Ru Ping Lee

Mesenchymal stem cells facilitate recovery from chemically induced liver damage and decrease liver fibrosis.

AIMS To investigate the feasibility and mechanism of liver damage repair using human bone marrow mesenchymal stem cells (hBMMSCs), we investigated the potential for hBMMSCs in recovery from liver damage, including fibrotic liver repair, using the CCl(4)-induced model for liver damage in the rat. MAIN METHODS Rats were injected with 0.5 ml/kg CCl(4) to induce liver damage and progressive liver fibrosis. hBMMSCs labeled with GFP were injected into the rats through the portal vein. KEY FINDINGS After one day of transplantation, GFP-labeled cells were found around the liver lobules, the hepatic blood vessels, and the edge of the liver lobes. Biochemical and histopathological analyses showed significantly increased recovery from liver damage in the transplanted group. In addition, transplanted hBMMSCs express matrix metalloproteinases (MMP), and liver fibrosis was significantly decreased. The degree of fibrosis reduction paralleled the number of hBMMSCs observed in liver sections. SIGNIFICANCE Our data suggest that hBMMSCs may facilitate recovery from chronic liver damage and may decrease liver fibrosis. Therefore, hBMMSCs are a potential option for treatment of liver cirrhosis.

The Lung Is The Major Site That Produces Nitric Oxide To Induce Acute Pulmonary Oedema In Endotoxin Shock

1. The present study was undertaken to determine the locus of nitric oxide (NO) production that is toxic to the lung and produces acute pulmonary oedema in endotoxin shock, to examine and compare the effects of changes in lung perfusate on endotoxin‐induced pulmonary oedema (EPE) and to evaluate the involvement of constitutive and inducible NO synthase (cNOS and iNOS, respectively).

Physiological and Chemical Indicators for Early and Late Stages of Sepsis in Conscious Rats

Endotoxin shock is a major cause of death in patients with septicemia. Endotoxin induces nitric oxide (NO) production and causes tissue damage. In addition, the release of oxygen free radicals has also been observed in endotoxin shock and was found to be responsible for the occurrence of multiple organ failure. The purpose of the present study was to evaluate suitable indicators for early and late stages of endotoxin shock. The experiments were designed to induce endotoxin shock in conscious rats by means of an Escherichia coli lipopolysaccharide (LPS) injection. Arterial pressure (AP) and heart rate (HR) were continuously monitored for 72 h after LPS administration. The maximal decrease in AP and increase in HR and nitrate/nitrite level occurred at 9-12 h following LPS administration. The white blood cell (WBC) count had decreased at 3 h. Hydroxyl radical (methyl guanidine, MG) decreased rapidly after LPS administration. Plasma levels of blood urea nitrogen (BUN), creatinine (Cr), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and glutamic oxaloacetic transaminase increased before the rise of amylase. Our results suggest that changes in AP, HR, WBC, free radicals, and chemical substances (BUN, Cr) can possibly serve as approximate indicators for the early stage of endotoxin shock. Severe multiple organ damage may be caused by amylase release in the late stage of endotoxin shock.

Adipose-Derived Stem Cells Can Abrogate Chemical-Induced Liver Fibrosis and Facilitate Recovery of Liver Function

Adipose-derived stem cells (ADSCs) are easy to harvest and have the ability for self-renewal and to differentiate into various cell types, including those of the hepatic lineage. Studies on the use of ADSCs for liver transplantation are, however, limited. The objective of this study was to investigate the feasibility of using human ADSCs and to better understand their mechanism of action for the repair of liver damage in a thioacetamide (TAA)-induced model of chronic liver damage in the rat. To induce liver damage, 200 mg/kg TAA was injected intraperitoneally into Wistar rats every 3 days for 60 days. For cell therapy, 1 × 106 human ADSCs suspended in 300 ml of phosphate-buffered saline were transplanted into each experimental rat by direct liver injection. Immunohistochemistry showed that the transplanted ADSCs differentiated into albumin- and α-fetoprotein-secreting liver-like cells 1 week after transplantation. In addition, liver function recovered significantly, as determined by biochemical analyses that analyzed total bilirubin, prothrombin time, and albumin levels. The Metavir score, derived from histopathological analysis, also showed a significant decrease in liver fibrosis and inflammatory activity after ADSC transplantation. Finally, we found a reduction in the expression of α-smooth muscle actin, a marker of hepatic stellate cells, which produce collagen fiber, and an increase in the expression of matrix metalloproteinase-9, which degrades collagen fiber, after ADSC transplantation. These findings are consistent with abrogation of liver fibrosis in the ADSC therapy group. Consequently, these results suggest that ADSC transplantation may facilitate recovery from chronic liver damage and thus may have clinical applications.

Effects of post-treatment with low-dose propofol on inflammatory responses to lipopolysaccharide-induced shock in conscious rats

1. In the present study, we used a low dose of propofol (5 mg/kg per h) to investigate its effects on the pro‐inflammatory cytokines (tumour necrosis factor (TNF)‐α, interleukin (IL)‐1β and IL‐10) and changes in nitric oxide (NO) following lipopolysaccharide (LPS) for a period of 12 h in conscious rats.

Nitric oxide in mesenteric vascular reactivity: A comparison between rats with normotension and hypertension

1. Nitric oxide (NO) plays an important role in various physiological functions. The continuous formation of endogenous NO from endothelial cells maintains a vasodilator tone and regulates blood flow and pressure. However, the role of NO in hypertension remains controversial.

A Modified Technique for Tail Cuff Pressure Measurement in Unrestrained Conscious Rats

In physiological experiments, it is essential to measure arterial pressure (AP) and heart rate (HR) in animals. Tail cuff pressure (TCP) measurement using photoelectric volume oscillometry has been commonly used. We designed a new technique for continuous measurement of AP and HR in conscious, unrestrained rats. This is based on the observation that fixation of the rats tail with tape keeps the animal in position without struggling. The animal is free to move its body. To test the accuracy of this new technique, Sprague-Dawley rats underwent four AP and HR measurement techniques. These included a new unrestrained method (UR), which was compared to the following three methods: traditional restrained TCP method with restrainer, direct monitoring of AP and HR with femoral artery catheterization and a combination of photoelectric volume oscillometry (with body heating to 37 degrees C) and femoral arterial recording. The results show that the modified UR measurement provides accurate data on AP and HR. This method obtains a lower value of HR and similar mean AP when compared to direct monitoring from femoral arterial catheterization. Accordingly, the modified unrestrained TCP measurement can be used in conscious rats as a noninvasive method.

Transplantation of Human Wharton's Jelly-Derived Stem Cells Alleviates Chemically Induced Liver Fibrosis in Rats

There is currently no effective treatment method available for liver fibrosis. We therefore evaluated the use of Whartons jelly stem cells (WJSCs; the major umbilical cord stem cell population) to treat chemically induced liver fibrosis via intraperitoneal injection of thioacetamide. WJSCs were transplanted into liver-damaged rats via the portal vein and the treatment was evaluated by assessing serum biochemistry and histopathology. Transplanted WJSCs were distributed in the fibrotic area and around blood vessels, and hepatic recovery was accelerated. Serum prothrombin time significantly recovered, and serum albumin also improved at 21 days posttransplantation; collagen accumulation also decreased at 14 days. Thus, human WJSCs promoted recovery after chronic liver damage. Using immunohistochemical analyses, we determined that transplanted WJSCs produce albumin, hepatocyte growth factor (HGF), and metalloproteinase (MMP) after transplantation to chemically injured liver, indicating that WJSC may help to decrease liver collagen and thus may be useful for treating liver fibrosis.

N-Acetylcysteine Ameliorates Lipopolysaccharide-Induced Organ Damage in Conscious Rats

Lipopolysaccharide is strongly associated with septic shock, leading to multiple organ failure. It can activate monocytes and macrophages to release proinflammatory mediators such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and nitric oxide (NO). The present experiments were designed to induce endotoxin shock by an intravenous injection of Klebsiella pneumoniae lipopolysaccharide (LPS, 10 mg/kg) in conscious rats. Arterial pressure and heart rate (HR) were continuously monitored for 48 h after LPS administration. N-Acetylcysteine was used to study its effects on organ damage. Biochemical substances were measured to reflect organ functions. Biochemical factors included blood urea nitrogen (BUN), creatinine (Cre), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate transferase (GOT), alanine transferase (GPT), TNF-alpha, IL-1 beta, methyl guanidine (MG), and nitrites/nitrates. LPS caused significant increases in blood BUN, Cre, LDH, CPK, GOT, GPT, TNF-alpha, IL-1 beta, MG levels, and HR, as well as a decrease in mean arterial pressure and an elevation of nitrites/nitrates. N-Acetylcysteine suppressed the release of TNF-alpha, IL-1 beta, and MG, but enhanced NO production. These actions ameliorate LPS-induced organ damage in conscious rats. The beneficial effects may suggest a potential chemopreventive effect of this compound in sepsis prevention and treatment.

The reduction of tumor necrosis factor-alpha release and tissue damage by pentobarbital in the experimental endotoxemia model.

Sepsis is the leading cause of death for intensive care patients. Lipopolysaccharide (LPS) administration to animals under anesthesia is a strategy for the study of uncontrolled release of proinflammatory cytokines. Anesthetics have been indicated that they can specially affect immune responses, such as the inflammatory response. Pentobarbital is an anesthetic used mainly in animal studies. Thus, the effect of pentobarbital on tumor necrosis factor-&agr; (TNF-&agr;) release was determined. The results revealed that pentobarbital suppressed the expression of TNF-&agr; mRNA and its proteins, which may result from the decrease in the activities of nuclear factor-&kgr;B and activator protein 1 and the reduction of the expression of p38 mitogen-activated protein kinase by pentobarbital. After the inhibitory activity of the pentobarbital for TNF-&agr; release was proven in vivo, the cytotoxic effects of LPS were examined in vivo with or without pentobarbital treatments. In vivo results indicated that plasma levels of alanine aminotransferase, aspartate aminotransferase, lactic dehydrogenase, creatine kinase, serum urea nitrogen, and amylase decreased dramatically in the anesthetic group with pentobarbital administration. Finally, the effect of pentobarbital on TNF-&agr;-related cell death was monitored in vitro, and the results indicated that pentobarbital could directly enhance the viabilities of cells under the treatment of TNF-&agr; and protected cells from apoptosis induced by deferoxamine mesylate-induced hypoxia. These results suggest that pentobarbital significantly influences the LPS-induced inflammatory responses and protects cells from death directly and indirectly induced by TNF-&agr;. The information provides a perspective to re-evaluate the results of the experiments in which animals were anesthetized with pentobarbital. The anti-inflammatory effects of the drugs may have been caused by the synergistic effect of pentobarbital.