ANGPTL4 variants E40K and T266M are associated with lower fasting triglyceride levels and predicts cardiovascular disease risk in Type 2 diabetic Tunisian population.

BACKGROUND: Angiopoietin-like protein 4 (ANGPTL4) is a metabolic factor that increases plasma triglyceride levels by inhibiting lipoprotein lipase (LPL). The objective of this study was to investigate the association of ANGPTL4 variants (E40K and T266M) with triglyceride levels and with cardiovascular risk factors, such as metabolic syndrome (MetS) and obesity in type 2 diabetic Tunisian population. METHODS: We investigated the effect of the tagging single nucleotide polymorphisms (SNPs) rs1044250 (T266M) and rs116843064 (E40K) with triglyceride (TG) levels and CAD risk factors in a cohort of 220 patients undergoing coronary angiography for the evaluation of stable CAD, all of whom had (type 2 diabetes) T2D and were at least overweight. Multivariate logistic regressions were performed on association studies. RESULTS: TT genotype of rs1044250 (T266M variant) showed a protective effect on CVD risk in CAD group patients (OR 1.92, 95% CI 0.601.42, p =0.05) compared with control Group patients (OR 1.17, 95% CI 0.70-1.66, p = 0.72). Likewise, GA genotype of rs116843064 (E40K variant): (OR 0.74, 95% CI 0.54-1.65, p =0.01) for the CAD group compared with control Group patients (OR 1.12, 95% CI 0.68-1.74, p = 0.074). CONCLUSIONS: ANGPTL4 variants are associated with, not only lower fasting triglyceride levels, but also a decreased cardiovascular risk in T2D Tunisian patients. So, T266M and E40K polymorphism predicts cardiovascular disease risk in Type 2 diabetic Tunisian population.

Involvement of C-jun NH2-terminal kinase and apoptosis induced factor in apoptosis induced by deglycosylated bleomycin in laryngeal carcinoma cells.

In our previous studies, we demonstrated that the deglycosylation of bleomycin-A2 (BLM-A2) does not affect the capacity of this drug to induce cell death by apoptosis in a caspase-independent manner in laryngeal cancer cells (HEp-2), but suppresses the ability of BLM-A2 to induce ROS formation. We have now investigated the consequence of BLM-A2 deglycosylation in terms of the involvement of apoptotic pathways in HEp-2 cells. Apoptosis induced by bleomycin-A2 and deglyco-BLM-A2 is associated with the release of cytochrome c and AIF. Only Bax was oligomerized with BLM-A2-induced HEp-2 cell death. BLM-A2 and deglyco-BLM-A2-induced apoptosis depended on JNK activation but was independent of death receptors expression. In contrast, both of these drugs would sensitize HEp-2 cells to death receptor ligand-induced cell death. These observations indicate that the deglycosylation of BLM does not impair the ability of the drug to trigger cell death through activation of the intrinsic pathway by the release of AIF responsible for mitochondrial permeability and chromatin condensation independent of caspases activation.

Effect of SP600125 on the mitotic spindle in HeLa Cells, leading to mitotic arrest, endoreduplication and apoptosis.

BACKGROUND: The JNK inhibitor SP600125 strongly inhibits cell proliferation in many human cancer cells by blocking mitosis progression and inducing cell death. Despite, all this study, the mechanism by which SP600125 inhibits mitosis-related effects in human cervical cells (HeLa cells) remains unclear. In this study, we investigated the effects of SP600125 on the cell viability, cell cycle, and on the spindle assembly during mitosis in HeLa cells. METHODS: To explore this approach, we used a viability test, an immunofluorescence microscopy to detect Histone phosphorylation and mitotic spindle aberrations. Apoptosis was characterised using Western Blotting. RESULTS: Treatment of HeLa cells with varying concentrations of SP600125 induces significant G2/M cell cycle arrest with elevated phosphorylation of histone H3 within 48 h, and endoreduplication after 48 h. SP600125 also induces significant abnormal mitotic spindle. High concentrations of SP600125 (20 µM) induce disturbing microtubule assembly in vitro. Additionally, SP600125- induced delayed apoptosis and cell death was accompanied by significant poly ADP-ribose polymerase (PARP) cleavage and caspase-3 activation in the late phase (at 72 h). CONCLUSION: Our results confirmed that SP600125 induce mitosis arrest in G2/M, endoreduplication, mitotic spindle aberrations and apoptosis.

Polymorphism on Chromosome 9p21.3 Is Associated with Severity and Early-Onset CAD in Type 2 Diabetic Tunisian Population.

Multiple association studies found that the human 9p21.3 chromosome locus is a risk factor for atherosclerosis. The purpose of this study was to investigate the association of the severity and early-onset of coronary artery disease with variant rs1333049 on chromosome 9p21.3 polymorphism and the impact of this variant on cardiovascular risk factors in type 2 diabetic patients. The study population consisted of a control CAD group (101 patients) and 273 consecutive type 2 diabetic patients. Severity and extent of coronary atherosclerosis were scored numerically using the Gensini scoring system. The diabetic population was divided into three groups according to Gensini score: Group 1: no stenosis; Group 2: moderate CAD; Group 3, severe CAD. The homozygous CC genotype of rs1333049 was significantly associated with CAD in Group 2 (OR: 1.36; p = 0.02) and Group 3 (OR: 5.77, p < 0.001) compared to Group 1 (OR: 0.18; p = 0.2) and control group (OR: 0.22; p = 0.21). Among diabetic patients with early-onset CAD, CC genotype carriers had significantly higher Gensini scores than non-CC genotype carriers (49 ± 21.3 versus 14.87 ± 25.22; p < 0.001). The homozygous CC genotype of rs1333049 confers a magnified risk of early-onset and severe CAD in type 2 diabetic Tunisian population.

Role of carbohydrate moiety of bleomycin-A2 in caspase-3 activation and internucleosomal chromatin fragmentation in apoptosis of laryngeal carcinoma cells.

Bleomycin (BLM), an antitumor antibiotic, is currently used during anticancer therapy. The therapeutic efficiency of BLM for the treatment of malignant tumors is related to its ability to cleave DNA. However, little is known about the biological activity of the glycannic moiety in BLM-induced cytotoxicity. In this study, cell death induced by BLM-A2 and deglycosylated BLM-A2 was studied in a laryngeal carcinoma cell line (HEp-2 cells). Our results indicate that HEp-2 cells showed morphological and biochemical changes associated with apoptosis in the presence of low concentrations of BLM-A2. In contrast, the same changes, except activation of caspase-3 and internucleosomal digestion of genomic DNA, were observed when cells were exposed to high concentrations of deglycosylated BLM-A2. These observations indicate that the glycannic moiety from the bleomycin molecule has important biological effects on the cytotoxicity of the drug.