Carbon Monoxide Improves Neurologic Outcomes by Mitochondrial Biogenesis after Global Cerebral Ischemia Induced by Cardiac Arrest in Rats.

Mitochondrial dysfunction contributes to brain injury following global cerebral ischemia after cardiac arrest. Carbon monoxide treatment has shown potent cytoprotective effects in ischemia/reperfusion injury. This study aimed to investigate the effects of carbon monoxide-releasing molecules on brain mitochondrial dysfunction and brain injury following resuscitation after cardiac arrest in rats. A rat model of cardiac arrest was established by asphyxia. The animals were randomly divided into the following 3 groups: cardiac arrest and resuscitation group, cardiac arrest and resuscitation plus carbon monoxide intervention group, and sham control group (no cardiac arrest). After the return of spontaneous circulation, neurologic deficit scores (NDS) and S-100B levels were significantly decreased at 24, 48, and 72 h, but carbon monoxide treatment improved the NDS and S-100B levels at 24 h and the 3-day survival rates of the rats. This treatment also decreased the number of damaged neurons in the hippocampus CA1 area and increased the brain mitochondrial activity. In addition, it increased mitochondrial biogenesis by increasing the expression of biogenesis factors including peroxisome proliferator-activated receptor-γ coactivator-1α, nuclear respiratory factor-1, nuclear respiratory factor-2 and mitochondrial transcription factor A. Thus, this study showed that carbon monoxide treatment alleviated brain injury after cardiac arrest in rats by increased brain mitochondrial biogenesis.

Repair of damaged intestinal mucosa in a mouse model of sepsis.

BACKGROUND: The intestine is not only the main target attacked by sepsis but also the vital organ which mediated sepsis. The recovery of the damaged intestinal barrier structure and function is related to the occurrence and outcome of multiple organ dysfunction syndrome (MODS). How to protect and reduce the damage of the intestinal mucosa and how to promote the reconstruction of the intestinal mucosa have been the important topics in sepsis for many years. This study aimed to investigate the influential factors of intestinal mucosal reconstruction after intestinal epithelial injury in vivo in a mouse model of sepsis. METHODS: Mice were subjected to cecal ligation and puncture (CLP) for induction of sepsis to assess intestinal mucosal damage, epithelial cell apoptosis, and transformed number of goblet cells, and to detect the concentration of TNF-α, IL-1 and TGF-ß1 and TFF3 (trefoil factor 3) expression in the small intestinal mucosa. All above were performed by HE staining, western blot, ELISA and immunohistochemistry respectively. The experimental animals were divided into a sepsis group and a sham-operation group. The animals with sepsis were separately killed at 6 (7 animals), 24 (7 animals) and 48 hours (7 animals) after CLP. RESULTS: Injured intestinal mucosa was observed in the 3 groups under a light microscope, in which damage scores in the 24-hour and 48-hour groups were higher than in the 6-hour group and no difference was found between the two groups. Moreover, less of goblet cells or other epithelial cells adjacent to the injured surface migrated into the wound to cover the denuded area. The number of goblet cells was substantially decreased in the three CLP groups compared with the sham-operation group. Protein levels of IL-1 and TNF-α were significantly increased by 3-4 fold at all time points when compared with the sham-operation group, and cleaved caspase-3 by 4 fold. Although TFF3 expression was modestly increased for 6 hours after the onset of CLP, it appeared to decline at 24 hours and 48 hours as shown by Western blot. A similar tendency was observed upon TGF-ß1, i.e. the protein level was not elevated at 24 hours and 48 hours, but increased modestly at 6 hours. CONCLUSIONS: Sepsis from CLP shows less restitution on the surface of injured intestinal mucosa. There is evidence that both constant inflammatory reaction and epithelial cell apoptosis may affect mucosal reestablishment of the intestine at the onset of sepsis. Mucosa after severe sepsis showed the state of high inflammation, and declined goblet cell function and mucosal reconstruction, which affected the repair of damaged intestinal barrier. Constant inflammatory reaction, and declined goblet cell function and mucosal reconstruction ability may affect the reestablishment of intestinal mucosa at the onset of sepsis.

[Effect of goblet cell in rat intestine on the restitution process of the gut barrier after hemorrhagic shock].

OBJECTIVE: To investigate the changes of the goblet cells in the intestine during the restitution process of the gut barrier after hemorrhagic shock. METHODS: Forty-nine Sprague-Dawley rats with body weight of 250-300 g were divided into control group (n=7) and experimental group (n=42). Rats in the experimental group was further divided into 6 groups (n=7 each) according to different time point at 1, 3, 6, 12, 24, and 36 hours after hemorrhagic shock resuscitation. The specimens from ileum tissue were taken to observe the morphological chan ges of the intestinal mucosa. The number of goblet cells was determined by light microscope and/or electron microscope. The contents of trefoil factor family 3 (TFF3) of goblet cells were examined using GC-9A gas chromatographic instrument. RESULTS: After hemorrhagic shock, mucosal epithelial injury was obvious in the small intestine. Tissue restitution was found after 3 hours, and mostly established after 12 hours. Following tissue restitution,the denuded mucosal surface was covered intensively by goblet cells. The number of goblet cells on the intestinal mucosa was reduced significantly from 243+/- 13 at 1 h to 157+/- 9 at 24 h (r=- 0.910, P< 0.01), and returned to normal level at 36 h. In the experimental group, the content of TFF3 in the intestinal mucosa increased significantly at 12 hours, decreased, but was still higher at 24 hours (t=3.24, P< 0.05). CONCLUSIONS: The goblet cells play a key role in the restitution of intestinal mucosa. High expression of TFF3 may facilitate the intestinal mucosal restitution in the early phase.

Functional and morphological changes of the gut barrier during the restitution process after hemorrhagic shock.

AIM: To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/reperfusion injury. METHODS: Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups: control group (sham shock n = 5) and experimental group (n = 42). Experimental group was further divided into six groups (n = 7 each) according to different time points after the hemorrhagic shock, including 0(th) h group, 1st h group, 3rd h group, 6th h group, 12th h group and 24th h group. All the rats were gavaged with 2 mL of suspension of lactulose (L) (100 mg/2 mL) and mannitol (M) (50 mg/each) at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides (LPS) from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument. RESULTS: After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0(th) h, and it became more serious at the 1st and the 3rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6 h and completed in 24 h. Two distinct models of cell death-apoptosis and necrosis-were involved in the destruction of rat intestinal epithelial cells. The number of goblet cells on intestinal mucosa was reduced significantly from 0 to 24 h (the number from 243+/-13 to 157+/-9 for ileum, 310+/-19 to 248+/-18 for colon; r = -0.910 and -0.437 respectively, all P<0.001), which was the same with the large intestine, but the grade of injury was lighter with the values of mucosal damage index in 3 h for jejunum, ileum, and colon being 2.8, 2.6, 1.2, respectively. The mucosal thickness and the height of villi in jejunum and ileum diminished in 1 h (the average height decreased from 309+/-24 to 204+/-23 microm and 271+/-31 to 231+/-28 microm, r = -0.758 and -0.659, all P<0.001; the thickness from 547+/-23 to 418+/-28 microm and 483+/-45 to 364+/-35 microm, r = -0.898 and -0.829, all P<0.001), but there was no statistical difference in the colon (F = 0.296, P = 0.934). Compared with control group, the urine L/M ratio and the blood LPS concentration in the experimental groups raised significantly, reaching the peak in 3-6 h (L/M: control vs 3 h vs 6 h was 0.029+/-0.09 vs 0.063+/-0.012 vs 0.078+/-0.021, r = -0.786, P<0.001; LPS: control vs 3 h vs 6 h was 0.09+/-0.021 vs 0.063+/-0.012 vs 0.25+/-0.023, r = -0.623, P<0.001), and it kept increasing in 24 h. CONCLUSION: The gut barrier of the rats was seriously damaged at the early phase of ischemic reperfusion injury after hemorrhagic shock, which included the injury and atrophy in intestinal mucosa and the increasing of intestinal permeability. Simultaneously, the intestinal mucosa also showed its great repairing potentiality, such as the improvement of the intestinal permeability and the recovery of the morphology at different phases after ischemic reperfusion injury. The restitution of gut barrier function was obviously slower than that of the morphology and there was no direct correlation between them. Compared with the small intestine, the large intestine had stronger potentiality against injury. The reduction of the amount of intestinal goblet cells by injury did not influence the ability of intestinal mucosal restitution at a certain extent and it appeared to be intimately involved in the restitution of the epithelium.

[Study on morphological change in intestinal mucosa from injury to repair after hemorrhagic shock].

OBJECTIVE: To study on morphological changes in mucosa of the small and large intestine mucosa after resuscitation of hemorrhagic shock. METHODS: The morphological changes in intestinal mucosa were observed under light and electron microscope, including the histology of intestinal mucosa, determination of height of villi and evaluation of mucosa damage index in the different phases after traumatic-hemorrhagic shock. RESULTS: Mucosa epithelial injury was obvious in small intestine were even at 0 hour, becoming more serious in 1 hour up to 3 hours. The tissue repair began after 3 hours, though the injury was still serious. Most of the inJured mucosa began to repair after 6 hours, and completed in 24 hours. The condition of the large intestine was similar to that of the small intestine, but the injury was less severe. The mucosal thickness and the height of villi were diminished after 1 hour of shock, but there was no obvious change in the colon. CONCLUSION: In the early phase after hemorrhagic shock, intestinal mucosal barrier are subJected to damage, but it could repair and recover in a short time. Compare with small intestine, large intestine have stronger potentiality against injury.