Miriam Kolko - Academia.edu (original) (raw)
Papers by Miriam Kolko
Acta Ophthalmologica, 2022
PurposeRetinal ganglion cell (RGC) death is a common characteristic for ocular neurodegenerative ... more PurposeRetinal ganglion cell (RGC) death is a common characteristic for ocular neurodegenerative diseases such as glaucoma and optic neuropathies. Recently, GPR81 agonist treatment has been identified as a key modulator of mitochondrial function and cell survival. Thus, we aimed to test whether GPR81 agonist treatment likewise promotes RGC survival and energy metabolism in retinal explants and wholemounts from mice.MethodsRetinal explants were treated with 5 mM of the GPR81 agonist, 3,5‐DHBA, for two, four, 24 & 72 hours, and compared to conditions with no treatment. Additionally, explants were also treated with 15 mM of L‐glutamate to induce toxicity and simultaneously treated with GPR81 agonist. Tissue survival was assessed through lactate dehydrogenase (LDH) viability assays. Retinal ganglion cell survival was measured in murine wholemount retinas through immunohistochemical staining (IHC). Total ATP levels were quantified through bioluminescence assays.ResultsGPR81 agonist treatment increased retinal explant survival after 24 and 72 hours of exposure. No significant effect was seen in retinal explants survival after GPR81 agonist treatment alone for two hours. However, during glutamate‐induced death, supplemented GPR81 agonist treatment increased survival compared to conditions with glutamate toxicity. IHC analysis revealed that GPR81 agonist treatment for two hours promoted RGC survival in retinal wholemounts compared with no treatment. GPR81 agonist treatment also enhanced ATP levels in retinal explants after two, 24, and 72 hr of exposure.ConclusionsThe present study reveals that GPR81 agonist treatment has a neuroprotective effect on specifically RGCs and on glutamate‐induced retinal degeneration. Hence, GPR81 agonist administration may be a potential new strategy to sustain RGCs, ultimately preventing visual disability as a consequence of RGC death.
Cellular and Molecular Neurobiology, 2020
Estrogen is essential in maintaining various physiological features in women, and a decline in es... more Estrogen is essential in maintaining various physiological features in women, and a decline in estrogen levels are known to give rise to numerous unfortunate symptoms associated with menopause. To alleviate these symptoms hormone replacement therapy with estrogen is often used, and has been shown to be fruitful in improving quality of life in women suffering from postmenopausal discomforts. An often forgotten condition associated with menopause is the optic nerve disorder, glaucoma. Thus, estrogen may also have an impact in maintaining the retinal ganglion cells (RGCs), which make up the optic nerve, thereby preventing glaucomatous neurodegeneration. This review aims to provide an overview of possible associations of estrogen and the glaucoma subtype, primary open-angle glaucoma (POAG), by evaluating the current literature through a PubMed-based literature search. Multiple in vitro and in vivo studies of RGC protection, as well as clinical and epidemiological data concerning the well-defined retinal neurodegenerative disorder POAG have been reviewed. Over all, deficiencies in retinal estrogen may potentially instigate RGC loss, visual disability, and eventual blindness. Estrogen replacement therapy may therefore be a beneficial future treatment. However, more studies are needed to confirm the relevance of estrogen in glaucoma prevention.
Cells
Background: Progressive retinal ganglion cell (RGC) dysfunction and death are common characterist... more Background: Progressive retinal ganglion cell (RGC) dysfunction and death are common characteristics of retinal neurodegenerative diseases. Recently, hydroxycarboxylic acid receptor 1 (HCA1R, GPR81) was identified as a key modulator of mitochondrial function and cell survival. Thus, we aimed to test whether activation of HCA1R with 3,5-Dihydroxybenzoic acid (DHBA) also promotes RGC survival and improves energy metabolism in mouse retinas. Methods: Retinal explants were treated with 5 mM of the HCA1R agonist, 3,5-DHBA, for 2, 4, 24, and 72 h. Additionally, explants were also treated with 15 mM of L-glutamate to induce toxicity. Tissue survival was assessed through lactate dehydrogenase (LDH) viability assays. RGC survival was measured through immunohistochemical (IHC) staining. Total ATP levels were quantified through bioluminescence assays. Energy metabolism was investigated through stable isotope labeling and gas chromatography-mass spectrometry (GC-MS). Lactate and nitric oxide le...
Cochrane Database of Systematic Reviews
Journal of Clinical Medicine
Purpose: To examine the physicochemical properties of five preservative-free (PF) 0.005% latanopr... more Purpose: To examine the physicochemical properties of five preservative-free (PF) 0.005% latanoprost ophthalmic products; Monoprost®, Latanest®, Gaap Ofteno®, Xalmono®, and Xaloptic® Free. Furthermore, the study investigated the mucin production and cell survival of primary cultured human conjunctival goblet cells when treated with PF eye drops. Method: The pH value, osmolality, and surface tension were examined. Cell survival was analyzed using lactate dehydrogenase and tetrazolium dye colorimetric assays. Mucin production was analyzed with immunohistochemical staining. Results: Monoprost® (pH value 6.84 ± 0.032) had a pH value closest to the pH value of tear fluid (pH value 7.4–7.6), whereas Gaap Ofteno® (pH value 6.34 ± 0.004) and Latanest® (pH value 6.33 ± 0.003) had the lowest pH values. Gaap Ofteno® (325.9 ± 2.9 mosmol/kg) showed iso-osmolar probabilities, whereas the other products were hypo-osmolar. Gaap Ofteno® (60.31 ± 0.35 mN/m) had a higher surface tension compared to th...
Acta Ophthalmologica, 2022
BMJ Open Ophthalmology, 2021
ObjectiveTo investigate the short-term impact on human conjunctival goblet cell (GC) survival and... more ObjectiveTo investigate the short-term impact on human conjunctival goblet cell (GC) survival and mucin release of acute exposure to benzalkonium chloride (BAK) preserved and preservative-free (PF) 0.005% (w/v) latanoprost (LT) eye drops, and to compare the eye drops’ physicochemical properties.Methods and analysisPrimary GC cultures were established from human conjunctival donor tissue. The impact of eye drops on GC survival was assessed using a lactate dehydrogenase assay. Mucin release was evaluated through mucin-specific immunostaining. pH value, osmolality, drop mass and surface tension for all LT eye drops were measured.ResultsAfter application with PF-LT for 30 min (min), the GC survival was maintained compared with control (p=0.9941), while all BAK-LT eye drops reduced survival with approximately 30% (p<0.02). Following application with PF-LT for 30 min, mucin was found around the GC nucleus, as seen in the vehicle control, indicating no secretion. In contrast, BAK-LT cau...
Journal of Glaucoma, 2021
Journal of Ophthalmology, 2021
Cellular and Molecular Neurobiology, 2021
Visual changes are some of the earliest symptoms that patients with Alzheimer's disease (AD) ... more Visual changes are some of the earliest symptoms that patients with Alzheimer's disease (AD) experience. Pathophysiological processes such as amyloid-β plaque formation, vascular changes, neuroinflammation, and loss of retinal ganglion cells (RGCs) have been detected in the retina of AD patients and animal models. However, little is known about the molecular processes that underlie retinal neurodegeneration in AD. The cellular architecture and constant sensory activity of the retina impose high metabolic demands. We thus hypothesized that energy metabolism might be compromised in the AD retina similarly to what has been observed in the AD brain. To address this question, we explored cellular alterations and retinal metabolic activity in the 5 × FAD mouse model of AD. We used 8-month-old female 5 × FAD mice, in which the AD-related pathology has been shown to be apparent. We observed that RGC density is selectively affected in the retina of 5 × FAD mice. To map retinal metabolic activity, we incubated isolated retinal tissue with [U-13C] glucose and analyzed tissue extracts by gas chromatography-mass spectrometry. We found that the retinas of 5 × FAD mice exhibit glucose hypometabolism. Moreover, we detected decreased glutamine synthesis in 5 × FAD retinas but no changes in the expression of markers of Müller glia, the main glial cell type responsible for glutamate uptake and glutamine synthesis in the retina. These findings suggest that AD presents with metabolic alterations not only in the brain but also in the retina that may be detrimental to RGC activity and survival, potentially leading to the visual impairments that AD patients suffer.
BMJ Open Ophthalmology, 2020
ObjectiveTo determine the effect of povidone iodine (PI), an antiseptic commonly used prior to oc... more ObjectiveTo determine the effect of povidone iodine (PI), an antiseptic commonly used prior to ocular surgery, on viability of mixed populations of conjunctival stratified squamous and goblet cells, purified conjunctival goblet cells and purified conjunctival stromal fibroblasts in primary culture.Methods and analysisMixed population of epithelial cells (stratified squamous and goblet cells), goblet cells and fibroblasts were grown in culture from pieces of human conjunctiva using either supplemented DMEM/F12 or RPMI. Cell type was evaluated by immunofluorescence microscopy. Cells were treated for 5 min with phosphate-buffered saline (PBS); 0.25%, 2.5%, 5% or 10% PI in PBS; or a positive control of 30% H2O2. Cell viability was determined using Alamar Blue fluorescence and a live/dead kit using calcein/AM and ethidium homodimer-1 (EH-1).ResultsMixed populations of epithelial cells, goblet cells and fibroblasts were characterised by immunofluorescence microscopy. As determined with Al...
Journal of Ophthalmology, 2021
Purpose To investigate whether patients with normal tension glaucoma (NTG) show an enhanced stres... more Purpose To investigate whether patients with normal tension glaucoma (NTG) show an enhanced stress response to reduced oxygen supply compared to age-matched healthy controls, measured by serum adrenaline and endothelin-1 (ET-1) levels and changes in distal finger temperature. Methods A thorough clinical characterization of patients with NTG and age-matched controls was performed prior to inclusion in the study. Twelve patients with NTG and eleven healthy controls met the inclusion criteria and were enrolled in the study. All subjects underwent a two-day investigation. Participants were randomly exposed to either hypoxia or normoxia during the first visit. Hypoxia or normoxia was induced for two hours through a tightly fitting face mask. In addition, the peripheral circulation was assessed with a thermographic camera. Blood samples were obtained before, during, and after hypoxia or normoxia to evaluate systemic stress molecules such as catecholamines and ET-1 levels. Results In patie...
Frontiers in Veterinary Science, 2021
Domestic dogs are superior models for translational medicine due to greater anatomical and physio... more Domestic dogs are superior models for translational medicine due to greater anatomical and physiological similarities with humans than rodents, including hereditary diseases with human equivalents. Particularly with respect to neurodegenerative medicine, dogs can serve as a natural, more relevant model of human disease compared to transgenic rodents. Herein we report attempts to develop a canine-derived in vitro model for neurodegenerative diseases through the generation of induced pluripotent stem cells from a 14-year, 9-month-old female West Highland white terrier with mild cognitive impairment (MCI). Canine induced pluripotent stem cells-like cells (ciPSCLC) were generated using human OSKM and characterized by positive expression of pluripotency markers. Due to inefficient viral vector silencing we refer to them as ciPSCLCs. Subsequently, the ciPSCLC were subjected to neural induction according to two protocols both yielding canine neural progenitor cells (cNPCs), which expressed...
Stem Cell Reports, 2021
Frontotemporal dementia type 3 (FTD3), caused by a point mutation in the charged multivesicular b... more Frontotemporal dementia type 3 (FTD3), caused by a point mutation in the charged multivesicular body protein 2B (CHMP2B), affects mitochondrial ultrastructure and the endolysosomal pathway in neurons. To dissect the astrocyte-specific impact of mutant CHMP2B expression, we generated astrocytes from human induced pluripotent stem cells (hiPSCs) and confirmed our findings in CHMP2B mutant mice. Our data provide mechanistic insights into how defective autophagy causes perturbed mitochondrial dynamics with impaired glycolysis, increased reactive oxygen species, and elongated mitochondrial morphology, indicating increased mitochondrial fusion in FTD3 astrocytes. This shift in astrocyte homeostasis triggers a reactive astrocyte phenotype and increased release of toxic cytokines, which accumulate in nuclear factor kappa b (NF-kB) pathway activation with increased production of CHF, LCN2, and C3 causing neurodegeneration.
Antioxidants, 2021
Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis... more Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber’s hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable r...
Chronobiology International, 2021
ABSTRACT Primary open angle glaucoma is associated with an increased risk of mood and sleep disor... more ABSTRACT Primary open angle glaucoma is associated with an increased risk of mood and sleep disorders. These adversities have been suggested to relate to a disrupted function of the intrinsically photosensitive retinal ganglion cells (ipRGCs). The ipRGCs are key components in the nonvisual photoreceptive system that mediates light effects on mood, sleep and circadian rhythm. We assessed the diurnal hormone levels, pupillary responses and mood and sleep under seasons with different photoperiods in 24 patients with glaucoma and 24 age- and sex-matched healthy controls to investigate responses to naturalistic seasonal changes in daylight. The patients had moderate-to-advanced glaucoma with substantial visual field defects and reductions in the ipRGC-mediated pupillary responses (p < .001). In winter, compared with summer, patients with glaucoma had higher daytime melatonin concentration (p < .001) and lower nighttime cortisol (p = .002). In winter, the daytime melatonin level was inversely correlated with the ipRGC-mediated pupillary responses in the control group (p = .04). In the control group, there were no significant changes in hormone levels between seasons or any correlations between neurohormone levels and the ipRGC-mediated responses. The two groups showed a similar response to season with lower depression scores in summer compared with winter. In between-group comparison, the nocturnal melatonin level (area under curve from 20:00 h to 08:00 h) in summer was lower in glaucoma compared with controls (p = .03). In winter, nocturnal cortisol (at 04:00 h) was lower (p = .004) and daytime cortisol (12:00 h and 16:00 h) was higher (p = .007) in glaucoma compared with controls. In conclusion, we found that patients with glaucoma displayed a seasonal variation in diurnal hormone levels that was not present in healthy controls. Such neurohormonal changes may contribute to the increased risk of mood and sleep disorders seen in patients with glaucoma.
Journal of the American Academy of Dermatology, 2021
BACKGROUND Conjunctivitis and several other ocular surface diseases (OSDs) have been linked to at... more BACKGROUND Conjunctivitis and several other ocular surface diseases (OSDs) have been linked to atopic dermatitis (AD) and its treatment. OBJECTIVES To examine the association between AD, conjunctivitis and other OSDs. METHODS A systematic review and meta-analysis was performed. Two authors independently searched EMBASE, PubMed, SCOPUS and Web of Science, performed title/abstract and full-text review and data abstraction. Pooled random-effects prevalence and odds ratios (OR) with 95% confidence intervals (CI) were estimated. RESULTS The search yielded 5,719 non-duplicate articles, 134 were included in the quantitative analysis. AD was associated with conjunctivitis compared to reference individuals (OR 2.78, 95% CI 2.33-3.32); the prevalence of conjunctivitis in AD patients and reference individuals being 31.7% (95% CI 27.7-35.9) and 13.3% (95% CI 11.0-15.7), respectively. Keratoconus (OR 3.71, 95% CI 1.99-6.94) and ocular herpes simplex (OR 3.65, 95% CI 2.04-6.51) were also associated with AD. LIMITATIONS Disease definitions differed and often relied on self-reports. Few studies provided data concerning AD phenotype or OSDs other than conjunctivitis. CONCLUSIONS Conjunctivitis is the most common ocular comorbidity in AD. Signs and symptoms of conjunctivitis and other OSDs in AD may be underreported, making proactive inquiry and examination by physicians treating AD patients important.
Acta Ophthalmologica, 2019
Acta Ophthalmologica, 2022
PurposeRetinal ganglion cell (RGC) death is a common characteristic for ocular neurodegenerative ... more PurposeRetinal ganglion cell (RGC) death is a common characteristic for ocular neurodegenerative diseases such as glaucoma and optic neuropathies. Recently, GPR81 agonist treatment has been identified as a key modulator of mitochondrial function and cell survival. Thus, we aimed to test whether GPR81 agonist treatment likewise promotes RGC survival and energy metabolism in retinal explants and wholemounts from mice.MethodsRetinal explants were treated with 5 mM of the GPR81 agonist, 3,5‐DHBA, for two, four, 24 & 72 hours, and compared to conditions with no treatment. Additionally, explants were also treated with 15 mM of L‐glutamate to induce toxicity and simultaneously treated with GPR81 agonist. Tissue survival was assessed through lactate dehydrogenase (LDH) viability assays. Retinal ganglion cell survival was measured in murine wholemount retinas through immunohistochemical staining (IHC). Total ATP levels were quantified through bioluminescence assays.ResultsGPR81 agonist treatment increased retinal explant survival after 24 and 72 hours of exposure. No significant effect was seen in retinal explants survival after GPR81 agonist treatment alone for two hours. However, during glutamate‐induced death, supplemented GPR81 agonist treatment increased survival compared to conditions with glutamate toxicity. IHC analysis revealed that GPR81 agonist treatment for two hours promoted RGC survival in retinal wholemounts compared with no treatment. GPR81 agonist treatment also enhanced ATP levels in retinal explants after two, 24, and 72 hr of exposure.ConclusionsThe present study reveals that GPR81 agonist treatment has a neuroprotective effect on specifically RGCs and on glutamate‐induced retinal degeneration. Hence, GPR81 agonist administration may be a potential new strategy to sustain RGCs, ultimately preventing visual disability as a consequence of RGC death.
Cellular and Molecular Neurobiology, 2020
Estrogen is essential in maintaining various physiological features in women, and a decline in es... more Estrogen is essential in maintaining various physiological features in women, and a decline in estrogen levels are known to give rise to numerous unfortunate symptoms associated with menopause. To alleviate these symptoms hormone replacement therapy with estrogen is often used, and has been shown to be fruitful in improving quality of life in women suffering from postmenopausal discomforts. An often forgotten condition associated with menopause is the optic nerve disorder, glaucoma. Thus, estrogen may also have an impact in maintaining the retinal ganglion cells (RGCs), which make up the optic nerve, thereby preventing glaucomatous neurodegeneration. This review aims to provide an overview of possible associations of estrogen and the glaucoma subtype, primary open-angle glaucoma (POAG), by evaluating the current literature through a PubMed-based literature search. Multiple in vitro and in vivo studies of RGC protection, as well as clinical and epidemiological data concerning the well-defined retinal neurodegenerative disorder POAG have been reviewed. Over all, deficiencies in retinal estrogen may potentially instigate RGC loss, visual disability, and eventual blindness. Estrogen replacement therapy may therefore be a beneficial future treatment. However, more studies are needed to confirm the relevance of estrogen in glaucoma prevention.
Cells
Background: Progressive retinal ganglion cell (RGC) dysfunction and death are common characterist... more Background: Progressive retinal ganglion cell (RGC) dysfunction and death are common characteristics of retinal neurodegenerative diseases. Recently, hydroxycarboxylic acid receptor 1 (HCA1R, GPR81) was identified as a key modulator of mitochondrial function and cell survival. Thus, we aimed to test whether activation of HCA1R with 3,5-Dihydroxybenzoic acid (DHBA) also promotes RGC survival and improves energy metabolism in mouse retinas. Methods: Retinal explants were treated with 5 mM of the HCA1R agonist, 3,5-DHBA, for 2, 4, 24, and 72 h. Additionally, explants were also treated with 15 mM of L-glutamate to induce toxicity. Tissue survival was assessed through lactate dehydrogenase (LDH) viability assays. RGC survival was measured through immunohistochemical (IHC) staining. Total ATP levels were quantified through bioluminescence assays. Energy metabolism was investigated through stable isotope labeling and gas chromatography-mass spectrometry (GC-MS). Lactate and nitric oxide le...
Cochrane Database of Systematic Reviews
Journal of Clinical Medicine
Purpose: To examine the physicochemical properties of five preservative-free (PF) 0.005% latanopr... more Purpose: To examine the physicochemical properties of five preservative-free (PF) 0.005% latanoprost ophthalmic products; Monoprost®, Latanest®, Gaap Ofteno®, Xalmono®, and Xaloptic® Free. Furthermore, the study investigated the mucin production and cell survival of primary cultured human conjunctival goblet cells when treated with PF eye drops. Method: The pH value, osmolality, and surface tension were examined. Cell survival was analyzed using lactate dehydrogenase and tetrazolium dye colorimetric assays. Mucin production was analyzed with immunohistochemical staining. Results: Monoprost® (pH value 6.84 ± 0.032) had a pH value closest to the pH value of tear fluid (pH value 7.4–7.6), whereas Gaap Ofteno® (pH value 6.34 ± 0.004) and Latanest® (pH value 6.33 ± 0.003) had the lowest pH values. Gaap Ofteno® (325.9 ± 2.9 mosmol/kg) showed iso-osmolar probabilities, whereas the other products were hypo-osmolar. Gaap Ofteno® (60.31 ± 0.35 mN/m) had a higher surface tension compared to th...
Acta Ophthalmologica, 2022
BMJ Open Ophthalmology, 2021
ObjectiveTo investigate the short-term impact on human conjunctival goblet cell (GC) survival and... more ObjectiveTo investigate the short-term impact on human conjunctival goblet cell (GC) survival and mucin release of acute exposure to benzalkonium chloride (BAK) preserved and preservative-free (PF) 0.005% (w/v) latanoprost (LT) eye drops, and to compare the eye drops’ physicochemical properties.Methods and analysisPrimary GC cultures were established from human conjunctival donor tissue. The impact of eye drops on GC survival was assessed using a lactate dehydrogenase assay. Mucin release was evaluated through mucin-specific immunostaining. pH value, osmolality, drop mass and surface tension for all LT eye drops were measured.ResultsAfter application with PF-LT for 30 min (min), the GC survival was maintained compared with control (p=0.9941), while all BAK-LT eye drops reduced survival with approximately 30% (p<0.02). Following application with PF-LT for 30 min, mucin was found around the GC nucleus, as seen in the vehicle control, indicating no secretion. In contrast, BAK-LT cau...
Journal of Glaucoma, 2021
Journal of Ophthalmology, 2021
Cellular and Molecular Neurobiology, 2021
Visual changes are some of the earliest symptoms that patients with Alzheimer's disease (AD) ... more Visual changes are some of the earliest symptoms that patients with Alzheimer's disease (AD) experience. Pathophysiological processes such as amyloid-β plaque formation, vascular changes, neuroinflammation, and loss of retinal ganglion cells (RGCs) have been detected in the retina of AD patients and animal models. However, little is known about the molecular processes that underlie retinal neurodegeneration in AD. The cellular architecture and constant sensory activity of the retina impose high metabolic demands. We thus hypothesized that energy metabolism might be compromised in the AD retina similarly to what has been observed in the AD brain. To address this question, we explored cellular alterations and retinal metabolic activity in the 5 × FAD mouse model of AD. We used 8-month-old female 5 × FAD mice, in which the AD-related pathology has been shown to be apparent. We observed that RGC density is selectively affected in the retina of 5 × FAD mice. To map retinal metabolic activity, we incubated isolated retinal tissue with [U-13C] glucose and analyzed tissue extracts by gas chromatography-mass spectrometry. We found that the retinas of 5 × FAD mice exhibit glucose hypometabolism. Moreover, we detected decreased glutamine synthesis in 5 × FAD retinas but no changes in the expression of markers of Müller glia, the main glial cell type responsible for glutamate uptake and glutamine synthesis in the retina. These findings suggest that AD presents with metabolic alterations not only in the brain but also in the retina that may be detrimental to RGC activity and survival, potentially leading to the visual impairments that AD patients suffer.
BMJ Open Ophthalmology, 2020
ObjectiveTo determine the effect of povidone iodine (PI), an antiseptic commonly used prior to oc... more ObjectiveTo determine the effect of povidone iodine (PI), an antiseptic commonly used prior to ocular surgery, on viability of mixed populations of conjunctival stratified squamous and goblet cells, purified conjunctival goblet cells and purified conjunctival stromal fibroblasts in primary culture.Methods and analysisMixed population of epithelial cells (stratified squamous and goblet cells), goblet cells and fibroblasts were grown in culture from pieces of human conjunctiva using either supplemented DMEM/F12 or RPMI. Cell type was evaluated by immunofluorescence microscopy. Cells were treated for 5 min with phosphate-buffered saline (PBS); 0.25%, 2.5%, 5% or 10% PI in PBS; or a positive control of 30% H2O2. Cell viability was determined using Alamar Blue fluorescence and a live/dead kit using calcein/AM and ethidium homodimer-1 (EH-1).ResultsMixed populations of epithelial cells, goblet cells and fibroblasts were characterised by immunofluorescence microscopy. As determined with Al...
Journal of Ophthalmology, 2021
Purpose To investigate whether patients with normal tension glaucoma (NTG) show an enhanced stres... more Purpose To investigate whether patients with normal tension glaucoma (NTG) show an enhanced stress response to reduced oxygen supply compared to age-matched healthy controls, measured by serum adrenaline and endothelin-1 (ET-1) levels and changes in distal finger temperature. Methods A thorough clinical characterization of patients with NTG and age-matched controls was performed prior to inclusion in the study. Twelve patients with NTG and eleven healthy controls met the inclusion criteria and were enrolled in the study. All subjects underwent a two-day investigation. Participants were randomly exposed to either hypoxia or normoxia during the first visit. Hypoxia or normoxia was induced for two hours through a tightly fitting face mask. In addition, the peripheral circulation was assessed with a thermographic camera. Blood samples were obtained before, during, and after hypoxia or normoxia to evaluate systemic stress molecules such as catecholamines and ET-1 levels. Results In patie...
Frontiers in Veterinary Science, 2021
Domestic dogs are superior models for translational medicine due to greater anatomical and physio... more Domestic dogs are superior models for translational medicine due to greater anatomical and physiological similarities with humans than rodents, including hereditary diseases with human equivalents. Particularly with respect to neurodegenerative medicine, dogs can serve as a natural, more relevant model of human disease compared to transgenic rodents. Herein we report attempts to develop a canine-derived in vitro model for neurodegenerative diseases through the generation of induced pluripotent stem cells from a 14-year, 9-month-old female West Highland white terrier with mild cognitive impairment (MCI). Canine induced pluripotent stem cells-like cells (ciPSCLC) were generated using human OSKM and characterized by positive expression of pluripotency markers. Due to inefficient viral vector silencing we refer to them as ciPSCLCs. Subsequently, the ciPSCLC were subjected to neural induction according to two protocols both yielding canine neural progenitor cells (cNPCs), which expressed...
Stem Cell Reports, 2021
Frontotemporal dementia type 3 (FTD3), caused by a point mutation in the charged multivesicular b... more Frontotemporal dementia type 3 (FTD3), caused by a point mutation in the charged multivesicular body protein 2B (CHMP2B), affects mitochondrial ultrastructure and the endolysosomal pathway in neurons. To dissect the astrocyte-specific impact of mutant CHMP2B expression, we generated astrocytes from human induced pluripotent stem cells (hiPSCs) and confirmed our findings in CHMP2B mutant mice. Our data provide mechanistic insights into how defective autophagy causes perturbed mitochondrial dynamics with impaired glycolysis, increased reactive oxygen species, and elongated mitochondrial morphology, indicating increased mitochondrial fusion in FTD3 astrocytes. This shift in astrocyte homeostasis triggers a reactive astrocyte phenotype and increased release of toxic cytokines, which accumulate in nuclear factor kappa b (NF-kB) pathway activation with increased production of CHF, LCN2, and C3 causing neurodegeneration.
Antioxidants, 2021
Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis... more Increasing evidence indicates that changes in the redox system may contribute to the pathogenesis of multiple optic neuropathies. Optic neuropathies are characterized by the neurodegeneration of the inner-most retinal neurons, the retinal ganglion cells (RGCs), and their axons, which form the optic nerve. Often, optic neuropathies are asymptomatic until advanced stages, when visual impairment or blindness is unavoidable despite existing treatments. In this review, we describe systemic and, whenever possible, ocular redox dysregulations observed in patients with glaucoma, ischemic optic neuropathy, optic neuritis, hereditary optic neuropathies (i.e., Leber’s hereditary optic neuropathy and autosomal dominant optic atrophy), nutritional and toxic optic neuropathies, and optic disc drusen. We discuss aspects related to anti/oxidative stress biomarkers that need further investigation and features related to study design that should be optimized to generate more valuable and comparable r...
Chronobiology International, 2021
ABSTRACT Primary open angle glaucoma is associated with an increased risk of mood and sleep disor... more ABSTRACT Primary open angle glaucoma is associated with an increased risk of mood and sleep disorders. These adversities have been suggested to relate to a disrupted function of the intrinsically photosensitive retinal ganglion cells (ipRGCs). The ipRGCs are key components in the nonvisual photoreceptive system that mediates light effects on mood, sleep and circadian rhythm. We assessed the diurnal hormone levels, pupillary responses and mood and sleep under seasons with different photoperiods in 24 patients with glaucoma and 24 age- and sex-matched healthy controls to investigate responses to naturalistic seasonal changes in daylight. The patients had moderate-to-advanced glaucoma with substantial visual field defects and reductions in the ipRGC-mediated pupillary responses (p < .001). In winter, compared with summer, patients with glaucoma had higher daytime melatonin concentration (p < .001) and lower nighttime cortisol (p = .002). In winter, the daytime melatonin level was inversely correlated with the ipRGC-mediated pupillary responses in the control group (p = .04). In the control group, there were no significant changes in hormone levels between seasons or any correlations between neurohormone levels and the ipRGC-mediated responses. The two groups showed a similar response to season with lower depression scores in summer compared with winter. In between-group comparison, the nocturnal melatonin level (area under curve from 20:00 h to 08:00 h) in summer was lower in glaucoma compared with controls (p = .03). In winter, nocturnal cortisol (at 04:00 h) was lower (p = .004) and daytime cortisol (12:00 h and 16:00 h) was higher (p = .007) in glaucoma compared with controls. In conclusion, we found that patients with glaucoma displayed a seasonal variation in diurnal hormone levels that was not present in healthy controls. Such neurohormonal changes may contribute to the increased risk of mood and sleep disorders seen in patients with glaucoma.
Journal of the American Academy of Dermatology, 2021
BACKGROUND Conjunctivitis and several other ocular surface diseases (OSDs) have been linked to at... more BACKGROUND Conjunctivitis and several other ocular surface diseases (OSDs) have been linked to atopic dermatitis (AD) and its treatment. OBJECTIVES To examine the association between AD, conjunctivitis and other OSDs. METHODS A systematic review and meta-analysis was performed. Two authors independently searched EMBASE, PubMed, SCOPUS and Web of Science, performed title/abstract and full-text review and data abstraction. Pooled random-effects prevalence and odds ratios (OR) with 95% confidence intervals (CI) were estimated. RESULTS The search yielded 5,719 non-duplicate articles, 134 were included in the quantitative analysis. AD was associated with conjunctivitis compared to reference individuals (OR 2.78, 95% CI 2.33-3.32); the prevalence of conjunctivitis in AD patients and reference individuals being 31.7% (95% CI 27.7-35.9) and 13.3% (95% CI 11.0-15.7), respectively. Keratoconus (OR 3.71, 95% CI 1.99-6.94) and ocular herpes simplex (OR 3.65, 95% CI 2.04-6.51) were also associated with AD. LIMITATIONS Disease definitions differed and often relied on self-reports. Few studies provided data concerning AD phenotype or OSDs other than conjunctivitis. CONCLUSIONS Conjunctivitis is the most common ocular comorbidity in AD. Signs and symptoms of conjunctivitis and other OSDs in AD may be underreported, making proactive inquiry and examination by physicians treating AD patients important.
Acta Ophthalmologica, 2019