Immunohistochemical analysis of TIMP-2 and collagen types I and IV in experimental spinal cord ischemia–reperfusion injury in rats

Abstract

Background: Thoracic and thoracoabdominal aortic intervention carries a significant risk of spinal cord ischemia. The pathophysiologic mechanisms that cause hypoxic/ischemic injury to the spinal cord have not been totally explained. In normal spinal cord, neurons and glial cells do not express type IV collagen. Type IV collagen produced by reactive astrocytes is reported to participate in glial scar formation. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the matrix metalloproteinases (MMPs). TIMP-2 binds strongly with MMP-2, facilitating activation by membrane-type MMP. Imbalance between TIMPs and MMPs can lead to excessive degradation of matrix components. Type IV collagen involved in the blood-brain barrier disruption and glial scar formation, TIMP-2 influences MMP-2 that controls degradation of collagen I and IV. Objective: To examine the immunohistochemical analysis of TIMP-2 and collagen types I-IV in experimental spinal cord ischemia-reperfusion in rats. Methods: Thirty-two male Wistar rats weighing 250-300 g were divided into four groups: group S: sham group (n = 8); group 0P: 30-minute occlusion without perfusion (n = 8); group 3P: 30-minute occlusion and 3-hour perfusion (n = 8); and group 24P: 30-minute occlusion and 24-hour perfusion (n = 8). Infrarenal aorta was cross-clamped at two sites by using two aneurysm clips for 30 minutes. Reperfusion was provided after removal of the clips. Lumbar spinal cord segments were removed for immunohistochemical analysis. Results: TIMP-2 and collagen staining in 3-hour perfused (3P) group were nearly the same with sham group (S). TIMP-2 and collagen staining increased in the 24-hour perfused group. Conclusion: Alterations in collagen levels may relate to the biphasic breakdown of the blood-brain barrier and collagen staining in new cell types with relation to glial scar formation. Our results demonstrate that 3-hour perfusion after occlusion in hypoxic/ischemic spinal cord injury seems to be the critical reversible period.

“White Cord Syndrome” of Acute Tetraplegia after Anterior Cervical Decompression and Fusion for Chronic Spinal Cord Compression: A Case Report

“…It has been suggested that acute and chronic spinal cord ischemic injury may in fact induce the passage of blood borne or neurotrophic substances (specifically TNF- α ) through the BBB past its saturation point [14, 16–18]. It appears that decoupling of astrocyte foot processes from endothelial cell surfaces inhibits tight junction function in the BBB [15, 19, 20]. Transport systems and ionic buffering would then be disrupted allowing worsened reperfusion injury upon decompression of a previously ischemic spinal cord.…”

Effects of hyperbaric oxygen therapy on RAGE and MCP-1 expression in rats with spinal cord injury

“…Histopathological samples were fixed, embedded in paraffin, and cut into 5-µm slices. Following deparaffinizing and rehydrating, antigen retrieval was performed according to standard protocols (17). Following treatment with 3% H 2 O 2 in methanol and normal non-immune goat serum (Invitrogen; Thermo Fisher Scientific, Inc., Waltham, MA, USA) for 20 min at room temperature, the sections were incubated overnight at 4˚C with primary antibodies against RAGE (1:1,000; catalog no.…”

Regulation and involvement of matrix metalloproteinases in vascular diseases

“…MMP-14 was the first MMP discovered possessing a transmembrane domain cloned from lung tumor cells conferring their invasiveness and metastasis (51). A study focusing on ischemia-reperfusion in the spinal cord injury of rats reported that TIMP-2 binding to MMP-2 activates MMP-14 (52). Furthermore, MMP-14 has been found to be involved in neuroinflammation (53).…”