Search

Salivary oligomeric α-synuclein (α-Syn) has been introduced as a promising biomarker for the diagnosis of Parkinson's disease. Herein, a fluorescence sensor array based on three carbon quantum dots (CQDs) with different surface functional groups was developed for the identification and quantification of salivary α-Syn oligomers. Each of the CQDs generated a different fluorescence response to the target analyte, and the responses were analyzed by NPLS-DA to create a unique response pattern for the target analyte. The developed three-element sensor array showed a linear response to α-Syn oligomers in the range of 0.5-32 μg/mL and a detection limit (LOD) of 0.5 μg/mL, with a cross-validation accuracy of 92% in aqueous solution. The sensor array could detect the analyte in a mixture of different proteins and in the complex medium of saliva, with the LOD of 0.3 μg/mL indicating the massive potential of CQD arrays for developing sensitive, simple, inexpensive, and label-free sensing platforms.

Objective: Although intracytoplasmic sperm injection (ICSI) is a way to deal with in vitro fertilization failure, 3% of couples still experience repeated fertilization failure after attempted ICSI, despite having sperm within normal parameters. These patients are a challenging group whose sperm cannot fertilize the egg during ICSI. Unfortunately, no test can predict the risk of fertilization failure. Phospholipase C zeta (PLCζ) and transition nuclear proteins (TNPs) are essential factors for chromatin packaging during sperm maturation. This study aimed to assess PLCζ1 and TNP1 expression in the sperm of patients with fertilization failure and the correlations among the DNA fragmentation index, PLCζ1 and TNP1 gene and protein expression, and the risk of fertilization failure., Methods: In this study, 12 infertile couples with low fertilization rates (<25%) and complete failure of fertilization in their prior ICSI cycles despite normal sperm parameters were chosen as the case group. Fifteen individuals who underwent ICSI for the first time served as the control group. After sperm analysis and DNA fragmentation assays, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to compare the gene and protein expression of PLCζ and TNP1 in both groups., Results: DNA fragmentation was significantly higher in the fertilization failure group. The qRT-PCR and Western blot results demonstrated significantly lower PLCζ and TNP1 gene and protein expression in these patients than in controls., Conclusion: The present study showed that fertilization failure in normozoospermic men was probably due to deficient DNA packaging and expression of TNP1.

Mesenchymal stem cells (MSCs) are multipotent cells which are popular in human regenerative medicine. These cells can renew themselves and differentiate into several specialized cell types including osteoblasts, adipocytes, and chondrocytes under physiological and experimental conditions. MSCs can secret a lot of components including proteins and metabolites. These components have significant effects on their surrounding cells and also can be used to characterize them. This characterization of multipotent MSCs plays a critical role in their therapeutic potential. The metabolic profile of culture media verified by applying matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS) techniques. Also, the differentiation and development of MSCs have monitored through culture media metabolome or secretome (secreted metabolites). Totally, 24 potential metabolites were identified. Between them 12 metabolites are unique to BM-MSCs and 5 metabolites are unique to AD-MSCs. Trilineage differentiation including chondrocytes, osteoblasts, and adipocytes, as well as metabolites that are being differentiated, have been shown in different weeks. In the present study, the therapeutic effects of MSCs analyzed by decoding the metabolome for MSCs secretome via metabolic profiling using MALDI-TOF-MS techniques., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Artemin is a potent molecular chaperone, which protects Artemia embryos undergoing encystment against extreme environmental stresses. In the present work, we have examined the structural changes of artemin from A. urmiana upon exposure to oxidant and heat, by using CD measurements as well as excitation-emission fluorescence spectroscopy as a powerful tool for monitoring the conformational transitions and molecular interactions in proteins. We have also provided here the first document on reporting the three dimensional fluorescence spectra of a protein using ANS. Totally, the fluorescence results indicated that the microenvironments of tyrosine and tryptophan residues and the hydrophobic pockets as well as the polypeptide backbone or secondary structure of the chaperone were influenced in responses to heat and H 2 O 2 in different degrees. Moreover, the native state of artemin did not induce a considerable exposure of the internal non-polar groups to the solvent. Besides, the excitation-emission spectra of heated artemin by ANS revealed new emission peaks at 430-450 nm when it was excited at 330 nm, which suggests probable exposure of new binding sites for hydrophobic or electrostatic interactions of the protein with ANS. The protein also showed a greater conformational sensitivity to the temperature fluctuations compared to oxidation. Here, we presented some evidence in support of the relation between artemin and its stress dependent activation in vitro and in vivo. This study can expect that the EEM fluorescence spectroscopy could provide a promising tool to study conformational transitions of proteins., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)