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Alzheimer's disease (AD), the most common form of dementia in the aged people, is a chronic and irreversible neurodegenerative disorder. Early prediction, intervention, and objective diagnosis are very critical in AD. In this chapter, we will introduce the current progress in the prediction and diagnosis of AD, including recent development in diagnostic criteria, genetic testing, neuroimaging techniques, and neurochemical assays. Focus will be on some new applied methods with more specific examples, that is, cerebrospinal fluid (CSF) and blood proteins and peptides, which might serve as biomarkers for the diagnosis of AD. We will also discuss biomarker-based diagnostic strategies and their practical application.

See editorial comment on page 1650Objective: Pulmonary hypertension is a lethal disease characterized by pulmonary vascular remodeling and is mediated by abnormal proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs). Plateletderived growth factor BB (PDGF-BB) is the most potent mitogen for PASMCs and is involved in vascular remodeling in pulmonary hypertension development. Therefore, the objective of our study is to identify novel mechanisms underlying vascular remodeling in pulmonary hypertension. Methods:We explored the effects and mechanisms of PTPRD downregulation in PASMCs and PTPRD knockdown rats in pulmonary hypertension induced by hypoxia. Results:We demonstrated that PTPRD is dramatically downregulated in PDGF-BB-treated PASMCs, pulmonary arteries from pulmonary hypertension rats, and blood and pulmonary arteries from lung specimens of patients with hypoxic pulmonary arterial hypertension (HPAH) and idiopathic PAH (iPAH). Subsequently, we found that PTPRD was downregulated by promoter methylation via DNMT1. Moreover, we found that PTPRD knockdown altered cell morphology and migration in PASMCs via modulating focal adhesion and cell cytoskeleton. We have demonstrated that the increase in cell migration is mediated by the PDGFRB/PLCg1 pathway. Furthermore, under hypoxic condition, we observed significant pulmonary arterial remodeling and exacerbation of pulmonary hypertension in heterozygous PTPRD knock-out rats compared with the wild-type group. We also demonstrated that HET group treated with chronic hypoxia have higher expression and activity of PLCg1 in the pulmonary arteries compared with wild-type group. Conclusion:We propose that PTPRD likely plays an important role in the process of pulmonary vascular remodeling and development of pulmonary hypertension in vivo. Video abstract http://links.lww.com/HJH/B989.

There is growing evidence that microRNAs (miRNAs) are implicated in cellular adaptation to osmotic stress, but the underlying osmosignaling pathways are still not completely understood. In this study, we found that a passenger strand miRNA miR-23a-5p was significantly down-regulated in response to high NaCl treatment in mouse inner medullary collecting duct cells (mIMCD3) through a miRNA profiling assay. The decrease of miR-23a-5p is hypertonicity-dependent and osmotolerant cell type-specific. Knockdown of miR-23a-5p increased cellular survival and proliferation in mIMCD3. In contrast, miR-23a-5p overexpression repressed cell viability and proliferation under hypertonic stress. RNA deep-sequencing revealed that a heat shock protein 70 (HSP70) isoform, HSP70 member 1B (HSPA1B), was significantly increased under hypertonic treatment. Based on the prediction analysis by Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG) and TargetScan, and a further validation via a dual-luciferase assay, HSPA1B was identified as a potential target of miR-23a-5p. Overexpressed miR-23a-5p suppressed HSPA1B while down-regulated miR-23a-5p promoted HSPA1B expression in mIMCD3. In addition, an in vivo study demonstrated that there is a reverse correlation between the levels of miR-23a-5p and HSPA1B in mouse renal inner medulla (papilla) that is exposed to extremely high osmolality. In summary, this study elucidates that passenger strand miR-23a-5p is a novel tonicity-responsive miRNA. The down-regulation of miR-23a-5p facilitates cellular adaptation to hypertonic stress in mammalian renal cells through modulating HSPA1B.

Background Advances in microRNAs (miRNAs) biomarkers have generated disease markers with potential clinical values. However, none of these published results have been applied in clinic until today. The main reason could be the lack of simple but robust miRNA measurements. Methods We built up a simple but ultrasensitive RT-qPCR protocol, Direct S-Poly(T) Plus assay, for detecting miRNAs without RNA purification. In this study, the method was optimized and compared with other RNA purification-based miRNA assays, and the sensitivity was tested. Using Direct S-Poly(T) Plus method, seven potential miRNA biomarkers of colorectal cancer were validated. Results It is possible to detect approximately 100 miRNAs with minimal plasma inputs (20 μl) and time (~ 140 min) with this approach. The sensitivity of this method was 2.7–343-fold higher than that of the stem-loop method, and comparable with S-Poly(T) plus method. 7 validated miRNA biomarkers of colorectal cancer by Direct S-Poly(T) plus assay could discriminate colorectal cancer stage I from healthy individuals, and promised satisfactory discrimination with the area under receiver operating characteristic (ROC) curve ranging from 0.79 to 0.94 (p value < 0.001). Conclusions This simple and robust protocol may have strong impact on the development of specific miRNAs as biomarkers in clinic.