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1.
Leukemia ; 38(2): 365-371, 2024 02.
Article in English | MEDLINE | ID: mdl-38245601

ABSTRACT

Teclistamab, a B-cell maturation antigen (BCMA) × CD3 directed bispecific antibody, has shown high response rates and durable remissions in the MAJESTEC-1 trial in patients with relapsed and refractory multiple myeloma (RRMM). We retrospectively assessed efficacy and tolerability in 123 patients treated at 18 different German centers to determine whether outcome is comparable in the real-world setting. Most patients had triple-class (93%) or penta-drug (60%) refractory disease, 37% of patients had received BCMA-directed pretreatment including idecabtagene vicleucel (ide-cel) CAR-T cell therapy (21/123, 17.1%). With a follow-up of 5.5 months, we observed an overall response rate (ORR) of 59.3% and a median progression-free survival (PFS) of 8.7 months. In subgroup analyses, we found significantly lower ORR and median PFS in patients with extramedullary disease (37%/2.1 months), and/or an ISS of 3 (37%/1.3 months), and ide-cel pretreated patients (33%/1.8 months). Nonetheless, the duration of response in ide-cel pretreated patients was comparable to that of anti-BCMA naive patients. Infections and grade ≥3 cytopenias were the most frequent adverse events. In summary, we found that teclistamab exhibited a comparable efficacy and safety profile in the real-world setting as in the pivotal trial.


Subject(s)
Antibodies, Bispecific , Antineoplastic Agents , Multiple Myeloma , Neoplasms, Plasma Cell , Humans , Multiple Myeloma/drug therapy , B-Cell Maturation Antigen , Retrospective Studies , Germany , Immunotherapy, Adoptive
2.
Eur J Radiol ; 155: 110493, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36027759

ABSTRACT

PURPOSE: We tested a novel multi-parametric (mp) whole body (WB)-MRI evaluation algorithm for medullary lesions in comparison to positron emission tomography (PET) radiotracers 18F-fluorodeoxyglucose (18F-FDG) and 11C-methionine (11C-MET). METHODS AND MATERIALS: This retrospective single-center study included 44 MM patients, who received both 18F-FDG-PET and WB-MRI within ten days. MRI classified focal lesions as vital when showing 1) significant diffusion-restriction, 2) a fat fraction (FF) less than 20 % and 3) homogenous hypointensity on T2-weighted images. On a lesion-by-lesion level the findings were compared to 18F-FDG PET by using a 5-point scoring system (analogous to the Deauville score [DS]). In 24/44 (55 %) patients additional comparison to 11C-MET PET was available. RESULTS: Among two radiologists, an excellent inter-observer reliability for mpWB-MRI in a total of 84 medullary lesions was observed (ICC = 1, k = 1, p <.01). 16/17 (94.1 %) MRI-classified vital lesions had a DS of 4 or 5 on either 18F-FDG-PET or 11C-MET-PET. MRI-rated non-vital lesions correlated with PET-based DS ≤ 3. When results of mpWB-MRI were compared to 18F-FDG, a fair inter-observer agreement was recorded (ICC = 0.52, k = 0.53, p <.01), while for 11C-MET, an excellent concordance rate was achieved (ICC = 0.81, k = 0.79, p <.01). CONCLUSION: The proposed mpWB-MRI interpretation algorithm allowed to assess tumor activity of myeloma lesions with high inter-observer reproducibility. We observed a substantial concordance between the mpWB-MRI classification of lesions and PET assessment based on a semi-automatically calculated 5-point scoring system analogous to the Deauville scores.


Subject(s)
Fluorodeoxyglucose F18 , Multiple Myeloma , Humans , Magnetic Resonance Imaging/methods , Methionine , Multiple Myeloma/diagnostic imaging , Multiple Myeloma/pathology , Positron Emission Tomography Computed Tomography/methods , Positron-Emission Tomography/methods , Racemethionine , Radiopharmaceuticals , Reproducibility of Results , Retrospective Studies , Tomography, X-Ray Computed/methods
3.
Ophthalmologe ; 119(3): 272-279, 2022 Mar.
Article in German | MEDLINE | ID: mdl-34351477

ABSTRACT

PURPOSE: Neovascular age-related macular degeneration (nAMD) often affects both eyes. This study compared real-life outcomes of the first affected eye (1st eye) and the last affected eye (2nd eye) after anti-vascular endothelial growth factor (anti-VEGF) treatment. MATERIAL AND METHODS: For this retrospective monocenter study 3217 eyes from 2793 patients with nAMD were identified, who received at least 3 anti-VEGF injections between 2006 and 2014 at the University Eye Hospital of Munich. Included in the study were patients with bilateral nAMD when the 1st and 2nd eyes were not previously treated and there was a strict adherence with continuous follow-up for at least 5 years. Corrected visual acuity, number of intravitreal injections and visits as well as central macular thickness were compared. RESULTS: A total of 72 eyes of 36 patients were included in this analysis. Before anti-VEGF therapy, the group of 2nd eyes showed significantly better mean visual acuity than the 1st eyes (p < 0.001). This difference in visual acuity between 1st and 2nd eyes was noted at all time points throughout the follow-up period (p < 0.05). The mean number of cumulative injections was higher in the group of 2nd eyes (p = 0.04) with a comparable number of visits between both groups. In more than half of all patients the 2nd eye became affected by nAMD within 12 months following treatment initiation of the 1st eye and the majority (83%) followed within 3 years. CONCLUSION: In unilateral nAMD, regular monitoring of the fellow eye is essential to avoid severe bilateral vision loss. Early diagnosis with rapid initiation of treatment can preserve visual acuity and quality of life.


Subject(s)
Quality of Life , Wet Macular Degeneration , Angiogenesis Inhibitors , Follow-Up Studies , Humans , Intravitreal Injections , Ranibizumab , Retrospective Studies , Treatment Outcome , Vascular Endothelial Growth Factor A , Wet Macular Degeneration/diagnosis , Wet Macular Degeneration/drug therapy
4.
Graefes Arch Clin Exp Ophthalmol ; 258(2): 345-350, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31863399

ABSTRACT

PURPOSE: To evaluate refractive outcomes for a standard industry calculator using anterior corneal astigmatism or total corneal refractive power. METHODS: This prospective interventional study evaluated the refractive outcomes of 56 eyes using a standard industry calculator (Zeiss ZCalc) and a digital IOL alignment software. After A-constant optimisation the ZCalc was recalculated with two different keratometry values using appropriate refractive indices: anterior corneal astigmatism (ACA) by IOLMaster 700 and total corneal refractive power (TCRP) by Pentacam. The Barrett toric calculator was used as a reference. RESULTS: Undercorrection of 0.04 ± 0.42 D after 1 week and 0.13 ± 0.48 D after 3 months was achieved for the spherical equivalent by using a standard industry calculator. IOL misalignment was 2.8° ± 3.4° using a digital alignment system. For the ZCalc, the mean absolute error could be reduced from 0.19 ± 0.40 D using ACA to 0.04 ± 0.48 D when considering total corneal refractive power (p = 0.06). The Barrett calculator delivered better refractive outcomes than using a standard industry calculator with ACA measurements only (- 0.06 ± 0.43 D; p < 0.01). CONCLUSION: Reliable and accurate refractive outcomes in toric IOL calculation were achieved by using the ZCalc calculator. The prediction error for a widely used standard industry toric IOL calculator could be reduced by using measured total corneal refractive power.


Subject(s)
Astigmatism/surgery , Cornea/pathology , Lens Implantation, Intraocular/methods , Lenses, Intraocular , Optics and Photonics , Refraction, Ocular , Visual Acuity , Adult , Aged , Aged, 80 and over , Astigmatism/diagnosis , Astigmatism/physiopathology , Biometry , Corneal Topography , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Prosthesis Design
5.
J Ophthalmol ; 2018: 2645280, 2018.
Article in English | MEDLINE | ID: mdl-29887991

ABSTRACT

BACKGROUND: Increasing government legislation and regulations in manufacturing have led to additional documentation regarding the pharmaceutical product requirements of corneal grafts in the European Union. The aim of this project was to develop a software within a hospital information system (HIS) to support the documentation process, to improve the management of the patient waiting list and to increase informational flow between the clinic and eye bank. MATERIALS AND METHODS: After an analysis of the current documentation process, a new workflow and software were implemented in our electronic health record (EHR) system. RESULTS: The software takes over most of the documentation and reduces the time required for record keeping. It guarantees real-time tracing of all steps during human corneal tissue processing from the start of production until allocation during surgery and includes follow-up within the HIS. Moreover, listing of the patient for surgery as well as waiting list management takes place in the same system. CONCLUSION: The new software for corneal eye banking supports the whole process chain by taking over both most of the required documentation and the management of the transplant waiting list. It may provide a standardized IT-based solution for German eye banks working within the same HIS.

6.
Blood Cancer J ; 6: e397, 2016 Feb 26.
Article in English | MEDLINE | ID: mdl-26918361

ABSTRACT

We employed a customized Multiple Myeloma (MM)-specific Mutation Panel (M(3)P) to screen a homogenous cohort of 142 untreated MM patients for relevant mutations in a selection of disease-specific genes. M(3)Pv2.0 includes 77 genes selected for being either actionable targets, potentially related to drug-response or part of known key pathways in MM biology. We identified mutations in potentially actionable genes in 49% of patients and provided prognostic evidence of STAT3 mutations. This panel may serve as a practical alternative to more comprehensive sequencing approaches, providing genomic information in a timely and cost-effective manner, thus allowing clinically oriented variant screening in MM.


Subject(s)
DNA Copy Number Variations , High-Throughput Nucleotide Sequencing , Multiple Myeloma/genetics , Mutation , Adult , Aged , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Clonal Evolution/genetics , DNA Mutational Analysis , Follow-Up Studies , Genetic Heterogeneity , Humans , Middle Aged , Multiple Myeloma/drug therapy , Multiple Myeloma/metabolism , Multiple Myeloma/mortality , Prognosis , Signal Transduction/drug effects
7.
Blood ; 124(4): 536-45, 2014 Jul 24.
Article in English | MEDLINE | ID: mdl-24914135

ABSTRACT

Cereblon (CRBN) mediates immunomodulatory drug (IMiD) action in multiple myeloma (MM). Using 2 different methodologies, we identified 244 CRBN binding proteins and established relevance to MM biology by changes in their abundance after exposure to lenalidomide. Proteins most reproducibly binding CRBN (>fourfold vs controls) included DDB1, CUL4A, IKZF1, KPNA2, LTF, PFKL, PRKAR2A, RANGAP1, and SHMT2. After lenalidomide treatment, the abundance of 46 CRBN binding proteins decreased. We focused attention on 2 of these-IKZF1 and IKZF3. IZKF expression is similar across all MM stages or subtypes; however, IKZF1 is substantially lower in 3 of 5 IMiD-resistant MM cell lines. The cell line (FR4) with the lowest IKZF1 levels also harbors a damaging mutation and a translocation that upregulates IRF4, an IKZF target. Clinical relevance of CRBN-binding proteins was demonstrated in 44 refractory MM patients treated with pomalidomide and dexamethasone therapy in whom low IKZF1 gene expression predicted lack of response (0/11 responses in the lowest expression quartile). CRBN, IKZF1, and KPNA2 levels also correlate with significant differences in overall survival. Our study identifies CRBN-binding proteins and demonstrates that in addition to CRBN, IKZF1, and KPNA2, expression can predict survival outcomes.


Subject(s)
Biomarkers, Tumor/metabolism , Carrier Proteins/metabolism , Drug Resistance, Neoplasm , Immunologic Factors/pharmacology , Multiple Myeloma/metabolism , Peptide Hydrolases/metabolism , Adaptor Proteins, Signal Transducing , Anti-Inflammatory Agents/pharmacology , Blotting, Western , Clinical Trials, Phase II as Topic , Dexamethasone/pharmacology , Flow Cytometry , Follow-Up Studies , Humans , Ikaros Transcription Factor/metabolism , Immunoprecipitation , Lenalidomide , Multiple Myeloma/drug therapy , Multiple Myeloma/mortality , Prognosis , Prospective Studies , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Survival Rate , Thalidomide/analogs & derivatives , Thalidomide/pharmacology , Tumor Cells, Cultured , Ubiquitin-Protein Ligases , alpha Karyopherins/metabolism
8.
Clin Lymphoma Myeloma Leuk ; 14(4): 284-290.e5, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24565465

ABSTRACT

BACKGROUND: More than 400 preclinical studies report ≥ 1 compound as cytotoxic to multiple myeloma (MM) cells; however, few of these agents became relevant in the clinic. Thus, the utility of such assays in predicting future clinical value is debatable. PATIENTS AND METHODS: We examined the application of early-phase trial experiences to predict future clinical adoption. We identified 129 drugs explored as single agents in 228 trials involving 7421 patients between 1961 and 2013. RESULTS: All drugs in common use in MM (melphalan, dexamethasone, prednisone, cyclophosphamide, bendamustine, thalidomide, lenalidomide, pomalidomide, bortezomib, carfilzomib, and doxorubicin) demonstrated a best reported response rate of ≥ 22%. Older agents, including teniposide, fotemustine, paclitaxel, and interferon, also appear active by this criterion; however, if mean response rates from all reported trials for an agent are considered, then only drugs with a mean response rate of 15% partial response are in clinical use. CONCLUSION: Our analysis suggests that thresholds of 20% for best or 15% for mean response are highly predictive of future clinical success. Below these thresholds, no drug has yet reached regulatory approval or widespread use in the clinic. Thus, this benchmark provides 1 element of the framework for guiding choice of drugs for late-stage clinical testing.


Subject(s)
Antineoplastic Agents/therapeutic use , Multiple Myeloma/drug therapy , Antineoplastic Agents/classification , Antineoplastic Agents/pharmacology , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Humans , Treatment Outcome
9.
PLoS One ; 9(2): e87113, 2014.
Article in English | MEDLINE | ID: mdl-24505276

ABSTRACT

Liposarcoma is the most common soft tissue sarcoma, but little is known about the genomic basis of this disease. Given the low cell content of this tumor type, we utilized flow cytometry to isolate the diploid normal and aneuploid tumor populations from a well-differentiated liposarcoma prior to array comparative genomic hybridization and whole genome sequencing. This work revealed massive highly focal amplifications throughout the aneuploid tumor genome including MDM2, a gene that has previously been found to be amplified in well-differentiated liposarcoma. Structural analysis revealed massive rearrangement of chromosome 12 and 11 gene fusions, some of which may be part of double minute chromosomes commonly present in well-differentiated liposarcoma. We identified a hotspot of genomic instability localized to a region of chromosome 12 that includes a highly conserved, putative L1 retrotransposon element, LOC100507498 which resides within a gene cluster (NAV3, SYT1, PAWR) where 6 of the 11 fusion events occurred. Interestingly, a potential gene fusion was also identified in amplified DDR2, which is a potential therapeutic target of kinase inhibitors such as dastinib, that are not routinely used in the treatment of patients with liposarcoma. Furthermore, 7 somatic, damaging single nucleotide variants have also been identified, including D125N in the PTPRQ protein. In conclusion, this work is the first to report the entire genome of a well-differentiated liposarcoma with novel chromosomal rearrangements associated with amplification of therapeutically targetable genes such as MDM2 and DDR2.


Subject(s)
Chromosomes, Human, Pair 11/genetics , Chromosomes, Human, Pair 12/genetics , Gene Rearrangement , Genomic Instability , Liposarcoma/genetics , Neoplasm Proteins/genetics , Synaptotagmin I/genetics , DNA, Neoplasm/genetics , Discoidin Domain Receptors , Female , Gene Amplification , Genes, Neoplasm , Genome-Wide Association Study , Humans , Male , Multigene Family , Receptor Protein-Tyrosine Kinases , Receptors, Mitogen
10.
Leuk Res ; 38(1): 23-8, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24129344

ABSTRACT

Cereblon (CRBN) mediates immunomodulatory drug (IMiD) action in multiple myeloma (MM). We demonstrate here that no patient with very low CRBN expression responded to IMiD plus dexamethasone therapy. In 53 refractory MM patients treated with pomalidomide and dexamethasone, CRBN levels predict for decreased response rates and significant differences in PFS (3.0 vs. 8.9 months, p<0.001) and OS (9.1 vs. 27.2 months, p=0.01) (lowest quartile vs. highest three quartiles). While higher CRBN levels can serve as a surrogate for low risk disease, our study demonstrates that low CRBN expression can predict resistance to IMiD monotherapy and is a predictive biomarker for survival outcomes.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Gene Expression Regulation, Neoplastic , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Peptide Hydrolases/genetics , Adaptor Proteins, Signal Transducing , Biomarkers, Tumor/genetics , Cell Line, Tumor , Dexamethasone/administration & dosage , Drug Resistance, Neoplasm/genetics , Humans , Multiple Myeloma/pathology , Prognosis , Survival Analysis , Thalidomide/administration & dosage , Thalidomide/analogs & derivatives , Treatment Outcome , Ubiquitin-Protein Ligases
11.
Leukemia ; 27(12): 2357-65, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23752175

ABSTRACT

RNA interference screening identified XPO1 (exportin 1) among the 55 most vulnerable targets in multiple myeloma (MM). XPO1 encodes CRM1, a nuclear export protein. XPO1 expression increases with MM disease progression. Patients with MM have a higher expression of XPO1 compared with normal plasma cells (P<0.04) and to patients with monoclonal gammopathy of undetermined significance/smoldering MM (P<0.0001). The highest XPO1 level was found in human MM cell lines (HMCLs). A selective inhibitor of nuclear export compound KPT-276 specifically and irreversibly inhibits the nuclear export function of XPO1. The viability of 12 HMCLs treated with KTP-276 was significantly reduced. KPT-276 also actively induced apoptosis in primary MM patient samples. In gene expression analyses, two genes of probable relevance were dysregulated by KPT-276: cell division cycle 25 homolog A (CDC25A) and bromodomain-containing protein 4 (BRD4), both of which are associated with c-MYC pathway. Western blotting and reverse transcription-PCR confirm that c-MYC, CDC25A and BRD4 are all downregulated after treatment with KPT-276. KPT-276 reduced monoclonal spikes in the Vk*MYC transgenic MM mouse model, and inhibited tumor growth in a xenograft MM mouse model. A phase I clinical trial of an analog of KPT-276 is ongoing in hematological malignancies including MM.


Subject(s)
Acrylamides/pharmacology , Biological Transport/drug effects , Cell Nucleus/drug effects , Genome-Wide Association Study , Karyopherins/genetics , Multiple Myeloma/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Thiazoles/pharmacology , Animals , Cell Line, Tumor , Cell Nucleus/metabolism , Gene Expression Profiling , Humans , Karyopherins/drug effects , Mice , RNA Interference , Receptors, Cytoplasmic and Nuclear/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Xenograft Model Antitumor Assays , Exportin 1 Protein
13.
Blood ; 121(6): 893-7, 2013 Feb 07.
Article in English | MEDLINE | ID: mdl-23393020

ABSTRACT

This spotlight review focuses on the second-generation proteasome inhibitor carfilzomib, which was recently approved by the U.S. Food and Drug Administration for treatment of relapsed and refractory multiple myeloma patients who have received at least 2 prior therapies, including bortezomib and an immunomodulatory agent, and have demonstrated disease progression on or within 60 days of the completion of the last therapy. This review focuses on clinical trial data leading to drug approval and provides advice for treating physicians who are now accessing this drug for patients.


Subject(s)
Drug Approval , Multiple Myeloma/drug therapy , Oligopeptides/therapeutic use , Proteasome Inhibitors/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Clinical Trials as Topic , Humans , Multiple Myeloma/metabolism , Oligopeptides/administration & dosage , Practice Guidelines as Topic , Proteasome Endopeptidase Complex/metabolism , Proteasome Inhibitors/administration & dosage , Treatment Outcome
14.
Leuk Lymphoma ; 54(4): 683-7, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22966948

ABSTRACT

Although several mechanisms have been proposed to explain the activity of thalidomide, lenalidomide and pomalidomide in multiple myeloma (MM), including demonstrable anti-angiogenic, anti-proliferative and immunomodulatory effects, the precise cellular targets and molecular mechanisms have only recently become clear. A landmark study recently identified cereblon (CRBN) as a primary target of thalidomide teratogenicity. Subsequently it was demonstrated that CRBN is also required for the anti-myeloma activity of thalidomide and related drugs, the so-called immune-modulatory drugs (IMiDs). Low CRBN expression was found to correlate with drug resistance in MM cell lines and primary MM cells. One of the downstream targets of CRBN identified is interferon regulatory factor 4 (IRF4), which is critical for myeloma cell survival and is down-regulated by IMiD treatment. CRBN is also implicated in several effects of IMiDs, such as down-regulation of tumor necrosis factor-α (TNF-α) and T cell immunomodulatory activity, demonstrating that the pleotropic actions of the IMiDs are initiated by binding to CRBN. Future dissection of CRBN downstream signaling will help to delineate the underlying mechanisms for IMiD action and eventually lead to development of new drugs with more specific anti-myeloma activities. It may also provide a biomarker to predict IMiD response and resistance.


Subject(s)
Immunologic Factors/therapeutic use , Multiple Myeloma/drug therapy , Thalidomide/analogs & derivatives , Thalidomide/therapeutic use , Adaptor Proteins, Signal Transducing , Gene Expression , Humans , Interferon Regulatory Factors/metabolism , Lenalidomide , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , Peptide Hydrolases/metabolism , Teratogens/toxicity , Thalidomide/adverse effects , Ubiquitin-Protein Ligases
15.
Neuroscience ; 109(3): 635-42, 2002.
Article in English | MEDLINE | ID: mdl-11823072

ABSTRACT

Axonal injury to CNS neurons results in apoptotic cell death. The processes by which axotomy signals apoptosis are diverse, and may include deprivation of target-derived factors, induction of injury factors, bursts of reactive oxygen species (ROS), and other mechanisms. Our previous studies demonstrated that death of a dissociated retinal ganglion cell, an identified CNS neuron, is ROS-dependent. To better define the mechanisms by which ROS induce retinal ganglion cell death after axotomy, we studied their effects in dissociated neonatal rat retinal cultures. Postnatal day 2-4 Long-Evans rat retinal ganglion cells were retrogradely labeled with the fluorescent tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI). Postnatal day 7-9 retinas were dissociated and cultured in the presence of specific ROS generating systems, scavengers, or redox modulators. Retinal ganglion cells were identified by DiI positivity and viability determined by metabolism of calcein-acetoxymethyl ester. We found that ROS scavengers protected against retinal ganglion cell death after acute dissociation, and the effects of ROS appeared to be due to shifts in the redox potential, as retinal ganglion cell survival was critically dependent on redox state, with greatest survival under mildly reducing conditions. Culture of retinal ganglion cell with the non-thiol-containing reducing agent tris(carboxyethyl)phosphine resulted in long-term survival equivalent to or better than with neurotrophic factors. Our data suggest that axotomy-associated neuronal death induced by acute dissociation may be partly dependent on ROS production, acting to shift the redox state and oxidize one or more key thiols. Understanding the mechanisms by which ROS signal neuronal death could result in strategies for increasing their long-term survival after axonal injury.


Subject(s)
Apoptosis/physiology , Cell Survival/physiology , Nerve Degeneration/metabolism , Reactive Oxygen Species/metabolism , Retinal Ganglion Cells/metabolism , Sulfhydryl Compounds/metabolism , Animals , Animals, Newborn , Apoptosis/drug effects , Carbocyanines , Cell Survival/drug effects , Cells, Cultured , Dithionitrobenzoic Acid/pharmacology , Dithiothreitol/pharmacology , Enzyme Inhibitors/pharmacology , Fluorescent Dyes , Indicators and Reagents/pharmacology , Nerve Degeneration/drug therapy , Nerve Degeneration/physiopathology , Nerve Growth Factors/pharmacology , Phosphines/pharmacology , Rats , Rats, Long-Evans , Reactive Oxygen Species/antagonists & inhibitors , Retinal Ganglion Cells/drug effects , Sulfhydryl Compounds/antagonists & inhibitors , Sulfhydryl Reagents/pharmacology
16.
Invest Ophthalmol Vis Sci ; 41(10): 3176-82, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10967081

ABSTRACT

PURPOSE: Retinal light exposure is a source of oxidative stress, and retinal cells contain molecules that scavenge or inactivate reactive oxygen species (ROS). Yet, ROS also play a role in signal transduction, and some retinal cells (e.g., neurotrophin-dependent retinal ganglion cells, RGCs) may use ROS as part of the signaling process for cell death. RGCs might therefore have specialized mechanisms for regulating ROS levels. The hypothesis that RGCs might regulate ROS differently from other retinal cells was tested by studying their differential response to oxidative stress in vitro. METHODS: RGCs were retrogradely labeled by injecting the fluorescent tracer DiI into the superior colliculi of postnatal day 2 through 4 Long-Evans rats. At postnatal days 7 through 9 the retinas were dissociated with papain and cultured with and without specific ROS-generating systems and/or scavengers. RGCs were identified by their DiI positivity using rhodamine filters. Living cells, determined by metabolism of calcein-AM viewed with fluorescein filters, were counted in triplicate. Degenerate reverse transcription-polymerase chain reaction (RT-PCR) using primers specific to peroxidase homology regions was used to survey for novel peroxidases expressed within normal retinas. RESULTS: Compared with other retinal cells, RGCs were remarkably resistant to cell death induced by superoxide anion, hydrogen peroxide, or hydroxyl radical. Catalase counteracted the effect of each ROS-generating system on retinal cells, consistent with damage occurring via a hydrogen peroxide intermediate. Aminotriazole, L-buthionine sulfoximine, and sodium azide partly abrogated the RGC resistance to oxidative stress, suggesting that this resistance may be mediated by catalase and/or glutathione peroxidase. A limited expression survey within the retina using degenerate RT-PCR did not demonstrate novel peroxidases. CONCLUSIONS: These data suggest a role for one or more endogenous peroxidases within RGCs, which could possibly be protective under conditions of axonal damage. Exploration of the unique characteristics of RGC resistance and susceptibility to injury may help in better understanding the pathophysiology of diseases associated with primary axonal damage.


Subject(s)
Neoplasm Proteins , Oxidative Stress , Reactive Oxygen Species , Retinal Ganglion Cells/physiology , Animals , Carbocyanines/metabolism , Catalase/genetics , Catalase/metabolism , Cell Count , Cell Survival , Cells, Cultured , DNA Primers/chemistry , Fluoresceins/metabolism , Fluorescent Dyes/metabolism , Hydrogen Peroxide/pharmacology , Oxidative Stress/physiology , Peroxidases/genetics , Peroxidases/metabolism , Peroxiredoxins , Rats , Rats, Long-Evans , Reactive Oxygen Species/physiology , Retinal Ganglion Cells/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Vitamin K/pharmacology , Xanthine Oxidase/pharmacology
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