Study of endothelial dysfunction and vascular inflammation in sleep apnea, obesity and aged humans

Background: Obstructive sleep apnea (OSA) has been associated with cardiovascular complications. The overnight repetitive hypoxia represents a form of oxidative stress in the vasculature which may activate the oxidant-sensitive, proinflammatory transcription factor nuclear factor κB (NF-κB), affecting endothelial function and atherosclerosis. Aim: We investigated whether the endothelial alterations attributed to OSA rather than to other confounding factors. Also, the production of inflammatory cytokine nuclear factor-kappa β (NF-Kβ) was investigated as the molecular mechanism involved in vascular endothelial dysfunction with OSA. Material and methods: Sixty subjects underwent attended nocturnal polysomnography were grouped by apnea hypopnea index: control (AHI5/h) the cases were further classified according to age and BMI into subgroup IIA: OSA, non-obese, middle age (35–52 y), subgroup IIB: OSA, non-obese, older age group (55–68 y), subgroup IIIA: OSA, obese, middle age group (35–52 y) and subgroup IIIB: OSA, obese, older age group (55–68 y). A morning venous blood sample was obtained. Neutrophils were isolated, and NF-κB activity was determined. Plasma sVCAM-1 was assayed by enzyme-linked immunosorbent assay and flow-mediated dilation (FMD) was performed. Results: NF-κB activation and plasma level of sVCAM-1 were significantly increased in OSA patients as compared to the control group and there was no significant difference between the obese and non-obese cases also no significant difference between the middle and old age cases. The degree of NF-κB activation was positively correlated with indices of apnea severity(r = 0.938; p < 0.001). FMD was significantly decreased in OSA patients as compared to the control group. Conclusion: These findings suggested that OSA is an independent risk factor for cardiovascular morbidity also that OSA leads to NF-κB activation, which may constitute an important pathway linking OSA with systemic inflammation and cardiovascular disease

Promising cytotoxic butenolides from the Soybean endophytic fungus <i>Aspergillus terreus</i>:a combined molecular docking and in-vitro studies

AimThis study aimed to use one strain many compounds approach (OSMAC) to investigate the cytotoxic potential of Aspergillus terreus associated with soybean versus several cancer cell lines, by means of in-silico and in vitro approaches.Methods and resultsFermentation of the isolated strain was done on five media. The derived extracts were investigated for their inhibitory activities against three human cancer cell lines; mammary gland breast cancer (MCF-7), colorectal adenocarcinoma (Caco-2), and hepatocellular carcinoma (HepG2) using MTT Assay. The fungal mycelia fermented in Modified Potato Dextrose Broth (MPDB) was the most cytotoxic extract against HepG2, MCF-7, and Caco-2 cell lines with IC50 4.2 ± 0.13, 5.9 ± 0.013 and 7.3 ± 0.004 μg mL−1, respectively. MPDB extract was scaled up resulting in the isolation of six metabolites; three fatty acids (1, 2, and 4), one sterol (3) and two butenolides (5 and 6) by column chromatography. The isolated compounds (1–6) were screened through a molecular docking approach for their binding aptitude to various active sites. butyrolactone-I (5) revealed a significant interaction within the CDK2 active site, while aspulvinone E (6) showed promising binding affinity to FLT3 and EGFR active sites that was confirmed by in vitro CDK2, FLT3 and EGFR inhibitory activity. Finally, the in vitro cytotoxic activities of butyrolactone-I (5) and aspulvinone E (6) revealed the antiproliferative activity of butyrolactone-I (5), against HepG2 cell line (IC50 = 17.85 ± 0.32 μM).ConclusionMolecular docking analysis and in vitro assays suggested the CDK2/A2 inhibitory potential of butyrolactone-I (5) in addition to the promising interaction abilities of aspulvinone E (6) with EGFR and FLT3 active sites as a possible mechanism of their biological activities

Thermal stability analyses of human PERIOD-2 C-terminal domain using dynamic light scattering and circular dichroism.

At the molecular level, the circadian clock is regulated by a time delayed transcriptional-translational feedback loop in which the core proteins interact with each other rhythmically to drive daily biological rhythms. The C-terminal domain of a key clock protein PER2 (PER2c) plays a critically important role in the loop, not only for its interaction with the binding partner CRY proteins but also for the CRY/PER complex's translocation from the cytosol to the nucleus. Previous circular dichroism (CD) spectroscopic studies have shown that mouse PER2c (mPER2c) is less structured in solution by itself but folded into stable secondary structures upon interaction with mouse CRYs. To understand the stability and folding of human PER2c (hPER2c), we expressed and purified hPER2c. Three oligomerization forms of recombinant hPER2c were identified and thoroughly characterized through a combination of biochemical and biophysical techniques. Different to mPER2c, both thermal unfolding DLS and CD analyses suggested that all forms of hPER2c have very stable secondary structures in solution by themselves with melting temperatures higher than the physiological body temperature, indicating that hPER2c does not require CRY to fold. Furthermore, we examined the effects of EDTA, salt concentration, and a reducing agent on hPER2c folding and oligomerization. The ability of hPER2c forming oligomers reflects the potential role of hPER2c in the assembly of circadian rhythm core protein complexes