Figure 4
Neuroendocrine pancreas in human development. (a) CLARITY enables multi-round immunolabeling of large human tissues, such as in this 1 mm thick sample from a 3 year old human pancreas stained for Type 4 Collagen (Col4), β-tubulin (Tuj1), Insulin (Ins), Neurofilament (NF), and Glucagon (Gcg) over two rounds and manually registered together using image features. Samples were embedded in A1B1P4 hydrogel and cleared for 2–3 weeks at 60 °C. Scale bar = 1000 μm. (b) 3D histological examination of two human pancreas samples at age 3 years and at 7 years illustrate differences in islet size (dashed lines) and innervation (arrows) during postnatal human development. Scale bar = 100 μm. (c) Analysis of islet populations across fetal (n = 3), neonatal (n = 3, 0–3yo), and juvenile (n = 3, 4–8yo) human samples reveals a distribution shift toward larger islets as humans age. (d) Analysis of innervation surrounding and within islet populations across fetal, neonatal, and juvenile human samples reveal distribution shift toward reduced innervation in islet neighborhoods during postnatal human development. (e) CLARITY may enable assessment of relevant features in diseased tissue. Here, an 8yo subject with history of T1D shows minimal evidence of insulin-expressing islets compared to healthy age-matched control. Samples were cleared and stained under identical conditions but in separate experiments. Scale bar = 500 μm.
