Meshwork Structures in Bovine Glomerular and Tubular Basement Membrane as Revealed by Ultra-High Resolution Scanning Electron Microscopy

Abstract

We examined the ultrastructure of the bovine glomerular basement membrane (GBM) and tubular basement membrane (TBM) using ultra-high-resolution scanning electron microscopy after conductive staining without metal coating. Purified basement membranes (BMs) were obtained by sonication and acellular BMs by detergent treatments. Purified GBMs (PGBMs) and acellular GBMs (AGBMs) showed similar meshwork structures composed of regular round or oval pores and branching strands. Pore diameters were 10.2 ± 2.4 nm (mean ± SD) in PGBMs and 9.8 ± 3.1 nm in AGBMs. Purified TBMs (PTBMs) and acellular TBMs (ATBMs) exhibited heterogeneous meshwork structures in which compact meshes in the cristae were combined with coarse meshes in the invaginations on the epithelial surfaces. Pore diameters were 12.6 ± 5.2 nm in PTBMs and 11.4 ± 4.0 nm in ATBMs which were significantly larger than those in GBMs. The width of the strands ranged from 3 to 15 nm in all BMs. A 4 M guanidine hydrochloride extraction of the acellular BMs revealed large polygonal networks in the invaginations of the TBM and twisted strands which were considered to be type IV collagen fibrils. Ultra-high-resolution scanning electron microscopy and conductive staining were useful for the study of three-dimensional architectures of BMs and revealed heterogeneous meshwork structures in the GBM and TBM which were probably caused by a different ratio of the major components.

Study of Glomerular Permselectivity for Proteins of the Glomerular Basement Membrane Using a Dialyzer Model

“…7], and this structure was subsequently confirmed by various methods [9][10][11]. We have recently confirmed the meshwork structure of G B M [21,22,24] as well as tubular basement 593 membrane. Bowman's capsule basement membrane and peritubular capillary basement membrane [22] by high-res olution scanning electron microscopy which has a resolving power o f 0.5 nm.…”

Epithelial contact guidance on well-defined micro- and nanostructured substrates

“…Epithelial cells adhere to specialized ECMs called basement membranes that, in addition to providing physical support, present chemical cues to cells through ligands that specifically bind cell-surface receptors. Basement membranes have a felt-like appearance with pores and fibers of nanoscale dimensions (Abrams et al, 2002;Abrams et al, 2000a;Abrams et al, 2000b;Hironaka et al, 1993;Inoue, 1994;Kubosawa and Kondo, 1994;Merker, 1994;Ruben and Yurchenco, 1994;Shirato et al, 1991;Yamasaki et al, 1994). In particular, the lateral dimensions of the features present on the human corneal basement membrane were reported to range from 22 nm to 191 nm (Abrams et al, 2000b).…”

Characterization of Endothelial Basement Membrane Nanotopography in Rhesus Macaque as a Guide for Vessel Tissue Engineering

“…Limited studies have sought to characterize the topography of the endothelial basement membrane, which include kidney, [32][33][34][35] and a single report qualitatively described the topographic features of the basement membrane associated with the bovine carotid artery. 34 From these studies, we know that the molecular components that comprise the endothelial basement membrane form a complex three-dimensional topography of pores and fibers that have been shown to impact cell shape, growth, migration, differentiation, and proliferation of endothelial cells.…”