Fig. 5: Optogenetic regulation effectively inhibits the in vivo release of PTH in an established rat model of secondary hyperparathyroidism.
From: An optogenetic approach for regulating human parathyroid hormone secretion
a HE staining of control rat parathyroid gland and hyperplastic parathyroid from secondary hyperparathyroidism (SHPT) rats at different magnifications. Heterogeneous distribution of chief cells, nodularity, and enlargement of connective fibrous tissue was observed in SHPT rat parathyroid. Scale bar = 100 μm. b Quantification of serum levels of PTH in the SHPT and control groups (n = 5 rats per group). Two-tailed unpaired t-test, p < 0.0001. Values represent mean ± SEM. c Schematic showing the injection of the CMV-ChETA-eYFP lentivirus into the parathyroid gland and blue light stimulation (470 nm, 20 Hz) of the gland for 30 min. d Immunofluorescence of representative parathyroid glands from the eYFP and ChETA groups. Strong florescence signals were observed in the ChETA group. Scale bar = 100 μm. e Double staining of ChETA-eYFP and PTH of the sectioned rat parathyroid gland. Scale bar = 50 μm. f Quantification of the number of PTH+/ChETA+ double positive cells per section. A total of 86% (865/1000) of ChETA-positive cells expressed PTH from 20 sections from three rats per group. Quantification of the number of ChETA+/ PTH+ double positive cells per section. A total of 46.7% of PTH-positive cells expressed ChETA+. Values represent mean ± SEM. g Quantification of serum PTH levels in the ChETA and eYFP groups before (B) and at 0, 5, 15, and 30 min after light stimulation. PTH levels in the ChETA group were lower than those of the control group at 5 and 15 min following light stimulation (n = 6 rats per group). Two-tailed unpaired t-test, p values as indicated. Values represent mean ± SEM. h Quantification of calcium levels in the serum of rats before (B) and at 0, 5, 15, and 30 min after light stimulation. Serum calcium was lower in ChETA group than the control group 30 min after blue light stimulation (n = 6 rats per group). Two-tailed unpaired t-test, p values as indicated. Values represent mean ± SEM. Source data are provided as a Source Data file.
