Biomarkers of exposure to endogenous oxidative and aldehyde stress

We observed an unexpectedly strong association of three different endogenous aldehydes and noted that the association could be explained by multiple reactions in which oxidative stress increased the formation of endogenous aldehydes and endogenous aldehydes increased oxidative stress. These interactions make it reasonable to assess multiple exposures to endogenous oxidative and aldehyde stress with less specific measures such as advanced glycation end-products or protein carbonyls.     

Curcumin improves memory deficits by inhibiting HMGB1-RAGE/TLR4-NF-κB signalling pathway in APPswe/PS1dE9 transgenic mice hippocampus

Amyloid-β (Aβ) deposition in the brain has been implicated in the development of Alzheimer's disease (AD), and neuroinflammation generates AD progression. Therapeutic effects of anti-inflammatory approaches in AD are still under investigation. Curcumin, a potent anti-inflammatory and antioxidant, has demonstrated therapeutic potential in AD models. However, curcumin's anti-inflammatory molecular mechanisms and its associated cognitive impairment mechanisms in AD remain unclear. The high-mobility group box-1 protein (HMGB1) participates in the regulation of neuroinflammation. Herein, we attempted to evaluate the anti-inflammatory effects of chronic oral administration of curcumin and HMGB1 expression in APP/PS1 transgenic mice AD model. We found that transgenic mice treated with a curcumin diet had shorter escape latencies and showed a significant increase in percent alternation, when compared with transgenic mice, in the Morris water maze and Y-maze tests. Additionally, curcumin treatment could effectively decrease HMGB1 protein expression, advanced glycosylation end product-specific receptor (RAGE), Toll-like receptors-4 (TLR4) and nuclear factor kappa B (NF-κB) in transgenic mice hippocampus. However, amyloid plaques detected with thioflavin-S staining in transgenic mice hippocampus were not affected by curcumin treatment. In contrast, curcumin significantly decreased GFAP-positive cells, as assessed by immunofluorescence staining. Taken together, these data indicate that oral administration of curcumin may be a promising agent to attenuate memory deterioration in AD mice, probably inhibiting the HMGB1-RAGE/TLR4-NF-κB inflammatory signalling pathway.     

Cleavage of α-Dicarbonyl Compounds by Terpene Hydroperoxide

Thermostabilities of component enzymes in the pyruvate dehydrogenase complex from Bacillus stearothermophilus decreased in the order lipoamide dehydrogenase, lipoate acetyltransferase, and pyruvate decarboxylase (E1). Fluorescence of an extrinsic 8-amino-1-naphthalenesulfonate (ANS) increased with inactivation of E1. The thermal denaturation of the enzymes resulted in disassembly of the complex. El was involved in a resulting aggregate of the complex. The interaction between ANS and denatured E1 accounted for an increase in fluorescence.     

Locally advanced breast cancer in Saudi Arabia: high frequency of stage III in a young population

In the Kingdom of Saudi Arabia (KSA), breast cancer constitutes 18% of all cancers in Saudi women. Whilst locally advanced breast cancer disease is unusual in Western countries, it constitutes more than 40% of all non-metastatic breast cancer in KSA. The relative frequency of locally advanced disease among our breast cancer population and the lack of a uniform consensus in the literature about its optimal management have prompted this retrospective analysis of the medical records of patients with Stage III breast cancer patients seen at King Faisal Specialist Hospital and Research Center between 1981 and 1991. In all, 315 patients were identified. Their median age ±SD was 46±11.6 years which is distinctly different from the 60–65 years median age in industrial Western nations. Most patients were younger than 50 years (64%) and premenopausal (62%). Patients were approximately equally divided between Stage III A and Stage III B Patients received multimodality treatment, including surgery., adjuvant chemotherapy, tamoxifen, and adjuvant radiotherapy. Sixty-one patients were excluded from survival analysis as they were considered lost to follow-up. Of the remaining 254 patients, 73 (29%) were alive and disease free, and 18 patients (7%) were alive but, with evidence of the disease. The remaining 163 (64%) had died from breast cancer or its related complications. Their median overall survival (OS) was 54 months, (95%, Cl, 27 to 121 months) and the median progression-free survival (PFS) was 28.8 months (95% Cl, 14.2 to 113 months). Cox proportional hazard, model identified Stage III B and the number of positive axillary lymph nodes as poor predictors of OS and PFS. Radiotherapy was the only adjuvant modality that affected survival favourably. The prognosis of patients with Stage III disease remains poor despite the use of a multimodality approach. The overall young age of our patients may have contributed to the poor outcome. Moreover, the adverse effect of Stage III B disease (as compared with Stage III A) and axillary nodal status was evident. Whilst the favourable effect of radiotherapy on survival was demonstrated, the lack of independent efficacy of other modalities (adjuvant chemotherapy and tamoxifen) or the apparent deleterious effect of neoadjuvant chemotherapy should be addressed with discretion in such retrospective analysis. Optimal management of patients with locally advanced breast cancer disease should be appraised in well designed, prospective, randomised studies.     

Neuroprotective effect of formononetin in ameliorating learning and memory impairment in mouse model of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common cause of dementia among elderly population. Deranged β-amyloid (Aβ) trafficking across the blood–brain barrier is known to be a critical element in the pathogenesis of AD. In the vascular endothelial cells of hippocampus, Aβ transport is mainly mediated by low-density lipoprotein-associated protein 1 (LRP1) and the receptor for advanced glycation end (RAGE) products; therefore, LRP1 and RAGE endothelial cells are potential therapeutic targets for AD. In this study, we explored the effects of Formononetin (FMN) on learning and memory improvement in APP/PS1 mice and the related mechanisms. We found that FMN significantly improved learning and memory ability by suppressing Aβ production from APP processing, RAGE-dependent inflammatory signaling and promoted LRP1-dependent cerebral Aβ clearance pathway. Moreover, FMN treatment alleviated ultrastructural changes in hippocampal vascular endothelial cells. In conclusion, we believe that FMN may be an efficacious and promising treatment for AD.     

On‐Line Control of Glucose Concentration in High‐Yielding Mammalian Cell Cultures Enabled Through Oxygen Transfer Rate Measurements

Glucose control is vital to ensure consistent growth and protein production in mammalian cell cultures. The typical fed‐batch glucose control strategy involving bolus glucose additions based on infrequent off‐line daily samples results in cells experiencing significant glucose concentration fluctuations that can influence product quality and growth. This study proposes an on‐line method to control and manipulate glucose utilizing readily available process measurements. The method generates a correlation between the cumulative oxygen transfer rate and the cumulative glucose consumed. This correlation generates an on‐line prediction of glucose that has been successfully incorporated into a control algorithm manipulating the glucose feed‐rate. This advanced process control (APC) strategy enables the glucose concentration to be maintained at an adjustable set‐point and has been found to significantly reduce the deviation in glucose concentration in comparison to conventional operation. This method has been validated to produce various therapeutic proteins across cell lines with different glucose consumption demands and is successfully demonstrated on micro (15 mL), laboratory (7 L), and pilot (50 L) scale systems. This novel APC strategy is simple to implement and offers the potential to significantly enhance the glucose control strategy for scales spanning micro‐scale systems through to full scale industrial bioreactors.     

Degradative covalent reactions important to protein stability

Commonly observed chemical modifications that occur in proteins during their in vitro purification, storage, and handling are discussed. Covalent modifications described include deamidation and isoaspartate formation, cleavage of peptide bonds at aspartic acid residues, cystine destruction and thioldisulfide interchange, oxidation of cysteine and methionine residues, and the glycation and carbamylation of amino groups.