Welcome Invaders?

Looking like a tangle of tubes, glomerular tufts are the functional units of your kidneys, filtering blood to create urine. The tufts form a filtration barrier using endothelial cells, podocytes and connective tissue, while parietal epithelial cells (PECs) line the capsules in which tufts sit – this anatomy is essential to proper kidney function. In the kidney disease focal segmental glomerulosclerosis (FSGS), tufts become scarred – but only in parts, with some regions remaining healthy. Researchers investigate how in a mouse FSGS model. Using immunohistochemistry to identify PECs and podocytes in sections of FSGS kidneys, the images of which were then digitally ‘stitched together’, they found layers of PECs invaded scarred regions (pictured). However, this invasion also protected neighbouring regions by making contacts with podocytes to restore the filtration barrier. These healthy regions remained connected to the tube through which essential nutrients are filtered out. Together, this reveals how parts of FSGS kidneys can remain functional.

Written by Lux Fatimathas

Video from work by Laura Miesen and colleagues

Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Disease Models & Mechanisms, March 2022

Fertile Findings

Like impossibly numerous coloured handkerchiefs rammed inside a clown’s pocket, a densely-packed network of tubules fill the testes. Here millions of sperm are produced every hour, but any knot in the system can cause infertility. Mutations in the genes NM2A or NM2B cause infertility in mice, and in humans are linked to conditions from deafness to glomerulosclerosis. Investigating the mechanisms of disruption could have far-reaching implications. A study has shown that mice with one of these mutations had smaller testes and defects in their Sertoli cells – key players in sperm production, pictured in the tubules. Further experiments found that the microtubule cytoskeleton – the internal scaffold marked in green and red – was disorganised, and that both NM2A and NM2B must be silenced to affect fertility. Given the wide ranging impacts of these mutations in humans, findings like this could potentially breed improved treatments for more than fertility alone.

Written by Anthony Lewis

Image from work by Derek C.Sung and colleagues

Laboratory of Molecular Cardiology, Cell and Developmental Biology Center, Bethesda, MD, USA

Image copyright Elsevier 2021. Reproduced with permission.

Published in Developmental Biology, February 2021