Fig. 1

Mesangial cell structure with its processes extending out to multiple capillaries. MC: mesangial cell, MM: mesangial matrix, P: podocytes, EC: endothelial cells, C: capillaries, GBM: glomerular basement membrane. The small arrows indicate the mesangial cell/GBM connections that oppose the hydrostatic pressures shown by long red arrow. The T-shaped marking indicates the mesangial cell process where the body of the T-shaped marking represents the axis of the mesangial processes, and the head of the T-shaped marking indicates the mesangial angles. The mesangial cell occupies a majority of the mesangium and is closely attached to the GBM directly by microfibrillar attachments or indirectly to the GBM via the mesangial matrix. The T-shaped mesangial processes are firmly embedded in between the capillaries and the GBM and enable the mesangial cell to maintain glomerular structure. Modified after [75] with permission