Shulan He

Comparing gene expression profiles of Kashin-Beck and Keshan diseases occurring within the same endemic areas of China

In this study, differentially expressed genes in peripheral blood from patients with Kashin-Beck disease and Keshan disease were compared to further investigate the etiology and pathogenesis of both diseases, which occur in a common endemic area of China. Twenty Kashin-Beck disease patients and 12 healthy controls, and 16 Keshan disease patients and 16 healthy controls, were grouped into four pairs. Patients and controls were selected from common endemic areas for the two diseases. Total RNA was isolated from peripheral blood mononuclear cells from all patients and controls, and gene expression profiles analyzed by oligonucleotide microarrays. Sixteen genes differentially expressed in both Kashin-Beck disease and Keshan disease (versus controls) were identified, and comprised nine genes showing synchronous and seven asynchronous expression. The Comparative Toxicogenomics Database shows that expression and biological function of these genes can be affected by multiple environmental factors, including mycotoxin and selenium content, potential environmental risk factors for the two diseases. Thus, these shared differentially expressed genes may contribute to the distinct organ lesions, caused by common environmental risk factors of Kashin-Beck disease and Keshan disease.

Mitochondrial-related gene expression profiles suggest an important role of PGC-1alpha in the compensatory mechanism of endemic dilated cardiomyopathy.

Keshan disease (KD) is an endemic dilated cardiomyopathy with unclear etiology. In this study, we compared mitochondrial-related gene expression profiles of peripheral blood mononuclear cells (PBMCs) derived from 16 KD patients and 16 normal controls in KD areas. Total RNA was isolated, amplified, labeled and hybridized to Agilent human 4 × 44k whole genome microarrays. Mitochondrial-related genes were screened out by the Third-Generation Human Mitochondria-Focused cDNA Microarray (hMitChip3). Quantitative real-time PCR, immunohistochemical and biochemical parameters related mitochondrial metabolism were conducted to validate our microarray results. In KD samples, 34 up-regulated genes (ratios ≥ 2.0) were detected by significance analysis of microarrays and ingenuity systems pathway analysis (IPA). The highest ranked molecular and cellular functions of the differentially regulated genes were closely related to amino acid metabolism, free radical scavenging, carbohydrate metabolism, and energy production. Using IPA, 40 significant pathways and four significant networks, involved mainly in apoptosis, mitochondrion dysfunction, and nuclear receptor signaling were identified. Based on our results, we suggest that PGC-1alpha regulated energy metabolism and anti-apoptosis might play an important role in the compensatory mechanism of KD. Our results may lead to the identification of potential diagnostic biomarkers for KD in PBMCs, and may help to understand the pathogenesis of KD.

Selenium deficiency induced damages and altered expressions of metalloproteinases and their inhibitors (MMP1/3, TIMP1/3) in the kidneys of growing rats

Selenium is an essential trace element for the maintenance of structures and functions of kidney. To evaluate the effects of low selenium on the kidneys of growing rats, newborn rats were fed with selenium deficient and normal diets respectively for 109 days. As a result, rats fed with low selenium diets resulted in a decline in the body weight and the concentration of selenium in the kidney, especially the male rats from the low selenium groups. Moreover, the ultrastructure of glomerulus and tubules were damaged in low selenium group: the glomeruli were observed with hyperplasia of mesangial cells, fusion of podocyte foot processes and thickening of basement membrane; and the tubules were observed with vacuolar degenerated epithelial cells, increased edema fluid or protein solution between cells, microvilli edema, increased cell gaps and decreased cell links. Furthermore, the pathological changes in selenium deficient group included the increase of fibers around renal hilum aorta and in the renal collecting duct, and shed of cells in the proximal convoluted tubules. In addition, up-regulated expressions of matrix metalloproteinases (MMP1/3) and down-regulated expressions of their inhibitors (TIMP1/3) at the mRNA and protein levels were also appeared to be relevant to low selenium. The results suggested that low selenium in diet may cause low selenium concentration in the kidney of growing rat and lead to damages of the ultrastructure and extracellular matrix (ECM) of kidney.

Gene Expression Analysis Suggests Bone Development-Related Genes GDF5 and DIO2 Are Involved in the Development of Kashin-Beck Disease in Children Rather than Adults

Objective To investigate the differences in gene expression between children and adults with Kashin-Beck disease (KBD). Methods 12 children with KBD and 12 healthy children were selected and divided into 4 KBD vs. control pairs matched according to age and gender, with each pair having 3 KBD children and 3 healthy children. Additionally, 15 adults with KBD and 15 healthy adults were selected and divided into 5 KBD vs. control pairs matched according to age and gender, with each pair having 3 KBD adults and 3 healthy adults. Total RNA was isolated from peripheral blood mononuclear cells (PBMCs) respectively. A total of 367 target genes were selected based on previous genome-wide gene expression profile analysis. Expression levels of the 367 genes were evaluated by customized oligonucleotide microarray and the differentially expressed genes were identified. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was conducted to validate the microarray data. Results A total of 95 (25.9%) genes in KBD children and 158 (43.1%) genes in KBD adults were found to exhibit more than two-fold change in gene expression level relative to healthy controls. By comparing differentially expressed genes identified in KBD children to those of KBD adults, 42 genes were found to be differentially expressed only in KBD children. And 105 genes were found to be differentially expressed only in KBD adults. Further, 16 differentially expressed genes common to both KBD children and adults were found to be asynchronously expressed in KBD children compared to KBD adults. Conclusion Significant differences in gene expression pattern were identified between KBD children and KBD adults, indicating different molecular mechanisms underlying cartilage lesions of KBD children and KBD adults. In addition, bone development-related genes GDF5 (expression ratio = 2.14±0.02) and DIO2 (expression ratio = 0.11±0.05) may contribute to the development of KBD in children rather than in adults.

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.

To screen the effective software for analysing gene interactions from Kashin-Beck disease genome profiling pathway and network, according to the tool of GeneMANIA

In order to screen the more effective software for the pathway and network analysis of Kashin-Beck disease, gene microarrays, TranscriptomeBrowser, MetaCore and GeneMANIA were used for analysis. Three significant chondrocytic pathways and one network were screened by TranscriptomeBrowser; one significant pathway and one network were identified by MetaCore. BAX, APAF1, CASP6, BCL2, VEGF, SOCS3, BAK, TGFBI, TNFAIP6, TNFRSF11B and THBS1 were significant genes associated with the biological function of chondrocyte or cartilage involved in the TranscriptomeBrowser or MetaCore results. The interactions between the significant genes and their adjacent genes were searched and classified in GeneMANIA. In pathway analysis results, TranscriptomeBrowser is superior to get the interaction of pathway and co-expression compared with MetaCore; MetaCore is superior to get the interaction of physical interaction compared with TranscriptomeBrowser. In network analysis results, TranscriptomeBrowser contains more interaction message of co-localisation, MetaCore contains, more interaction message of co-expression.