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: Cell Death Discovery

Article Title: NR4A1 enhances MKP7 expression to diminish JNK activation induced by ROS or ER-stress in pancreatic β cells for surviving

doi: 10.1038/s41420-021-00521-0

Figure Lengend Snippet: A ROS may result in ER-stress. ROS or/and ER-stress incurs JNK activation. The activated JNK leads to pancreatic β cell apoptosis via mitochondria-dependent or independent pathways. B Acute ROS or ER-stress results in the expression of NR4A1, which in turn enhances the expression of MKP7, while MKP7 is able to abolish partial JNK activation by exerting its phosphatase activity, therefore, largely reduces pancreatic β cell apoptosis. The fate of pancreatic β cells depends on the balance between the availability of NR4A1 or MKP7 and the severity of ROS or ER-stress.

Article Snippet: The mouse pancreatic β cell lines (MIN6 and β-TC6) were from ATCC.

Techniques: Activation Assay, Expressing, Activity Assay

Journal: PLoS ONE

Article Title: A Novel Role for the Centrosomal Protein, Pericentrin, in Regulation of Insulin Secretory Vesicle Docking in Mouse Pancreatic β-cells

doi: 10.1371/journal.pone.0011812

Figure Lengend Snippet: A. Immunofluorescence of shRNA treated stable insulinoma cell lines (both NIT-1 and MIN6 were used with similar results) in low glucose shows co-localization of insulin (red) and Sec6 (green) in scrambled (control) shRNA-treated cells and decreased Sec6 staining and disrupted co-localization with insulin in pericentrin shRNA-treated cells (inset-enlargement). Scale bar represents 10 µm. B. Glucose stimulation (25 mM) for 1 hr induced refilling of the insulin granules and return of Sec6 co-localization with insulin in pericentrin-depleted cells (inset-enlargement). C. Quantitation of fluorescence intensities for Sec6 from A and B. D. Immunoblot analysis of Sec6 in pericentrin-depleted NIT-1 cells demonstrates reduced Sec6 at low glucose, with a return to normal following high glucose stimulation. Protein band densities were measured by densitometry and normalized to actin; numbers are relative to control (1.00). Data shown are representative of three independent experiments.

Article Snippet: Mouse insulinoma (MIN6, NIT1, and TC6) cells were obtained from ATCC (Bethesda, MD).

Techniques: Immunofluorescence, shRNA, Control, Staining, Quantitation Assay, Fluorescence, Western Blot

Journal: PLoS ONE

Article Title: A Novel Role for the Centrosomal Protein, Pericentrin, in Regulation of Insulin Secretory Vesicle Docking in Mouse Pancreatic β-cells

doi: 10.1371/journal.pone.0011812

Figure Lengend Snippet: A. Quantitation of insulin granule density and fluorescence intensities before and after glucose stimulation of MIN6 insulinoma cells stably expressing scrambled (control) or pericentrin shRNAs. Values represent means ± s.d; *p<0.05, **p<0.01. All data shown are representative of multiple independent experiments. B. TIRF microscopy showing insulin immunofluorescence at the cell membrane (docked granules) before glucose stimulation and C. 1 hr after 25 mM glucose stimulation of MIN6 cells stably expressing scrambled or pericentrin shRNAs. GFP reporter indicates shRNA transduced cells. Fluorescence intensity bar to the right, scale bar represents 5 µm.

Article Snippet: Mouse insulinoma (MIN6, NIT1, and TC6) cells were obtained from ATCC (Bethesda, MD).

Techniques: Quantitation Assay, Fluorescence, Stable Transfection, Expressing, Control, Microscopy, Immunofluorescence, Membrane, shRNA

Journal: PLoS ONE

Article Title: A Novel Role for the Centrosomal Protein, Pericentrin, in Regulation of Insulin Secretory Vesicle Docking in Mouse Pancreatic β-cells

doi: 10.1371/journal.pone.0011812

Figure Lengend Snippet: A. Schematic representation of the experimental time course. Streptozotocin (STZ)-induced diabetic mice were transplanted with B. syngeneic islets (pericentrin shRNA, n = 3 mice; scrambled shRNA, n = 3 mice) or D. MIN6 insulinoma cells (pericentrin shRNA, n = 3; scrambled shRNA, n = 4) which were previously transduced in culture with scrambled or pericentrin shRNAs. After indicated days of transplantation, the mice were fasted and then given a glucose tolerance test (GTT). Blood glucose (BG) was determined at the days and times shown. C. Mice transplanted with LV-transduced islets were bled at fasting (time 0) or 15 min following glucose infusion, and plasma insulin levels were determined by RIA. Insulin levels are plotted for one representative experiment (n = 3 per group). For analysis of the change in insulin levels between 0 and 15 min, 2 separate experiments (each with n = 3 per group) were pooled and statistical analysis was based on log transformed data. E. Mice transplanted with insulinoma cells were bled at fasting (time 0), and plasma insulin levels were determined by RIA. These graphs show means ± s.e., *P<0.05, **P<0.01.

Article Snippet: Mouse insulinoma (MIN6, NIT1, and TC6) cells were obtained from ATCC (Bethesda, MD).

Techniques: shRNA, Transplantation Assay, Clinical Proteomics, Transformation Assay