Development and characterization of a new human hepatic cell line

The increasing demand and hampered use of primary human hepatocytes for research purposes have urged scientists to search for alternative cell sources, such as immortalized hepatic cell lines. The aim of this study was to develop a human hepatic cell line using the combined overexpression of TERT and the cell cycle regulators cyclin D1 and mutant isoform CDK4R24C. Following transduction of adult human primary hepatocytes with the selected immortalization genes, cell growth was triggered and a cell line was established. When cultured under appropriate conditions, the cell line expressed several hepatocytic markers and liver-enriched transcription factors at the transcriptional and/or translational level, secreted liver-specific proteins and showed glycogen deposition. These results suggest that the immortalization strategy applied to primary human hepatocytes could generate a novel hepatic cell line that seems to retain some key hepatic characteristics

Development and characterization of a new human hepatic cell line

The increasing demand and hampered use of primary human hepatocytes for research purposes have urged scientists to search for alternative cell sources, such as immortalized hepatic cell lines. The aim of this study was to develop a human hepatic cell line using the combined overexpression of TERT and the cell cycle regulators cyclin D1 and mutant isoform CDK4R24C. Following transduction of adult human primary hepatocytes with the selected immortalization genes, cell growth was triggered and a cell line was established. When cultured under appropriate conditions, the cell line expressed several hepatocytic markers and liver-enriched transcription factors at the transcriptional and/or translational level, secreted liver-specific proteins and showed glycogen deposition. These results suggest that the immortalization strategy applied to primary human hepatocytes could generate a novel hepatic cell line that seems to retain some key hepatic characteristics

Effects of Trichostatin A on drug uptake transporters in primary rat hepatocyte cultures

The present study was set up to investigate the effects of Trichostatin A (TSA), a prototypical epigenetic modifier, on the expression and activity of hepatic drug uptake transporters in primary cultured rat hepatocytes. To this end, the expression of the sinusoidal transporters sodium-dependent taurocholate cotransporting polypeptide (Ntcp) and organic anion transporting polypeptide 4 (Oatp4) was monitored by real-time quantitative reverse transcriptase polymerase chain reaction analysis and immunoblotting. The activity of the uptake transporters was analyzed using radiolabeled substrates and chemical inhibitors. Downregulation of the expression and activity of Oatp4 and Ntcp was observed as a function of the cultivation time and could not be counteracted by TSA. In conclusion, the epigenetic modifier TSA does not seem to exert a positive effect on the expression and activity of the investigated uptake transporters in primary rat hepatocyte cultures

Long-Term Ranibizumab Treatment in Neovascular Age-Related Macular Degeneration: A Belgian Subanalysis from the Global Real-World LUMINOUS TM Study

To evaluate long-term, real-world treatment patterns and outcomes of ranibizumab 0.5 mg for neovascular age-related macular degeneration (nAMD) in a Belgian cohort.; This Belgian (BE) cohort of the 5-year global observational LUMINOUS study included 229 patients with nAMD. Outcomes included visual acuity (VA), central retinal thickness (CRT) and safety.; The mean age was 79.5±7.7 years. The majority of patients (67.7%) were female and all patients were Caucasian. Most patients previously received ranibizumab with only 17.5% of patients being treatment-naïve. The injection frequency declined over time irrespective of prior treatment status (p<0.0001), with treatment-naïve eyes receiving a mean of 4.2±2.9 yearly injections and prior-ranibizumab eyes 3.6±2.7. Regression analysis confirmed first-year VA increases for treatment-naïve eyes (p=0.002) followed by a slight decrease of -1.8 letters per year. For prior-ranibizumab eyes, the visual changes over 1 year were statistically non-significant (p=0.90) but declined slightly after year one (p<0.0001). Anatomically, the CRT of treatment-naïve eyes decreased over time from baseline (p<0.0001), whereas the CRT of prior-ranibizumab eyes remained stable (p=0.43). No new safety findings were identified.; LUMINOUS-BE reconfirms the well-characterized benefit-risk profile of ranibizumab for nAMD treatment. The observed low injection frequency reflects a need for more rigorous treatment in real-world settings.; NCT01318941

Strategies for immortalization of primary hepatocytes

SummaryThe liver has the unique capacity to regenerate in response to a damaging event. Liver regeneration is hereby largely driven by hepatocyte proliferation, which in turn relies on cell cycling. The hepatocyte cell cycle is a complex process that is tightly regulated by several well-established mechanisms. In vitro, isolated hepatocytes do not longer retain this proliferative capacity. However, in vitro cell growth can be boosted by immortalization of hepatocytes. Well-defined immortalization genes can be artificially overexpressed in hepatocytes or the cells can be conditionally immortalized leading to controlled cell proliferation. This paper discusses the current immortalization techniques and provides a state-of-the-art overview of the actually available immortalized hepatocyte-derived cell lines and their applications

Real-World Outcomes in Patients with Diabetic Macular Edema Treated Long Term with Ranibizumab (VISION Study)

Evaluate long-term real-world treatment patterns and associated effectiveness and safety outcomes in patients with diabetic macular edema (DME) treated ≥36 months with 0.5mg ranibizumab.; Open-label observational effectiveness study in 9 Belgian clinics. Included were primary treated eyes of 55 DME patients between August 2014 and March 2015 and followed for 3.5±1.8 years. Eyes were 21.8% treatment (TX)-naïve, 9.1% non-naïve with exclusive prior anti-VEGF treatment (PRIOR-anti-VEGF), and 63.6% non-naïve with other prior treatments (PRIOR-other). Intravitreal injections with ranibizumab were administered per ophthalmologists' best clinical judgment. Trend testing of changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) over time occurred using mixed regression analysis.; The mean±SD number of treatments in the first year was 5.1±3.0 (TX-naïve), 4.5±2.7 (PRIOR-anti-VEGF) and 5.6±3.1 (PRIOR-other). At 12 months, BCVA increased by 8.9±16.4 letters from 59.7±9.3 at baseline in TX-naïve (p<0.0001), by 11.8±9.9 from 61.6±8.5 in PRIOR-anti-VEGF (p=0.03), and by 4.2±10.6 from 58.2±14.6 in PRIOR-other groups (p=0.0002). BCVA remained stable for the remainder of follow-up in all groups. CRT decreased over the first 2 months by monthly rates of -43.8µm in TX-naïve (p=0.04), -75.7µm in PRIOR-anti-VEGF (p=0.02), and -65.8µm in PRIOR-other eyes (p=0.0003), showing stability afterwards. No unknown adverse events were recorded; a painful eye following injection was registered with a possible relationship to the treatment.; This real-world study confirms the effectiveness of ranibizumab in preventing a decline in BCVA and demonstrated initial improvement and subsequent retention of BCVA in DME patients ≥36 months. Ranibizumab initially reduced and then maintained CRT. However, these data reveal that treatment intensity and BCVA and CRT outcomes are lower than those found in early efficacy trials. Under-treatment likely accounts for this efficacy-effectiveness gap. Yet, intravitreal ranibizumab is an effective and safe long-term treatment for DME under conditions of significant heterogeneity in patients and treatment patterns

Characterization of spontaneous cell death in monolayer cultures of primary hepatocytes

Monolayer cultures of primary hepatocytes, isolated from freshly removed livers, represent widely used in vitro tools in the area of liver physiology and pathology, pharmacology and toxicology. However, a major shortcoming of these systems is that they cope with dedifferentiation, which is accompanied by spontaneous cell death. The goal of the present study was to elucidate the mechanisms that drive the process of self-generated cell demise in primary hepatocyte cultures. For this purpose, isolated rat hepatocytes were cultivated under conventional conditions, and the occurrence of apoptosis and necrosis was monitored during 4 days by performing a set of acknowledged cell death assays. These included examination of cell morphology by light microscopy, quantification of apoptotic and necrotic cell populations by Hoechst 33342 and propidium iodide in situ staining, assessment of apoptotic and necrotic activities by measuring caspase 3-like activity and extracellular leakage of lactate dehydrogenase, and studying the expression of apoptosis regulators through immunoblot analysis. In essence, two cell death peaks were observed, namely shortly after cell seeding and in the final stages of the cultivation period, both involving apoptotic and necrotic actions. The outcome of this study not only sheds new light onto the molecular processes that underlie spontaneous cell death in primary hepatocyte cultures, but also opens perspectives for the establishment of strategies to increase cell survival in these popular in vitro systems