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Oishi K, Itamoto T, Kohashi T, Matsugu Y, Nakahara H, Kitamoto M. Safety of hepatectomy for elderly patients with hepatocellular carcinoma. World J Gastroenterol 2014; 20:15028-36. [PMID: 25386051 PMCID: PMC4223236 DOI: 10.3748/wjg.v20.i41.15028] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/11/2014] [Accepted: 07/22/2014] [Indexed: 02/06/2023] Open
Abstract
The number of elderly patients with hepatocellular carcinoma (HCC) has been increasing. Characteristics of elderly HCC patients are a higher proportion of females, a lower rate of positive hepatitis B surface antigen, and a higher rate of positive hepatitis C antibodies. Careful patient selection is vital for performing hepatectomy safely in elderly HCC patients. Treatment strategy should be decided by not only considering tumor stage and hepatic functional reserve, but also physiological status, including comorbid disease. Various assessment tools have been applied to predict the risk of hepatectomy. The reported mortality and morbidity rates after hepatectomy in elderly HCC patients ranged from 0% to 42.9% and from 9% to 51%, respectively. Overall survival rate after hepatectomy in elderly HCC patients at 5 years ranged from 26% to 75.9%. Both short-term and long-term results after hepatectomy for strictly selected elderly HCC patients are almost the same as those for younger patients. However, considering physiological characteristics and the high prevalence of comorbid disease in elderly patients, it is important to assess patients more meticulously and to select them strictly if scheduled to undergo major hepatectomy.
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Impact of N-acetylcysteine and sesame oil on lipid metabolism and hypothalamic-pituitary-adrenal axis homeostasis in middle-aged hypercholesterolemic mice. Sci Rep 2014; 4:6806. [PMID: 25348324 PMCID: PMC4210865 DOI: 10.1038/srep06806] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 10/07/2014] [Indexed: 12/21/2022] Open
Abstract
Hyperlipidemia and stress are important factors affecting cardiovascular health in middle-aged individuals. We investigated the effects of N-acetylcysteine (NAC) and sesame oil on the lipidemic status, liver architecture and the hypothalamic-pituitary-adrenal (HPA) axis of middle-aged mice fed a cholesterol-enriched diet. We randomized 36 middle-aged C57bl/6 mice into 6 groups: a control group, a cholesterol/cholic acid diet group, a cholesterol/cholic acid diet group with NAC supplementation, a cholesterol/cholic acid diet enriched with 10% sesame oil and two groups receiving a control diet enriched with NAC or sesame oil. NAC administration prevented the onset of the disturbed lipid profile, exhibiting decreased lipid peroxidation and alkaline phosphatase (ALP) levels, restored nitric oxide bioavailability and reduced hepatic damage, compared to non-supplemented groups. High-cholesterol feeding resulted in increased hypothalamic glucocorticoid receptors (GR) levels, while NAC supplementation prevented this effect. NAC supplementation presented significant antioxidant capacity by means of preventing serum lipid status alterations, hepatic damage, and HPA axis disturbance due to high-cholesterol feeding in middle-aged mice. These findings suggest a beneficial preventive action of plant-derived antioxidants, such as NAC, on lipid metabolism and on the HPA axis.
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Abstract
Aging is marked by changes that affect organs and resident stem cell function. Shorting of telomeres, DNA damage, oxidative stress, deregulation of genes and proteins, impaired cell-cell communication, and an altered systemic environment cause the eventual demise of cells. At the same time, reparative activities also decline. It is intriguing to correlate aging with the decline of regenerative abilities. Animal models with strong regenerative capabilities imply that aging processes might not be affecting regeneration. In this review, we selectively present age-dependent changes in stem/progenitor cells that are vital for tissue homeostasis and repair. In addition, the aging effect on regeneration following injury in organs such as lung, skeletal muscle, heart, nervous system, cochlear hair, lens, and liver are discussed. These tissues are also known for diseases such as heart attack, stroke, cognitive impairment, cataract, and hearing loss that occur mostly during aging in humans. Conclusively, vertebrate regeneration declines with age with the loss of stem/progenitor cell function. Future studies on improving the function of stem cells, along with studies in fish and amphibians where regeneration does not decline with age, will undoubtedly provide insights into both processes.
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Affiliation(s)
- Konstantinos Sousounis
- Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio, USA
| | - Joelle A Baddour
- Department of Chemical and Materials Engineering and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio, USA
| | - Panagiotis A Tsonis
- Department of Biology and Center for Tissue Regeneration and Engineering, University of Dayton, Dayton, Ohio, USA.
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MIMURA SHIMA, IWAMA HISAKAZU, KATO KIYOHITO, NOMURA KEI, KOBAYASHI MITSUYOSHI, YONEYAMA HIROHITO, MIYOSHI HISAAKI, TANI JOJI, MORISHITA ASAHIRO, HIMOTO TAKASHI, DEGUCHI AKIHIRO, NOMURA TAKAKO, SAKAMOTO TEPPEI, FUJITA KOJI, MAEDA EMIKO, IZUISHI KUNIHIKO, OKANO KEIICHI, SUZUKI YASUYUKI, MASAKI TSUTOMU. Profile of microRNAs associated with aging in rat liver. Int J Mol Med 2014; 34:1065-72. [DOI: 10.3892/ijmm.2014.1892] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 07/30/2014] [Indexed: 11/05/2022] Open
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Abstract
Donor organ scarcity remains a significant clinical challenge in transplantation. Older organs, increasingly utilized to meet the growing demand for donor organs, have been linked to inferior transplant outcomes. Susceptibility to organ injury, reduced repair capacity, and increased immunogenicity are interrelated and impacted by physiological and pathological aging processes. Insights into the underlying mechanisms are needed to develop age-specific interventional strategies with regards to organ preservation, immunosuppression, and allocation. In this overview, we summarize current knowledge of injury and repair mechanisms and the effects of aging relevant to transplantation.
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106
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Abstract
Acute liver failure (ALF) is uncommon but fatal. Current management is based mostly on clinical experience. We aimed to investigate the incidence, etiology, outcomes, and prognostic factors of ALF in Taiwan. Patients with the admission diagnosis of ALF between January 2005 and September 2007 were identified from the Longitudinal Health Insurance Database of Taiwan. ALF was further confirmed by disease severity based on laboratory orders, prescriptions, and duration of hospital stay, and acute onset without prior liver disease. Prognostic factors were identified using Cox regression analysis. During the study period, 218 eligible cases were identified from 28,078 potential eligible ALF patients. The incidence was 80.2 per million person-years in average and increased with age. The mean age was 57.9 ± 17.1 years and median survival was 171 days. The most common etiologies were viral (45.4%, mainly hepatitis B virus) and followed by alcohol/toxin (33.0%). Independent prognostic factors included alcohol consumption (hazard ratio, HR, 1.67 [1.01-2.77]), malignancy (HR 2.90 [1.92-4.37]), frequency of checkups per week for total bilirubin (HR 1.57 [1.40-1.76]), sepsis (HR 1.85 [1.20-2.85]), and the use of hemodialysis/hemofiltration (HR 2.12 [1.15-3.9]) and proton pump inhibitor (HR 0.94 [0.90-0.98]). Among the 130 patients who survived ≥90 days, 66 (50.8%) were complicated by liver cirrhosis. Eight (3.7%) were referred for liver transplantation evaluation, but only 1 received transplantation and survived. ALF in Taiwan is mainly due to viral infection. Patients with malignancy and alcohol exposure have worst prognosis. The use of proton pump inhibitor is associated with improved survival. Half of the ALF survivors have liver cirrhosis.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biliary Tract Neoplasms/classification
- Biliary Tract Neoplasms/epidemiology
- Biliary Tract Neoplasms/mortality
- Cause of Death
- Comorbidity
- Cross-Sectional Studies
- Female
- Hepatitis B, Chronic/classification
- Hepatitis B, Chronic/diagnosis
- Hepatitis B, Chronic/epidemiology
- Hepatitis B, Chronic/mortality
- Hepatitis, Alcoholic/classification
- Hepatitis, Alcoholic/diagnosis
- Hepatitis, Alcoholic/epidemiology
- Hepatitis, Alcoholic/mortality
- Humans
- Incidence
- Liver Cirrhosis/classification
- Liver Cirrhosis/diagnosis
- Liver Cirrhosis/epidemiology
- Liver Cirrhosis/mortality
- Liver Failure, Acute/classification
- Liver Failure, Acute/diagnosis
- Liver Failure, Acute/epidemiology
- Liver Failure, Acute/etiology
- Liver Failure, Acute/mortality
- Liver Transplantation/mortality
- Longitudinal Studies
- Male
- Middle Aged
- Prognosis
- Referral and Consultation/statistics & numerical data
- Risk Factors
- Severity of Illness Index
- Survival Analysis
- Taiwan
- Young Adult
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Affiliation(s)
- Cheng-Maw Ho
- Department of Surgery (CMH, PHL, HSL, RHH), Department of Internal Medicine (JYW), National Taiwan University Hospital, Graduate Institute of Clinical Medicine (CMH, PHL, HSL), and Department of Internal Medicine (JYW), College of Medicine, National Taiwan University, Department of Pulmonary Medicine (CHL), Wanfang Hospital, Taipei Medical University, Taipei, Taiwan
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107
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Shin M, Moon HH, Kim JM, Park JB, Kwon CHD, Kim SJ, Joh JW. Importance of donor-recipient age gradient to the prediction of graft outcome after living donor liver transplantation. Transplant Proc 2014; 45:3005-12. [PMID: 24157024 DOI: 10.1016/j.transproceed.2013.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Advanced donor age is a well-known risk factor for poor graft function after living donor liver transplantation (LDLT). In addition, advanced recipient age has a significant impact because of the high prevalence of comorbidities. We investigated the relationship between donor-recipient age gradient (DRAG) and the posttransplant outcomes in LDLT. METHODS We included 821 consecutive adult recipients who underwent LDLT from June 1997 to May 2011. According to the value of DRAG, they were divided into 2 groups: Negative years (the donor was younger than the recipient) and positive years (the donor was older than the recipient). These groups were further divided into subgroups (≤-21, -20 to -1, 0 to 20, and ≥21 years). We collected retrospectively patient characteristics, laboratory results, medical and surgical complications, and graft loss. RESULTS The positive DRAG group had higher level of posttransplant alkaline phosphatase, but a lower incidence of biliary complications. The negative DRAG group, particularly DRAG ≤ -21 years was associated with the superior 1-, 3-, 5-, and 10-year graft survivals. Recipients with DRAG ≥ 21 showed persistently inferior graft survival during the observation period. In cases of young donors, transplants utilizing lower DRAG seen between young donors and older recipients showed more favorable graft survival than that of young-to-young transplants. CONCLUSION This study demonstrated that DRAG and a fixed donor age limit could be significant factors to predict graft survival after LDLT. Patients should carefully consider the worse graft survival if the donor is older than the recipient by ≥20.
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Affiliation(s)
- M Shin
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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108
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Zhu C, Ikemoto T, Utsunomiya T, Yamada S, Morine Y, Imura S, Arakawa Y, Takasu C, Ishikawa D, Shimada M. Senescence-related genes possibly responsible for poor liver regeneration after hepatectomy in elderly patients. J Gastroenterol Hepatol 2014; 29:1102-8. [PMID: 24325248 DOI: 10.1111/jgh.12468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIM Liver regeneration likely decreases with age by an, as yet, incompletely understood mechanism, restricting the extent of hepatectomy. We therefore analyzed the effect of aging on liver regeneration and investigated mechanisms associate with poor regeneration of human liver. METHODS We assessed 130 patients who underwent hepatectomy at our institute between 2005 and 2012. The patients were divided into two groups, a younger (age < 65 years, n = 59) and an older (age > 65 years, n = 71) group. The expression of hepatocyte growth factor (HGF), its ligand Met, and the senescence-related genes p16, SIRT1 and SMP30 were assessed by qRT-PCR. Simulated preoperative and 1 week and 6 month postoperative liver volumes were evaluated in 11 younger and 11 older patients using a 3D simulation imaging system. Regenerated liver volumes were calculated and compared with clinicopathological factors, and correlations between liver regeneration and gene expression were calculated. RESULTS HGF and Met expression was significantly lower, and p16 expression significantly higher in older than in younger patients (P < 0.05 each). Mean increases in liver volume after 6 months were significantly greater in younger than in older patients (396.5 mL, 45.6% vs 159.4 mL, 23.3%, P < 0.05) but did not differ significantly at 1 week. Furthermore, p16 expression was negatively correlated with liver regeneration in older patients (R = -0.67, P < 0.05). CONCLUSION Poor liver regeneration in older patients may be associated with the upregulation of senescence-related genes, such as p16, and the downregulation of regeneration-promoting genes, such as HGF and Met.
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Affiliation(s)
- Chengzhan Zhu
- Department of Surgery, The University of Tokushima, Tokushima, Japan
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109
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Detry O, Deroover A, Meurisse N, Hans MF, Delwaide J, Lauwick S, Kaba A, Joris J, Meurisse M, Honoré P. Donor age as a risk factor in donation after circulatory death liver transplantation in a controlled withdrawal protocol programme. Br J Surg 2014; 101:784-92. [PMID: 24771475 DOI: 10.1002/bjs.9488] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Results of donation after circulatory death (DCD) liver transplantation are impaired by graft loss, resulting mainly from non-anastomotic biliary stricture. Donor age is a risk factor in deceased donor liver transplantation, and particularly in DCD liver transplantation. At the authors' institute, age is not an absolute exclusion criterion for discarding DCD liver grafts, DCD donors receive comfort therapy before withdrawal, and cold ischaemia is minimized. METHODS All consecutive DCD liver transplantations performed from 2003 to 2012 were studied retrospectively. Three age groups were compared in terms of donor and recipient demographics, procurement and transplantation conditions, peak laboratory values during the first post-transplant 72 h, and results at 1 and 3 years. RESULTS A total of 70 DCD liver transplants were performed, including 32 liver grafts from donors aged 55 years or less, 20 aged 56-69 years, and 18 aged 70 years or more. The overall graft survival rate at 1 month, 1 and 3 years was 99, 91 and 72 per cent respectively, with no graft lost secondary to non-anastomotic stricture. No difference other than age was noted between the three groups for donor or recipient characteristics, or procurement conditions. No primary non-function occurred, but one patient needed retransplantation for artery thrombosis. Biliary complications were similar in the three groups. Graft and patient survival rates were no different at 1 and 3 years between the three groups (P = 0.605). CONCLUSION Results for DCD liver transplantation from younger and older donors were similar. Donor age above 50 years should not be a contraindication to DCD liver transplantation if other donor risk factors (such as warm and cold ischaemia time) are minimized.
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Affiliation(s)
- O Detry
- Department of Abdominal Surgery and Transplantation, Centre Hospitalier Universitaire de Liège, University of Liège, Liège, Belgium
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Suv39h1 mediates AP-2α-dependent inhibition of C/EBPα expression during adipogenesis. Mol Cell Biol 2014; 34:2330-8. [PMID: 24732798 DOI: 10.1128/mcb.00070-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have shown that CCAAT/enhancer-binding protein α (C/EBPα) plays a very important role during adipocyte terminal differentiation and that AP-2α (activator protein 2α) acts as a repressor to delay the expression of C/EBPα. However, the mechanisms by which AP-2α prevents the expression of C/EBPα are not fully understood. Here, we present evidence that Suv39h1, a histone H3 lysine 9 (H3K9)-specific trimethyltransferase, and G9a, a euchromatic methyltransferase, both interact with AP-2α and enhance AP-2α-mediated transcriptional repression of C/EBPα. Interestingly, we discovered that G9a mediates dimethylation of H3K9, thus providing the substrate, which is methylated by Suv39h1, to H3K9me3 on the C/EBPα promoter. The expression level of AP-2α was consistent with enrichment of H3K9me2 and H3K9me3 on the C/EBPα promoter in 3T3-L1 preadipocytes. Knockdown of Suv39h markedly increased C/EBPα expression and promoted adipogenesis. Conversely, ectopic expression of Suv39h1 delayed C/EBPα expression and impaired the accumulation of triglyceride, while simultaneous knockdown of AP-2α or G9a partially rescued this process. These findings indicate that Suv39h1 enhances AP-2α-mediated transcriptional repression of C/EBPα in an epigenetic manner and further inhibits adipocyte differentiation.
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111
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Sheedfar F, Biase SD, Koonen D, Vinciguerra M. Liver diseases and aging: friends or foes? Aging Cell 2013; 12:950-4. [PMID: 23815295 DOI: 10.1111/acel.12128] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2013] [Indexed: 12/14/2022] Open
Abstract
The liver is the only internal human organ capable of natural regeneration of lost tissue, as little as 25% of a liver can regenerate into a whole liver. The process of aging predisposes to hepatic functional and structural impairment and metabolic risk. Therefore, understanding how aging could affect the molecular pathology of liver diseases is particularly important, and few studies to date have tackled this complex process. The most common liver disease, affecting one-third of the overall population, is nonalcoholic fatty liver disease (NAFLD), characterized by an intrahepatic accumulation of lipids. NAFLD can evolve into nonalcoholic steatohepatitis (NASH) in the presence of oxidative stress and inflammation. NASH is a serious risk factor for disabling and deadly liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). Old age seems to favor NAFLD, NASH, and ultimately HCC, in agreement with the inflamm-aging theory, according to which aging accrues inflammation. However, the incidence of HCC drops significantly in the very elderly (individuals aged more than 70) and the relationship between the progression of NAFLD/NASH/HCC and very old age is obscure. In this review, we discuss the literature and we argue that there might be an age window in which the liver becomes resistant to the development of injury; this needs to be studied to understand fully the interaction between age and liver diseases from a therapeutic perspective.
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Affiliation(s)
- Fareeba Sheedfar
- Molecular Genetics; University of Groningen; University Medical Center Groningen (UMCG); Groningen The Netherlands
| | - Stefano Di Biase
- Andrus Gerontology Center and Department of Biological Sciences; University of Southern California; Los Angeles CA USA
| | - Debby Koonen
- Molecular Genetics; University of Groningen; University Medical Center Groningen (UMCG); Groningen The Netherlands
| | - Manlio Vinciguerra
- Division of Medicine; University College London (UCL) - Institute for Liver and Digestive Health; Royal Free Hospital; London UK
- Euro-Mediterranean Institute for Science and Technology (IEMEST); Palermo Italy
- Department of Medical Sciences; Division of Internal Medicine; IRCCS “Casa Sollievo della Sofferenza”; S. Giovanni Rotondo Italy
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112
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Hong IH, Lewis K, Iakova P, Jin J, Sullivan E, Jawanmardi N, Timchenko L, Timchenko N. Age-associated change of C/EBP family proteins causes severe liver injury and acceleration of liver proliferation after CCl4 treatments. J Biol Chem 2013; 289:1106-18. [PMID: 24273171 DOI: 10.1074/jbc.m113.526780] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The aged liver is more sensitive to the drug treatments and has a high probability of developing liver disorders such as fibrosis, cirrhosis, and cancer. Here we present mechanisms underlying age-associated severe liver injury and acceleration of liver proliferation after CCl4 treatments. We have examined liver response to CCl4 treatments using old WT mice and young C/EBPα-S193D knockin mice, which express an aged-like isoform of C/EBPα. Both animal models have altered chromatin structure as well as increased liver injury and proliferation after acute CCl4 treatments. We found that these age-related changes are associated with the repression of key regulators of liver biology: C/EBPα, Farnesoid X Receptor (FXR) and telomere reverse transcriptase (TERT). In quiescent livers of old WT and young S193D mice, the inhibition of TERT is mediated by HDAC1-C/EBPα complexes. After CCl4 treatments, TERT, C/EBPα and FXR are repressed by different mechanisms. These mechanisms include the increase of a dominant negative isoform, C/EBPβ-LIP, and subsequent repression of C/EBPα, FXR, and TERT promoters. C/EBPβ-LIP also disrupts Rb-E2F1 complexes in C/EBPα-S193D mice after CCl4 treatments. To examine if these alterations are involved in drug-mediated liver diseases, we performed chronic treatments of mice with CCl4. We found that C/EBPα-S193D mice developed fibrosis much more rapidly than WT mice. Thus, our data show that the age-associated alterations of C/EBP proteins create favorable conditions for the increased liver proliferation after CCl4 treatments and for development of drug-mediated liver diseases.
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113
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Elucidating the metabolic regulation of liver regeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:309-21. [PMID: 24139945 DOI: 10.1016/j.ajpath.2013.04.034] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/26/2013] [Accepted: 04/01/2013] [Indexed: 02/08/2023]
Abstract
The regenerative capability of liver is well known, and the mechanisms that regulate liver regeneration are extensively studied. Such analyses have defined general principles that govern the hepatic regenerative response and implicated specific extracellular and intracellular signals as regulated during and essential for normal liver regeneration. Nevertheless, the most proximal events that stimulate liver regeneration and the distal signals that terminate this process remain incompletely understood. Recent data suggest that the metabolic response to hepatic insufficiency might be the proximal signal that initiates regenerative hepatocellular proliferation. This review provides an overview of the data in support of a metabolic model of liver regeneration and reflects on the clinical implications and areas for further study suggested by these findings.
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114
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Wierstra I. The transcription factor FOXM1 (Forkhead box M1): proliferation-specific expression, transcription factor function, target genes, mouse models, and normal biological roles. Adv Cancer Res 2013; 118:97-398. [PMID: 23768511 DOI: 10.1016/b978-0-12-407173-5.00004-2] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor, which stimulates cell proliferation and exhibits a proliferation-specific expression pattern. Accordingly, both the expression and the transcriptional activity of FOXM1 are increased by proliferation signals, but decreased by antiproliferation signals, including the positive and negative regulation by protooncoproteins or tumor suppressors, respectively. FOXM1 stimulates cell cycle progression by promoting the entry into S-phase and M-phase. Moreover, FOXM1 is required for proper execution of mitosis. Accordingly, FOXM1 regulates the expression of genes, whose products control G1/S-transition, S-phase progression, G2/M-transition, and M-phase progression. Additionally, FOXM1 target genes encode proteins with functions in the execution of DNA replication and mitosis. FOXM1 is a transcriptional activator with a forkhead domain as DNA binding domain and with a very strong acidic transactivation domain. However, wild-type FOXM1 is (almost) inactive because the transactivation domain is repressed by three inhibitory domains. Inactive FOXM1 can be converted into a very potent transactivator by activating signals, which release the transactivation domain from its inhibition by the inhibitory domains. FOXM1 is essential for embryonic development and the foxm1 knockout is embryonically lethal. In adults, FOXM1 is important for tissue repair after injury. FOXM1 prevents premature senescence and interferes with contact inhibition. FOXM1 plays a role for maintenance of stem cell pluripotency and for self-renewal capacity of stem cells. The functions of FOXM1 in prevention of polyploidy and aneuploidy and in homologous recombination repair of DNA-double-strand breaks suggest an importance of FOXM1 for the maintenance of genomic stability and chromosomal integrity.
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115
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Ramakrishna G, Rastogi A, Trehanpati N, Sen B, Khosla R, Sarin SK. From cirrhosis to hepatocellular carcinoma: new molecular insights on inflammation and cellular senescence. Liver Cancer 2013; 2:367-83. [PMID: 24400224 PMCID: PMC3881319 DOI: 10.1159/000343852] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Sequential progression from chronic liver disease to fibrosis and to cirrhosis culminates in neoplasia in hepatocellular carcinoma (HCC). The preneoplastic setting of the cirrhotic background provides a conducive environment for cellular transformation. The role of classical inflammation in cirrhosis is widely known, but the exact mechanism linking inflammation and cancer remains elusive. Recent studies have elucidated roles for NF-κB, STAT3 and JNK as possible missing links. In addition, the "inflammasome" (a multiprotein complex and sensor of cellular damage) is a recently identified player in this field. The hallmarks of cirrhosis include necroinflammation, deposition of extracellular matrix and shortening of telomeres, leading to senescence and regeneration. Additionally, the accumulation of genetic/epigenetic changes propels atypical cells toward a malignant phenotype. This review provides recent information on the classical inflammatory pathway, together with a spotlight on inflammasomes and the immunomodulatory role of cellular senescence during the progression from cirrhosis to HCC. Moreover, lacunae in the current knowledge were identified and key questions raised on whether the observed adaptive responses are beneficial or detrimental to tissue homeostasis in a complex organ like liver.
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Affiliation(s)
- Gayatri Ramakrishna
- Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Archana Rastogi
- Department of Pathology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Nirupama Trehanpati
- Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Bijoya Sen
- Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Ritu Khosla
- Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Shiv K. Sarin
- Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India,*Shiv K. Sarin, MD, DM, Department of Hepatology, Institute of Liver and Biliary Sciences, D1, Vasant Kunj, New Delhi 110070 (India), Tel. +91 11 2670 6700, E-Mail
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Jin J, Iakova P, Breaux M, Sullivan E, Jawanmardi N, Chen D, Jiang Y, Medrano EM, Timchenko NA. Increased expression of enzymes of triglyceride synthesis is essential for the development of hepatic steatosis. Cell Rep 2013; 3:831-43. [PMID: 23499441 DOI: 10.1016/j.celrep.2013.02.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 12/12/2012] [Accepted: 02/06/2013] [Indexed: 12/14/2022] Open
Abstract
Molecular mechanisms underpinning nonalcoholic fatty liver disease (NAFLD) are not well understood. The earliest step of NAFLD is hepatic steatosis, which is one of the main characteristics of aging liver. Here, we present a molecular scenario of age-related liver steatosis. We show that C/EBPα-S193D knockin mice have age-associated epigenetic changes and develop hepatic steatosis at 2 months of age. The underlying mechanism of the hepatic steatosis in old wild-type (WT) mice and in young S193D mice includes increased amounts of tripartite p300-C/EBPα/β complexes that activate promoters of five genes that drive triglyceride synthesis. Knockdown of p300 in old WT mice inhibits hepatic steatosis. Indeed, transgenic mice expressing dominant-negative p300 have fewer C/EBPα/β-p300 complexes and do not develop age-dependent hepatic steatosis. Notably, the p300-C/EBPα/β pathway is activated in the livers of patients with NAFLD. Thus, our results show that p300 and C/EBP proteins are essential participants in hepatic steatosis.
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Affiliation(s)
- Jingling Jin
- Huffington Center on Aging and Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
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Jiang Y, Iakova P, Jin J, Sullivan E, Sharin V, Hong IH, Anakk S, Mayor A, Darlington G, Finegold M, Moore D, Timchenko NA. Farnesoid X receptor inhibits gankyrin in mouse livers and prevents development of liver cancer. Hepatology 2013; 57:1098-106. [PMID: 23172628 PMCID: PMC3649861 DOI: 10.1002/hep.26146] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/07/2012] [Indexed: 12/13/2022]
Abstract
UNLABELLED One of the early events in the development of liver cancer is a neutralization of tumor suppressor proteins Rb, p53, hepatocyte nuclear factor 4α (HNF4α), and CCAAT/enhancer binding protein (C/EBP) α. The elimination of these proteins is mediated by a small subunit of proteasome, gankyrin, which is activated by cancer. The aim of this study was to determine the mechanisms that repress gankyrin in quiescent livers and mechanisms of activation of gankyrin in liver cancer. We found that farnesoid X receptor (FXR) inhibits expression of gankyrin in quiescent livers by silencing the gankyrin promoter through HDAC1-C/EBPβ complexes. C/EBPβ is a key transcription factor that delivers HDAC1 to gankyrin promoter and causes epigenetic silencing of the promoter. We show that down-regulation of C/EBPβ in mouse hepatoma cells and in mouse livers reduces C/EBPβ-HDAC1 complexes and activates the gankyrin promoter. Deletion of FXR signaling in mice leads to de-repression of the gankyrin promoter and to spontaneous development of liver cancer at 12 months of age. Diethylnitrosoamine (DEN)-mediated liver cancer in wild-type mice also involves the reduction of FXR and activation of gankyrin. Examination of liver cancer in old mice and liver cancer in human patients revealed that FXR is reduced, while gankyrin is elevated during spontaneous development of liver cancer. Searching for animal models with altered levels of FXR, we found that long-lived Little mice have high levels of FXR and do not develop liver cancer with age and after DEN injections due to failure to activate gankyrin and eliminate Rb, p53, HNF4α and C/EBPα proteins. CONCLUSION FXR prevents liver cancer by inhibiting the gankyrin promoter via C/EBPβ-HDAC1 complexes, leading to subsequent protection of tumor suppressor proteins from degradation.
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Affiliation(s)
| | | | | | | | | | | | - Sayee Anakk
- Huffington Center on Aging and Departments of Pathology and Immunology and Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030
| | | | | | | | - David Moore
- Huffington Center on Aging and Departments of Pathology and Immunology and Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030
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Wang Y, Ye F, Ke Q, Wu Q, Yang R, Bu H. Gender-dependent Histone Deacetylases Injury May Contribute to Differences in Liver Recovery Rates of Male and Female Mice. Transplant Proc 2013; 45:463-73. [DOI: 10.1016/j.transproceed.2012.06.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 06/08/2012] [Accepted: 06/26/2012] [Indexed: 02/07/2023]
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Sato A, Yamada N, Ogawa Y, Ikegami M. CCAAT/enhancer-binding protein-α suppresses lung tumor development in mice through the p38α MAP kinase pathway. PLoS One 2013; 8:e57013. [PMID: 23437297 PMCID: PMC3577786 DOI: 10.1371/journal.pone.0057013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 01/16/2013] [Indexed: 01/02/2023] Open
Abstract
The transcription factor CCAAT/enhancer-binding protein α (C/EBPα) is a basic leucine zipper transcription factor and is expressed in alveolar type II cells, alveolar macrophages and Clara cells in the lung. Although decrease or absence of C/EBPα expression in human non-small cell lung cancer suggests a possible role of C/EBPα as a lung tumor suppressor, there is no direct proof for this hypothesis. In this study, we investigated, for the first time, the role of C/EBPα in lung tumors in vivo using transgenic mice with lung epithelial specific conditional deletion of Cebpa (Cebpα(Δ/Δ) mice) and a urethane-induced lung tumor model. C/EBPα expression in the lung was dispensable, and its deletion was not oncogenic under unstressed conditions. However, at 28 wk after urethane injection, the number and size of tumors and the tumor burden were significantly higher in Cebpα(Δ/Δ) mice than in littermate control mice. Urethane-injected Cebpα(Δ/Δ) mice showed highly proliferative adenomas and adenocarcinomas in the lung, and survival time after urethane-injection was significantly shorter than that in control mice. In control mice, C/EBPα was strongly induced in the tumor tissues at 28 weeks after urethane-injection, but became weakened or absent as tumors progressed after long-term observation for over 1 year. Using intraperitoneal injection of p38 inhibitor (SB203580), we demonstrated that the induction of C/EBPα is strongly regulated by the p38 MAP kinase in murine alveolar epithelial cells. A high correlation was demonstrated between the expression of C/EBPα and p38α MAP kinase in tumor cells, suggesting that C/EBPα silencing in tumor cells is caused by down-regulation of p38α MAP kinase. In conclusion, the role of C/EBPα as a lung tumor suppressor was demonstrated for the first time in the present study, and the extinguished C/EBPα expression through p38α inactivation leads tumor promotion and progression.
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Affiliation(s)
- Atsuyasu Sato
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Norishige Yamada
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Yuya Ogawa
- Division of Reproductive Sciences, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Machiko Ikegami
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
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120
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Liu D, Li H, Lu J, Bai Y. Tissue-specific implications of mitochondrial alterations in aging. Front Biosci (Elite Ed) 2013; 5:734-47. [PMID: 23277028 DOI: 10.2741/e654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Aging is a multifactorial process during which physiological alterations occur in all tissues. A decline in mitochondrial function plays an important role in the process of aging and in aging-associated diseases. The mitochondrial genome encodes 13 essential subunits of protein complexes belonging to the oxidative phosphorylation system, while most of the mitochondria-related genes are encoded by the nuclear genome. Coordination between the nucleus and mitochondria is crucial for the regulation of mitochondrial biogenesis and function. In this review, we will discuss aging-related mitochondrial dysfunction in various tissues and its implication in aging-related diseases and the aging process.
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Affiliation(s)
- Danhui Liu
- Zhejiang Provincial Key Laboratory of Medical Genetics, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
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121
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Postnatal development, maturation and aging in the mouse cochlea and their effects on hair cell regeneration. Hear Res 2012; 297:68-83. [PMID: 23164734 DOI: 10.1016/j.heares.2012.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/22/2012] [Accepted: 11/07/2012] [Indexed: 12/23/2022]
Abstract
The organ of Corti in the mammalian inner ear is comprised of mechanosensory hair cells (HCs) and nonsensory supporting cells (SCs), both of which are believed to be terminally post-mitotic beyond late embryonic ages. Consequently, regeneration of HCs and SCs does not occur naturally in the adult mammalian cochlea, though recent evidence suggests that these cells may not be completely or irreversibly quiescent at earlier postnatal ages. Furthermore, regenerative processes can be induced by genetic and pharmacological manipulations, but, more and more reports suggest that regenerative potential declines as the organ of Corti continues to age. In numerous mammalian systems, such effects of aging on regenerative potential are well established. However, in the cochlea, the problem of regeneration has not been traditionally viewed as one of aging. This is an important consideration as current models are unable to elicit widespread regeneration or full recovery of function at adult ages yet regenerative therapies will need to be developed specifically for adult populations. Still, the advent of gene targeting and other genetic manipulations has established mice as critically important models for the study of cochlear development and HC regeneration and suggests that auditory HC regeneration in adult mammals may indeed be possible. Thus, this review will focus on the pursuit of regeneration in the postnatal and adult mouse cochlea and highlight processes that occur during postnatal development, maturation, and aging that could contribute to an age-related decline in regenerative potential. Second, we will draw upon the wealth of knowledge pertaining to age related senescence in tissues outside of the ear to synthesize new insights and potentially guide future research aimed at promoting HC regeneration in the adult cochlea.
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122
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Kawamura K, Kitamura S, Sekida S, Tsuda M, Sunanaga T. Molecular anatomy of tunicate senescence: reversible function of mitochondrial and nuclear genes associated with budding cycles. Development 2012; 139:4083-93. [PMID: 23014695 DOI: 10.1242/dev.083170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Zooids of the asexual strain of Polyandrocarpa misakiensis have a lifespan of 4-5 months; before dying, they produce many buds, enabling continuation of the strain. This study was designed to investigate the nature of gene inactivation and reactivation during this continuous process of senescence and budding. During senescence, the zooidal epidermis showed acid β-galactosidase activity, lost proliferating cell nuclear antigen immunoreactivity and became ultrastructurally worn, indicating that the epidermis is a major tissue affected by the ageing process. Semi-quantitative PCR analysis showed that the genes encoding mitochondrial respiratory chains (MRCs) engaged in decreased transcriptional activity in senescent adults compared with younger adults. The results of in situ hybridization showed that the epidermis dramatically attenuates MRC expression during ageing but restores gene activity when budding commences. During budding and ageing, the nuclear gene Eed (a polycomb group component) was activated and inactivated in a pattern similar to that observed in MRCs. In buds, RNA interference (RNAi) of Eed attenuated Eed transcripts but did not affect the gene expression of pre-activated MRCs. A tunicate humoral factor, TC14-3, could induce Eed, accompanying the reactivation of MRC in adult zooids. When RNAi of Eed and Eed induction were performed simultaneously, zooidal cells and tissues failed to engage in MRC reactivation, indicating the involvement of Eed in MRC activation. Results of this study provide evidence that the mitochondrial gene activities of Polyandrocarpa can be reversed during senescence and budding, suggesting that they are regulated by nuclear polycomb group genes.
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Affiliation(s)
- Kaz Kawamura
- Laboratory of Cellular and Molecular Biotechnology, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
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123
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Sugimachi K, Shirabe K, Tokunaga N, Akiho H, Taketomi A, Soejima Y, Gion T, Nakamura K, Higashi H, Maehara Y. Assessment of delayed gastric emptying after major hepatectomy using a 13C-acetic acid breath test. Surg Today 2012; 42:1046-50. [PMID: 22941387 DOI: 10.1007/s00595-012-0321-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/12/2011] [Indexed: 11/26/2022]
Abstract
PURPOSES Delayed gastric emptying (DGE) after hepatectomy affects the quality of life of patients, although the causes and related conditions have not been investigated. This study evaluated the relationship between hepatectomy and DGE by the objective assessment of gastric emptying (GE). METHODS Nineteen patients who underwent major hepatectomy were prospectively enrolled in the study. Their GE was studied using the (13)C-acetic acid breath test before and after hepatectomy. The results of the GE analysis were correlated with the postoperative course after hepatectomy. RESULTS Clinically evident DGE, which was defined as the inability to take in an appropriate amount of solid food orally by postoperative day 14, was not found in these patients, but the gastric half-emptying times before and after hepatectomy were 20.2 ± 9.7 and 28.6 ± 12.2 min, respectively (P = 0.01). The GE time was significantly delayed in patients aged ≥ 41 years, or who underwent right hemihepatectomy. CONCLUSIONS Gastric emptying was significantly inhibited in patients who underwent major hepatectomy, and aging and a right-sided hemihepatectomy may be related to the development of DGE.
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Affiliation(s)
- Keishi Sugimachi
- Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
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124
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Jones K, Timchenko L, Timchenko NA. The role of CUGBP1 in age-dependent changes of liver functions. Ageing Res Rev 2012; 11:442-9. [PMID: 22446383 DOI: 10.1016/j.arr.2012.02.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 12/14/2022]
Abstract
Aging liver is characterized by alterations of liver biology and by a reduction of many functions which are important for the maintenance of body homeostasis. The main dysfunctions include appearance of enlarged hepatocytes, impaired liver regeneration after partial hepatectomy (PH), development of hepatic steatosis, reduction of secretion of proteins and alterations in the hepatic sinusoid. RNA binding proteins are involved in the regulation of gene expression in all tissues including regulation of biological processes in the liver. This review is focused on the role of a conserved, multi-functional RNA-binding protein, CUGBP1, in the development of aging phenotype in the liver. CUGBP1 has been identified as a protein which binds to RNA CUG repeats expanded in Myotonic Dystrophy type 1 (DM1). CUGBP1 is highly expressed in the liver and regulates translation of proteins which are critical for maintenance of liver functions. In livers of young mice, CUGBP1 forms complexes with eukaryotic translation initiation factor eIF2 and supports translation of C/EBPβ and HDAC1 proteins, which are involved in liver growth, differentiation and liver cancer. Aging changes several signaling pathways which lead to the elevation of the CUGBP1-eIF2α complex and to an increase of translation of C/EBPβ and HDAC1. These proteins form multi-protein complexes with additional transcription factors and with chromatin remodeling proteins causing epigenetic alterations of gene expression in livers of old mice. It appears that CUGBP1-mediated translational elevation of HDAC1 is one of the key events in the epigenetic changes in livers of old mice, leading to the development of age-associated dysfunctions of the liver. This review will also discuss a possible role of CUGBP1 in liver dysfunction in patients affected with DM1.
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125
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Lee KH, Chiu S, Lee YK, Greenhalgh DG, Cho K. Age-dependent and tissue-specific structural changes in the C57BL/6J mouse genome. Exp Mol Pathol 2012; 93:167-72. [DOI: 10.1016/j.yexmp.2012.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 03/06/2012] [Accepted: 04/10/2012] [Indexed: 10/28/2022]
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126
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Fouraschen SMG, Pan Q, de Ruiter PE, Farid WRR, Kazemier G, Kwekkeboom J, Ijzermans JNM, Metselaar HJ, Tilanus HW, de Jonge J, van der Laan LJW. Secreted factors of human liver-derived mesenchymal stem cells promote liver regeneration early after partial hepatectomy. Stem Cells Dev 2012; 21:2410-9. [PMID: 22455365 DOI: 10.1089/scd.2011.0560] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Rapid liver regeneration is required after living-donor liver transplantation and oncologic liver resections to warrant sufficient liver function and prevent small-for-size syndrome. Recent evidence highlights the therapeutic potential of mesenchymal stem cells (MSC) for treatment of toxic liver injury, but whether MSC and their secreted factors stimulate liver regeneration after surgical injury remains unknown. Therefore, the aim of this study is to investigate the effect of human liver-derived MSC-secreted factors in an experimental liver resection model. C57BL/6 mice were subjected to a 70% partial hepatectomy and treated with either concentrated MSC-conditioned culture medium (MSC-CM) or vehicle control. Animals were analyzed for liver and body weight, hepatocyte proliferation, and hepatic gene expression. Effects of MSC-CM on gene expression in a human hepatocyte-like cell line (Huh7 cells) were analyzed using genome-wide gene expression arrays. Liver regeneration was significantly stimulated by MSC-CM as shown by an increase in liver to body weight ratio and hepatocyte proliferation. MSC-CM upregulated hepatic gene expression of cytokines and growth factors relevant for cell proliferation, angiogenesis, and anti-inflammatory responses. In vitro, treatment of Huh7 cells with MSC-CM significantly altered expression levels of ~3,000 genes. Functional analysis revealed strong effects on networks associated with protein synthesis, cell survival, and cell proliferation. This study shows that treatment with MSC-derived factors can promote hepatocyte proliferation and regenerative responses in the early phase after surgical resection. MSC-CM may represent a feasible new strategy to promote liver regeneration in patients undergoing extensive liver resection or after transplantation of small liver grafts.
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Affiliation(s)
- Suomi M G Fouraschen
- Laboratory of Experimental Transplantation and Intestinal Surgery, Department of Surgery, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
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127
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Faber W, Seehofer D, Puhl G, Guckelberger O, Bertram C, Neuhaus P, Bahra M. Donor age does not influence 12-month outcome after orthotopic liver transplantation. Transplant Proc 2012; 43:3789-95. [PMID: 22172848 DOI: 10.1016/j.transproceed.2011.10.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 10/12/2011] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease to date. The discrepancy between the numbers of donor livers and recipients has become a significant problem, resulting in a high patient mortality on the waiting list. Due to this, an expansion of the donor pool is necessary, for example, by accepting donor grafts from elderly donors. The aim of this study was to investigate the outcome after OLT depending on donor age. METHODS We retrospectively evaluated the outcome of 272 full-size cadaveric initial single OLTs within 12 months after OLT. The outcome was analyzed by dividing the collective into four donor age categories: donor age under 50, between 50 and 59, between 60 and 69, and 70 years or above. The outcome after OLT in these patients was retrospectively reviewed by using a prospective database. Patients positive for hepatitis C were excluded from the analysis. RESULTS No increase of initial nonfunction was observed. Furthermore, no significant differences with regard to surgical complications and serum liver parameter were observed between the groups. Neither patient mortality rates nor rejection rates were different between the groups. However, ischemic-type biliary lesion rates increased significantly with donor age over 70 years (P<.05). CONCLUSIONS The acceptance of liver grafts from older donors is a possible alternative to narrow the gap between donated and required organs. Safe use under optimal protocols is necessary to avoid a deterioration of post-OLT results.
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Affiliation(s)
- W Faber
- Department of General, Visceral, and Transplantation Surgery, Charité, Campus Virchow-Klinikum, Humboldt-University, Berlin, Germany.
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Liver regeneration and aging: a current perspective. Curr Gerontol Geriatr Res 2011; 2011:526379. [PMID: 21912543 PMCID: PMC3170699 DOI: 10.1155/2011/526379] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 07/06/2011] [Indexed: 12/22/2022] Open
Abstract
Many organ systems exhibit significant age-related deficits, but,
based on studies in old rodents and elderly humans, the liver
appears to be relatively protected from such changes. A
remarkable feature of the liver is its capacity to regenerate its
mass following partial hepatectomy. Reports suggests that aging
compromises the liver's regenerative capacity, both in the
rate and to the extent the organ's original volume is
restored. There has been modest definitive information as to which
cellular and molecular mechanisms regulating hepatic regeneration
are affected by aging. Changes in hepatic sensitivity to growth
factors, for example, epidermal growth factor (EGF), appear to influence
regeneration in old animals. Studies have demonstrated (a) a 60%
decline in EGF binding to hepatocyte plasma membranes, (b) reduced
expression of the hepatic high affinity EGF receptor and (c) a
block between G1 and S-phases of the cell cycle in old rats
following EGF stimulation. Recent studies suggest that reduced
phosphorylation and dimerization of the EGF receptor, critical
steps in the activation of the extracellular signal-regulated
kinase pathway and subsequent cell proliferation are responsible.
Other studies have demonstrated that aging affects the
upregulation of a Forkhead Box transcription factor, FoxM1B, which
is essential for growth hormone-stimulated liver regeneration in
hepatectomized mice. Aging appears to compromise liver
regeneration by influencing several pathways, the result of which
is a reduction in the rate of regeneration, but not in the
capacity to restore the organ to its original volume.
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129
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Jin J, Iakova P, Jiang Y, Medrano EE, Timchenko NA. The reduction of SIRT1 in livers of old mice leads to impaired body homeostasis and to inhibition of liver proliferation. Hepatology 2011; 54:989-98. [PMID: 21638299 PMCID: PMC3242815 DOI: 10.1002/hep.24471] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 05/25/2011] [Indexed: 12/23/2022]
Abstract
Age declines liver functions, leading to the development of age-associated diseases. A member of the sirtuins family, SIRT1, is involved in the control of glucose homeostasis and fat metabolism. Because aging livers have alterations in glucose and fat metabolism, we examined a possible role of SIRT1 in these alterations. We found that aged livers have a reduced expression of SIRT1 and have lost proper control of the regulation of SIRT1 after partial hepatectomy (PH). Down-regulation of SIRT1 in the liver of old mice is mediated by CCAAT/Enhancer Binding Protein/histone deacetylase 1 (C/EBPβ-HDAC1) complexes, which bind to and repress the SIRT1 promoter. In the livers of young mice, SIRT1 is activated after PH and supports high levels of glucose and triglycerides during liver regeneration. In old mice, however, C/EBPβ-HDAC1-mediated repression of the SIRT1 promoter blocks activation of SIRT1, leading to low levels of glucose and triglycerides during liver regeneration. Down-regulation of SIRT1 in the livers of young mice resulted in alterations similar to those observed in the livers of old mice, whereas the normalization of SIRT1 in the livers of old mice corrects the levels of glucose and triglycerides after PH. The normalization of SIRT1 in old mice also improves liver regeneration via the elimination of the C/EBPα-Brm complex. These studies showed a critical role of the reduction of SIRT1 in age-associated liver dysfunctions and provide a potential tool for the correction of liver functions in old patients after surgical resections.
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Affiliation(s)
- Jingling Jin
- Huffington Center on Aging and Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
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130
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Hierarchies of transcriptional regulation during liver regeneration. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 97:201-27. [PMID: 21074734 DOI: 10.1016/b978-0-12-385233-5.00007-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The remarkable capacity of the liver to regenerate after severe injury or disease has excited interest for centuries. The goal of harnessing this process in treatment of liver disease, and the appreciation of the parallels between regeneration and tumor development in the liver, remain a major driver for research in this area. Studies of liver regeneration as a model system offer a view of intricate and precisely timed regulatory pathways that drive the process toward completion. Successful regeneration of the liver mass demands a hierarchal and well-controlled balance between proliferative and metabolic functions, which is orchestrated by signaling and regulation of transcription factors. Control and regulation of these cascades of transcriptional activities, necessary for induction, renewal, and cessation of liver growth, are the focus of this chapter.
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131
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Elchaninov AV, Bolshakova GB. Dynamics of hepatocyte proliferation in regenerating fetal rat liver. Bull Exp Biol Med 2011; 151:374-7. [PMID: 22451891 DOI: 10.1007/s10517-011-1334-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We studied hepatocyte proliferation in the regenerating liver of 17-day fetuses of outbred albino rats. The animals were sacrificed every 3 h over 2 days after resection of 20% liver. The number of mitoses beyond the zone of injury increased sharply 12 and 24 h after resection. The hepatocyte mitotic index in the perifocal zone did not surpass the mitotic index in regions distant from the focus of injury during any of the studied periods. No circadian rhythm of hepatocyte mitotic activity was detected for resected or intact fetal liver. The injury caused virtually no changes in hepatocyte mitosis phase ratio in the operated compared to intact liver, which attested to stable course of mitosis. The weight of fetal liver recovered at the expense of enhanced mitotic activity of hepatocytes in the entire liver.
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Affiliation(s)
- A V Elchaninov
- Laboratory of Growth and Development, Institute of Human Morphology, the Russian Academy of Medical Sciences, Moscow, Russia.
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Sirma H, Kumar M, Meena JK, Witt B, Weise JM, Lechel A, Ande S, Sakk V, Guguen-Guillouzo C, Zender L, Rudolph KL, Günes C. The promoter of human telomerase reverse transcriptase is activated during liver regeneration and hepatocyte proliferation. Gastroenterology 2011; 141:326-37, 337.e1-3. [PMID: 21447332 DOI: 10.1053/j.gastro.2011.03.047] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 03/01/2011] [Accepted: 03/11/2011] [Indexed: 01/13/2023]
Abstract
BACKGROUND & AIMS Telomerase activity has not been detected in healthy human liver biopsy samples, but it is up-regulated in most human liver tumors. It is not clear whether telomerase is activated in response to acute or chronic liver injury. Telomerase activity is closely associated with expression of its catalytic subunit, telomerase reverse transcriptase (TERT). We analyzed the activity of the human TERT (hTERT) promoter during liver regeneration in vivo and hepatocyte proliferation in vitro. METHODS We used hTERTp-lacZ transgenic mice, which contain an 8.0-kilobase pair fragment of the hTERT gene promoter, to study the role of TERT in liver regeneration following partial hepatectomy. As an in vitro model, we used the HepaRG cell line as a new model system for human hepatocyte proliferation and differentiation. RESULTS Activity of the hTERT promoter increased significantly after partial hepatectomy; it was also induced in hepatocytes, based on immunohistologic analysis. Similar to the in vivo results, telomerase activity and hTERT expression were up-regulated in proliferating HepaRG cells and repressed in response to growth arrest and differentiation. Promoter mapping revealed that a proximal 0.3-kilobase pair fragment contains all elements necessary for regulation of hTERT in HepaRG cells. We identified E2F2 and E2F7 as transcription factors that control the differential expression of hTERT in proliferating hepatocytes, in vitro and in vivo. CONCLUSIONS hTERT is induced in hepatocytes during liver regeneration, indicating a functional role for telomerase in human liver.
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133
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Ono Y, Kawachi S, Hayashida T, Wakui M, Tanabe M, Itano O, Obara H, Shinoda M, Hibi T, Oshima G, Tani N, Mihara K, Kitagawa Y. The influence of donor age on liver regeneration and hepatic progenitor cell populations. Surgery 2011; 150:154-61. [PMID: 21719061 DOI: 10.1016/j.surg.2011.05.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 05/12/2011] [Indexed: 12/18/2022]
Abstract
BACKGROUND Recent reports suggest that donor age might have a major impact on recipient outcome in adult living donor liver transplantation (LDLT), but the reasons underlying this effect remain unclear. The aims of this study were to compare liver regeneration between young and aged living donors and to evaluate the number of Thy-1+ cells, which have been reported to be human hepatic progenitor cells. METHODS LDLT donors were divided into 2 groups (Group O, donor age ≥ 50 years, n = 6 and Group Y, donor age ≤ 30 years, n = 9). The remnant liver regeneration rates were calculated on the basis of computed tomography volumetry on postoperative days 7 and 30. Liver tissue samples were obtained from donors undergoing routine liver biopsy or patients undergoing partial hepatectomy for metastatic liver tumors. Thy-1+ cells were isolated and counted using immunomagnetic activated cell sorting (MACS) technique. RESULTS Donor liver regeneration rates were significantly higher in young donors compared to old donors (P = .042) on postoperative day 7. Regeneration rates were significantly higher after right lobe resection compared to rates after left lobe resection. The MACS findings showed that the number of Thy-1+ cells in the human liver consistently tended to decline with age. CONCLUSION Our study revealed that liver regeneration is impaired with age after donor hepatectomy, especially after right lobe resection. The declining hepatic progenitor cell population might be one of the reasons for impaired liver regeneration in aged donors.
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Affiliation(s)
- Yoshihiro Ono
- Department of Surgery, Keio University School of Medicine, Tokyo, Japan
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Wang K, Brems JJ, Gamelli RL, Holterman AX. C/EBPα and C/EBPβ binding proteins modulate hepatocyte apoptosis through iNOS signaling pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1395-403. [PMID: 21539866 DOI: 10.1016/j.bbamcr.2011.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/06/2011] [Accepted: 04/11/2011] [Indexed: 01/05/2023]
Abstract
Inducible nitric oxide synthase (iNOS) and nitric oxide (NO) involve many pathophysiologic conditions. The expression of iNOS is regulated at multiple stages. Presently, the regulatory details of iNOS signaling are still unclear. This study aimed to investigate the regulatory role of C/EBPα and C/EBPβ in iNOS signaling pathway. By employing the techniques such as EMSA, ChIP assay, site-directed mutagenesis, and siRNA silencing, the relationship between iNOS and C/EBPα/C/EBPβ in rat hepatocytes was clarified. iNOS promoter was the direct transcriptional targets of the C/EBPα, C/EBPβ, and NF-κB binding proteins. There was the interactive influence between NF-κB and C/EBPα/C/EBPβ. The expression of iNOS was modulated by C/EBPα/C/EBPβ transcription factors. Moreover, the iNOS expression mediated glycochenodeoxycholate (GCDC)-induced apoptosis in hepatocytes. C/EBPα/C/EBPβ binding proteins could affect the GCDC-induced apoptosis through iNOS cascade. These findings indicate that C/EBPα and C/EBPβ regulate the iNOS expression, which may further modify cell responses such as apoptosis and cell survival.
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Affiliation(s)
- Kewei Wang
- Departments of Pediatrics and Surgery/Section of Pediatric Surgery, Rush University Medical Center, Chicago, IL 60612, USA.
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135
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Shirts BH, Hasstedt SJ, Hopkins PN, Hunt SC. Evaluation of the gene-age interactions in HDL cholesterol, LDL cholesterol, and triglyceride levels: the impact of the SORT1 polymorphism on LDL cholesterol levels is age dependent. Atherosclerosis 2011; 217:139-41. [PMID: 21466885 DOI: 10.1016/j.atherosclerosis.2011.03.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/24/2011] [Accepted: 03/06/2011] [Indexed: 12/16/2022]
Abstract
Several genes that influence HDL-C, LDL-C, and triglyceride levels have been identified. The effects of genetic polymorphisms on lipid levels may be age dependent. We replicated 17 of these previously identified associations and then used cross-sectional and longitudinal analysis to investigate age-SNP interaction effects. The rs646776 SNP at the SORT1 locus showed an age interaction that was significant in cross-sectional analyses of 1350 individuals from Utah (p = 0.0003) and in 2977 individuals from the NHLBI Family Heart Study (p = 0.007) as well as in longitudinal analysis of a subsample of 1099 individuals from the Utah cohort that had been followed for over 20 years (p = 0.0001). The rs646776 genotype-specific difference in LDL-C levels was significantly greater for younger individuals than for older individuals. These findings may help elucidate the mode of action of the SORT1 gene and impact potential therapeutic interventions targeting this pathway.
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Affiliation(s)
- Brian H Shirts
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA.
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136
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Menthena A, Koehler CI, Sandhu JS, Yovchev MI, Hurston E, Shafritz DA, Oertel M. Activin A, p15INK4b signaling, and cell competition promote stem/progenitor cell repopulation of livers in aging rats. Gastroenterology 2011; 140:1009-20. [PMID: 21147108 PMCID: PMC3087123 DOI: 10.1053/j.gastro.2010.12.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2010] [Revised: 11/17/2010] [Accepted: 12/02/2010] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Highly proliferative fetal liver stem/progenitor cells (FLSPCs) repopulate livers of normal recipients by cell competition. We investigated the mechanisms by which FLSPCs repopulate livers of older compared with younger rats. METHODS Fetal liver cells were transplanted from DPPIV(+) F344 rats into DPPIV(-) rats of different ages (2, 6, 14, or 18 months); liver tissues were analyzed 6 months later. Cultured cells and liver tissues were analyzed by reverse transcription polymerase chain reaction, immunoblot, histochemistry, laser-capture microscopy, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling analyses. RESULTS We observed 4- to 5-fold increases in liver repopulation when FLSPCs were transplanted into older compared with younger rats. Messenger RNA levels of cyclin-dependent kinase inhibitors increased progressively in livers of older rats; hepatocytes from 20-month-old rats had 6.1-fold higher expression of p15INK4b and were less proliferative in vitro than hepatocytes from 2-month-old rats. Expression of p15INK4b in cultured hepatocytes was up-regulated by activin A, which increased in liver during aging. Activin A inhibited proliferation of adult hepatocytes, whereas FLSPCs were unresponsive because they had reduced expression of activin receptors (eg, ALK-4). In vivo, expanding cell clusters derived from transplanted FLSPCs had lower levels of ALK-4 and p15INK4b and increased levels of Ki-67 compared with the host parenchyma. Liver tissue of older rats had 3-fold more apoptotic cells than that of younger rats. CONCLUSIONS FLSPCs, resistant to activin A signaling, repopulate livers of older rats; hepatocytes in older rats have less proliferation because of increased activin A and p15INK4b levels and increased apoptosis than younger rats. These factors and cell types might be manipulated to improve liver cell transplantation strategies in patients with liver diseases in which activin A levels are increased.
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Salminen A, Ojala J, Kaarniranta K. Apoptosis and aging: increased resistance to apoptosis enhances the aging process. Cell Mol Life Sci 2011; 68:1021-31. [PMID: 21116678 PMCID: PMC11114781 DOI: 10.1007/s00018-010-0597-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 10/28/2010] [Accepted: 11/11/2010] [Indexed: 12/14/2022]
Abstract
Apoptosis is a vital component in the evolutionarily conserved host defense system. Apoptosis is the guardian of tissue integrity by removing unfit and injured cells without evoking inflammation. However, apoptosis seems to be a double-edged sword since during low-level chronic stress, such as in aging, increased resistance to apoptosis can lead to the survival of functionally deficient, post-mitotic cells with damaged housekeeping functions. Senescent cells are remarkably resistant to apoptosis, and several studies indicate that host defense mechanisms can enhance anti-apoptotic signaling, which subsequently induces a senescent, pro-inflammatory phenotype during the aging process. At the molecular level, age-related resistance to apoptosis involves (1) functional deficiency in p53 network, (2) increased activity in the NF-κB-IAP/JNK axis, and (3) changes in molecular chaperones, microRNAs, and epigenetic regulation. We will discuss the molecular basis of age-related resistance to apoptosis and emphasize that increased resistance could enhance the aging process.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
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Serotonin reverts age-related capillarization and failure of regeneration in the liver through a VEGF-dependent pathway. Proc Natl Acad Sci U S A 2011; 108:2945-50. [PMID: 21282654 DOI: 10.1073/pnas.1012531108] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The function of the liver is well-preserved during the aging process, although some evidence suggests that liver regeneration might be impaired with advanced age. We observed a decreased ability of the liver to restore normal volume after partial hepatectomy in elderly mice, and we identified a pathway that rescued regeneration and was triggered by serotonin. 2,5-dimethoxy-4-iodoamphetamine (DOI), a serotonin receptor agonist, reversed the age-related pseudocapillarization of old liver and improved hepatosinusoidal blood flow. After hepatectomy, the open fenestrae were associated with a restored attachment of platelets to endothelium and the initiation of a normal regenerative response, including the up-regulation of essential growth mediators and serotonin receptors. In turn, hepatocyte proliferation recovered along with regain of liver volume and animal survival. DOI operates through the release of VEGF, and its effects could be blocked with anti-VEGF antibodies both in vitro and in vivo. These results suggest that pseudocapillarization in the aged acts as a barrier to liver regeneration. DOI breaks this restraint through an endothelium-dependent mechanism driven by VEGF. This pathway highlights a target for reversing the age-associated decline in the capacity of the liver to regenerate.
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139
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Fan HY, Liu Z, Johnson PF, Richards JS. CCAAT/enhancer-binding proteins (C/EBP)-α and -β are essential for ovulation, luteinization, and the expression of key target genes. Mol Endocrinol 2010; 25:253-68. [PMID: 21177758 DOI: 10.1210/me.2010-0318] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
LH activation of the epidermal growth factor receptor/RAS/ERK1/2 pathway is essential for ovulation and luteinization because granulosa cell (GC) depletion of ERK1/2 (ERK1/2(gc)(-/-) mice) renders mice infertile. As mediators of ERK1/2-dependent GC differentiation, the CCAAT/enhancer-binding proteins, (C/EBP)α and C/EBPβ, were also disrupted. Female Cebpb(gc)(-/-) mutant mice, but not Cebpa(gc)(-/-) mice, were subfertile whereas Cebpa/b(gc)(-/-) double-mutant females were sterile. Follicles failed to ovulate, ovaries were devoid of corpora lutea, luteal cell marker genes (Lhcgr, Prlr, Ptgfr, Cyp11a1, and Star) were absent, and serum progesterone levels were low. Microarray analyses identified numerous C/EBPα/β target genes in equine chorionic gonadotropin (eCG)-human (h)CG-treated mice. At 4 h post-hCG, a subset (19%) of genes altered in the Cebpa/b-depleted cells was also altered in ERK1/2-depleted cells; hence they are common effectors of ERK1/2. Additional genes down-regulated in the Cebpa/b-depleted cells at 8 and 24 h post-hCG include known (Akr1b7, Runx2, Star, Saa3) and novel (Abcb1b, Apln, Igfbp4, Prlr, Ptgfr Timp4) C/EBP targets and effectors of luteal and vascular cell development. Bhmt, a gene controlling methionine metabolism and thought to be expressed exclusively in liver and kidney, was high in wild-type luteal cells but totally absent in Cebpa/b mutant cells. Because numerous genes potentially associated with vascular development were suppressed in the mutant cells, C/EBPα/β appear to dictate the luteinization process by also controlling genes that regulate the formation of the extensive vascular network required to sustain luteal cells. Thus, C/EBPα/β mediate the terminal differentiation of GCs during the complex process of luteinization.
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Affiliation(s)
- Heng-Yu Fan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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140
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Suzuki A, Sakaguchi T, Inaba K, Suzuki S, Konno H. Impact of cell cycle disruption on impaired hepatic regeneration in aged livers with ischemic insult. J Surg Res 2010; 173:267-77. [PMID: 21109256 DOI: 10.1016/j.jss.2010.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 10/07/2010] [Accepted: 10/13/2010] [Indexed: 12/19/2022]
Abstract
BACKGROUND The number of elderly patients with hepatobiliary malignancies has increased with the steady growth of elderly population. However, the safety of major hepatectomy for elderly patients remains controversial. This study investigated the effect of aging on the hepatic regenerative response after partial resection of livers subjected to ischemic insult. METHODS Two-thirds hepatectomy following 1-h hepatic ischemia was performed in young (12-wk-old) and old (18-mo-old) rats under portosystemic shunt establishment by subcutaneous transposition of the spleen. RESULTS The survival rate 48 h after hepatectomy of the old rats was significantly lower (20%) than that of the young rats (53%), whereas all animals without hepatic ischemia were alive at 48 h. Hepatic necrosis and hepatocyte apoptosis during the early post-hepatectomy phase were more severe in the aged livers, which also showed delayed Akt activation. Liver mass restoration was significantly retarded in the old rats, despite higher plasma IL-6 levels, rapid and prolonged activation of hepatic STAT3, and increased hepatocyte nuclear cyclin D1 levels. In the young livers, cyclin E, which is essential for G1/S transition, and cyclin A, a marker of S phase, were observed in the nucleus from 24 h, reaching peaks 48 h after hepatectomy. In contrast, the old livers showed greatly delayed and decreased nuclear cyclin E and cyclin A levels. CONCLUSION Age-related reductions in the regenerative ability of ischemically damaged livers may be caused by cell cycle disruption at either the late G1 phase or the G1/S transition, despite increased cyclin D1 levels and compensatory IL-6/STAT3 activation.
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Affiliation(s)
- Atsushi Suzuki
- Second Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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141
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Jin J, Wang GL, Iakova P, Shi X, Haefliger S, Finegold M, Timchenko NA. Epigenetic changes play critical role in age-associated dysfunctions of the liver. Aging Cell 2010; 9:895-910. [PMID: 20698834 DOI: 10.1111/j.1474-9726.2010.00617.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
CCAAT/Enhancer Binding Proteins family proteins are important regulators of liver functions. Here, we show the critical role of C/EBPα-mediated chromatin remodeling in the age-associated dysfunctions of the liver and in the maintenance of physiological homeostasis. Because ph-S193 isoform of C/EBPα is increased in livers of old mice, we have generated C/EBPα-S193D knockin mice, which mimic the ph-S193 isoform of C/EBPα. Analyses of these mice showed that the S193D mutation causes chromatin remodeling leading to histological appearance of 'foci-like' nodules, which are also observed in livers of old mice. These 'foci-like' structures contain K9 trimethylated histone H3, a marker of heterochromatin. The increase of heterochromatin regions in S193D mice correlates with the elevation of S193D-C/EBPα-HDAC1 complexes and with dys-regulation of gene expression including epigenetic silencing of cyclin D1 and D2 promoters and the inhibition of liver proliferation. The elimination of C/EBPα-HDAC1 complexes in S193D mice by inhibition of HDAC1 corrects chromatin structure and normalizes expression of cyclin D1 and D2. We found that epigenetic dys-regulation is also associated with the elevation of C/EBPβ and with the increase of C/EBPα/β heterodimers in S193D mice. The C/EBPα/β heterodimers activate transcription of Glut4 and increase the levels of Glut4. As the result, S193D livers have accelerated uptake of glucose and accumulation of glycogen in the liver. Thus, this study demonstrates that the phosphorylation of C/EBPα at S193 leads to the appearance of heterochromatin regions, which correlates with the development of age-related dysfunctions of the liver.
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Affiliation(s)
- Jingling Jin
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
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142
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Iakova P, Timchenko L, Timchenko NA. Intracellular signaling and hepatocellular carcinoma. Semin Cancer Biol 2010; 21:28-34. [PMID: 20850540 DOI: 10.1016/j.semcancer.2010.09.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 09/05/2010] [Accepted: 09/09/2010] [Indexed: 12/13/2022]
Abstract
Liver cancer is the fifth most common cancer and the third most common cause of cancer related death in the world. The recent development of new techniques for the investigations of global change in the gene expression, signaling pathways and wide genome binding has provided novel information for the mechanisms underlying liver cancer progression. Although these studies identified gene expression signatures in hepatocellular carcinoma, the early steps of the development of hepatocellular carcinomas (HCC) are not well understood. The development of HCC is a multistep process which includes the progressive alterations of gene expression leading to the increased proliferation and to liver cancer. This review summarizes recent progress in the identification of the key steps of the development of HCC with the focus on early events of carcinogenesis and on the role of translational and epigenetic alterations in the development of HCC. Quiescent stage of the liver is supported by several tumor suppressor proteins including p53, Rb and C/EBPα. Studies with chemical models of liver carcinogenesis and with human HCC have shown that the elevation of gankyrin is responsible for the elimination of these three proteins at early steps of carcinogenesis. Later stages of progression of the liver cancer are associated with alterations in many signaling pathways including translation which leads to epigenetic silencing/activation of many genes. Particularly, recent reports suggest a critical role of histone deacetylase 1, HDAC1, in the development of HCC through the interactions with transcription factors such as C/EBP family proteins.
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Affiliation(s)
- Polina Iakova
- Department of Pathology and Immunology and Huffington Center on Aging, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, United States
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Lui JC, Chen W, Barnes KM, Baron J. Changes in gene expression associated with aging commonly originate during juvenile growth. Mech Ageing Dev 2010; 131:641-9. [PMID: 20816690 DOI: 10.1016/j.mad.2010.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/22/2010] [Accepted: 08/25/2010] [Indexed: 01/06/2023]
Abstract
In mammals, proliferation is rapid in many tissues during early postnatal life, causing rapid somatic growth. This robust proliferation is then suppressed as the animal approaches adult size, bringing many tissues to a quiescent state where proliferation occurs only as needed to replace dying cells. Recent evidence suggests that the mechanism responsible for this decline in proliferation involves a multi-organ genetic program. We hypothesized that this genetic program continues to progress into later adult life, eventually suppressing proliferation to levels below those needed for tissue renewal, thus contributing to aging. We therefore used expression microarray to compare the temporal changes in gene expression that occur in adult mouse organs during aging to those occurring as juvenile proliferation slows. We found that many of the changes in gene expression that occur during the aging process originate during the period of juvenile growth deceleration. Bioinformatic analyses of the genes that show persistent decline in expression throughout postnatal life indicated that cell-cycle-related genes are strongly over-represented. Thus, the findings support the hypothesis that the genetic program that slows juvenile growth to limit body size persists into adulthood and thus may eventually hamper tissue maintenance and repair, contributing to the aging process.
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Affiliation(s)
- Julian C Lui
- Developmental Endocrinology Branch, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1103, USA.
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144
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Wang GL, Shi X, Haefliger S, Jin J, Major A, Iakova P, Finegold M, Timchenko NA. Elimination of C/EBPalpha through the ubiquitin-proteasome system promotes the development of liver cancer in mice. J Clin Invest 2010; 120:2549-62. [PMID: 20516642 DOI: 10.1172/jci41933] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 04/07/2010] [Indexed: 01/08/2023] Open
Abstract
Despite significant advancements in our understanding of cancer development, the molecular mechanisms that underlie the formation of liver cancer remain largely unknown. C/EBPalpha is a transcription factor that regulates liver quiescence. Phosphorylation of C/EBPalpha at serine 193 (S193-ph) is upregulated in older mice and is thought to contribute to age-associated liver dysfunction. Because development of liver tumors is associated with increasing age, we investigated the role of S193-ph in the development of liver cancer using knockin mice expressing a phospho-mimetic aspartic acid residue in place of serine at position 193 (S193D) of C/EBPalpha. The S193D isoform of C/EBPalpha was able to completely inhibit liver proliferation in vivo after partial hepatectomy. However, treatment of these mice with diethylnitrosamine/phenobarbital (DEN/PB), which induces formation of liver cancer, actually resulted in earlier development of liver tumors. DEN/PB treatment was associated with specific degradation of both the S193-ph and S193D isoforms of C/EBPalpha through activation of the ubiquitinproteasome system (UPS). The mechanism of UPS-mediated elimination of C/EBPalpha during carcinogenesis involved elevated levels of gankyrin, a protein that was found to interact with the S193-ph isoform of C/EBPalpha and target it for UPS-mediated degradation. This study identifies a molecular mechanism that supports the development of liver cancer in older mice and potential therapeutic targets for the prevention of liver cancer.
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Affiliation(s)
- Guo-Li Wang
- Department of Pathology and Immunology and Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030, USA
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Orellana D, Liu X, Wang GL, Jin J, Iakova P, Timchenko NA. Calmodulin controls liver proliferation via interactions with C/EBPbeta-LAP and C/EBPbeta-LIP. J Biol Chem 2010; 285:23444-56. [PMID: 20498378 DOI: 10.1074/jbc.m110.129825] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
A truncated isoform of C/EBPbeta, C/EBPbeta-LIP, is required for liver proliferation. This isoform is expressed at high levels in proliferating liver and in liver tumors. However, high levels of C/EBPbeta-LIP are also observed in non-proliferating livers during acute phase response (APR). In this paper we present mechanisms by which liver regulates activities of C/EBPbeta-LIP. We found that calmodulin (CaM) inhibits the ability of C/EBPbeta-LIP to promote liver proliferation during APR through direct interactions. This activity of CaM is under negative control of Ca(2+), which is reduced in nuclei of livers with APR, whereas it is increased in nuclei of proliferating livers. A mutant CaM, which does not interact with C/EBPbeta-LIP, also fails to inhibit the growth promotion activity of C/EBPbeta-LIP. Down-regulation of CaM in livers of LPS-treated mice causes liver proliferation via activation of C/EBPbeta-LIP. Overexpression of C/EBPbeta-LIP above levels of CaM also initiates liver proliferation in LPS-treated mice. In addition, CaM regulates transcriptional activity of another isoform of C/EBPbeta, C/EBPbeta-LAP, and might control liver biology through the regulation of both isoforms of C/EBPbeta. In searching for molecular mechanisms by which C/EBPbeta-LIP promotes cell proliferation, we found that C/EBPbeta-LIP releases E2F.Rb-dependent repression of cell cycle genes by a disruption of E2F1.Rb complexes and by a direct interaction with E2F-dependent promoters. CaM inhibits these growth promotion activities of C/EBPbeta-LIP and, therefore, supports liver quiescence. Thus, our findings discover a new pathway of the regulation of liver proliferation that involves calcium-CaM signaling.
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Affiliation(s)
- Daniel Orellana
- Huffington Center on Aging and Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas 77030, USA
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Kurinna S, Barton MC. Cascades of transcription regulation during liver regeneration. Int J Biochem Cell Biol 2010; 43:189-97. [PMID: 20307684 DOI: 10.1016/j.biocel.2010.03.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Revised: 01/13/2010] [Accepted: 03/15/2010] [Indexed: 01/20/2023]
Abstract
An increasing demand for new strategies in cancer prevention and regenerative medicine requires a better understanding of molecular mechanisms that control cell proliferation in tissue-specific manner. Regenerating liver is a unique model allowing use of biochemical, genetic, and engineering tools to uncover molecular mechanisms and improve treatment of hepatic cancers, liver failure, and fibrotic disease. Molecular mechanisms of liver regeneration involve extra- and intracellular factors to activate transcription of genes normally silenced in quiescent liver. While many upstream signaling pathways of the regenerating liver have been extensively studied, our knowledge of the downstream effectors, transcription factors (TFs), remains limited. This review describes consecutive engagement of pre-existing and de novo synthesized TFs, as cascades that regulate expression of growth-related and metabolic genes during liver regeneration after partial hepatectomy in mice. Several previously recognized regulators of regenerating liver are described in the light of recently identified co-activator and co-repressor complexes that interact with primary DNA-binding TFs. Published results of gene expression and chromatin immunoprecipitation analyses, as well as studies of transgenic mouse models, are used to emphasize new potential regulators of transcription during liver regeneration. Finally, a more detailed description of newly identified transcriptional regulators of liver regeneration illustrates the tightly regulated balance of proliferative and metabolic responses to partial hepatectomy.
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Affiliation(s)
- Svitlana Kurinna
- Department of Biochemistry and Molecular Biology, UT-Houston Graduate School of Biomedical Sciences, UT MD Anderson Cancer Center, Houston, TX 77030, USA
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Ozcan S, Andrali SS, Cantrell JEL. Modulation of transcription factor function by O-GlcNAc modification. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:353-64. [PMID: 20202486 DOI: 10.1016/j.bbagrm.2010.02.005] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Revised: 02/19/2010] [Accepted: 02/25/2010] [Indexed: 12/22/2022]
Abstract
O-linked beta-N-acetylglucosamine (O-GlcNAc) modification of nuclear and cytoplasmic proteins is important for many cellular processes, and the number of proteins that contain this modification is steadily increasing. This modification is dynamic and reversible, and in some cases competes for phosphorylation of the same residues. O-GlcNAc modification of proteins is regulated by cell cycle, nutrient metabolism, and other extracellular signals. Compared to protein phosphorylation, which is mediated by a large number of kinases, O-GlcNAc modification is catalyzed only by one enzyme called O-linked N-acetylglucosaminyl transferase or OGT. Removal of O-GlcNAc from proteins is catalyzed by the enzyme beta-N-acetylglucosaminidase (O-GlcNAcase or OGA). Altered O-linked GlcNAc modification levels contribute to the establishment of many diseases, such as cancer, diabetes, cardiovascular disease, and neurodegeneration. Many transcription factors have been shown to be modified by O-linked GlcNAc modification, which can influence their transcriptional activity, DNA binding, localization, stability, and interaction with other co-factors. This review focuses on modulation of transcription factor function by O-linked GlcNAc modification.
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Affiliation(s)
- Sabire Ozcan
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA.
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148
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Frith J, Newton JL. Liver disease in older women. Maturitas 2010; 65:210-4. [DOI: 10.1016/j.maturitas.2009.11.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 11/04/2009] [Indexed: 01/10/2023]
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149
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Aydin S, Atukeren P, Cakatay U, Uzun H, Altuğ T. Gender-dependent oxidative variations in liver of aged rats. Biogerontology 2009; 11:335-46. [PMID: 19946747 DOI: 10.1007/s10522-009-9257-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2009] [Accepted: 11/18/2009] [Indexed: 11/25/2022]
Abstract
A shift from redox regulation to oxidative damage is known to contribute organ dysfunction and aging-related disorders. Exposure to reactive oxygen species throughout the life-span increases the incidence of several liver diseases. A redox basis of the loss of antioxidant capacity of aged livers has not been fully elucidated in both genders. In the current study, we investigated the gender-dependent relations between protein carbonyl (PCO), a commonly used marker of protein oxidation and other protein oxidation parameters such as advanced oxidation protein products (AOPP) and total thiol (T-SH). Our study also covered other oxidative stress markers, such as malondialdehyde (MDA), lipid hydroperoxides (LHP), and glutathione (GSH) in liver tissue of the male and female aged rats. PCO and AOPP levels in old male and female rats were significantly higher than those in the young control groups (P < 0.001 and P < 0.01, respectively for male rats; P < 0.001 for both parameters in female rats). On the other hand, T-SH levels were not found to be different between young and old rat groups. Plasma MDA levels of old male and female rats were significantly higher compared to those of the young control groups (P < 0.01 and P < 0.001, respectively). LHP levels were only found out to be significantly higher in old female rats when compared to those in young male rats. GSH levels in old male and female rats were significantly lower than in the corresponding young control groups (P < 0.01 for male rats; P < 0.05 for female rats). Our results demonstrated greater susceptibility to hepatic oxidative damage in females than in males. This appears to contradict the general assumption that females are less susceptible to oxidative injury than males are.
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Affiliation(s)
- Seval Aydin
- Cerrahpaşa Faculty of Medicine, Department of Biochemistry, Istanbul University, Istanbul, Turkey
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150
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Willis-Martinez D, Richards HW, Timchenko NA, Medrano EE. Role of HDAC1 in senescence, aging, and cancer. Exp Gerontol 2009; 45:279-85. [PMID: 19818845 DOI: 10.1016/j.exger.2009.10.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 10/01/2009] [Indexed: 12/27/2022]
Abstract
HDAC1 is a member of the class I of histone deacetylases that also includes HDAC2, -3 and -8. Although HDAC1 has been mostly studied in the context of cancer, recent evidence strongly suggests that it plays critical roles in cellular senescence, aging of the liver, myelination, and adult neurogenesis. Here we review such roles and discuss the entangled relationships between HDAC1 with histone acetyltransferases and other HDACs including SIRT1.
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