ABSTRACT
BACKGROUND: Vibrio vulnificus inside the body could activate the NF-κB signaling pathway and initiate the inflammatory cascade. The lung is one of the earliest organs affected by sepsis associated with acute lung injury. High mobility group protein B1 (HMGB1) is an important late-acting pro-inflammatory cytokine involving in the pathophysiology of sepsis. It is also involved in the injury process in the lung, liver and intestine. There has been no report on the involvement of HMGB1 in Vibrio vulnificus sepsis-induced lung injury. METHODS: Sixty rats were randomly divided into a normal control group (group A,n=10) and a Vibrio vulnificus sepsis group (group B,n=50). Sepsis was induced in the rats by subcutaneous injection of Vibrio vulnificus (concentration 6×108 cfu/mL, volume 0.1 mL/100g)) into the left lower limbs. The rats in group B were sacrificed separately 1, 6, 12, 24, and 48 hours after the infection. Their lungs were stored as specimens, lung water content was measured, and lung pathology was observed under a light microscope. The expressions of the HMGB1 gene and protein in the lungs were detected by RT-PCR and Western blot. Data were analyzed with one-way analysis of variance (ANOVA) and the LSD method for pair-wise comparison between the two groups.P<0.05 was considered statistically significant. RESULTS: Compared to group A (0.652±0.177), HMGB1 mRNA expression in the lungs of group B was significantly higher at 0 hour (1.161±0.358,P=0.013), 24 hours (1.679±0.235,P=0.000), and 48 hours (1.258±0.274,P=0.004) (P<0.05), and peaked at 24 hours. Compared to group A (0.594±0.190), HMGB1 protein expression at 6 hours (1.408±0.567,P=0.026) after infection was significantly increased (P<0. 05), and peaked at 24 hours (2.415±1.064,P=0.000) after infection. Compared to group A (0.699±0.054), lung water content was significantly increased at 6 hours (0.759±0.030,P=0.001),12 hours (0.767±0.023,P=0.000), 24 hours (0.771±0.043,P=0.000) and 48 hours (0.789±0.137,P=0.000) after infection (P<0.05). Compared to group A, pathological changes at 12 hours in group B indicate marked pulmonary vascular congestion, interstitial edema and inflammatory infiltration. Alveolar cavity collapse and boundaries of the alveolar septum could not be clearly identified. CONCLUSION:Vibrio vulnificus sepsis can lead to injury in rat lungs, and increased HMGB1 expression in lung tissue may be one of the mechanisms for injury from Vibrio vulnificus sepsis.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of inflammatory factors in lung tissue of acute paraquat (PQ) poisoned rats.</p><p><b>METHODS</b>Fifty male SD rats were randomized divided into two groups: the normal control group (NC group, n = 10) and the PQ group (n = 40). The 1 ml saline was administered once in normal control group. The PQ group was administered with 20 mg/kg 1% PQ by intraperitoneal injection to establish the model of PQ induced lung injury. At six hours, at the first, the third and the seventh day the PQ group were sacrificed, while at the first day the normal control group was sacrificed. The level of tumor necrosis factor alpha (TNF-alpha) mRNA, interleukin 10 (IL-10) mRNA, high mobility group box 1 (HMGB-1) mRNA in lung of rats were detected. Meanwhile, pathological changes of the lung were examined under optical microscope.</p><p><b>RESULTS</b>Compared with that in normal control group, TNF-alpha mRNA expression in lung tissue of PQ group reached the peak at the six hour and decreased slowly at the first day [(0.740 +/- 0.100) and (0.584 +/- 0.049) respectively]. At the six hour and the first day in PQ group it was significantly higher than that in normal control group (P < 0.05 or P < 0.01). IL-10 mRNA expression in lung tissue of PQ group was elevated at the six hour, reached the peak at the first day, at the third day [(0.551 +/- 0.016) and (0.524 +/- 0.010) respectively] and the seventh day also higher than that in normal control group. At the first and the seventh day in the PQ group it was significantly higher than that in normal control group (P < 0.01). Meanwhile, HMGB-1 mRNA expression in lung tissue of PQ group was also elevated at the six hour, reached the peak at the first day, at the third [(0.695 +/- 0.060), (0.871 +/- 0.154) and (0.819 +/- 0.188) respectively] and the seventh day also higher than that in normal control group. At six hour, the first and the third day in the PQ group it was significantly higher than that in normal control group (P < 0.01). The histological changes such as alveolar edema, hemorrhage and inflammatory cell infiltration in the PQ group were more than those in the normal control group.</p><p><b>CONCLUSION</b>In rats after PQ intoxication the levels of the inflammatory factors TNF-alpha, IL-10 and HMGB-1 are higher than normal rats, and inflammatory could play an important role in lung injury of poisoned rats.</p>