Antisense RNA transcripts in the blood may be novel diagnostic markers for colorectal cancer.

Numerous genetic studies have been conducted regarding the occurrence of colorectal cancer (CRC) and the prognosis using microarrays. However, adequate investigations into the diagnostic application of microarrays have yet to be performed. The simplicity and accuracy of diagnosis and prognosis tracking are important requirements for its processes, and the use of blood cells for diagnosis is considered to be suitable to meet these requirements. The patients involved in the study were 28 preoperative patients with CRC and 6 healthy individuals who served as controls. RNA was extracted from the blood cells of the patients and analyzed using a sense/antisense RNA custom microarray. In the patients with CRC, the expression levels of 20 sense RNA and 20 antisense RNA species were identified as being significantly altered compared with that of the healthy volunteers (P<0.05; fold-change, >2.0). Cluster analysis of these RNA species revealed that the top 10 antisense RNAs significantly clustered patients with cancer and healthy individuals separately. Patients with stage I or II CRC exhibited significant changes in the expression levels of 33 sense and 39 antisense RNA species, as compared with healthy volunteers (P<0.01; fold-change >2.0). Cluster analysis demonstrated that patients with stage I or II CRC and healthy volunteers formed separate clusters only among the top 20 antisense RNA species. A tracking study of expression levels of haloacid dehalogenase-like hydrolase domain-containing 1 (HDHD1) antisense RNA was performed and a significant difference was identified between the CRC and healthy groups revealing that the levels at one week and three months following surgical removal of the cancerous tissue, decreased to almost same levels of the healthy individuals. The results of the current study indicate that HDHD1 antisense RNA may serve as a potential biomarker for the prognosis of CRC.

The Effect of Three-Dimensional Preoperative Simulation on Liver Surgery.

BACKGROUND: In the past decade, three-dimensional (3D) simulation has been commonly used for liver surgery. However, few studies have analyzed the usefulness of this 3D simulation. The aim of this study was to evaluate the effect of 3D simulation on the outcome of liver surgery. METHODS: We retrospectively analyzed 240 consecutive patients who underwent liver resection. The patients were divided into two groups: those who received 3D preoperative simulation ("3D group", n = 120) and those who did not undergo 3D preoperative simulation ("without 3D group", n = 120). The perioperative outcomes, including operation time, blood loss, maximum aspartate transaminase level, length of postoperative stay, postoperative complications and postoperative mortality, were compared between the two groups. The predicted resected liver volume was compared with the actual resected volume. RESULTS: The median operation time for the 3D group was 36 min shorter than that for the without 3D group (P = 0.048). There were no significant differences in other outcomes between the two groups. A subgroup analysis revealed that the operation time of repeated hepatectomy and segmentectomy for the 3D group was shorter than that for the without 3D group (P = 0.03). There was a strong correlation between the predicted liver volume and the actual resected liver weight (r = 0.80, P < 0.001). CONCLUSION: These findings demonstrate that 3D preoperative simulation may reduce the operation time, particularly for repeated hepatectomy and segmentectomy.

Platelet × CRP Multiplier Value as an Indicator of Poor Prognosis in Patients With Resectable Pancreatic Cancer.

OBJECTIVE: Thrombocytosis in patients with various cancers has been considered a parameter for poor prognosis; however, its contribution to pancreatic cancer remains controversial. METHODS: Potential preoperative prognostic parameters (platelets, neutrophils, lymphocytes, the platelet-lymphocyte ratio, the neutrophil-lymphocyte ratio, the serum C-reactive protein [CRP], and carbohydrate antigen 19-9) were retrospectively analyzed in 95 patients with pancreatic cancer. Cutoff values were defined according to receiver operating characteristic curve analysis, and median survival times (MSTs) were compared. RESULTS: Median survival times (days) significantly differed according to platelet count (high [552] vs low [735], P = 0.017), CRP (high [471] vs low [750], P = 0.001), and carbohydrate antigen 19-9 level (high [639] vs low [765], P = 0.021), whereas there was no difference in the platelet-lymphocyte ratio and the neutrophil-lymphocyte ratio. Multivariate analysis identified thrombocytosis (hazard ratio, 2.015) and CRP level (hazard ratio, 1.771) as independent prognostic factors. The combinatory effects of platelets and the inflammatory response using a platelet × CRP multiplier value could effectively distinguished the MSTs (days) of patients with pancreatic cancer (high [482] vs low [812], P < 0.001). CONCLUSIONS: Thrombocytosis and CRP influenced pancreatic cancer patient prognosis. Platelet × CRP multiplier is assumed as a useful parameter that reflects the contribution of activated platelets to cancer progression.

Three-dimensional simulation of pancreatic surgery showing the size and location of the main pancreatic duct.

PURPOSE: We performed three-dimensional (3D) surgical simulation of pancreatic surgery, including the size and location of the main pancreatic duct on the resected pancreatic surface. METHODS: The subjects of this retrospective analysis were 162 patients who underwent pancreatic surgery. This cohort was sequentially divided into a "without-3D" group (n = 81) and a "with-3D" group (n = 81). We compared the pancreatic duct diameter and its location, using nine sections in a grid pattern, with the intraoperative findings. The perioperative outcomes were also compared between patients who underwent pancreaticoduodenectomy (PD) and those who underwent distal pancreatectomy (DP). RESULTS: There were no significant differences in the main pancreatic duct diameter between the 3D-simulated values and the operative findings. The 3D-simulated main pancreatic duct location was consistent with its actual location in 80 % of patients (65/81). In comparing the PD and DP groups, the intraoperative blood loss was 1174 ± 867 and 817 ± 925 ml in the without-3D group, and 828 ± 739 and 307 ± 192 ml in the with-3D group, respectively (p = 0.024, 0.026). CONCLUSION: The 3D surgical simulation provided useful information to promote our understanding of the pancreatic anatomy, including details on the size and location of the main pancreatic duct.

The Eltrombopag antitumor effect on hepatocellular carcinoma.

Currently, sorafenib is the only available chemotherapeutic agent for advanced hepatocellular carcinoma (HCC), but it cannot be used in patients with liver cirrhosis (LC) or thrombocytopenia. In these cases, sorafenib is likely effective if given in combination with treatments that increase the number of platelets, such as thrombopoietin (TPO) receptor agonists. Increasing the platelet count via TPO treatment resulted in reduction of LC. Eltrombopag (EP), a TPO receptor agonist, has been reported to have antitumor effects against certain cancers, despite their lack of TPO receptor expression. We hypothesized that EP may possess antitumor activity against HCC in addition to its ability to suppress hepatic fibrosis by increasing the platelet count. In the present study, the antitumor activity of EP was examined by assessing the inhibition of cell proliferation and then ascertaining the ability of iron supplementation to reverse these effects in HepG2, Hep3B and Huh7 cells. In addition, a cell cycle assay was performed using flow cytometry, and signal transduction was evaluated by analyzing cell cycle-related protein expression. The results of EP were compared with those of the most common iron chelator, deferoxamine (DFO). The combined effect of EP and sorafenib was also assessed. The results revealed that EP exerts antitumor activity in HCC that is mediated by the modulation of intracellular iron content. EP suppressed the expression of the cell cycle-related protein cyclin D1 and elicited cell cycle arrest in the G0/G1 phase. The activity of EP was comparable to that of DFO in HCC, and EP did not compete with sorafenib at low concentrations. In conclusion, our findings suggest that EP is a good candidate chemotherapeutic agent for the treatment of HCC in patients with LC and thrombocytopenia.

The Tight Adaptation at Pancreatic Anastomosis Without Parenchymal Laceration: An Institutional Experience in Introducing and Modifying the New Procedure.

BACKGROUND: Among the types of pancreatic anastomosis used after pancreatoduodenectomy (PD), Blumgart type reconstruction has rapidly been distributed for its theoretical reasonableness, including secure tight adaptation of jejunal wall and pancreatic parenchyma without cause of parenchymal laceration. The clinical appropriateness of our modified Blumgart method was demonstrated by comparing to that of Kakita method. METHODS: Retrospective analysis of 156 patients underwent elective open PD, reconstructed former 78 patients with the Kakita method, utilizing a full-thickness penetrating suture for tight stump adhesion. The later 78 patients were treated with the modified Blumgart method, which involved clamping the pancreatic parenchymal stump by the jejunal seromuscular layers with horizontal mattress-type penetration sutures. Evaluated variables were the rate of pancreatic fistula (PF) and the length of postoperative hospital stay (POHS). RESULTS: The rate of ISGPF grade B+C PF was 29/78 (37.2%) in the Kakita group and 16/78 (20.5%) in the Blumgart group (P=0.033). The median POHS for the Kakita group was 23 days, whereas that for the Blumgart group was 16 days (P<0.001), one of the shortest value among Japanese high-volume centers. There was no perioperative intensive hemorrhage or deaths in either group. CONCLUSION: A unique concept of Blumgart pancreatic anastomosis, i.e., utilizing the jejunum as an interstitial cushion to prevent pancreatic laceration at the knot site, has become realistic through a simple "one step" modification. This technique, also providing flexible handling space at main pancreatic duct anastomosis, should contribute to the improved PF prevention and shortening the POHS.

Three-dimensional imaging identified the accessory bile duct in a patient with cholangiocarcinoma.

The development of diagnostic imaging technology, such as multidetector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP), has made it possible to obtain detailed images of the bile duct. Recent reports have indicated that a 3-dimensional (3D) reconstructed imaging system would be useful for understanding the liver anatomy before surgery. We have investigated a novel method that fuses MDCT and MRCP images. This novel system easily made it possible to detect the anatomical relationship between the vessels and bile duct in the portal hepatis. In this report, we describe a very rare case of extrahepatic cholangiocarcinoma associated with an accessory bile duct from the caudate lobe connecting with the intrapancreatic bile duct. We were unable to preoperatively detect this accessory bile duct using MDCT and MRCP. However, prior to the second operation, we were able to clearly visualise the injured accessory bile duct using our novel 3D imaging modality. In this report, we suggest that this imaging technique can be considered a novel and useful modality for understanding the anatomy of the portal hepatis, including the hilar bile duct.

Peritransplant absolute lymphocyte count as a predictive factor for advanced recurrence of hepatitis C after liver transplantation.

UNLABELLED: Lymphocytes play an active role in natural immunity against hepatitis C virus (HCV). We hypothesized that a lower absolute lymphocyte count (ALC) may alter HCV outcome after liver transplantation (LT). The aim of this study was to investigate the impact of peritransplant ALC on HCV recurrence following LT. A total of 289 LT patients between 2005 and 2011 were evaluated. Peritransplant ALC (pre-LT, 2-week, and 1-month post-LT) and immunosuppression were analyzed along with recipient and donor factors in order to determine risk factors for HCV recurrence based on METAVIR fibrosis score. When stratifying patients according to pre- and post-LT ALC (<500/µL versus 500-1,000/µL versus >1,000/µL), lymphopenia was significantly associated with higher rates of HCV recurrence with fibrosis (F2-4). Multivariate Cox regression analysis showed posttransplant ALC at 1 month remained an independent predictive factor for recurrence (P = 0.02, hazard ratio [HR] = 2.47 for <500/µL). When peritransplant ALC was persistently low (<500/µL pre-LT, 2-week, and 1-month post-LT), patients were at significant risk of developing early advanced fibrosis secondary to HCV recurrence (F3-4 within 2 years) (P = 0.02, HR = 3.16). Furthermore, severe pretransplant lymphopenia (<500/µL) was an independent prognostic factor for overall survival (P = 0.01, HR = 3.01). The use of rabbit anti-thymocyte globulin induction (RATG) had a remarkable protective effect on HCV recurrence (P = 0.02, HR = 0.6) despite its potential to induce lymphopenia. Subgroup analysis indicated that negative effects of posttransplant lymphopenia at 1 month (<1,000/µL) were significant regardless of RATG use and the protective effects of RATG were independent of posttransplant lymphopenia. CONCLUSION: Peritransplant ALC is a novel and useful surrogate marker for prediction of HCV recurrence and patient survival. Immunosuppression protocols and peritransplant management should be scrutinized depending on peritransplant ALC.

A stand-alone synbiotic treatment for the prevention of D-lactic acidosis in short bowel syndrome.

Synbiotics are combinations of probiotics and prebiotics that have recently been used in the context of various gastrointestinal diseases, including infectious enteritis, inflammatory bowel disease, and bowel obstruction. We encountered a patient with recurrent D-lactic acidosis who was treated successfully for long periods using synbiotics. The patient was diagnosed as having short bowel syndrome and had recurrent episodes of neurologic dysfunction due to D-lactic acidosis. In addition to fasting, the patient had been treated with antibiotics to eliminate D-lactate-producing bacteria. After the failure of antibiotic treatment, a stand-alone synbiotic treatment was started, specifically Bifidobacterium breve Yakult and Lactobacillus casei Shirota as probiotics, and galacto-oligosaccharide as a prebiotic. Serum D-lactate levels declined, and the patient has been recurrence-free for 3 years without dietary restriction. Synbiotics allowed the reduction in colonic absorption of D-lactate by both prevention of D-lactate-producing bacterial overgrowth and stimulation of intestinal motility, leading to remission of D-lactate acidosis.

Effects of switching from calcium carbonate to lanthanum carbonate on bone mineral metabolism in hemodialysis patients.

Phosphate binders are useful for the treatment of hyperphosphatemia in hemodialysis (HD) patients. This study was performed to examine the effects of switching from calcium carbonate (CC) to lanthanum carbonate (LC) on bone mineral metabolism and inflammatory markers in HD patients. We conducted 29 stable HD patients receiving CC, which was replaced by LC and followed-up for 12 weeks. Patients underwent determinants of blood chemistries such as serum calcium (Ca), phosphorus, parathyroid hormone (PTH) and vitamin D status, and interleukin-6 (IL-6) mRNA levels in whole blood cells were evaluated by real-time PCR just before and after the treatment with LC. Corrected Ca [corrected] levels were significantly reduced, but serum phosphorus levels (P levels) were unchanged after LC treatment. Switching to LC increased whole-PTH, osteocalcin, 1,25(OH)(2) D(3) levels and 1,25(OH)(2) D(3)/25(OH)D(3) ratio. 1,25(OH)(2) D(3)/25(OH)D(3) ratio was negatively correlated with HD duration. Furthermore, whole blood cell IL-6 mRNA levels were significantly reduced by LC treatment. We provided that the switching from CC to LC improved Ca overload and ameliorated vitamin D and inflammatory status in HD patients. These observations suggest that LC may play a protective role for the progression of atherosclerosis and vascular calcification in these patients.

Differential expression profiles of sense and antisense transcripts between HCV-associated hepatocellular carcinoma and corresponding non-cancerous liver tissue.

Recent studies have demonstrated that natural antisense transcripts, which are complementary sequences to messenger RNA, have important cellular functions such as the stabilization and silencing of mRNA. However, the possible contribution of antisense transcripts in hepatocellular carcinoma (HCC) development has not been described. Therefore, we simultaneously investigated the sense and antisense transcripts of HCC and non-cancerous tissues to explore the possible contribution of antisense transcripts to HCC progression. RNA was prepared from 15 HCV-associated HCCs and from 6 corresponding non-cancerous tissues and was subjected to expression profile analysis of sense and antisense transcripts using a human custom microarray. Differential expression of 161 sense and 25 antisense transcripts was observed with more than 2-fold between HCC and non-cancerous tissue (p<0.001). The expression of the sense and antisense transcripts was used to cluster cancer and non-cancerous tissues, and the cancer and non-cancerous tissues were found to be clearly separated into different clusters. Additionally, the sense and antisense expression profiles were analyzed with regard to HCC differentiation (p<0.001), resulting in 71 sense and 43 antisense transcripts. These unique transcripts did not overlap with those found in the discrimination of HCC from non-cancerous tissues. When the HCC tissues were clustered by transcript expression, the antisense transcripts resulted in clustering of HCC that was consistent with grouping based on histology. These findings strongly indicate that the antisense transcripts together with the sense transcripts are involved in liver tumorigenesis.

Comprehensive expressional analyses of antisense transcripts in colon cancer tissues using artificial antisense probes.

BACKGROUND: Recent studies have identified thousands of sense-antisense gene pairs across different genomes by computational mapping of cDNA sequences. These studies have shown that approximately 25% of all transcriptional units in the human and mouse genomes are involved in cis-sense-antisense pairs. However, the number of known sense-antisense pairs remains limited because currently available cDNA sequences represent only a fraction of the total number of transcripts comprising the transcriptome of each cell type. METHODS: To discover novel antisense transcripts encoded in the antisense strand of important genes, such as cancer-related genes, we conducted expression analyses of antisense transcripts using our custom microarray platform along with 2376 probes designed specifically to detect the potential antisense transcripts of 501 well-known genes suitable for cancer research. RESULTS: Using colon cancer tissue and normal tissue surrounding the cancer tissue obtained from 6 patients, we found that antisense transcripts without poly(A) tails are expressed from approximately 80% of these well-known genes. This observation is consistent with our previous finding that many antisense transcripts expressed in a cell are poly(A)-. We also identified 101 and 71 antisense probes displaying a high level of expression specifically in normal and cancer tissues respectively. CONCLUSION: Our microarray analysis identified novel antisense transcripts with expression profiles specific to cancer tissue, some of which might play a role in the regulatory networks underlying oncogenesis and thus are potential targets for further experimental validation. Our microarray data are available at http://www.brc.riken.go.jp/ncrna2007/viewer-Saito-01/index.html.

Elevation and characteristics of Rab30 and S100a8/S100a9 expression in an early phase of liver regeneration in the mouse.

Recent studies have revealed that cytokines, including TNFα and IL-6 play key roles in the priming phase of liver regeneration. However, further knowledge of molecular events in the priming phase is needed for more comprehensively understanding the initiation of liver regeneration. In the present study, we attempted to identify additional genes involved in an early phase (2-6 h post partial hepatectomy, PH). The expression of 71 genes was shown to be up-regulated more than 3-fold in the liver at 2 h and 6 h post PH, as compared to 0 h (normal livers) using microarray analysis. Among them, Rab30 and S100a8/S100a9, were identified as novel genes up-regulated over 20-fold at 2 h post PH as compared to normal liver, and were further examined by RT-qPCR to confirm microarray results. Rab30 showed no significant up-regulation in organs other than the liver, whereas S100a8/S100a9 showed significant up-regulation in other organs, such as the lung and spleen at 6 h post PH as compared to those of sham-operated mice, indicating the existence of a different up-regulation machinery between Rab30 and S100a8/S100a9. Their expression was further investigated in the liver at various developmental stages. Rab30 was shown to be expressed only in newborn liver, whereas S100a8/S100a9 was highly expressed in embryo stages, and exhibited the highest levels in newborn liver. These findings imply that Rab30 and S100a8/S100a9 are possibly involved in the functional switch from hematopoiesis support to metabolism in the newborn stage, but might play different roles in liver development. In conclusion, Rab30 and S100a8/S100a9 were indicated to play roles in the initiation of liver regeneration as well as possibly in the functional switch of the liver in the newborn stage.

Platelets prevent acute hepatitis induced by anti-fas antibody.

BACKGROUND AND AIM: Platelets provide many functions in the body, especially to the liver. The purpose of this study is to investigate the effect of thrombocytosis with acute hepatitis induced by anti-Fas antibody and its mechanism. METHODS: Acute hepatitis was induced by administration of anti-Fas antibody in normal and thrombocytotic C57BL6J mice. For thrombocytosis, thrombopoietin; PEG-rHuMGDF was injected 5 days before and just prior to administration of anti-Fas antibody. To investigate the mechanisms, hepatocyte cell line (AML12) and sinusoidal endothelial cell line (M1) were induced apoptosis by staurosporine. They were cultured with platelets or thrombopoietin. Examination items were as follows: platelet number, alanine aminotransferase (ALT), histological findings, TUNEL (TdT-mediated dUTP-biotin Nick End Labeling) staining, and the expression of proteins associated with apoptosis in vivo and in vitro. RESULTS: Platelets were significantly increased in the thrombocytotic group (P < 0.01). Serum ALT levels were significantly reduced by thrombocytosis at 6, 24 and 72 h after the administration (P < 0.05). In histological findings, hemorrhagic necrosis was observed in the normal group, but not observed in the thrombocytotic group. TUNEL-positive hepatocytes were reduced and the expression of cleaved caspase-3 was significantly decreased in the thrombocytotic group. The phosphorylation of Akt, the increment of Bcl-xL and the decrease of cleaved caspase-3 were observed in AML12 cells cultured with platelets, but were not observed cultured with thrombopoietin. Platelets and thrombopoietin had no anti-apoptotic effect on M1 cells. CONCLUSION: Increase of platelets has a preventative effect against acute hepatitis induced by the anti-Fas antibody. It is suggested that platelets have a direct protective effect against apoptosis of hepatocytes.

Identification of natural antisense transcripts involved in human colorectal cancer development.

Natural antisense transcripts (NATs) constitute a class of non-coding RNAs that have emerged as important regulators of gene expression. However, involvement of NATs in colorectal cancer (CRC) development has not been reported to date. In the present study, the up- and down-regulation of NATs were investigated in human CRC for their possible involvement in CRC development. Total RNAs isolated from 51 CRC tissues, 9 corresponding non-cancerous tissues and 19 liver metastatic tissues from surgically resected samples were subjected to expression analysis using a custom-microarray containing human sense/antisense probes for ca. 21,000 genes. Comparing CRC tissues with non-cancerous tissues, we identified 415 NATs differentially expressed in CRC and non-cancerous tissues to a significant degree (p<0.001, fold change >4.0 or ≤4.0). When a hierarchical clustering was performed on CRC and non-cancerous samples using these 415 NATs, the samples were separately clustered. Principal component analysis with the same NATs showed clear separation of CRC and non-cancerous samples using the first two principal components (PC1, 80%; PC2, 10%). To validate the expression results obtained from the microarray, the expressions of the 3 selected NATs were examined by strand-specific RT-qPCR, revealing that these expression profiles were consistent with those obtained from microarray analysis. In addition, the NAT expression patterns were found to be different between primary tumors with liver metastasis and those without liver metastasis. In conclusion, these findings taken together indicated that NATs identified in the present study would be involved in CRC development as well as possibly in its metastasis.

Platelets prevent acute liver damage after extended hepatectomy in pigs.

BACKGROUND/PURPOSE: Platelets develop tissue repair and promote liver regeneration. We investigated whether platelets prevented acute liver damage after extended hepatectomy in pigs. METHODS: Thrombocytosis was induced by the following two methods; afterwards 80% hepatectomy was performed in pigs. In the first method, the pigs received administration of thrombopoietin [TPO (+) group], and they were compared with a control group [TPO (-) group]. In the second method, the pigs received a splenectomy [Sp (+) group], and theywere compared with another control group [Sp (-) group]. Platelet counts, biochemical examination of blood, and histopathological findings of the residual liver were examined. RESULTS: Serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and total bilirubin (T-Bil) levels were significantly decreased in the thrombocytotic groups compared with the control groups in the early period after hepatectomy. In the histopathological findings, hemorrhagic necrosis with a bile plug was observed in the control groups, but this phenomenon was not observed in the thrombocytotic groups. On transmission electron microscopy, the sinusoidal endothelial lining was destroyed and detached into the sinusoidal space with enlargement of Disse's spaces in the thrombocytotic groups, but these findings were not observed in the control groups. CONCLUSION: An increased number of platelets prevents acute liver damage after extended hepatectomy.

Autonomic regulation of liver regeneration after partial hepatectomy in mice.

BACKGROUND/AIMS: The autonomic vagus nerve is thought to play an essential role in liver regeneration since hepatic vagotomy delays hepatic DNA synthesis. However, how the parasympathetic vagus nerve is involved in liver regeneration remains obscure. Kupffer cells are located in liver sinusoids adjacent to hepatocytes and might regulate liver regeneration by releasing interleukin-6 (IL-6). The present study examines the role of the vagus nerve and how Kupffer cells are involved in parasympathetic nerve-mediated liver regeneration in mice. METHODS: We performed surgical vagotomy of the hepatic branch and then partial hepatectomy (PH); some mice received acetylcholine (ACh) agonist/antagonist before PH. We then evaluated liver regeneration and signal transducer and activator of transcription-3 (STAT3) activation. We also investigated whether ACh stimulates IL-6 release from Kupffer cells. RESULTS: Surgical vagotomy impaired liver regeneration. STAT3, which is activated by IL-6 after hepatectomy and plays a pivotal role in liver regeneration, was less activated in vagotomized mice after PH. Post-PH STAT3 activation was recovered by administering vagotomized mice with an ACh agonist. Furthermore, ACh stimulated IL-6 release in Kupffer cells in vitro. CONCLUSION: The parasympathetic system (vagus nerve) contributes to liver regeneration after hepatectomy by stimulating IL-6 release from Kupffer cells followed by STAT3 activation in hepatocytes.

Role of platelets on liver regeneration after 90% hepatectomy in mice.

BACKGROUND/AIMS: Mortality after 90% partial hepatectomy in mice was associated with severe acute liver failure. Recently, we revealed that platelets have a strong promotional effect on hepatic regeneration. In the present study, we investigated the effect of thrombocytosis on liver regeneration after 90% hepatectomy in mice. METHODS: For thrombocytosis induction PEG-rHuMGDF was injected 5 days before operation. Hepatectomy, sparing only the caudate lobe, was performed in normal and thrombocytotic BALB/c mice. Survival rate, platelet number, liver weight/body weight ratio, proliferating cell nuclear antigen, serum parameters, signal transduction and overexpressed genes were examined. RESULTS: Platelet number was significantly higher in thrombocytotic group. All mice in normal group died within 30 h after hepatectomy. Survival rate in thrombocytotic group was 6/11 at 30 h and 3/11 one week after hepatectomy. Activation of Akt and STAT3 signaling pathways in thrombocytotic group was observed earlier and recognized to be stronger compared to normal group. Cell cycle, signaling pathways, metabolism and transport genes were significantly overexpressed in thrombocytotic group up to 24h after hepatectomy. CONCLUSIONS: Under the thrombocytotic condition, liver regeneration occurred even in 90% hepatectomized mice. Platelets contribute to cell cycle progression and metabolic pathways in addition to preventing acute liver failure.

Platelet dynamics in the early phase of postischemic liver in vivo.

BACKGROUND: In liver surgery, ischemia/reperfusion injury occasionally leads to liver failure by activating Kupffer cells (KCs) and leukocytes. However, few reports have demonstrated a relationship between KCs and platelets in vivo. This study investigated the relationship between these cells using intravital microscopy. MATERIALS AND METHODS: Male Wistar rats were divided into two groups: (1) KC+ group, receiving 1 mL saline; and (2) KC- group, intravenously injected with liposome-encapsulated dichloromethylene disphosphonate for elimination of KCs. At 48 h after administration, 20 min of total normothermic hepatic ischemia was induced. Rhodamine-6G-labeled platelets and sinusoidal alterations were monitored using intravital microscopy up to 120 min after reperfusion. P-selectin, accumulated leukocytes and morphological damage, and alanine aminotransferase were evaluated. RESULTS: In the KC+ group, numbers of adherent platelets increased significantly within 30 min after reperfusion. Endothelial cells of sinusoids in which KCs were mainly located were destroyed and the sinusoids were significantly constricted after reperfusion. Conversely, in the KC- group, adherent platelets in sinusoids were suppressed, and sinusoidal perfusion, endothelial cell damage and serum alanine aminotransferase levels were significantly improved. P-selectin on sinusoidal endothelial cells was not observed up to 120 min after reperfusion in either group. CONCLUSIONS: Adherent platelets appear to reflect activation of KCs and lead to leukocyte accumulation, resulting in sinusoidal perfusion disturbance and liver failure. Evaluation of adherent platelets in the microcirculation offers an important marker of hepatic injury.