Pre-clinical study of human umbilical cord mesenchymal stem cell transplantation for the treatment of traumatic brain injury: safety evaluation from immunogenic and oncogenic perspectives.

Stem cell therapy is a promising strategy for the treatment of traumatic brain injury (TBI). However, animal experiments are needed to evaluate safety; in particular, to examine the immunogenicity and tumorigenicity of human umbilical cord mesenchymal stem cells (huMSCs) before clinical application. In this study, huMSCs were harvested from human amniotic membrane and umbilical cord vascular tissue. A rat model of TBI was established using the controlled cortical impact method. Starting from the third day after injury, the rats were injected with 10 µL of 5 × 106/mL huMSCs by cerebral stereotaxis or with 500 µL of 1 × 106/mL huMSCs via the tail vein for 3 successive days. huMSC transplantation decreased the serum levels of proinflammatory cytokines in rats with TBI and increased the serum levels of anti-inflammatory cytokines, thereby exhibiting good immunoregulatory function. The transplanted huMSCs were distributed in the liver, lung and brain injury sites. No abnormal proliferation or tumorigenesis was found in these organs up to 12 months after transplantation. The transplanted huMSCs negligibly proliferated in vivo, and apoptosis was gradually observed at later stages. These findings suggest that huMSC transplantation for the treatment of traumatic brain injury displays good safety. In addition, huMSCs exhibit good immunoregulatory function, which can help prevent and reduce secondary brain injury caused by the rapid release of inflammatory factors after TBI. This study was approved by the Ethics Committee of Wuhan General Hospital of PLA (approval No. 20160054) on November 1, 2016.

[Inhibitory effects of protease inhibitor on endotoxin-induced acute lung injury in rats].

OBJECTIVE: To investigate the effects of protease inhibitor on lipopolysaccharide-induced acute lung injury in rats and its possible mechanisms. METHODS: Thirty-two male Wister rats, weighting 250-270 g, were divided into four groups randomly. C, normal controls (n=8); A: acute lung injury group (n=8), receiving intravenous endotoxin (lipopolysaccharide O55:B5, LPS 5 mg/kg); V, low-dose group (n=8), U, high-dose intervention group (n=8, receiving Ulinastatin 50,000 U/kg and 100,000 U/kg respectively and LPS 5 mg/kg). The specimens were collected 2 hours later, We observed the following changes: blood gas analysis, the lung wet/dry weight ratio, the pulmonary vascular permeability, histological manifestations, lung tissue myeloperoxidase activity, plasma endothelin-1, lung tissue malonaldehyde and conjugated-diene. RESULTS: Compared with Group C, the lungs of the rats in Group A had significant hyperemia and spotted hemorrhage. The inflammatory granulocyte infiltrating, diffused alveolar septum thickening and spotted hemorrhage were observed in pathological examinations. The lung wet/dry weight ratio and Evans Blue content (per gram) increased significantly in group A [(5.41+/-0.06), (27.64+/-2.48) microg] compared with group C [(4.95+/-0.08), (12.99+/-2.83) microg], in the intervention groups (U: 5.0+/-0.05, 19.47+/- 2.09; V: 4.98+/-0.06, 21.44+/-3.12) however the difference was not significant between the intervention groups; The plasma endothelin-1 and lung tissue myeloperoxidase activity increased significantly in group A [(948.23+/-103.45) u/g, (152.90+/-8.41) u/g] compared with group C [(729.38+/-88.64) u/g ], [(54.62+/-15.49) u/g] but intervention groups [U: (633.27+/-93.27) u/g, (119.40+/-11.32) u/g; V: (671.87+/-105.45) u/g, (129.55+/-9.57) u/g] decreased significantly compared with group A, no significant difference between intervention groups; lung tissue Lipid-peroxide (malonaldehyde, MDA and conjugated-diene, C-diene) increased significantly in group A [MDA: (73.95+/-4.62) nmol/g; C-diene: (10.96+/-0.81) nmol/g] compared with group C [MDA: (39.65+/-6.21) nmol/g; C-diene: (3.34+/-0.51) nmol/g], intervention groups [U: MDA: (51.26+/-5.56) nmol/g, C-diene: (7.59+/-0.84) nmol/g; V: MDA: (59.87+/-4.62) nmol/g, C-diene: (8.79+/-0.45) nmol/g] decreased significantly compared with group A. MDA decreased significantly in group U compared with group V. CONCLUSION: The protease inhibitor, Ulinastatin, may decrease inflammatory reaction and further decrease lung damage induced by LPS in rats, all indicating protection of protease inhibitor against acute lung injury.

[Protective effect of protease inhibitor on renal function of rat challenged by lipopolysaccharide].

OBJECTIVE: To investigate the protective effects of protease inhibitor on lipopolysaccharide (LPS)-induced kidney injury in rats and its possible mechanism. METHODS: Thirty-two male Wistar rats were divided into four groups randomly: normal control (n=6); LPS group (n=10), receiving intravenous endotoxin (LPS, O55:B5, 5 mg/kg); low-dose ulinastatin (UT) intervention group (n=8), receiving intraperitoneal UT 50 000 U/kg and LPS 5 mg/kg as above; high-dose UT intervention group (n=8), UT 100,000 U/kg and LPS 5 mg/kg. The following examinations were carried out: blood gas analysis, kidney pathological changes, plasma endothelin-1, plasma lactic acid, N-acetylglucosaminidase (NAG) in urine, and plasma creatinine (Cr) level. RESULTS: Blood gas analysis showed that pH, partial pressure of oxygen in artery (PaO(2)) and base excess (BE) lowered significantly (all P<0.01) in LPS group compared with normal control group, and elevated in low-dose and large dose UT intervention groups compared with LPS group, the differences were statistically significant (P<0.01). The plasma endothelin-1 increased significantly (P<0.01) in LPS group compared with normal control group and intervention groups. Plasma lactate increased significantly in LPS group compared with normal control group (P<0.001), decreased significantly in intervention groups compared with LPS group (P<0.01). No significant difference was found between two intervention groups (P>0.05). Plasma Cr and urine NAG level increased in LPS groups, and the difference was significant compared with normal control groups and intervention groups (P<0.01). Pathohistologic examination revealed normal glomeruli but vacuolar degeneration of tubular epithelial cells, and part of them disrupted and desquamated, and also tubular dilatation. Only mild pathological changes were seen in the intervention groups. There was no obvious difference in morphology between two intervention groups. CONCLUSION: The protease inhibitor, UT, may alleviate LPS-induced inflammatory reaction and damage to kidney in rats.