Chronic Hepatitis B Virus Infection: The Relation between Hepatitis B Antigen Expression, Telomere Length, Senescence, Inflammation and Fibrosis.

BACKGROUND: Chronic Hepatitis B virus (HBV) infection can lead to the development of chronic hepatitis, cirrhosis and hepatocellular carcinoma. We hypothesized that HBV might accelerate hepatocyte ageing and investigated the effect of HBV on hepatocyte cell cycle state and biological age. We also investigated the relation between inflammation, fibrosis and cell cycle phase. METHODS: Liver samples from patients with chronic HBV (n = 91), normal liver (n = 55) and regenerating liver (n = 15) were studied. Immunohistochemistry for cell cycle phase markers and HBV antigens was used to determine host cell cycle phase. Hepatocyte-specific telomere length was evaluated by quantitative fluorescent in-situ hybridization (Q-FISH) in conjunction with hepatocyte nuclear area and HBV antigen expression. The effects of induced cell cycle arrest and induced cellular senescence on HBV production were assessed in vitro. RESULTS: 13.7% hepatocytes in chronic HBV had entered cell cycle, but expression of markers for S, G2 and M phase was low compared with regenerating liver. Hepatocyte p21 expression was increased (10.9%) in chronic HBV and correlated with liver fibrosis. Mean telomere length was reduced in chronic HBV compared to normal. However, within HBV-affected livers, hepatocytes expressing HBV antigens had longer telomeres. Telomere length declined and hepatocyte nuclear size increased as HBV core antigen (HBcAg) expression shifted from the nucleus to cytoplasm. Nuclear co-expression of HBcAg and p21 was not observed. Cell cycle arrest induced in vitro was associated with increased HBV production, in contrast to in vitro induction of cellular senescence, which had no effect. CONCLUSION: Chronic HBV infection was associated with hepatocyte G1 cell cycle arrest and accelerated hepatocyte ageing, implying that HBV induced cellular senescence. However, HBV replication was confined to biologically younger hepatocytes. Changes in the cellular location of HBcAg may be related to the onset of cellular senescence

Preoperative Fascia Iliaca Compartment Block for Positioning Patients With Hip Fractures for Central Nervous Blockade A Randomized Trial

Background and Objectives: Appropriate pain management may positively affect outcome following hip fractures. Positioning patients for spinal anesthesia (SA) can be extremely painful. Peripheral nerve blockades are gaining popularity in this setting. This prospective, randomized study compares the efficacy of fascia iliaca compartment block (FICB) to intravenous (IV) fentanyl for positioning hip fracture patients for SA. Methods: Forty-one patients scheduled for hip fracture surgery were randomized to receive a bolus dose of IV fentanyl (IVFE) 1.5 g/kg (IVFE group) or an FICB using 40 mL ropivacaine 0.5% (FICB group) 5 or 20 minutes before positioning for SA, respectively. Numeric rating pain scale scores before and following the analgesic intervention, time needed and quality of patient position for SA performance, postoperative analgesia in terms of time to first IV morphine dose demand and morphine consumption during the first 24 hours, and patient satisfaction were documented. Results: Compared with the IVFE group, the FICB group showed significantly lower numeric rating pain scale scores in all instances following the analgesic intervention (P < 0.001), shorter spinal performance time (P = 0.001), and better quality of position (P = 0.001). Postoperative morphine consumption was lower (P = 0.026), the time to first dose demand was longer (P = 0.001), and patient satisfaction rates were higher (P < 0.001) in the FICB group. Conclusions: Performing an FICB before positioning for SA provides superior pain management compared with IVFE administration, facilitates spinal performance, and yields satisfactory postoperative analgesia and wide patient acceptance, hence improving overall quality and efficiency of care

Chronic Hepatitis B Virus Infection: The Relation between Hepatitis B Antigen Expression, Telomere Length, Senescence, Inflammation and Fibrosis.

BACKGROUND: Chronic Hepatitis B virus (HBV) infection can lead to the development of chronic hepatitis, cirrhosis and hepatocellular carcinoma. We hypothesized that HBV might accelerate hepatocyte ageing and investigated the effect of HBV on hepatocyte cell cycle state and biological age. We also investigated the relation between inflammation, fibrosis and cell cycle phase. METHODS: Liver samples from patients with chronic HBV (n = 91), normal liver (n = 55) and regenerating liver (n = 15) were studied. Immunohistochemistry for cell cycle phase markers and HBV antigens was used to determine host cell cycle phase. Hepatocyte-specific telomere length was evaluated by quantitative fluorescent in-situ hybridization (Q-FISH) in conjunction with hepatocyte nuclear area and HBV antigen expression. The effects of induced cell cycle arrest and induced cellular senescence on HBV production were assessed in vitro. RESULTS: 13.7% hepatocytes in chronic HBV had entered cell cycle, but expression of markers for S, G2 and M phase was low compared with regenerating liver. Hepatocyte p21 expression was increased (10.9%) in chronic HBV and correlated with liver fibrosis. Mean telomere length was reduced in chronic HBV compared to normal. However, within HBV-affected livers, hepatocytes expressing HBV antigens had longer telomeres. Telomere length declined and hepatocyte nuclear size increased as HBV core antigen (HBcAg) expression shifted from the nucleus to cytoplasm. Nuclear co-expression of HBcAg and p21 was not observed. Cell cycle arrest induced in vitro was associated with increased HBV production, in contrast to in vitro induction of cellular senescence, which had no effect. CONCLUSION: Chronic HBV infection was associated with hepatocyte G1 cell cycle arrest and accelerated hepatocyte ageing, implying that HBV induced cellular senescence. However, HBV replication was confined to biologically younger hepatocytes. Changes in the cellular location of HBcAg may be related to the onset of cellular senescence

The mean number of telomeres in normal and HBV-infected liver tissue according to viral load.

<p>The mean number of telomeres in normal and HBV-infected liver tissue according to viral load.</p

(a) Nuclear and cytoplasmic HBcAg staining detected by Q-FISH in liver from a representative patient with chronic HBV infection.

<p>HBcAg stains bright green, nuclei stain blue with DAPI and telomeres stain pink. (b) Nuclear HBcAg staining detected by Q-FISH in liver from a representative patient with chronic HBV infection. HBcAg stains bright green, nuclei stain blue with DAPI and telomeres stain pink.</p

Characterising the association of latency with α(1)-antitrypsin polymerisation using a novel monoclonal antibody.

α1-Antitrypsin is primarily synthesised in the liver, circulates to the lung and protects pulmonary tissues from proteolytic damage. The Z mutant (Glu342Lys) undergoes inactivating conformational change and polymerises. Polymers are retained within the hepatocyte endoplasmic reticulum (ER) in homozygous (PiZZ) individuals, predisposing the individuals to hepatic cirrhosis and emphysema. Latency is an analogous process of inactivating, intra-molecular conformational change and may co-occur with polymerisation. However, the relationship between latency and polymerisation remained unexplored in the absence of a suitable probe. We have developed a novel monoclonal antibody specific for latent α1-antitrypsin and used it in combination with a polymer-specific antibody, to assess the association of both conformers in vitro, in disease and during augmentation therapy. In vitro kinetics analysis showed polymerisation dominated the pathway but latency could be promoted by stabilising monomeric α1-antitrypsin. Polymers were extensively produced in hepatocytes and a cell line expressing Z α1-antitrypsin but the latent protein was not detected despite manipulation of the secretory pathway. However, α1-antitrypsin augmentation therapy contains latent α1-antitrypsin, as did the plasma of 63/274 PiZZ individuals treated with augmentation therapy but 0/264 who were not receiving this medication (p<10(-14)). We conclude that latent α1-antitrypsin is a by-product of the polymerisation pathway, that the intracellular folding environment is resistant to formation of the latent conformer but that augmentation therapy introduces latent α1-antitrypsin into the circulation. A suite of monoclonal antibodies and methodologies developed in this study can characterise α1-antitrypsin folding and conformational transitions, and screen methods to improve augmentation therapy

Telomere length, telomere number and nuclear area according to the subcellular location of HBcAg.

<p>Telomere length, telomere number and nuclear area according to the subcellular location of HBcAg.</p