Renal telocytes contribute to the repair of ischemically injured renal tubules

Telocytes (TCs), a distinct type of interstitial cells, have been identified in many organs via electron microscopy. However, their precise function in organ regeneration remains unknown. This study investigated the paracrine effect of renal TCs on renal tubular epithelial cells (TECs) in vitro, the regenerative function of renal TCs in renal tubules after ischaemia–reperfusion injury (IRI) in vivo and the possible mechanisms involved. In a renal IRI model, transplantation of renal TCs was found to decrease serum creatinine and blood urea nitrogen (BUN) levels, while renal fibroblasts exerted no such effect. The results of histological injury assessments and the expression levels of cleaved caspase‐3 were consistent with a change in kidney function. Our data suggest that the protective effect of TCs against IRI occurs via inflammation‐independent mechanisms in vivo. Furthermore, we found that renal TCs could not directly promote the proliferation and anti‐apoptosis properties of TECs in vitro. TCs did not display any advantage in paracrine growth factor secretion in vitro compared with renal fibroblasts. These data indicate that renal TCs protect against renal IRI via an inflammation‐independent pathway and that growth factors play a significant role in this mechanism. Renal TCs may protect TECs in certain microenvironments while interacting with other cells.     

Meta-Analysis of Flowering-Related Traits and Mining of Candidate Genes in Maize

Maize flowering is an important agronomic character, which is controlled by quantitative trait loci (QTL). Over the years, a large number of flowering-related QTL have been found in maize and exist in public databases. However, combining these data, re-analyzing and mining candidate loci and fine mapping of flowering-related traits to reduce confidence intervals has become a hot issue in maize. In this study, the QTL of 6 important agronomic traits of maize flowering were collected from 15 published articles, including flowering period (DA), Days to tasseling (DTT), Days to silking (DS), Days to pollen shedding (DTP), anthesis-silking interval (ASI) and the photosensitive (PS). Through meta-analysis, 622 QTL were integrated into 26 meta-QTLs (MQTL). Finally, the candidate genes related to maize flowering (Gene IDs: ZM00001D005791, ZM00001D019045, ZM00001D050697, ZM00001D011139) were identified by Gene Ontology (GO) enrichment and hierarchical cluster analysis of expression profile. Based on the results of this study, the genetic characteristics of maize flowering traits will be further analyzed, which is of great significance to guide the improvement of important agronomic characters and improve the efficiency of breeding.     

A new method for classifying different phenotypes of kidney transplantation

For end-stage renal diseases, kidney transplantation is the most efficient treatment. However, the unexpected rejection caused by inflammation usually leads to allograft failure. Thus, a systems-level characterization of inflammation factors can provide potentially diagnostic biomarkers for predicting renal allograft rejection. Serum of kidney transplant patients with different immune status were collected and classified as transplant patients with stable renal function (ST), impaired renal function with negative biopsy pathology (UNST), acute rejection (AR), and chronic rejection (CR). The expression profiles of 40 inflammatory proteins were measured by quantitative protein microarrays and reduced to a lower dimensional space by the partial least squares (PLS) model. The determined principal components (PCs) were then trained by the support vector machines (SVMs) algorithm for classifying different phenotypes of kidney transplantation. There were 30, 16, and 13 inflammation proteins that showed statistically significant differences between CR and ST, CR and AR, and CR and UNST patients. Further analysis revealed a protein-protein interaction (PPI) network among 33 inflammatory proteins and proposed a potential role of intracellular adhesion molecule-1 (ICAM-1) in CR. Based on the network analysis and protein expression information, two PCs were determined as the major contributors and trained by the PLS-SVMs method, with a promising accuracy of 77.5 % for classification of chronic rejection after kidney transplantation. For convenience, we also developed software packages of GPS-CKT (Classification phenotype of Kidney Transplantation Predictor) for classifying phenotypes. By confirming a strong correlation between inflammation and kidney transplantation, our results suggested that the network biomarker but not single factors can potentially classify different phenotypes in kidney transplantation.     

Synthesis,binding ability,and cell cytotoxicity of fluorescent probes for l‐arginine detection based on naphthalene derivatives: Experiment and theory

Inspired by biological related parts, Schiff base derivatives and functional groups of chemical modification can provide efficient detection method of amino acids. Therefore, we have designed and prepared 4 compounds based on Schiff base derivatives involving ─NO₂, ─OH, and naphthyl group. Results indicated that compound 4 containing 2 nitro groups showed strong sensitivity and high selectivity for arginine (Arg) among normal 18 kinds of standard amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, and cysteine). Theoretical investigation also approved the strong binding ability of compound 4 for Arg. In addition, compound 4 displayed high combining ability of Arg and low cytotoxicity of MCF‐7 cell in the 0 to 150 μg mL^?1 of concentration range; it can be used for Arg in vivo detection of fluorescent probe.     

Geranylgeranyl pyrophosphate-mediated protein geranylgeranylation regulates endothelial cell proliferation and apoptosis during vasculogenesis in mouse embryo

Vascular development is essential for the establishment of the circulatory system during embryonic development and requires the proliferation of endothelial cells. However, the underpinning regulatory mechanisms are not well understood. Here, we report that geranylgeranyl pyrophosphate(GGPP), a metabolite involved in protein geranylgeranylation, plays an indispensable role in embryonic vascular development. GGPP is synthesized by geranylgeranyl pyrophosphate synthase(GGPPS) in the mevalonate pathway. The selective knockout of Ggpps in endothelial cells led to aberrant vascular development and embryonic lethality, resulting from the decreased proliferation and enhanced apoptosis of endothelial cells during vasculogenesis. The defect in protein geranylgeranylation induced by GGPP depletion inhibited the membrane localization of Rho A and enhanced yes-associated protein(YAP) phosphorylation, thereby prohibiting the entry of YAP into the nucleus and the expression of YAP target genes related to cell proliferation and the antiapoptosis process. Moreover, inhibition of the mevalonate pathway by simvastatin induced endothelial cell proliferation defects and apoptosis, which were ameliorated by GGPP. Geranylgeraniol(GGOH), a precursor of GGPP, ameliorated the harmful effects of simvastatin on vascular development of developing fetuses in pregnant mice. These results indicate that GGPP-mediated protein geranylgeranylation is essential for endothelial cell proliferation and the antiapoptosis process during embryonic vascular development.     

Methylcap-seq reveals novel DNA methylation markers for the diagnosis and recurrence prediction of bladder cancer in a Chinese population

Purpose

There is a need to supplement or supplant the conventional diagnostic tools, namely, cystoscopy and B-type ultrasound, for bladder cancer (BC). We aimed to identify novel DNA methylation markers for BC through genome-wide profiling of BC cell lines and subsequent methylation-specific PCR (MSP) screening of clinical urine samples.

Experimental Design

The methyl-DNA binding domain (MBD) capture technique, methylCap/seq, was performed to screen for specific hypermethylated CpG islands in two BC cell lines (5637 and T24). The top one hundred hypermethylated targets were sequentially screened by MSP in urine samples to gradually narrow the target number and optimize the composition of the diagnostic panel. The diagnostic performance of the obtained panel was evaluated in different clinical scenarios.

Results

A total of 1,627 hypermethylated promoter targets in the BC cell lines was identified by Illumina sequencing. The top 104 hypermethylated targets were reduced to eight genes (VAX1, KCNV1, ECEL1, TMEM26, TAL1, PROX1, SLC6A20, and LMX1A) after the urine DNA screening in a small sample size of 8 normal control and 18 BC subjects. Validation in an independent sample of 212 BC patients enabled the optimization of five methylation targets, including VAX1, KCNV1, TAL1, PPOX1, and CFTR, which was obtained in our previous study, for BC diagnosis with a sensitivity and specificity of 88.68% and 87.25%, respectively. In addition, the methylation of VAX1 and LMX1A was found to be associated with BC recurrence.

Conclusions

We identified a promising diagnostic marker panel for early non-invasive detection and subsequent BC surveillance.     

Docosahexaenoic Acid Alleviates Oxidative Stress-Based Apoptosis Via Improving Mitochondrial Dynamics in Early Brain Injury After Subarachnoid Hemorrhage

Mitochondrial dysfunction is considered a crucial therapeutic target for early brain injury following subarachnoid hemorrhage (SAH). Emerging evidence indicates that docosahexaenoic acid (DHA), an essential omega-3 fatty acid, protects mitochondria in various chronic diseases. This study aimed to investigate the neuroprotective effects of DHA on mitochondrial dynamic dysfunction after EBI using in vivo and in vitro approaches. For in vivo experiments, the rat endovascular perforation SAH model was performed, whereby DHA was administered intravenously 1 h after induction of SAH. Primary cultured neurons treated with oxyhemoglobin (OxyHb) for 24 h were used to mimic SAH in vitro. Our results demonstrated that DHA improved neurological deficits and reduced brain edema in rats with SAH, and attenuated OxyHb-induced neuronal death in primary cultured cells. DHA reduced the amount of reactive oxygen species-positive cells and improved cell viability when compared to the SAH?+?vehicle group in vitro. DHA attenuated malondialdehyde levels and superoxide dismutase stress, increased Bcl2 and Bcl-xl, and decreased Bax and cleaved caspase-3 in vivo. Additionally, DHA ameliorated mitochondrial dysfunction, upregulated the mitochondrial fusion-related protein Optic Atrophy 1, and downregulated the mitochondrial fission-related protein Dynamin-Related-Protein 1 (Drp1) and Serine 616 phosphorylated Drp1 after SAH both in vitro and in vivo. Taken together, our current study demonstrates that DHA might prevent oxidative stress-based apoptosis after SAH. The characterization of the underlying molecular mechanisms may further improve mitochondrial dynamics-related signaling pathways.