Detection of serum proteomic changes and discovery of serum biomarkers for Kashin-Beck disease using surface-enhanced laser desorption ionization mass spectrometry (SELDI-TOF MS)

Serum biomarkers of Keshan disease assessed using a protein profiling approach based on ClinProt technique

The etiology of Keshan disease (KD), an endemic myocardiopathy in regions of China, is largely unknown. To show the protein changes in serum from KD patients versus controls and idiopathic dilated cardiomyopathy (IDCM) and to search specific biological markers for differential diagnosis for KD. Serum of 65 patients with KD was compared with 29 patients with IDCM, 62 controls from KD areas and 28 controls from non-KD areas by ClinProt/MALDI-ToF technique. The genetic algorithm, quick classifier algorithm and supervised neural network algorithm methods were used to screen marker proteins and establish diagnostic model. Thirty-four differential peaks were identified in KD patients compared with the healthy controls from non-KD areas. Thirty-eight differentially peaks were identified in KD patients and controls from KD areas; and sixty-seven differentially peaks were identified in patients with KD and patients with IDCM. We believe that marker protein peaks screened in KD patients, healthy controls and IDCM patients may provide clues for the differential diagnosis and treatment of KD.

Recent advances in the research of an endemic osteochondropathy in China: Kashin-Beck disease

Kashin-Beck disease (KBD) is an endemic chronic osteochondral disease, which has a high prevalence and morbidity in the Eastern Siberia of Russia, and in the broad diagonal, northern-east to southern-west belt in China and North Korea. In 1990's, it was estimated that in China 1-3 million people had some degree of symptoms of the disease, although even higher estimates have been presented. In China, the extensive prevalence peaked in the late 1950's, but since then, in contrast to the global trend of the osteoarthritis (OA), the number of cases has been dramatically falling. Up to 2013, there are 0.64 millions patients with the KBD and 1.16 millions at risk in 377 counties of 13 provinces or autonomous regions. This is obviously thanks to the preventive efforts carried out, which include providing millions of people with dietary supplements and clean water, as well as relocation of whole villages in China. However, relatively little is known about the molecular mechanisms behind the cartilage damage, the genetic and the environmental risk factors, and the rationale of the preventive effects. During the last decade, new data on a cellular and molecular level has begun to accumulate, which hopefully will uncover the grounds of the disease.

Identification of differentially expressed genes and pathways between primary osteoarthritis and endemic osteoarthritis (Kashin-Beck disease)

OBJECTIVES

Primary osteoarthritis (OA) and Kashin-Beck disease (KBD) exhibit similar clinical manifestations and common articular cartilage lesions. Revealing the pathogenetic differences between OA and KBD is helpful for differential diagnosis and may provide new insights into the pathogenesis of OA and KBD. In this study, we compared the genome-wide gene ontology (GO) and pathway expression patterns of articular cartilage derived from both OA and KBD patients.

METHODS

Total RNA was isolated, amplified, labelled, and hybridized using Agilent whole genome microarray analysis. Gene set enrichment analysis (GSEA) was used to identify differentially expressed genes and pathways between OA and KBD. Nine differentially expressed GO categories and 85 differentially expressed pathways were identified by this study.

RESULTS

The reactive oxygen species (ROS)-related HOUSTIS_ROS pathway and the vascular endothelial growth factor (VEGF)-related ABE_VEGFA_TARGETS_2HR pathway were significantly up-regulated in OA compared to KBD. Higher expression levels of the collagen-related COLLAGEN GO, EXTRACELLULAR_MATRIX_PART GO, and nitric oxide (NO)-related BIOCARTA_NO1_PATHWAY pathways were detected in KBD than in OA.

CONCLUSIONS

ROS-induced cartilage lesions seem to be more involved in the pathogenesis of OA whereas NO-mediated chondrocyte apoptosis contributes more to the development of KBD.

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL.

Efficacy of calcium supplementation for human bone health by mass spectrometry profiling and cathepsin K measurement in plasma samples

Osteoporosis is a common disease among older people, especially postmenopausal women. Calcium supplementation is effective in decreasing the occurrence of osteoporosis. We tested the effect of different calcium sources (i.e., calcium carbonate chew, milk mineral chew, milk drink and placebo chew) by direct mass spectrometry (dMS) profiling and cathepsin K measurement in the serum of subjects. The dMS method is promising for plasma biomarker discovery, and cathepsin K level in the plasma is an indicator for osteoporosis. Our result shows that dMS detected characteristic ion peaks after different calcium supplement interventions; ion peak 4281.0 m/z was commonly inhibited by all three treatments. This ion peak was identified to be a fragment of follistatin-related protein 3 precursor by means of the "Lift" mode of MS/MS. The other differential ion peaks were also successfully identified: 1786.5 m/z (upregulated after calcium carbonate chew) was shown to be one fragment of transcription factor jun-B; the parent protein of 3504.7 m/z (upregulated after milk drink) was a collagen alpha-2 (type I) chain precursor; the ion peak of 3359.6 m/z (downregulated after milk mineral chew) was one fragment of family 31 glucosidase. Cathepsin K is significantly inhibited only by calcium carbonate chew treatment, indicating this form of calcium supplement has some advantage over other sources of supplementation.

Proteomic changes in articular cartilage of human endemic osteoarthritis in China

Kashin-Beck disease (KBD) is a chronic endemic osteochondropathy with unclear pathogenesis. It is a degenerative disease similar to osteoarthritis, but with different manifestations of cartilage damage. The aim of this investigation was to show the protein changes in KBD cartilage and to identify the candidate proteins in order to understand the pathogenesis of the disease. Proteins were extracted from the media of primary cell cultures of KBD and normal chondrocytes, and separated by two-dimensional fluorescence difference gel electrophoresis (2-D DIGE). MALDI-TOF/TOF analysis revealed statistically significant differences in 27 proteins from KBD chondrocyte cultures, which consisted of 17 up-regulated and ten down-regulated proteins. The results were further validated by Western blot analysis. The proteins identified are mainly involved in cellular redox homeostasis and stress response (MnSOD, Hsp27, Peroxiredoxin-1, and Cofilin-1), glycolysis (PGK-1, PGM-1, α-enolase), and cell motility and cytoskeletal organization (Actin, Calponin-2, and Keratin). These KBD-associated proteins indicate that cytoskeletal remodeling, glycometabolism, and oxidative stress are abnormal in KBD articular cartilage.

Selenium in human health and disease

This review covers current knowledge of selenium in the environment, dietary intakes, metabolism and status, functions in the body, thyroid hormone metabolism, antioxidant defense systems and oxidative metabolism, and the immune system. Selenium toxicity and links between deficiency and Keshan disease and Kashin-Beck disease are described. The relationships between selenium intake/status and various health outcomes, in particular gastrointestinal and prostate cancer, cardiovascular disease, diabetes, and male fertility, are reviewed, and recent developments in genetics of selenoproteins are outlined. The rationale behind current dietary reference intakes of selenium is explained, and examples of differences between countries and/or expert bodies are given. Throughout the review, gaps in knowledge and research requirements are identified. More research is needed to improve our understanding of selenium metabolism and requirements for optimal health. Functions of the majority of the selenoproteins await characterization, the mechanism of absorption has yet to be identified, measures of status need to be developed, and effects of genotype on metabolism require further investigation. The relationships between selenium intake/status and health, or risk of disease, are complex but require elucidation to inform clinical practice, to refine dietary recommendations, and to develop effective public health policies.

Separation of peptides with polyionic nanosponges for MALDI-MS analysis

A polymer brush consisting of 70% poly(N-isopropylacrylamide) (PNIPAAM) and 30% polymethacrylic acid (PMAA) was synthesized from gold substrates with a "grafting from" AIBN-type free-radical initiator. Fractionation of two peptides, bradykinin and buccalin, was accomplished in less than 120 s by placing a 30 pM (pH approximately 6.2) droplet onto the polymer brush substrate. The eluant containing the anionic buccalin is pipetted away for MALDI analysis while the cationic bradykinin adsorbed to the swollen anionic brush and was subsequently released by adding a droplet of formic acid to the substrate. This caused the brush to collapse and release the bradykinin, much like squeezing a sponge; these nanosponge substrates exhibited very high loading capacity (>2.0 mg/mL) compared to plasma-polymer-modified MALDI substrates. Ellipsometric measurements showed that complementary peptides adsorb rapidly while those of the same charge do not, and MALDI-MS analysis of the two fractions showed separation of both peptides. The adsorption of bradykinin was monitored over time, and 85% of the peptide had been adsorbed to the nanosponge in 1 min from a 0.5 mg/mL aqueous solution.