue and restore corneal transparency. This review highlights the current status of ECM-scaffold-based engineering with cells, along with the development of drug and growth factor delivery systems, and elucidates the potential uses of stromal lenticule scaffolds in regenerative therapeutics.
Collapse
Affiliation(s)
- Mithun Santra
- Corneal Regeneration Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (M.S.); (V.J.)
| | - Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore;
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Vishal Jhanji
- Corneal Regeneration Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (M.S.); (V.J.)
| | - Gary Hin-Fai Yam
- Corneal Regeneration Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; (M.S.); (V.J.)
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore;
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Correspondence:
| |
Collapse
|
5
|
Mechanistic Insight into the Fragmentation of Type I Collagen Fibers into Peptides and Amino Acids by a Vibrio Collagenase. Appl Environ Microbiol 2022; 88:e0167721. [PMID: 35285716 DOI: 10.1128/aem.01677-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vibrio collagenases of the M9A subfamily are closely related to Vibrio pathogenesis for their role in collagen degradation during host invasion. Although some Vibrio collagenases have been characterized, the collagen degradation mechanism of Vibrio collagenase is still largely unknown. Here, an M9A collagenase, VP397, from marine Vibrio pomeroyi strain 12613 was characterized, and its fragmentation pattern on insoluble type I collagen fibers was studied. VP397 is a typical Vibrio collagenase composed of a catalytic module featuring a peptidase M9N domain and a peptidase M9 domain and two accessory bacterial prepeptidase C-terminal domains (PPC domains). It can hydrolyze various collagenous substrates, including fish collagen, mammalian collagens of types I to V, triple-helical peptide [(POG)10]3, gelatin, and 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-o-Arg (Pz-peptide). Atomic force microscopy (AFM) observation and biochemical analyses revealed that VP397 first assaults the C-telopeptide region to dismantle the compact structure of collagen and dissociate tropocollagen fragments, which are further digested into peptides and amino acids by VP397 mainly at the Y-Gly bonds in the repeating Gly-X-Y triplets. In addition, domain deletion mutagenesis showed that the catalytic module of VP397 alone is capable of hydrolyzing type I collagen fibers and that its C-terminal PPC2 domain functions as a collagen-binding domain during collagenolysis. Based on our results, a model for the collagenolytic mechanism of VP397 is proposed. This study sheds light on the mechanism of collagen degradation by Vibrio collagenase, offering a better understanding of the pathogenesis of Vibrio and helping in developing the potential applications of Vibrio collagenase in industrial and medical areas. IMPORTANCE Many Vibrio species are pathogens and cause serious diseases in humans and aquatic animals. The collagenases produced by pathogenic Vibrio species have been regarded as important virulence factors, which occasionally exhibit direct pathogenicity to the infected host or facilitate other toxins' diffusion through the digestion of host collagen. However, our knowledge concerning the collagen degradation mechanism of Vibrio collagenase is still limited. This study reveals the degradation strategy of Vibrio collagenase VP397 on type I collagen. VP397 binds on collagen fibrils via its C-terminal PPC2 domain, and its catalytic module first assaults the C-telopeptide region and then attacks the Y-Gly bonds in the dissociated tropocollagen fragments to release peptides and amino acids. This study offers new knowledge regarding the collagenolytic mechanism of Vibrio collagenase, which is helpful for better understanding the role of collagenase in Vibrio pathogenesis and for developing its industrial and medical applications.
Collapse
|
6
|
Structure of Vibrio collagenase VhaC provides insight into the mechanism of bacterial collagenolysis. Nat Commun 2022; 13:566. [PMID: 35091565 PMCID: PMC8799719 DOI: 10.1038/s41467-022-28264-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 01/10/2022] [Indexed: 02/06/2023] Open
Abstract
The collagenases of Vibrio species, many of which are pathogens, have been regarded as an important virulence factor. However, there is little information on the structure and collagenolytic mechanism of Vibrio collagenase. Here, we report the crystal structure of the collagenase module (CM) of Vibrio collagenase VhaC and the conformation of VhaC in solution. Structural and biochemical analyses and molecular dynamics studies reveal that triple-helical collagen is initially recognized by the activator domain, followed by subsequent cleavage by the peptidase domain along with the closing movement of CM. This is different from the peptidolytic mode or the proposed collagenolysis of Clostridium collagenase. We propose a model for the integrated collagenolytic mechanism of VhaC, integrating the functions of VhaC accessory domains and its collagen degradation pattern. This study provides insight into the mechanism of bacterial collagenolysis and helps in structure-based drug design targeting of the Vibrio collagenase. The collagenolytic mechanism of Vibrio collagenase, a virulence factor, remains unclear. Here, the authors report the structure of Vibrio collagenase VhaC and propose the mechanism for collagen recognition and degradation, providing new insight into bacterial collagenolysis.
Collapse
|
7
|
The extracellular matrix complexity of idiopathic epiretinal membranes and the bilaminar arrangement of the associated internal limiting membrane in the posterior retina. Graefes Arch Clin Exp Ophthalmol 2021; 259:2559-2571. [PMID: 33760980 PMCID: PMC8380574 DOI: 10.1007/s00417-021-05156-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/22/2021] [Accepted: 03/09/2021] [Indexed: 11/02/2022] Open
Abstract
PURPOSE To study the composition of the internal limiting membrane (ILM) of the retina, the extracellular matrix (ECM) of idiopathic epiretinal membranes (iERMs), and the relationships occurring between the two membranes. METHODS Forty-six iERMs, 24 of them associated with the ILM, were collected and included in this study. The investigation has been carried out by immunofluorescence and confocal microscopy on glutaraldehyde- and osmium-fixed epon-embedded samples and on frozen samples. Sections were double or triple labelled with antibodies against vimentin; collagens I, III, IV, α5(IV), and VI; laminin 1 + 2; laminin α2-, α4-, α5-, β1-, β2-, β3-, γ1-, and γ2-chains; entactin; and fibronectin. RESULTS iERM thickness was not uniform. Almost 14% of iERMs showed thickenings due to folding of their ECM component under the cell layer. The vitreal side of iERMs was often shorter than the attached ILM. In this case, the ILM resulted folded under the iERM. ILMs contained laminin 111; laminin α2-, α5-, β1-, β2-, and γ1-chains; entactin; collagens I; α5(IV); [α1(IV)]2α2(IV); and VI. Laminins, entactin, and α5(IV) were gathered on the retinal half of the ILM, whereas collagens [α1(IV)]2α2(IV) and I were restricted to the vitreal side. Collagen VI was detected on both sides of the ILM. iERMs expressed laminin 111, collagens III, [α1(IV)]2α2(IV) and VI, entactin, and fibronectin. Entactin co-localized with laminins and collagen IV. CONCLUSIONS Analysis of laminins and collagen chain expression indicates that ILM contains laminin 111 (former laminin 1), laminin 521 (former laminin 11), laminin 211 (former laminin 2), collagen [α1(IV)]2α2(IV), and collagen α3(IV)α4(IV)α5. In contrast, iERMs express only collagen [α1(IV)]2α2(IV) and laminin 111. In addition, both iERMs and ILMs contain entactin. The presence of three major constituents of the basement membranes co-localized together in iERMs is suggestive for a deranged process of basement membrane formation which fails to assemble properly. In view of the many interactions occurring among its proteins, the ECM of either the iERMs or the ILMs can account for their reciprocal adhesiveness. In addition, the peculiar deposition of the ECM observed in some samples of iERM is suggestive for its involvement in the formation of macular puckers.
Collapse
|
8
|
Studies on Vibrio mimicus derived collagenase variants providing insights into critical role(s) played by the FAXWXXT motifs in its collagen-binding domain. Enzyme Microb Technol 2021; 147:109779. [PMID: 33992402 DOI: 10.1016/j.enzmictec.2021.109779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 11/22/2022]
Abstract
Vibrio mimicus collagenase (VMC), a Class II Vibrio metalloprotease, contains an HEXXH motif in a zinc-binding catalytic domain, and two FAXWXXT motifs in its C-terminal domain, which is its collagen binding domain (CBD). To understand the functional role of the individual CBD motifs in the activity of VMC, if any, we created and characterized a series of VMC variants: i) VMA, with 51 amino acids deleted from the C-terminal end of full-length VMC; ii) VMT1, a form of VMA mutated in the first CBD motif; iii) VMT2, a form of VMA mutated in the second CBD motif; iv) DM, a form of VMA with both CBD motifs mutated; v) CT, a truncated form of VMA, lacking the entire CBD region; and vi) CBD, a construct containing the collagen binding domain alone. The activity of each variant was assessed by multiple means, in relation to VMA. We report that VMT1 and VMT2 show 1.6-fold and 10-fold reduced activity, respectively. The reduced activity of VMT2 correlates with reduced binding to insoluble collagen as well as an inability to cause structural perturbation of collagen. VMC appears to cause unwinding and structural alteration of the collagen triple helix prior to hydrolysis of the substrate (using both motifs for collagen binding), like Clostridium collagenases. In the absence of a known structure for VMC, our findings suggest that Vibrio collagenase, functions like Clostridium collagenases, although the two show very little sequence similarity. Also, VMC shows reduced activity with respect to Clostridium collagenases, making it an ideal enzyme for therapeutic applications.
Collapse
|
9
|
Baghban R, Farajnia S, Ghasemi Y, Hoseinpoor R, Safary A, Mortazavi M, Zarghami N. Mutational Analysis of Ocriplasmin to Reduce Proteolytic and Autolytic Activity in Pichia pastoris. Biol Proced Online 2020; 22:25. [PMID: 33308171 PMCID: PMC7734836 DOI: 10.1186/s12575-020-00138-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Ocriplasmin (Jetrea) is using for the treatment of symptomatic vitreomacular adhesion. This enzyme undergoes rapid inactivation and limited activity duration as a result of its autolytic nature after injection within the eye. Moreover, the proteolytic activity can cause photoreceptor damage, which may result in visual impairment in more serious cases. RESULTS The present research aimed to reduce the disadvantages of ocriplasmin using site-directed mutagenesis. To reduce the autolytic activity of ocriplasmin in the first variant, lysine 156 changed to glutamic acid and, in the second variant for the proteolytic activity reduction, alanine 59 mutated to threonine. The third variant contained both mutations. Expression of wild type and three mutant variants of ocriplasmin constructs were done in the Pichia pastoris expression system. The mutant variants were analyzed in silico and in vitro and compared to the wild type. The kinetic parameters of ocriplasmin variants showed both variants with K156E substitution were more resistant to autolytic degradation than wild-type. These variants also exhibited reduced Kcat and Vmax values. An increase in their Km values, leading to a decreased catalytic efficiency (the Kcat/Km ratio) of autolytic and mixed variants. Moreover, in the variant with A59T mutation, Kcat and Vmax values have reduced compared to wild type. The mix variants showed the most increase in Km value (almost 2-fold) as well as reduced enzymatic affinity to the substrate. Thus, the results indicated that combined mutations at the ocriplasmin sequence were more effective compared with single mutations. CONCLUSIONS The results indicated such variants represent valuable tools for the investigation of therapeutic strategies aiming at the non-surgical resolution of vitreomacular adhesion.
Collapse
Affiliation(s)
- Roghayyeh Baghban
- Medical Biotechnology Department, Faculty of Advanced Medical Science, Tabriz University of Medical Sciences, Tabriz, Iran
- Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Biotechnology Research Center, Tabriz University of Medical Sciences, Daneshgah Ave, Tabriz, Iran
| | - Safar Farajnia
- Biotechnology Research Center, Tabriz University of Medical Sciences, Daneshgah Ave, Tabriz, Iran.
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Younes Ghasemi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Shiraz University of Medical Science, Shiraz, Iran
| | - Reyhaneh Hoseinpoor
- Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Azam Safary
- Connective Tissue Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mojtaba Mortazavi
- Department of Biotechnology, Institute of Science and High Technology and Environmental Science, Graduate University of Advanced Technology, Kerman, Iran
| | - Nosratollah Zarghami
- Medical Biotechnology Department, Faculty of Advanced Medical Science, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|