Development of Conformational Antibodies to Detect Bcl-xL's Amyloid Aggregates in Metal-Induced Apoptotic Neuroblastoma Cells.

Bcl-xL, a member of the Bcl-2 family, is a pro-survival protein involved in apoptosis regulation. We have previously reported the ability of Bcl-xL to form various types of fibers, from native to amyloid conformations. Here, we have mimicked the effect of apoptosis-induced caspase activity on Bcl-xL by limited proteolysis using trypsin. We show that cleaved Bcl-xL (ΔN-Bcl-xL) forms fibers that exhibit the features of amyloid structures (BclxLcf37). Moreover, three monoclonal antibodies (mAbs), produced by mouse immunization and directed against ΔN-Bcl-xL or Bcl-xL fibers, were selected and characterized. Our results show that these mAbs specifically target ΔN-Bcl-xL in amyloid fibers in vitro. Upon metal-stress-induced apoptosis, these mAbs are able to detect the presence of Bcl-xL in amyloid aggregates in neuroblastoma SH-SY5Y cell lines. In conclusion, these specific mAbs directed against amyloidogenic conformations of Bcl-xL constitute promising tools for studying, in vitro and in cellulo, the contribution of Bcl-xL in apoptosis. These mAbs may further help in developing new diagnostics and therapies, considering Bcl-xL as a strategic target for treating brain lesions relevant to stroke and neurodegenerative diseases.

Genetic variations in toll-like receptors 7 and 8 modulate natural hepatitis C outcomes and liver disease progression.

BACKGROUND & AIMS: The natural outcomes of hepatitis C virus (HCV) as well as the progression of the liver disease are highly variable and depend primarily on an efficient immune response. As toll-like receptors seven (TLR7) and eight (TLR8) are important effectors of the innate immunity, this study aims to evaluate the association between TLR7 and TLR8 polymorphisms and the HCV infection outcomes in Moroccan subjects. METHODS: In this case-control study, 643 subjects including 293 mild chronic hepatitis patients, 119 with advanced liver disease (AdLD), 93 with HCV spontaneous clearance and 138 healthy controls were genotyped using TaqMan SNPs assays. RESULTS: Patients carrying TLR7 rs179008-A allele were more likely to clear the virus spontaneously (P = .0001 for women, and P < .001 for men). Besides, carriage of TLR7 rs179009-A allele was associated with a twofold increase in spontaneous viral clearance in female patients (P = .0002), but not in men. In addition, we observed that TLR7 rs179008-T and rs179009-G alleles increased the risk of disease progression in both sexes (P < .05). TLR8 rs3764880-G allele was associated with spontaneous HCV clearance in both sexes (P < .0001) albeit with an apparently stronger association in males (OR = 6.02 for men vs 2.2 for women). In males, TLR8 rs3764879-C and TLR8 rs3764880-A alleles were significantly associated with AdLD status (P < .05). CONCLUSIONS: Our results suggest that variations in TLR7 and TLR8 genes modulate the clearance and progression of HCV infection with different magnitudes between sexes. Our results refine, therefore, our understanding of the sex-specific differences observed regarding the susceptibility to chronic hepatitis.

The -94Ins/DelATTG polymorphism in NFκB1 promoter modulates chronic hepatitis C and liver disease progression.

Infection with Hepatitis C Virus (HCV) is one of the most important risk factor of hepatocellular carcinoma (HCC). HCV is suspected to induce HCC primarily through chronic inflammation and promotion of cirrhosis, a well-known pre-neoplastic condition. The NF-κB pathway is a key regulator of immune and inflammatory processes and plays a pivotal role in oncogenesis. Genetic variations affecting the pathway may alter NF-κB activity in response to HCV infection and contribute to liver tumorigenesis. The present study aims to evaluate the association between -94Ins/DelATTG (rs28362491) polymorphism in NF-κB1 gene promoter region and 2758G>A (rs696) single nucleotide polymorphism in the 3'UTR region of NFκBIA and the outcomes of HCV infection. In this case-control study, 559 subjects (343 patients with HCV infection including 237 mild chronic hepatitis patients and 106 patients with Advanced Liver Disease (AdLD), 78 individuals who naturally cleared HCV and 138 healthy subjects) were genotyped for the NFκB1 and NFκBIA SNPs using PCR-RFLP. Logistic regression was used to assess the association between polymorphisms and the outcome and progression of the infection. Variation at rs696 was not associated with HCV resolution or progression (P>0.05). By contrast, the Ins/Ins genotype was associated with a 4-fold increase of AdLD risk when compared to mild chronic hepatitis C (OR=4.69; 95% CI, 2.15-10.19; P=0.0001) and the risk was more pronounced when compared to healthy controls (OR=5.02; 95% CI, 2.30-10.98; P=0.00005). Furthermore, carriage of Ins allele at rs28362491 was significantly associated with higher viral loads (P=0.003). Our results suggest that variation in NFκB1 gene promoter modulates the progression of chronic hepatitis C toward advanced liver disease.

Genetic variation in the interleukin-28B gene is associated with spontaneous clearance and progression of hepatitis C virus in Moroccan patients.

BACKGROUND: Genetic variation in the IL28B gene has been strongly associated with treatment outcomes, spontaneous clearance and progression of the hepatitis C virus infection (HCV). The aim of the present study was to investigate the role of polymorphisms at this locus with progression and outcome of HCV infection in a Moroccan population. METHODS: We analyzed a cohort of 438 individuals among them 232 patients with persistent HCV infection, of whom 115 patients had mild chronic hepatitis and 117 had advanced liver disease (cirrhosis and hepatocellular carcinoma), 68 individuals who had naturally cleared HCV and 138 healthy subjects. The IL28B SNPs rs12979860 and rs8099917 were genotyped using a TaqMan 5' allelic discrimination assay. RESULTS: The protective rs12979860-C and rs8099917-T alleles were more common in subjects with spontaneous clearance (77.9% vs 55.2%; p = 0.00001 and 95.6% vs 83.2%; p = 0.0025, respectively). Individuals with clearance were 4.69 (95% CI, 1.99-11.07) times more likely to have the C/C genotype for rs12979860 polymorphism (p = 0.0017) and 3.55 (95% CI, 0.19-66.89) times more likely to have the T/T genotype at rs8099917. Patients with advanced liver disease carried the rs12979860-T/T genotype more frequently than patients with mild chronic hepatitis C (OR = 1.89; 95% CI, 0.99-3.61; p = 0.0532) and this risk was even more pronounced when we compared them with healthy controls (OR = 4.27; 95% CI, 2.08-8.76; p = 0.0005). The rs8099917-G allele was also associated with advanced liver disease (OR = 2.34; 95% CI, 1.40-3.93; p = 0.0100). CONCLUSIONS: In the Moroccan population, polymorphisms near the IL28B gene play a role both in spontaneous clearance and progression of HCV infection.