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63 result(s) for "Framme Carsten"
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Long-term in vitro monitoring of AAV-transduction efficiencies in real-time with Hoechst 33342
Adeno-associated viral transduction allows the introduction of nucleic fragments into cells and is widely used to modulate gene expressions in vitro and in vivo . It enables the study of genetic functions and disease mechanisms and, more recently, serves as a tool for gene repair. To achieve optimal transduction performance for a given cell type, selecting an appropriate serotype and the number of virus particles per cell, also known as the multiplicity of infection, is critical. Fluorescent proteins are one of the common reporter genes to visualize successfully transduced cells and assess transduction efficiencies. Traditional methods of measuring fluorescence-positive cells are endpoint analysis by flow cytometry or manual counting with a fluorescence microscope. However, the flow cytometry analysis does not allow further measurement in a test run, and manual counting by microscopy is time-consuming. Here, we present a method that repeatedly evaluates transduction efficiencies by adding the DNA-stain Hoechst 33342 during the transduction process combined with a microscope or live-cell imager and microplate image analysis software. The method achieves fast, high-throughput, reproducible, and real-time post-transduction analysis and allows for optimizing transduction parameters and screening for a proper approach.
MiR-302d inhibits TGFB-induced EMT and promotes MET in primary human RPE cells
Transforming growth factor-beta (TGFB)-mediated epithelial-mesenchymal transition (EMT) plays a crucial role in the pathogenesis of retinal fibrosis, which is one of the leading causes of impaired vision. Current approaches to treating retinal fibrosis focus, among other things, on inhibiting the TGFB signaling pathway. Transient expression of microRNAs (miRNAs) is one way to inhibit the TGFB pathway post-transcriptionally. Our previous study identified the miRNA miR-302d as a regulator of multiple TGFB-related genes in ARPE-19 cells. To further explore its effect on primary cells, the effect of miR-302d on TGFB-induced EMT in primary human retinal pigment epithelium (hRPE) was investigated in vitro. hRPE cells were extracted from patients receiving enucleation. Transfection of hRPE cells with miR-302d was performed before or after TGFB1 stimulation. Live-cell imaging, immunocytochemistry staining, Western blot, and ELISA assays were utilized to identify the alterations of cellular morphology and EMT-related factors expressions in hRPE cells. hRPE cells underwent EMT by TGFB1 exposure. The transfection of miR-302d inhibited the transition with decreased production of mesenchymal markers and increased epithelial factors. Meanwhile, the phosphorylation of SMAD2 activated by TGFB1 was suppressed. Moreover, miR-302d expression promoted TGFB1-induced fibroblast-like hRPE cells to revert towards an epithelial stage. As confirmed by ELISA, miR-302d reduced TGFB receptor 2 (TGFBR2) and vascular endothelial growth factor A (VEGFA) levels 48 hours after transfection. The protective effect of miR-302d might be a promising approach for ameliorating retinal fibrosis and neovascularization. MiR-302d suppresses TGFB-induced EMT in hRPE cells via downregulation of TGFBR2, even reversing the process. Furthermore, miR-302d reduces the constitutive secretion of VEGFA from hRPE cells.
A simple dissection method for the isolation of mouse trabecular meshwork cells
The outflow pathway, especially trabecular meshwork (TM), plays an essential role in glaucoma, and the availability of TM cells is crucial for in vitro research. So far, the isolation of TM cells from mice has been anything but manageable due to the small size of the eye. Direct isolation using a stereomicroscope and forceps requires a high grade of dexterity. Indirect isolation is based on the phagocytic properties of TM cells and involves injecting magnetic microspheres into the anterior chamber of live mice followed by isolation. Therefore, a simpler, less expensive, and nonexperimental strategy for isolating mouse TM cells would be desirable. After enucleation, the eyes were cut in half anterior-to-posteriorly. The lens and posterior segment were removed. Iris and the attached ciliary body were gently pulled backward and disconnected from the remaining tissue to expose the TM. By incising through the cornea anteriorly and posteriorly of the TM, the cornea/TM stripe could be isolated. The cornea/TM stripe was cultured with the pigmented side down in a 6-well. The outgrowing pigmented cells were analyzed by immunocytochemistry and mRNA expression for previously described TM cell markers. The phagocytic properties of the cells were additionally confirmed using fluorescent microspheres. Pigmented phagocytic cells were the first to grow out of the cornea/TM strips after approximately 4-7 days. Cells were positive for Collagen IV, Fibronectin1, Vimentin, and Actin alpha 2 and could phagocytize fluorescent microbeads. Cross-linked actin networks were visible after 9 days of exposure to TGFB2 (transforming growth factor-beta 2). Additionally, treatment with 500 nM Dexamethasone for one week increased myocilin expression, as previously reported for TM cells. In addition, we proved that this method can also be used in albino mice, which lack pigmentation of the trabecular meshwork. The isolated cells show phagocytic properties and specific expression of markers reported in TM cells. Therefore, our dissection-based method is inexpensive and reproducible for isolating TM cells in mice.
In vitro comparison of human and murine trabecular meshwork cells: implications for glaucoma research
The trabecular meshwork (TM) is crucial for regulating intraocular pressure (IOP), and its dysfunction significantly contributes to glaucoma, a leading cause of vision loss and blindness worldwide. Although rodents are commonly used as animal models in glaucoma research, the applicability of these findings to humans is limited due to the insufficient understanding of murine TM. This study aimed to compare primary human TM (hTM) and murine TM (mTM) cells in vitro to enhance the robustness and translatability of murine glaucoma models. In this in vitro study, we compared primary hTM and mTM cells under simulated physiological and pathological conditions by exposing both cell types to the glucocorticoid dexamethasone (DEX) and Transforming Growth Factor β (TGFB2), both of which are critical in the pathogenesis of several ophthalmological diseases, including glaucoma. Phagocytic properties were assessed using microbeads. Cells were analyzed through immunocytochemistry (ICC) and Western blot (WB) to evaluate the expression of extracellular matrix (ECM) components, such as Fibronectin 1 (FN1) and Collagen IV (COL IV). Filamentous-Actin (F-Act) staining was used to analyze cross-linked actin network (CLAN) formation. Additionally, we evaluated cytoskeletal components, including Vimentin (VIM), Myocilin (MYOC), and Actin-alpha-2 (ACTA2). Our results demonstrated significant similarities between human and murine TM cells in basic morphology, phagocytic properties, and ECM and cytoskeletal component expression under both homeostatic and pathological conditions in vitro. Both human and murine TM cells exhibited epithelial-to-mesenchymal transition (EMT) after exposure to DEX or TGFB2, with comparable CLAN formation observed in both species. However, there were significant differences in FN1 and MYOC induction between human and murine TM cells. Additionally, MYOC expression in hTM cells depended on fibronectin coating. Our study suggests that murine glaucoma models are potentially translatable to human TM. The observed similarities in ECM and cytoskeletal component expression and the comparable EMT response and CLAN formation support the utility of murine models in glaucoma research. The differences in FN1 and MYOC expression between hTM and mTM warrant further investigation due to their potential impact on TM properties. Overall, this study provides valuable insights into the species-specific characteristics of TM and highlights opportunities to refine murine models for better relevance to human glaucoma.
MiR-302d inhibits TGFB-induced EMT and promotes MET in primary human RPE cells
Purpose Transforming growth factor-beta (TGFB)-mediated epithelial-mesenchymal transition (EMT) plays a crucial role in the pathogenesis of retinal fibrosis, which is one of the leading causes of impaired vision. Current approaches to treating retinal fibrosis focus, among other things, on inhibiting the TGFB signaling pathway. Transient expression of microRNAs (miRNAs) is one way to inhibit the TGFB pathway post-transcriptionally. Our previous study identified the miRNA miR-302d as a regulator of multiple TGFB-related genes in ARPE-19 cells. To further explore its effect on primary cells, the effect of miR-302d on TGFB-induced EMT in primary human retinal pigment epithelium (hRPE) was investigated in vitro. Methods hRPE cells were extracted from patients receiving enucleation. Transfection of hRPE cells with miR-302d was performed before or after TGFB1 stimulation. Live-cell imaging, immunocytochemistry staining, Western blot, and ELISA assays were utilized to identify the alterations of cellular morphology and EMT-related factors expressions in hRPE cells. Results hRPE cells underwent EMT by TGFB1 exposure. The transfection of miR-302d inhibited the transition with decreased production of mesenchymal markers and increased epithelial factors. Meanwhile, the phosphorylation of SMAD2 activated by TGFB1 was suppressed. Moreover, miR-302d expression promoted TGFB1-induced fibroblast-like hRPE cells to revert towards an epithelial stage. As confirmed by ELISA, miR-302d reduced TGFB receptor 2 (TGFBR2) and vascular endothelial growth factor A (VEGFA) levels 48 hours after transfection. Conclusions The protective effect of miR-302d might be a promising approach for ameliorating retinal fibrosis and neovascularization. MiR-302d suppresses TGFB-induced EMT in hRPE cells via downregulation of TGFBR2, even reversing the process. Furthermore, miR-302d reduces the constitutive secretion of VEGFA from hRPE cells.
Successful management with Paul® Glaucoma Drainage Implant after complicated bleb needling with uveal prolapse into the bleb ten years after trabeculectomy
Background Fibrosis is the primary cause of failure following glaucoma surgery. Wound healing modulation with 5-fluorouracil and mitomycin-C is routinely employed to reduce ocular fibrosis and improve surgical success rates; however, it also increases the risk of postoperative complications. Case presentation A 59-year-old patient with a family history of glaucoma presented a decade after bilateral trabeculectomy with an intraocular pressure (IOP) of 30 mmHg in the right eye and 42 mmHg in the left eye. Both eyes underwent multiple cyclophotocoagulations in the past and showed ocular surface inflammation due to eyedrop intolerance as well as scarred blebs without scleral thinning. Simultaneous bilateral bleb needling reduced IOP to 7 mmHg on the right eye and 12 mmHg on the left eye. The postoperative course of the right eye was favorable with a stable IOP at the low teens. However, IOP of the left eye rose to 34 mmHg within 3 days, accompanied by a uveal prolapse into the bleb. A subsequent vitrectomy with Tutopatch ® and anterior chamber washout was performed after 10 days, followed by implantation of the novel Paul ® Glaucoma Drainage Implant after sufficient scleral healing. This resulted in a postoperative IOP of 8 mmHg. After 12 months, no eyedrops were required, there were no signs of ocular surface inflammation, and the IOP was stable at 13 mmHg in the right eye and 12 mmHg in the left eye. Conclusion This case highlights a rare occasion of scleral thinning leading to perforation with uveal prolapse after needling, 10 years post-trabeculectomy. Likely causes include the use of antimetabolites, cyclodestructive procedures, and chronic conjunctival inflammation from eyedrops. Although needling is typically low-risk, it can lead to complications similar to trabeculectomy. Preoperative screening for scleral thinning using slit lamp and anterior segment OCT is recommended for high-risk patients. The presented two-stage treatment strategy proved successful in managing this complex case.
PERSEUS 24-month analysis: a prospective non-interventional study to assess the effectiveness of intravitreal aflibercept in routine clinical practice in Germany in patients with neovascular age-related macular degeneration
PurposeTo evaluate the real-world effectiveness of intravitreal aflibercept injections in Germany in patients with neovascular age-related macular degeneration over 24 months.MethodsPERSEUS was a prospective, non-interventional cohort study. The primary endpoint was the mean change in visual acuity (VA) from baseline. Secondary endpoints included the proportion of patients with a VA gain or loss of ≥ 15 letters and the frequency of injections and examinations. Patients with regular (bimonthly after 3 monthly injections during year 1 and ≥ 4 injections in year 2) and irregular (any other) treatment were analyzed. The last observation carried forward (LOCF) and the observed cases (OC) approach was applied for primary endpoint analysis to account for missing data.Results803 patients were considered for effectivity analysis. At month 24, only 38% of the patients were still under observation. The LOCF population included 727, the OC population 279 patients. Treatment-naïve patients improved by 6.3 (LOCF)/8.1 (OC) letters with regular treatment over 24 months but only by 3.3 (LOCF)/3.1 (OC) letters with irregular treatment. The proportion of treatment-naïve patients achieving a VA improvement of ≥ 15 letters was similar between regularly and irregularly treated cohorts. However, considerably more patients in the irregular cohorts experienced a VA worsening of ≥ 15 letters than in the regular cohorts (LOCF: 18.7% vs. 7.4%).ConclusionsRegular IVT-AFL treatment resulted in better VA outcomes than irregular treatment at month 24. However, only a minority of patients received regular treatment over a 2-year period.
Individualized treat-and-extend regime for optimization of real-world vision outcome and improved patients’ persistence
Background Intravitreal injections are a mandatory treatment for macular edema due to nAMD, DME and RVO. These chronic diseases usually need chronic treatment using intravitreal injections with anti-VEGF agents. Thus, many trials were performed to define the best treatment interval using pro re nata regimes (PRN), fixed regimes or treat-and-extend regimes (TE). However, real-world studies reveal a high rate of losing patients within a 2-year interval of treatment observation causing worse results. In this study we analyzed retrospectively 2 years of real-world experience with an individualized treat-and-extend injection scheme. Methods Since 2015 our treatment scheme for intravitreal injections has been switched from PRN to TE. Out of 102 patients 59 completed a follow up time of 2 years. Every patient received visual acuity testing, SD-OCT and slit lamp examination prior to every injection. At each visit an injection was performed and the treatment interval was adjusted mainly on SD-OCT based morphologic changes by increasing or reducing in 2-week steps. Individual changes of the treatment protocol by face-to-face communication between physician and patient were possible. Results After 1 year of treatment visual acuity gain in nAMD was 7.4 ± 2.2 ETDRS letters ( n  = 34; injection frequency: 7.4 ± 0.4) respectively 6.1 ± 4.7 in DME ( n  = 9; injection frequency: 8.4 ± 1.1) and 9.7 ± 4.5 in RVO ( n  = 16; injection frequency: 7.6 ± 0.5). After 2 years of treatment results were as following: nAMD: visual acuity gain 6.9 ± 2.1 (injection frequency: 12.6 ± 0.7); DME: 11.1 ± 5.1 (injection frequency: 14.0 ± 1.0); RVO: 7.5 ± 5.0 (injection frequency: 11.2 ± 0.9). Planned treatment exit after 2 year was achieved in 29.4% of patients in nAMD (0% after 1 year); 0% in DME (0% after 1 year); and 31.3% in RVO (0% after 1 year). Patients’ persistence was 94.1% during the follow-up. Conclusion Using a consequent and individualized TE regime in daily practice may lead to a high patients’ persistence and visual acuity gains nearly comparable to those of large prospective clinical trials. Crucial factors are face-to-face communication with the patient as well as a stringent management regime. At this time TE may be the only instrument for proactive therapy which should therefore be regarded as a first-line tool in daily practice.
Clinical and paraclinical characteristics of optic neuritis in the context of the McDonald criteria 2017
Optic neuritis is often an initial symptom in multiple sclerosis (MS) or clinically isolated syndrome (CIS), yet comprehensive studies using the 2017 McDonald criteria for MS are scarce. Patient records from our academic centre (2010–2018) were reviewed. Using the 2017 McDonald criteria, three groups were formed: MS optic neuritis (optic neuritis with confirmed MS), CIS optic neuritis (optic neuritis without confirmed MS) and suspected optic neuritis (sON). We compared clinical and paraclinical findings among the groups to identify predictors for CIS- or MS-optic neuritis. The study included 129 MS, 108 CIS, and 44 sON cases. The combination of visual impairment, dyschromatopsia, and retrobulbar pain was observed in 47% of MS patients, 42% of CIS patients, and 30% of sON patients. Dyschromatopsia was the strongest indicator of MS or CIS diagnosis in the backward regression model. 56% of MS patients had relative afferent pupillary defect, 61% optic nerve anomalies within magnetic resonance imaging, and 81% abnormal visual evoked potentials. Our results emphasize the challenges in diagnosing optic neuritis, as not all patients with objectively diagnosed MS exhibit the triad of typical symptoms. To address potentially missing clinical features, incorporating additional paraclinical findings is proposed.