3.2 | Structural analysis of LF tissues
Growing evidence has demonstrated the structural disorder of LF tissues
of LSCS patients (Sakai et al., 2017; Sun et al., 2020). In order to
fully present the structural changes of LF tissues, we next conducted
H&E, EVG, and MT staining, and transmission electron microscope
observation experiments to detect the basic structure and ultrastructure
of LF. As illustrated in Figure 2A, the normal LF from LDH group were
rich in elastic fibers. The fibers were arrayed in a regular order (H&E
and EVG staining, ×200). Nevertheless, consistent with those previous
studies (Sakai et al., 2017; Sun et al., 2020), the hypertrophic LF
showed marked loss of elastic fibers in the LSCS group. The morphology
of the elastic fibers was uneven, fragmented, disorganized, and
partially absent (H&E, EVG and MT staining, ×200). In the MT staining,
the elastic fibers were stained pink, while the collagen fibers were
stained blue. In the LDH group, a large area was stained pink. But in
the LSCS group, most of the area was stained blue, showing fibrotic
change (MT staining, ×200). As compared with LDH group, a large number
of fibrosis-related proteins, including collagen I and Collagen III,
were observed in LSCS group detected by immunohistochemistry.
Moreover, ultrastructural observation by the transmission electron
microscopy (TEM) also showed that the LF tissues from LDH group
abundantly contained elastic fibers with very few collagen fibers among
them (Fig. 2B). However, there was a significant loss of elastic fibers
and an increase in collagen fibers in the LSCS group. The morphology of
elastic fibers on the coronal plane manily displayed long fusiform or
irregular shapes in the LSCS group, while that of LDH group was round or
short fusiform (Fig. 2B). The scale bar 5μm indicates 80000×
magnification and the 1μm indicates 40000× magnification.