Rapid Ex-Vivo Ciliogenesis and Dose-Dependent Effect of Notch Inhibition on Ciliogenesis of Respiratory Epithelia.

Background: Cilia are actin based cellular protrusions conserved from algae to complex multicellular organisms like Homo sapiens. Respiratory motile cilia line epithelial cells of the tracheobronchial tree, beat in a synchronous, metachronal wave, moving inhaled pollutants and pathogens cephalad. Their role in both congenital disorders like primary ciliary dyskinesia (PCD) to acquired disorders like chronic obstructive pulmonary disease (COPD) continues to evolve. In this current body of work we outline a protocol optimized to reciliate human nasal epithelial cells and mouse tracheal cells in vitro. Using this protocol, we knocked down known cilia genes, as well as use a small molecule inhibitor of Notch, N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl Ester (DAPT), to assess the effect of these on ciliogenesis in order to show the validity of our protocol. Methods: Tracheas were harvested from wild-type, adult C57B6 mice, pronase digested and sloughed off epithelial cells grown to confluence in stationary culture on rat-tail collagen coated wells. Upon reaching confluence, collagen was digested and cells placed suspension culture protocol to reciliate the cells. Using this suspension culture protocol, we employed siRNA gene knockdown to assay gene functions required for airway ciliogenesis. Knock down of Dynein axonemal heavy chain 5 (Dnah5), a ciliary structural protein, was confirmed using immunostaining. Mouse tracheal cells were treated in suspension with varying doses of DAPT, an inhibitor of Notch, with the purpose of evaluating its effect and dose response on ciliogenesis. The optimum dose was then used on reciliating human nasal epithelial cells. Results: siRNA knockdown of Foxj1 prevented ciliation, consistent with its role as a master regulator of motile cilia. Knockdown of Dnai1 and Dnah5 resulted in immotile cilia, and Cand1 knockdown, a centrosome protein known to regulate centrosome amplification, inhibited airway ciliogenesis. Dnah5 knockdown was confirmed with significantly decreased immunostaining of cilia for this protein. Inhibiting Notch signaling by inhibiting gamma secretase with DAPT enhanced the percentage of ciliation, and resulted in longer cilia that beat with higher frequency in both mouse and human airway epithelia. Conclusions: Modifying existing reciliation protocols to suit both human nasal epithelial and mouse tracheal tissue, we have shown that knockdown of known cilia-related genes have the expected effects. Additionally, we have demonstrated the optimal dosage for significantly improving reciliation of airway epithelia using DAPT. Given that cilia length and function are significantly compromised in COPD, these findings open up interesting avenues for further exploration.

Elimination of Hepatitis C in Liver Transplant Recipients.

Background and Aims: Recurrent hepatitis C (HCV) disease in liver transplant (LT) recipients is associated with significant morbidity and mortality. With the availability of noninterferon-based therapy, eliminating HCV may be achievable in LT recipients. Methods: We studied all consecutive recipients who underwent LT at the University of California Los Angeles between January 2005 and June 2017. We collected data on date of transplant and last follow-up, as well as laboratory values. We also recorded type and timing of antiviral therapy relative to LT. Analyses were performed to assess the proportion of LT recipients who are viremic after transplant. Results: Six hundred thirty-four patients underwent LT with a diagnosis of HCV. There was a statistically significant trend for patients to be cured before (p < 0.001) and after liver transplantation (p < 0.001) for the study period of 2014 to 2016 relative to 2005 and 2013, respectively. Of the 634 recipients eligible for therapy, 8% and 74% were treated within 12 months of transplant for the study periods 2005 to 2013 and 2014 to 2016, respectively. There was a significant decrease between the two study periods in the proportion of patients undergoing re-LT 1 year after the original LT: 5.5% (n = 28/510) and 1.5% (n = 2/124) respectively for study periods 2005 to 2013 and 2014 to 2016 respectively (p = 0.011). Conclusions: The proportion of LT recipients who are viremic has decreased over time. Eliminating HCV in LT recipients is feasible after the introduction of direct-acting agents. Curing HCV should translate to improved clinical outcomes in LT recipients who were transplanted for HCV infection with longer follow-up. Preliminary results suggest the decreased need for transplant in the direct-acting agents era.

Hepatitis C and human immunodeficiency virus coinfection in the era of direct-acting antiviral agents: No longer a difficult-to-treat population.

The treatment of chronic hepatitis C (HCV) in human immunodeficiency virus 1 (HIV)-infected individuals has been historically marked by low sustained virologic response (SVR) rates in comparison to those without HIV infection, resulting in the Food and Drug Administration labeling those coinfected as a "special population with an unmet medical need." We systematically reviewed the treatment of chronic HCV infection in those infected with HIV. We propose that with the advent of direct-acting antiviral (DAA) agents, patients coinfected with HCV and HIV have similar SVR rates as HCV-monoinfected persons and that DAAs address an unmet medical need in this population. A review was performed using Medical Subject Heading terms within the PubMed, EMBASE, and Cochrane Library databases to search for studies dated between January 2004 and July 2017. Keywords used in the study included "hepatitis C," "HIV," "coinfection," and "direct-acting antiviral." SVR rates for those with HCV and HIV coinfection treated with interferon-based therapies were substantially lower that SVR rates of HCV-monoinfected individuals. The advent of DAA agents has resulted in similar SVR rates between monoinfected and coinfected individuals, with SVR >93%. These medications have been demonstrated to have improved safety, efficacy, and tolerability in comparison to interferon-based regimens. CONCLUSION: The designation of a "special population" for those with coinfection requires reconsideration; DAA therapies have resulted in similarly high rates of SVR for HCV infection in those with and without HIV infection; despite these improvements, however, clinicians must be cognizant of negative predictors of SVR and barriers to treatment that may be more common in the coinfected population. (Hepatology 2018;67:847-857).