Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Surface Plasmon Resonance Microscopy (SPRM) of pancreatic beta-cells ( a ) Schematic presenting the experimental setup for SPRM, depicting the layered structure of gold thin film on glass substrate with cells adhered to the gold surface in Hanks’ balanced salt solution (HBSS). A fiber-coupled laser (690 nm) is collimated before focusing on the back focal plane (BFP) of a high numerical aperture oil immersion objective to produce a collimated beam at the sample. The angle of illumination is varied by laterally scanning the focus on the BFP. The sample is imaged using a 2D CMOS pixelated detector. ( b ) A magnified view of the SPR sensor and cell interface showing the interface layers (glass, Au thin film of 50 nm, medium (HBSS), cell membrane of c. 7 nm thickness, and cytosol), with an illustration of the penetration depth of SPs in both metal and dielectric media. This indicates sensitivity to the cell membrane and the proximal intra- and extracellular spaces. ( c ) SPR curves presenting the reflection coefficient for various angles of incidence, simulated for bare gold with HBSS and for the gold-cell interface respectively. ( d ) The corresponding first derivative of reflectivity with respect to the angle of incidence, showing the variations in the sensitivity of the measurement for optimising the angle of illumination. ( e ) (i). Brightfield microscopy image of live MIN6 beta-cells cultured on PLL-modified Au thin film. e (ii), e (iii), and e (iv) are the corresponding SPRM images at different angles of illumination. The angle of incidence is selected in region iii, although this gives reduced sensitivity, it allows simultaneous tracking of cells and the extracellular regions where cells are not present on the sensor.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: SPR Assay, Microscopy, Membrane, Cell Culture, Modification

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: SPRM reveals correlated oscillations in pancreatic beta-cells. ( a ) Brightfield image of MIN6 cells cultured on PLL-modified Au thin film. ( b ) Corresponding SPRM image with five regions of interest highlighting cells (1, 2 and 3) and the extracellular background (4 and 5). ( c ) Time-resolved reflectivity recorded over 130 s in HBSS with 10 mM glucose for the five regions shown in ( b ), inset shows a magnified view of a selected time window, indicated by t to t’, for the three cells which shows synchronised intensity oscillations. Traces appear synchronised but the background ROIs are anticorrelated. ( d ) Heat map displaying the correlation between signals extracted from ROIs 1 – 5 investigating signaling at the cellular ROIs (1–3) and the background ROIs (4, 5), where cells are not present.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: Cell Culture, Modification

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Intracellular calcium oscillations in pancreatic beta cells within HBSS supplemented with 10 mM glucose. ( a ) Fluorescence image of MIN6 cells loaded with FLUO-4, excited at 450–490 nm, with 0–50 regions of interest (ROIs) indicated (0 denotes the background). Average fluorescence image of 3,000 frames of a field of MIN6 cells, with each measured cell labelled to indicate its 2D geography . ( b ) Cross-correlation matrix showing the Pearson correlation coefficients (threshold of 0.3) calculated between ROIs 0–50. ( c ) Exemplary 100-s traces of selected ROIs (band-pass filtered between 0.1 and 5 Hz), including clusters with high correlation {C8, C9}, {C11– C15}, {C16–C21}, {C23, C24}, {C44, C45}, alongside other ROIs selected at random.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: Fluorescence

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Synchronised network oscillations are suppressed in the presence of a calcium channel blocker. ( a ) Brightfield image of MIN6 cells cultured on PLL-modified Au thin film. Scale bar 10 μm. ( b ) Corresponding SPRM image with 6 cellular regions of interest. ( c ) Time-series recordings from the six cellular ROIs presenting time-resolved reflectivity, under treatment with: 1) Hanks balanced salt solution (HBSS) without glucose; 2) HBSS supplemented with 10 mM glucose; and 3) HBSS supplemented with 10 mM glucose and 40 µM nifedipine. ( d ) Comparison of the effect of the three treatments on cells displaying the average amplitude profiles of the cells. Prior to identifying the amplitude profile, each signal was filtered between 0.1–15 Hz (see Methods) before standardization using the standard deviation over all the three recordings. Pairwise comparisons were performed using paired t‑tests, with p‑values adjusted for multiple comparisons (n = 6 cells) using the Bonferroni correction. Whiskers extend to 1.5 times the interquartile range (IQR).

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: Cell Culture, Modification, Comparison, Standard Deviation

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Glucose modulation of MIN6 electrical behaviour assessed using MEA recordings. ( a ) Bright-field micrograph of the circular microelectrode array used for recordings, displaying the radial arrangement of electrodes and the central culture region where MIN6 cells were seeded. Scale bar = 1000 μm. ( b ) Impedance-based viability maps for three independent wells (W1-W3). Each heatmap shows the impedance magnitude measured at the electrode–cell interface, serving as a surrogate metric for cell coverage and viability. Higher impedance indicates greater cell attachment. The four rows depict: no glucose, 10 mM glucose, 2 μM nifedipine, and two days after nifedipine treatment, illustrating condition-dependent variations in cell viability and adherence. ( c ) Representative 100-s extracellular voltage traces recorded from the same MEA electrode under three conditions: glucose-free HBSS, HBSS supplemented with 10 mM glucose, and HBSS supplemented with 10 mM glucose plus 2 μM nifedipine. The traces, filtered with a standard 0–15 Hz band-pass, reveal condition-dependent variations in the amplitude of MIN6 electrical activity. ( d ) Frequency-resolved decomposition of the same electrode shown in ( a ). Glucose enhances electrical activity, while nifedipine suppresses it within the 1–15 Hz range.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: Microelectrode Array, Cell Attachment Assay, Activity Assay

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Cell-attached patch-clamp recordings of glucose-induced activity in a MIN6 β-cell and quantification of spike frequency. ( a ) Representative current trace recorded under three consecutive conditions: HBSS buffer (0 mM glucose), 10 mM glucose, and 10 mM glucose + 10 µM nifedipine. The black trace shows the analysed current, while grey segments correspond to periods of perfusion during which mechanical noise was introduced. Red ticks mark automatically detected downward current deflections identified as action-current events using a dynamic threshold-based detection algorithm (threshold = baseline – 3 × noise; 50 ms refractory period). Coloured horizontal bars indicate the duration of each condition (blue = HBSS, yellow = HBSS + glucose, green = HBSS + glucose + nifedipine). Expanded regions below illustrate zoomed view of spike events during the baseline and glucose phases, with an inset showing a single representative event (amplitude ≈ 3 pA, width ≈ 0.02 ms). ( b ) Quantification of firing activity for the three conditions for three experiments. Each box represents the distribution of windowed spike rates (10-s windows, 2-s step) across three cells analysed (286 spike events). Box edges denote the inter-quartile range (25th–75th percentile); the centre line shows the median; whiskers extend to 1.5 times the IQR. Diamond symbols indicate the mean rate for each condition. Mean ± SEM firing rates were 0.88 ± 0.06 spikes/s for 0 mM glucose, 1.57 ± 0.07 spikes/s for 10 mM glucose, and 0.26 ± 0.02 spikes/s for 10 mM glucose + 10 µM nifedipine. Nifedipine effectively suppressed activity, consistent with its role as a channel blocker.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques: Patch Clamp, Activity Assay

Journal: Scientific Reports

Article Title: Plasmonic imaging of living pancreatic beta-cell networks

doi: 10.1038/s41598-025-34094-0

Figure Lengend Snippet: Network analysis. ( a, b ) Brightfield and SPRM images of MIN6 cells, respectively. Scale bar 10 μm. ( c ) Connectivity matrices for the following conditions: baseline HBSS ( c.i ), HBSS supplemented with 10 mM glucose ( c.ii ) HBSS supplemented with 10 mM glucose and 40 μM nifedipine ( c.iii ). ( d ) Corresponding directed graphs represent cells ROIs as nodes, with edges (i.e. arrows) indicating patterns of directional connectivity and their associated weights. ( e ) Panels e(i) to e(iii) show examples of time series and their associated amplitude envelopes. Time-resolved connectivity, is presented for each of the above experimental conditions, measured via phase locking factor (PLF) and compared to amplitude correlation coefficient (ACC). PLF was calculated for a 10-s window with one second overlaps, for all cells and for each treatment. Similarly, ACC was computed by obtaining undirected correlation between the amplitude envelopes. ( f ) Boxplots depicting the mean undirected PLF (i) and the mean ACC (ii), calculated from their respective dynamic observations and averaged across six cells, are presented in panels e(i) and e(ii). In each boxplot, horizontal lines indicate the median values, while the boxes represent the IQR. Whiskers extend to 1.5 times the IQR. Paired t-tests were performed for multiple comparisons, with all P-values adjusted using the Bonferroni correction.

Article Snippet: The mouse pancreatic cell line, MIN6 (Beta-TC-6, ATCC; CRL-11506), was maintained in high Glucose DMEM (Merck, D5671) supplemented with 10% FBS (Merck, F9665), 10 mM HEPES (Merck, R0887), 50 mg/ml penicillin and streptomycin (Merck, P0781) and 50 mM b-mercaptoethanol (Merck, M3148).

Techniques:

Journal: Communications Biology

Article Title: Activation of the urotensin-II receptor by remdesivir induces cardiomyocyte dysfunction

doi: 10.1038/s42003-023-04888-x

Figure Lengend Snippet: a Serum-starved HEK293 cells overexpressing UTS2R were stimulated with the indicated concentrations of remdesivir for 5 min with or without urantide, a UTS2R antagonist, and the lysates subjected to western blotting analysis. ERK1 and ERK2 activation ratios (pERK1/ERK1 and pERK2/ERK2) were calculated with data normalized to the vehicle. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001 by Tukey’s multiple comparisons test. Data are represented as means ± SEM ( n = 3). b Left, Temporal correlation between the field potential duration and the QT interval on the surface ECG. Right, Schematic of the multielectrode array (MEA) platform. c Representative field potential waveform in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) treated with 1 µM remdesivir in the presence or absence of urantide for 72 h. d Effect of remdesivir and urantide on field potential prolongation in hiPSC-CMs. * p < 0.05, ** p < 0.01 by two-way ANOVA followed by Šídák’s multiple comparisons tests. Data are represented as means ± SEM ( n = 3). e Perforated patch-clamp to record spontaneous action potentials of hiPS-CMs in current-clamp models. The hiPSC-CMs were treated with 10 µM remdesivir in the presence or absence of 50 µM urantide for 72 h. * p < 0.05 and ** p < 0.01 by Tukey’s multiple comparisons test. Data are represented as means ± SEM ( n ≥ 3).

Article Snippet: Right, Schematic of the multielectrode array (MEA) platform. c Representative field potential waveform in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) treated with 1 µM remdesivir in the presence or absence of urantide for 72 h. d Effect of remdesivir and urantide on field potential prolongation in hiPSC-CMs.

Techniques: Western Blot, Activation Assay, Derivative Assay, Patch Clamp

Journal: Communications Biology

Article Title: Activation of the urotensin-II receptor by remdesivir induces cardiomyocyte dysfunction

doi: 10.1038/s42003-023-04888-x

Figure Lengend Snippet: a , b Left, Representative waveform of contractility under pacing in neonatal rat cardiomyocytes (NRCMs) by 1 µM remdesivir with or without a urantide or b pertussis toxin (PTX), a Gα i/o inhibitor, and YM-254890, a Gα q/11 inhibitor, at 48 h. Right, the effect of remdesivir with a urantide or b PTX and YM-254890 on contractility under pacing in NRCMs. ** p < 0.01, *** p < 0.001, **** p < 0.0001 by Tukey’s multiple comparisons test. Data are represented as means ± SEM ( n = 3). c , d Representative western blot for phosphorylation of c ERK1/2 and d protein kinase B (AKT). Serum-starved HEK293 cells overexpressing UTS2R were stimulated with the indicated concentrations of remdesivir for 48 h. For G i/o protein inhibition, cells were incubated with PTX for at least 18 h at 150 ng/mL. ERK1, ERK2, and AKT activation ratios were calculated with data normalized to the vehicle. * p < 0.05, ** p < 0.01, *** p < 0.001 by Tukey’s multiple comparisons test. Data are shown as means ± SEM ( n = 3). e , f The effects of remdesivir on the contractility of adult mouse cardiomyocytes. Isolated adult mouse cardiomyocytes were treated with remdesivir (10 µM) for 30 min, and the percentile change in cell area ( e ) and the ratio of cardiomyocyte shortening ( f ) was measured during electrical pacing. **** p < 0.001 by unpaired t -test. Data are shown as means ± SEM (a total of 54 cells from 3 mice).

Article Snippet: Right, Schematic of the multielectrode array (MEA) platform. c Representative field potential waveform in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) treated with 1 µM remdesivir in the presence or absence of urantide for 72 h. d Effect of remdesivir and urantide on field potential prolongation in hiPSC-CMs.

Techniques: Western Blot, Inhibition, Incubation, Activation Assay, Isolation