Micro-RNAs in transplant tolerance

Identification and comparative analysis of miRNA transcriptomes after allograft and xenograft transplantation in Pinctada fucata martensii

Effective immune regulation after transplantation during pearl production is crucial for the cultivation of high-quality pearls. MicroRNAs (miRNAs) play an important role in a variety of physiological processes. To understand the regulatory rules of miRNAs after transplantation in Pinctada funcata martensii, we constructed 13 miRNA transcriptomes, including the control group (Con), allograft (Al), and xenograft (Xe) transplantation at six time points (6, 12, and 24 h and 3, 6, and 12 days), in which the xenografted mantle tissue was from Pinctada maxima. We identified 159 differentially expressed miRNAs (DEMs) and found that these DEMs showed high expression at 12 h, 24 h, and 3 days after transplantation. A total of 130 DEMs, such as Let-7, were present in the Al and Xe groups; miR-34 and 16 other DEMs were specifically present in the Al group; miR-216b and 13 other DEMs were specifically present in the Xe group. Compared with the Con group, the target genes of DEMs in the Al group were significantly enriched in protein complex, cytoskeleton, and macromolecular complex, and the Xe group was significantly enriched in ribonucleoside metabolic process, nucleoside binding, and cell division. Compared with the Al group, the target genes in the Xe group were significantly enriched in response to DNA damage stimulation. Overall, multiple pathways associated with cellular activity were enriched in higher numbers of genes in the Xe group than in the Al group. These findings enriched the information on immune regulatory mechanisms at the expression level of miRNAs in P. f. martensii after transplantation.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

The Effect of Composol Medium on miR-16 Expression during Platelet Storage up to Day 7 at Room Temperature

Objective

MicroRNAs (miRNAs) are short, noncoding RNAs that play vital roles in gene regulation. It has been shown that storage has an effect on platelet miRNAs. MiR-16 is highly expressed in platelets and it appears to target the genes involved in cell death. It has been shown that platelets could be stored in Composol for a longer period of time. The aim of the present study was to assess and compare the expression pattern of miR-16 in platelet concentrates (PCs) in plasma and Composol media.

Materials and Methods

In an experimental study, ten PC bags were collected and each bag was divided into two separate bags, one with the 70% Composol and the other with only plasma. Both bags were stored for 7 days at 22˚C and tested on days 1, 3, 5, and 7 of storage. For each sample, we performed quantitative real-time polymerase chain reaction (qRT-PCR). The water-soluble tetrazolium salt-1 (WST-1) test was used to assess platelet viability in all of the samples. Statistical analysis was done by SPSS and REST software. A P<0.05 was considered statistically significant.

Results

miR-16 was significantly elevated during the storage days, with fold changes of 3.47 (plasma) and 2.77 (Composol). The Composol group had significantly decreased miR-16 expression compared with the plasma group. Results of the WST-1 test showed less decrease in optical density (OD) in the Composol group (0.93 ± 0.4) during the storage days compared with the plasma group (0.75 ± 0.3).

Conclusion

Our finding supported results from previous studies that reported an increase in miR-16 expression during platelet storage. In addition, miR-16 down-regulation in Composol medium implied that Composol might be a good solution for long-term platelet storage because it has the potential to elevate the shelf-life of platelets stored at 22˚C.

Circular RNA hsa_circ_0004277 contributes to malignant phenotype of colorectal cancer by sponging miR-512-5p to upregulate the expression of PTMA

In recent years, extensive reports have been published concerning the molecular mechanism underlying the occurrence and progression of colorectal cancer. Circular RNAs (circRNAs) have been identified as important modulators in the biological processes of colorectal cancer. Microarray analysis unveiled that differential circ-0004277 expression was identified in tissue samples of colorectal cancer. High circ-0004277 expression was then verified in tissue samples and cell lines of colorectal cancer via qRT-PCR. Kaplan-Meier analysis was used for identifying the association between circ-0004277 expression and the overall survival rate of colorectal cancer patients. A relationship existed between higher circ-0004277 expression and decreased overall survival rate of colorectal cancer patients. From a functional perspective, circ-0004277 knockdown accelerated cell apoptosis and restrained cell proliferation of colorectal cancer. From mechanistic perspective, circ-0004277 upregulated PTMA by sponging miR-512-5p. Rescue assay was used for verifying the roles of the circ-0004277-miR-512-5p-PTMA axis. Both miR-512-5p and PTMA participated in circ-0004277-mediated colorectal cancer cell proliferation based on experiments. In summary, our study showed that circ-0004277 promoted the proliferation of colorectal cancer cells as a miR-512-5p sponge to upregulate the PTMA expression.

History and progress of hypotheses and clinical trials for Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss along with neuropsychiatric symptoms and a decline in activities of daily life. Its main pathological features are cerebral atrophy, amyloid plaques, and neurofibrillary tangles in the brains of patients. There are various descriptive hypotheses regarding the causes of AD, including the cholinergic hypothesis, amyloid hypothesis, tau propagation hypothesis, mitochondrial cascade hypothesis, calcium homeostasis hypothesis, neurovascular hypothesis, inflammatory hypothesis, metal ion hypothesis, and lymphatic system hypothesis. However, the ultimate etiology of AD remains obscure. In this review, we discuss the main hypotheses of AD and related clinical trials. Wealthy puzzles and lessons have made it possible to develop explanatory theories and identify potential strategies for therapeutic interventions for AD. The combination of hypometabolism and autophagy deficiency is likely to be a causative factor for AD. We further propose that fluoxetine, a selective serotonin reuptake inhibitor, has the potential to treat AD.