The effect of histone deacetylase inhibitors on the efficiency of the CRISPR/Cas9 system.

The CRISPR/Cas9 technology is a prominent genome-editing tool capable of producing a double-strand break in the genome. However, the modification of hematopoietic stem cells via the homology-directed repair pathway is still inefficient. Therefore, we hypothesize that histone deacetylase inhibitors, such as valproic acid (VPA) and sodium butyrate (NaB), could enhance HDR efficiency by increasing the accessibility of the genome-editing machinery. To address the potential utilization of HDAC inhibitors therapeutically, we began by assessing the effect of VPA and NaB on two cell lines representative of the two hematopoietic stem cell lineages. No statistically significant effect on cell growth or viability was observed at concentrations as high as 5 mM. At a concentration as low as 0.005 mM NaB, an enhancement in CRISPR cutting efficiency was evidenced in both cell lines. This enhancement did not appear to be locus-specific. However, an enhancement in cutting efficiency following VPA treatment does appear to be. HDR efficiency was enhanced greater than two-fold with the use of 0.005 mM VPA. These results are promising and suggest the consideration of treatment with an HDAC inhibitor in CRISPR/Cas9 genome editing protocols.

Linking hepatitis C virus infection to pre-1994 blood transfusions in female patients. / Asociación del antecedente transfusional antes de 1994 con hepatitis vírica tipo C en mujeres.

INTRODUCTION: Most blood transfusions occur in female patients. The introduction of serologic screening practices by blood banks reduced the transfusion-related rate of infection with hepatitis C virus (HCV). In Mexico patients with pre-1994 transfusion history are at high risk of being detected with HCV infection. We aimed at establishing an interrelationship between two variables: pre-1994 transfusion history and rate of infection in women treated in the Guadalajara Metropolitan Area hospitals, in Mexico. METHODS: Analytical observational case-control study which included both non-infected women and patients diagnosed with hepatitis C virus infection, in whom the pre-1994 transfusion history was determined. The cases were 150 women with confirmed hepatitis C virus serologic diagnosis. The controls were 150 women whose hepatitis C virus-detection serologic tests had yielded negative results. RESULTS: An odds ratio of 9.07 (95% CI: 5.37 ­ 15.3; p< 0.001) was found where the rate of infection for the case group was 0.72 while the control group had a ratio of 0.22; population attributable risk (PAR) was 0.64 (95% CI: 0.53 ­ 0.73), while etiologic fraction was 0.88 (95% CI: 0.81 ­ 0.93). CONCLUSIONS: Among women, having been exposed to pre-1994 blood transfusion means a risk 9.07 times higher than not being exposed to blood transfusion in the same time frame.

La mayor parte de las transfusiones se llevan a cabo en mujeres. La introducción en los bancos de sangre de las técnicas serológicas disminuyó la incidencia de infección por virus de hepatitis C después de una transfusión. En México, las pacientes que se transfundieron antes de 1994 están en riesgo de presentar una infección por virus de hepatitis C. El objetivo de este estudio fue medir la asociación entre el antecedente transfusional antes de 1994 e infección por virus de hepatitis C en mujeres atendidas en la zona metropolitana de Guadalajara, México.

Leptin and leptin receptor polymorphisms are associated with poor outcome (death) in patients with non-appendicular secondary peritonitis.

INTRODUCTION: Leptin (LEP) and its receptor (LEPR) participate in the immunological response during infection. LEP serum levels rise during sepsis. In patients with peritonitis, an insufficient elevation in serum LEP is associated with an increased risk of death. As gene variants of LEP and LEPR have been associated with diverse pathologic conditions, we explored the association of genetic polymorphisms of LEP or LEPR with death in patients with secondary peritonitis. METHODS: A case control study was undertaken. LEP Gene -2548G > A and the LEPR Gene 223A > G polymorphism were determined in 74 patients. The odds ratio of genotype and allele distribution in survival (control) versus death (case) among patients was calculated. Serum LEP, interleukin (IL)-6, tumour necrosis factor alpha, C-reactive protein (C-RP), IL-10 and IL-13 levels were analyzed in 34 patients. RESULTS: There were significant differences in genotype and allele distribution between survivors and non-survivors for -2548G > A and 223A > G polymorphisms. The presence of the mutant allele A, in -2548, had an odds ratio of 4.64 (95% CI 1.22, 17.67) with significance (P = 0.017) in the risk of death. The presence of mutant allele G, in 223, had an odds ratio of 3.57 (95% CI 1.06, 12.01) with significance in the risk of death (P = 0.033). The presence of allele A in the -2548 polymorphism was associated with differences in serum LEP (P = 0.013), and IL-10 (P = 0.0001). The presence of allele G in 223 polymorphism was likewise correlated with differences in serum LEP (P < 0001), C-RP (P = 0.033), and IL-10 (P = 0.043). CONCLUSIONS: The polymorphisms studied are associated with death in patients with peritonitis of non-appendicular origin. This association is stronger than many known risk-factors related to peritonitis severity, and is independent of body mass. The physiopathologic mechanism is possibly related to an insufficient increase in the elevation of serum LEP levels, and is unrelated to body mass.