Cytoprotective effects of urinary trypsin inhibitor on astrocytes injured by sustained compression

Abstract

Decreased cell membrane integrity is a primary pathological change observed in traumatic brain injury (TBI) that activates a number of complex intercellular and intracellular pathological events, leading to further neural injury. In this paper, we assessed the effects of urinary trypsin inhibitor (UTI) on astrocyte membrane integrity by determining the percentage of lactate dehydrogenase (LDH) released after sustained compression injury using a hydrostatic pressure model of mechanical-like TBI. Astrocytes isolated from SD rat pups were injured by sustained compression. At a pressure of 0.3 MPa for 5 min, a significant increase in LDH release was observed compared with control samples. Astrocytes displayed extensive structural disruption of mitochondrial cristae reflected in their swelling. Based on our initial results, injured astrocytes were treated with UTI at a final concentration of 500, 1,000, 3,000 or 5,000 U/ml for 24 h. The percentage of LDH released from injured astrocytes was significantly decreased when 1,000 and 3,000 U/ml of UTI were used. In a separate experiment, astrocytes were treated with UTI at a final concentration of 1,000 U/ml immediately, or at 30 min, 2, 6, or 24 h after sustained compression. The percentage of LDH release was significantly reduced (P < 0.05) when astrocytes were treated with UTI immediately or 30 min later. Together, our results suggest that UTI may have protective effects on astrocytes injured by sustained compression injury. Furthermore, the early administration (<2 h after injury) of UTI may result in a better outcome compared with delayed administration.

Cortical spheroids show strain-dependent cell viability loss and neurite disruption following sustained compression injury

“…In in vivo rodent models, cortical compression has led to increased oxidative stress, astrocyte reactivity, and blood-brain barrier permeability (15), and neuronal hyperexcitability (14). Other in vitro studies of sustained compression have observed increased lactate dehydrogenase in response to pressurized 2D cell cultures with neuronal and astrocyte cell lines (16,17). In the present study, we showed strain-dependent decreased cell viability and disrupted neurite network organization in 3D multicellular cortical spheroids.…”

“…and implantation of a hemispherical plastic bead inside rat somatosensory cortices to compress the brain statically (15). In vitro SCI studies have typically applied pressurized air to 2D cultures of neural cell lines in pressurized culture chambers (16,17). These studies have begun to provide a time window into cellular events that occur after the exposure of the brain and neuronal cells to forces.…”

Blockade of NF-κB and MAPK pathways by ulinastatin attenuates wear particle-stimulated osteoclast differentiation in vitro and in vivo

“…Beyond its inhibition of inflammatory proteases mentioned above, UTI exhibits anti-inflammatory activity and suppresses the infiltration of neutrophils and release of elastase and chemical mediators from them [29,30]. As well, UTI reportedly inhibits the production of TNF-α and IL-1 in LPS-stimulated human monocytes and LPS- or neutrophil elastase-stimulated IL-8 gene expression in HL60 cells or bronchial epithelial cells in vitro [31].…”