Elena Dragicevic - Academia.edu (original) (raw)
Uploads
Papers by Elena Dragicevic
Cytotoxicity monitoring for safety assessments: iPS cardiomyocytes and cancer cells
Journal of Pharmacological and Toxicological Methods
Combining Physiological Relevance and Throughput for in vitro Cardiac Contractility Measurement
Biophysical Journal
Nature Communications
Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkins... more Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkinson’s disease. The mechanisms underlying this age-dependent and region-selective neurodegeneration remain unclear. Here we identify Cav2.3 channels as regulators of nigral neuronal viability. Cav2.3 transcripts were more abundant than other voltage-gated Ca2+ channels in mouse nigral neurons and upregulated during aging. Plasmalemmal Cav2.3 protein was higher than in dopaminergic neurons of the ventral tegmental area, which do not degenerate in Parkinson’s disease. Cav2.3 knockout reduced activity-associated nigral somatic Ca2+ signals and Ca2+-dependent after-hyperpolarizations, and afforded full protection from degeneration in vivo in a neurotoxin Parkinson’s mouse model. Cav2.3 deficiency upregulated transcripts for NCS-1, a Ca2+-binding protein implicated in neuroprotection. Conversely, NCS-1 knockout exacerbated nigral neurodegeneration and downregulated Cav2.3. Moreover, NCS-1 level...
Predicting cardiac safety using human induced pluripotent stem cell-derived cardiomyocytes combined with multi-electrode array (MEA) technology: A conference report
Journal of Pharmacological and Toxicological Methods
EBioMedicine
Background: Small fiber neuropathy (SFN) is a severe and disabling chronic pain syndrome with no ... more Background: Small fiber neuropathy (SFN) is a severe and disabling chronic pain syndrome with no causal and limited symptomatic treatment options. Mechanistically based individual treatment is not available. We report an in-vitro predicted individualized treatment success in one therapy-refractory Caucasian patient suffering from SFN for over ten years. Methods: Intrinsic excitability of human induced pluripotent stem cell (iPSC) derived nociceptors from this patient and respective controls were recorded on multi-electrode (MEA) arrays, in the presence and absence of lacosamide. The patient's pain ratings were assessed by a visual analogue scale (10: worst pain, 0: no pain) and treatment effect was objectified by microneurography recordings of the patient's single nerve C-fibers. Findings: We identified patient-specific changes in iPSC-derived nociceptor excitability in MEA recordings, which were reverted by the FDA-approved compound lacosamide in vitro. Using this drug for individualized treatment of this patient, the patient's pain ratings decreased from 7.5 to 1.5. Consistent with the pain relief reported by the patient, microneurography recordings of the patient's single nerve fibers mirrored a reduced spontaneous nociceptor (C-fiber) activity in the patient during lacosamide treatment. Microneurography recordings yielded an objective measurement of altered peripheral nociceptor activity following treatment. Interpretation: Thus, we are here presenting one example of successful patient specific precision medicine using iPSC technology and individualized therapeutic treatment based on patient-derived sensory neurons.
Complementary automated patch clamp, extracellular field potential and impedance recordings of iPSCs: Safety screening tool box for the future
Journal of Pharmacological and Toxicological Methods, 2016
Neuroscience, Jan 22, 2015
Dopamine (DA) releasing midbrain neurons are essential for multiple brain functions, such as volu... more Dopamine (DA) releasing midbrain neurons are essential for multiple brain functions, such as voluntary movement, working memory, emotion and cognition. DA midbrain neurons within the substantia nigra (SN) and the ventral tegmental area (VTA) exhibit a variety of distinct axonal projections and cellular properties, and are differentially affected in diseases like schizophrenia, attention deficit hyperactivity disorder, and Parkinson's disease (PD). Apart from having diverse functions in health and disease states, DA midbrain neurons display distinct electrical activity patterns, crucial for DA release. These activity patterns are generated and modulated by specific sets of ion channels. Recently, two ion channels have been identified, not only contributing to these activity patterns and to functional properties of DA midbrain neurons, but also seem to render SN DA neurons particularly vulnerable to degeneration in PD and its animal models: L-type calcium channels (LTCCs) and ATP-...
Progressive loss of substantia nigra dopamine neurons (SN DA) is a hallmark of aging and of Parki... more Progressive loss of substantia nigra dopamine neurons (SN DA) is a hallmark of aging and of Parkinson's disease (PD). Mutations in PARK genes cause familial PD forms. Increased expression of alpha-synuclein (PARK4) is a disease-triggering event in familial PD and also observed in SN DA neurons in sporadic PD but related transcriptional changes are unknown. With optimized single-cell quantitative real-time polymerase chain reaction analysis, we compared messenger RNA and microRNA levels in SN DA neurons from sporadic PD patients and controls. Non-optimally matched donor ages and RNA integrities are common problems when analyzing human samples. We dissected the influence of distinct ages and RNA integrities of our samples by applying a specifically-optimized, linear-mixed-effects model to quantitative real-time polymerase chain reaction-data. We identified that elevated alpha-synuclein messenger RNA levels in SN DA neurons of human PD brains were positively correlated with corresponding elevated levels of mRNAs for functional compensation of progressive SN DA loss and for enhanced proteasomal (PARK5/UCHL1) and lysosomal (PARK9/ATPase13A2) function, possibly counteracting alpha-synuclein toxicity. In contrast, microRNA miR-133b levels, previously implicated in transcriptional dysregulation in PD, were not altered in SN DA neurons in PD.
for the scientific commentary on this article. Dopamine midbrain neurons within the substantia ni... more for the scientific commentary on this article. Dopamine midbrain neurons within the substantia nigra are particularly prone to degeneration in Parkinson's disease. Their selective loss causes the major motor symptoms of Parkinson's disease, but the causes for the high vulnerability of SN DA neurons, compared to neighbouring, more resistant ventral tegmental area dopamine neurons, are still unclear. Consequently, there is still no cure available for Parkinson's disease. Current therapies compensate the progressive loss of dopamine by administering its precursor L-DOPA and/or dopamine D2-receptor agonists. D2-autoreceptors and Ca v 1.3-containing L-type Ca 2 + channels both contribute to Parkinson's disease pathology. L-type Ca 2 + channel blockers protect SN DA neurons from degeneration in Parkinson's disease and its mouse models, and they are in clinical trials for neuroprotective Parkinson's disease therapy. However, their physiological functions in SN DA neurons remain unclear. D2-autoreceptors tune firing rates and dopamine release of SN DA neurons in a negative feedback loop through activation of G-protein coupled potassium channels (GIRK2, or KCNJ6). Mature SN DA neurons display prominent, non-desensitizing somatodendritic D2-autoreceptor responses that show pronounced desensitization in PARK-gene Parkinson's disease mouse models. We analysed surviving human SN DA neurons from patients with Parkinson's disease and from controls, and detected elevated messenger RNA levels of D2-autoreceptors and GIRK2 in Parkinson's disease. By electrophysiological analysis of postnatal juvenile and adult mouse SN DA neurons in in vitro brain-slices, we observed that D2-autoreceptor desensitization is reduced with postnatal maturation. Furthermore, a transient high-dopamine state in vivo, caused by one injection of either L-DOPA or cocaine, induced adultlike, non-desensitizing D2-autoreceptor responses, selectively in juvenile SN DA neurons, but not ventral tegmental area dopamine neurons. With pharmacological and genetic tools, we identified that the expression of this sensitized D2-autoreceptor phenotype required Ca v 1.3 L-type Ca 2 + channel activity, internal Ca 2 + , and the interaction of the neuronal calcium sensor NCS-1 with D2-autoreceptors. Thus, we identified a first physiological function of Ca v 1.3 L-type Ca 2 + channels in SN DA neurons for
Scientific reports, Jan 18, 2015
The preferential degeneration of Substantia nigra dopamine midbrain neurons (SN DA) causes the mo... more The preferential degeneration of Substantia nigra dopamine midbrain neurons (SN DA) causes the motor-symptoms of Parkinson's disease (PD). Voltage-gated L-type calcium channels (LTCCs), especially the Cav1.3-subtype, generate an activity-related oscillatory Ca(2+) burden in SN DA neurons, contributing to their degeneration and PD. While LTCC-blockers are already in clinical trials as PD-therapy, age-dependent functional roles of Cav1.3 LTCCs in SN DA neurons remain unclear. Thus, we analysed juvenile and adult Cav1.3-deficient mice with electrophysiological and molecular techniques. To unmask compensatory effects, we compared Cav1.3 KO mice with pharmacological LTCC-inhibition. LTCC-function was not necessary for SN DA pacemaker-activity at either age, but rather contributed to their pacemaker-precision. Moreover, juvenile Cav1.3 KO but not WT mice displayed adult wildtype-like, sensitised inhibitory dopamine-D2-autoreceptor (D2-AR) responses that depended upon both, interaction...
Neuron, 2008
In the mammalian central nervous system, slow synaptic excitation involves the activation of meta... more In the mammalian central nervous system, slow synaptic excitation involves the activation of metabotropic glutamate receptors (mGluRs). It has been proposed that C1-type transient receptor potential (TRPC1) channels underlie this synaptic excitation, but our analysis of TRPC1-deficient mice does not support this hypothesis. Here, we show unambiguously that it is TRPC3 that is needed for mGluRdependent synaptic signaling in mouse cerebellar Purkinje cells. TRPC3 is the most abundantly expressed TRPC subunit in Purkinje cells. In mutant mice lacking TRPC3, both slow synaptic potentials and mGluR-mediated inward currents are completely absent, while the synaptically mediated Ca 2+ release signals from intracellular stores are unchanged. Importantly, TRPC3 knockout mice exhibit an impaired walking behavior. Taken together, our results establish TRPC3 as a new type of postsynaptic channel that mediates mGluR-dependent synaptic transmission in cerebellar Purkinje cells and is crucial for motor coordination.
Cytotoxicity monitoring for safety assessments: iPS cardiomyocytes and cancer cells
Journal of Pharmacological and Toxicological Methods
Combining Physiological Relevance and Throughput for in vitro Cardiac Contractility Measurement
Biophysical Journal
Nature Communications
Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkins... more Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkinson’s disease. The mechanisms underlying this age-dependent and region-selective neurodegeneration remain unclear. Here we identify Cav2.3 channels as regulators of nigral neuronal viability. Cav2.3 transcripts were more abundant than other voltage-gated Ca2+ channels in mouse nigral neurons and upregulated during aging. Plasmalemmal Cav2.3 protein was higher than in dopaminergic neurons of the ventral tegmental area, which do not degenerate in Parkinson’s disease. Cav2.3 knockout reduced activity-associated nigral somatic Ca2+ signals and Ca2+-dependent after-hyperpolarizations, and afforded full protection from degeneration in vivo in a neurotoxin Parkinson’s mouse model. Cav2.3 deficiency upregulated transcripts for NCS-1, a Ca2+-binding protein implicated in neuroprotection. Conversely, NCS-1 knockout exacerbated nigral neurodegeneration and downregulated Cav2.3. Moreover, NCS-1 level...
Predicting cardiac safety using human induced pluripotent stem cell-derived cardiomyocytes combined with multi-electrode array (MEA) technology: A conference report
Journal of Pharmacological and Toxicological Methods
EBioMedicine
Background: Small fiber neuropathy (SFN) is a severe and disabling chronic pain syndrome with no ... more Background: Small fiber neuropathy (SFN) is a severe and disabling chronic pain syndrome with no causal and limited symptomatic treatment options. Mechanistically based individual treatment is not available. We report an in-vitro predicted individualized treatment success in one therapy-refractory Caucasian patient suffering from SFN for over ten years. Methods: Intrinsic excitability of human induced pluripotent stem cell (iPSC) derived nociceptors from this patient and respective controls were recorded on multi-electrode (MEA) arrays, in the presence and absence of lacosamide. The patient's pain ratings were assessed by a visual analogue scale (10: worst pain, 0: no pain) and treatment effect was objectified by microneurography recordings of the patient's single nerve C-fibers. Findings: We identified patient-specific changes in iPSC-derived nociceptor excitability in MEA recordings, which were reverted by the FDA-approved compound lacosamide in vitro. Using this drug for individualized treatment of this patient, the patient's pain ratings decreased from 7.5 to 1.5. Consistent with the pain relief reported by the patient, microneurography recordings of the patient's single nerve fibers mirrored a reduced spontaneous nociceptor (C-fiber) activity in the patient during lacosamide treatment. Microneurography recordings yielded an objective measurement of altered peripheral nociceptor activity following treatment. Interpretation: Thus, we are here presenting one example of successful patient specific precision medicine using iPSC technology and individualized therapeutic treatment based on patient-derived sensory neurons.
Complementary automated patch clamp, extracellular field potential and impedance recordings of iPSCs: Safety screening tool box for the future
Journal of Pharmacological and Toxicological Methods, 2016
Neuroscience, Jan 22, 2015
Dopamine (DA) releasing midbrain neurons are essential for multiple brain functions, such as volu... more Dopamine (DA) releasing midbrain neurons are essential for multiple brain functions, such as voluntary movement, working memory, emotion and cognition. DA midbrain neurons within the substantia nigra (SN) and the ventral tegmental area (VTA) exhibit a variety of distinct axonal projections and cellular properties, and are differentially affected in diseases like schizophrenia, attention deficit hyperactivity disorder, and Parkinson's disease (PD). Apart from having diverse functions in health and disease states, DA midbrain neurons display distinct electrical activity patterns, crucial for DA release. These activity patterns are generated and modulated by specific sets of ion channels. Recently, two ion channels have been identified, not only contributing to these activity patterns and to functional properties of DA midbrain neurons, but also seem to render SN DA neurons particularly vulnerable to degeneration in PD and its animal models: L-type calcium channels (LTCCs) and ATP-...
Progressive loss of substantia nigra dopamine neurons (SN DA) is a hallmark of aging and of Parki... more Progressive loss of substantia nigra dopamine neurons (SN DA) is a hallmark of aging and of Parkinson's disease (PD). Mutations in PARK genes cause familial PD forms. Increased expression of alpha-synuclein (PARK4) is a disease-triggering event in familial PD and also observed in SN DA neurons in sporadic PD but related transcriptional changes are unknown. With optimized single-cell quantitative real-time polymerase chain reaction analysis, we compared messenger RNA and microRNA levels in SN DA neurons from sporadic PD patients and controls. Non-optimally matched donor ages and RNA integrities are common problems when analyzing human samples. We dissected the influence of distinct ages and RNA integrities of our samples by applying a specifically-optimized, linear-mixed-effects model to quantitative real-time polymerase chain reaction-data. We identified that elevated alpha-synuclein messenger RNA levels in SN DA neurons of human PD brains were positively correlated with corresponding elevated levels of mRNAs for functional compensation of progressive SN DA loss and for enhanced proteasomal (PARK5/UCHL1) and lysosomal (PARK9/ATPase13A2) function, possibly counteracting alpha-synuclein toxicity. In contrast, microRNA miR-133b levels, previously implicated in transcriptional dysregulation in PD, were not altered in SN DA neurons in PD.
for the scientific commentary on this article. Dopamine midbrain neurons within the substantia ni... more for the scientific commentary on this article. Dopamine midbrain neurons within the substantia nigra are particularly prone to degeneration in Parkinson's disease. Their selective loss causes the major motor symptoms of Parkinson's disease, but the causes for the high vulnerability of SN DA neurons, compared to neighbouring, more resistant ventral tegmental area dopamine neurons, are still unclear. Consequently, there is still no cure available for Parkinson's disease. Current therapies compensate the progressive loss of dopamine by administering its precursor L-DOPA and/or dopamine D2-receptor agonists. D2-autoreceptors and Ca v 1.3-containing L-type Ca 2 + channels both contribute to Parkinson's disease pathology. L-type Ca 2 + channel blockers protect SN DA neurons from degeneration in Parkinson's disease and its mouse models, and they are in clinical trials for neuroprotective Parkinson's disease therapy. However, their physiological functions in SN DA neurons remain unclear. D2-autoreceptors tune firing rates and dopamine release of SN DA neurons in a negative feedback loop through activation of G-protein coupled potassium channels (GIRK2, or KCNJ6). Mature SN DA neurons display prominent, non-desensitizing somatodendritic D2-autoreceptor responses that show pronounced desensitization in PARK-gene Parkinson's disease mouse models. We analysed surviving human SN DA neurons from patients with Parkinson's disease and from controls, and detected elevated messenger RNA levels of D2-autoreceptors and GIRK2 in Parkinson's disease. By electrophysiological analysis of postnatal juvenile and adult mouse SN DA neurons in in vitro brain-slices, we observed that D2-autoreceptor desensitization is reduced with postnatal maturation. Furthermore, a transient high-dopamine state in vivo, caused by one injection of either L-DOPA or cocaine, induced adultlike, non-desensitizing D2-autoreceptor responses, selectively in juvenile SN DA neurons, but not ventral tegmental area dopamine neurons. With pharmacological and genetic tools, we identified that the expression of this sensitized D2-autoreceptor phenotype required Ca v 1.3 L-type Ca 2 + channel activity, internal Ca 2 + , and the interaction of the neuronal calcium sensor NCS-1 with D2-autoreceptors. Thus, we identified a first physiological function of Ca v 1.3 L-type Ca 2 + channels in SN DA neurons for
Scientific reports, Jan 18, 2015
The preferential degeneration of Substantia nigra dopamine midbrain neurons (SN DA) causes the mo... more The preferential degeneration of Substantia nigra dopamine midbrain neurons (SN DA) causes the motor-symptoms of Parkinson's disease (PD). Voltage-gated L-type calcium channels (LTCCs), especially the Cav1.3-subtype, generate an activity-related oscillatory Ca(2+) burden in SN DA neurons, contributing to their degeneration and PD. While LTCC-blockers are already in clinical trials as PD-therapy, age-dependent functional roles of Cav1.3 LTCCs in SN DA neurons remain unclear. Thus, we analysed juvenile and adult Cav1.3-deficient mice with electrophysiological and molecular techniques. To unmask compensatory effects, we compared Cav1.3 KO mice with pharmacological LTCC-inhibition. LTCC-function was not necessary for SN DA pacemaker-activity at either age, but rather contributed to their pacemaker-precision. Moreover, juvenile Cav1.3 KO but not WT mice displayed adult wildtype-like, sensitised inhibitory dopamine-D2-autoreceptor (D2-AR) responses that depended upon both, interaction...
Neuron, 2008
In the mammalian central nervous system, slow synaptic excitation involves the activation of meta... more In the mammalian central nervous system, slow synaptic excitation involves the activation of metabotropic glutamate receptors (mGluRs). It has been proposed that C1-type transient receptor potential (TRPC1) channels underlie this synaptic excitation, but our analysis of TRPC1-deficient mice does not support this hypothesis. Here, we show unambiguously that it is TRPC3 that is needed for mGluRdependent synaptic signaling in mouse cerebellar Purkinje cells. TRPC3 is the most abundantly expressed TRPC subunit in Purkinje cells. In mutant mice lacking TRPC3, both slow synaptic potentials and mGluR-mediated inward currents are completely absent, while the synaptically mediated Ca 2+ release signals from intracellular stores are unchanged. Importantly, TRPC3 knockout mice exhibit an impaired walking behavior. Taken together, our results establish TRPC3 as a new type of postsynaptic channel that mediates mGluR-dependent synaptic transmission in cerebellar Purkinje cells and is crucial for motor coordination.