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Mitochondrial dysfunction in proximal tubular epithelial cells is a key event in acute kidney injury (AKI), which is a risk factor for the development of chronic kidney disease (CKD). Apelin is a bioactive peptide that protects against AKI by alleviating inflammation, inhibiting apoptosis, and preventing lipid oxidation, but its role in protecting against mitochondrial damage remains unknown. Herein, we examined the protective effects of apelin on mitochondria in cisplatin-stimulated human renal proximal tubular epithelial cells and evaluated its therapeutic efficacy in cisplatin-induced AKI mice. In vitro, apelin inhibited the cisplatin-induced mitochondrial fission factor (MFF) upregulation and the fusion-promoting protein optic atrophy 1 (OPA1) downregulation. Apelin co-treatment reversed the decreased levels of the deacetylase, Sirt3, and the increased levels of protein acetylation in mitochondria of cisplatin-stimulated cells. Overall, apelin improved the mitochondrial morphology and membrane potential in vitro. In the AKI model, apelin administration significantly attenuated mitochondrial damage, as evidenced by longer mitochondrial profiles and increased ATP levels in the renal cortex. Suppression of MFF expression, and maintenance of Sirt3 and OPA1 expression in apelin-treated AKI mice was also observed. Finally, exogenous administration of apelin normalized the serum level of creatinine and urea nitrogen and the urine levels of NGAL and Kim-1. We also confirmed a regulatory pathway that drives mitochondrial homeostasis including PGC-1α, ERRα and Sirt3. In conclusion, we demonstrated that apelin ameliorates renal functions by protecting tubular mitochondria through Sirt3 upregulation, which is a novel protective mechanism of apelin in AKI. These results suggest that apelin has potential renoprotective effects and may be an effective agent for AKI treatment to significantly retard CKD progression.

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is associated with vascular dysfunction. The polypeptide apelin mediates two major actions on blood vessels. However, their combined effects on vascular function are not fully understood. The present study aimed to determine the effect of apelin-13 on myosin light chain (MLC) phosphorylation in vascular smooth muscle cells (VSMCs) under ADMA-induced endothelial leakage conditions. To assess the increased permeability induced by ADMA, human umbilical vein endothelium cells (HUVECs) were plated in transwell dishes. The FITC-dextran flux and FITC-apelin-13 flux through the endothelial monolayer were measured. To examine the effect of leakage of apelin-13 on MLC phosphorylation in HUVSMCs, transwell dishes were used to establish a coculture system with HUVECs in upper chambers and HUVSMCs in lower chambers. Western blot was performed to assess the phospho-MLC levels. ADMA increased endothelial permeability in a concentration- and time-dependent manner, accompanied by actin stress fiber assembly and intercellular gap formation. When HUVECs were treated with ADMA, the permeability to both macromolecular dextran and micromolecular apelin-13 increased significantly. Both p38 MAPK inhibitor and NADPH oxidase inhibitor could prevent HUVECs from the increased permeability, and the changes of cytoskeleton and intercellular junction, which were induced by ADMA. Apelin-13 passed through the ADMA-stimulated endothelial monolayer and increased the expression of phospho-MLC in VSMCs. These results suggest that ADMA increases endothelial permeability, which may involve the p38 MAPK and NADPH oxidase pathway. Apelin-13 can pass through the damaged endothelial barrier, and acts directly on VSMCs to increase MLC phosphorylation.

Information on systematic analysis of olfactory memory-related proteins is poor. In this study, the odor discrimination task to investigate olfactory recognition memory of adult male C57BL/6J mice was used. Subsequently, olfactory bulbs (OBs) were taken, proteins extracted, and run on two-dimensional gel electrophoresis with in-gel-protein digestion, followed by mass spectrometry and quantification of differentially expressed proteins. Dual specificity mitogen-activated protein kinase kinase 1 (MEK1), dihydropyrimidinase-related protein 1 (DRP1), and fascin are related with Lemon odor memory. Microtubule-associated protein RP/EB family member 3 is related to Rose odor memory. Hypoxanthine-guanine phosphoribosyltransferase is related with both Lemon and Rose odors memory. MEK1 and DRP1 levels were increased, while microtubule-associated protein RP/EB family member 3, fascin and hypoxanthine-guanine phosphoribosyltransferase levels were decreased during olfactory memory. In summary, neurogenesis, signal transduction, cytoskeleton, and nucleotide metabolism are involved in olfactory memory formation and storage of C57BL/6J mice.

Epidermal growth factor receptor (EGFR) is imptortant for cell activities, oncogenesis and cell migration, and EGFR inhibitor can treat cancer efficiently, but its side effects, for example, in skin, limited its usage. On the other hand, EGFR interacting proteins may also lead to oncogenesis and its interacting protein as drug targets can avoid cutaneous side effect, which implies possibly a better outcome and life quality of cancer patients. For the multiple EGFR interaction proteins, B1R enhances Erk/MAPK signaling, while PTPN12, Kek1, CEACAM1 and NHERF repress Erk/MAPK signaling. CaM may alter charge of EGFR juxamembrane domain and regulate activation of PI3K/Akt and PLC-gamma/PKC. STAT1, STAT5b are widely thought to be activated by EGFR, while there is unexpectedly inhibiting sequence within EGFR to repress the activity of STATs. LRIG1 and ACK1 enhance the internalization and degration of EGFR, while NHERF and HIP1 repress it. In this article, proteins interacting with EGFR, their interacting sites and their regulation on EGFR signal transduction will be reviewed.

Sensitive and specific biomarkers for identifying early stage of non-small cell lung cancer (NSCLC) are urgently needed to improve the therapeutic outcome and reduce the mortality. Small non-coding microRNAs (miRNAs) are key components of cancer development and are considered as potential biomarkers for cancer diagnosis and for monitoring treatment. The aim of this study was to determine whether aberrant miRNA expression can be used as a marker in peripheral blood mononuclear cells (PBMC) for the diagnosis of NSCLC.The levels of two mature miRNAs (miR-143 and miR-150) were detected by probe-based stem-loop quantitative reverse-transcriptase PCR (RT-qPCR) in PBMC of 64 patients with NSCLC and 26 healthy individuals, and the relationship between miR-143 and miR-150 levels and clinical and pathological factors was explored.All endogenous miRNAs were present in peripheral blood in a remarkably stable form and detected by RT-qPCR. MiR-143 expression in the PBMC specimens was significantly lower in NSCLC patients than in healthy individuals (P0.0001). MiR-150 expression in the PBMC specimens was not significantly different between NSCLC patients and healthy individuals (P = 0.260). MiR-150 expression was significantly higher in lung adenocarcinoma patients than in healthy individuals (P = 0.001). There was a very strong difference in the expression level of miR-150 between lung adenocarcinoma patients and lung squamous cell carcinoma patients (P0.0001). In receiver operating characteristic curve (ROC) analysis, low expression of miR-143 showed the area under the ROC (AUC) of 0.885 for distinguishing cancer patients from healthy subjects. High expression of miR-150 had an AUC of 0.834 for distinguishing lung adenocarcinoma patients from healthy subjects. High expression of miR-150 had an AUC of 0.951 for distinguishing lung adenocarcinoma from lung squamous cell carcinoma. The miR-150 level was significantly associated with distant metastasis (P = 0.014).It is indicated that there is a potential for using miR-143 as a novel diagnostic biomarker for NSCLC. Moreover, miR-150 can be a highly accurate marker for differentiating adenocarcinoma from squamous cell carcinoma.

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is considered to be an independent risk factor in the progression of chronic kidney diseases (CKD). It can induce kidney fibrosis by increasing transforming growth factor (TGF)-β1 expression, but its molecular mechanism is unclear. The aim of the present study was to investigate the role of actin cytoskeleton in ADMA-induced TGF-β1 high expression in human renal glomerular endothelial cells (HRGECs). The structure of stress fibers was visualized by immunofluorescence, nuclear factor-κB (NF-κB) DNA-binding activity was assessed by an electrophoretic mobility shift assay and TGF-β1 expression was assessed by western blot analysis. Results showed that ADMA induced the assembly of stress fibers, DNA binding of NF-κB, and increasing expression of TGF-β1. When the dynamics of actin cytoskeleton was perturbed by the actin-depolymerizing agent cytochalasin D and the actin-stabilizing agent jasplakinolide, or ablation of stress fiber bundles by the nicotineamide adenine dinucleotide phosphate oxidase inhibitor apocynin and p38 mitogen-activated protein kinase inhibitor SB203580, ADMA-induced DNA binding of NF-κB and TGF-β1 expression were inhibited. These results revealed an actin cytoskeleton-dependent mechanism in ADMA-induced NF-κB activation and TGF-β1 high expression in HRGECs. The specific targeting of the actin cytoskeleton may be a useful strategy to prevent ADMA-activated kidney fibrosis in CKD.

Studying fear extinction is a major topic in neuroscience. No information on systematic studies on the linkage of contextual fear conditioning (cFC) with hippocampal protein levels is available and we were therefore interested in protein differences between animals with poor and good extinction. cFC was carried out in C57BL/6J mice, hippocampi were taken and proteins were run on two-dimensional gel electrophoresis with subsequent quantification of protein spots. In-gel digestion with trypsin and identification by ion trap MS/MS (high-capacity ion trap) was used for the identification of significantly different hippocampal proteins between mice with good and poor performance of extinction. Signaling protein ras-related protein rab-7A and septin 8 levels were significantly higher in hippocampus of poor extinguishers, whereas ubiquitin carboxyterminal hydrolase isozyme L1 showed higher levels in animals with good extinction performance. A series of additional proteins showed significantly different levels between groups but the abovementioned were confirmed by immunoblotting. The abovementioned proteins have never been reported to be linked to extinction, memory, or learning and herein evidence for the involvement of several proteins in extinction mechanism as well as probably representing pharmaceutical targets is provided. Moreover, it is intriguing to demonstrate the differences between good and poor extinction performance at the protein level.

The Multiple T-maze (MTM) and the Barnes maze (BM) are land mazes used for the evaluation of spatial memory. The observation that mice are performing differently in individual mazes made us test the hypothesis that differences in cognitive performances in the two land mazes would be accompanied by differences in hippocampal protein levels. C57BL/6J mice were tested in the BM and in the MTM, hippocampi were extirpated 6 h following the probe trials each, and proteins were extracted for gel-based proteomic analysis. Mice learned the task in both paradigms. Levels of hippocampal proteins from several pathways including signaling, chaperone, and metabolic cascades were significantly different between the two spatial memory tasks. Protein levels were linked to spatial memory specifically as yoked controls were used.

Previous research reveals that the genome structures of rhizobial type strains and reference strains can reflect their phylogenetic relationships. In order to further explore the potential application of genome structure as a phylogenetic marker in rhizobial natural taxonomy, this study analyzed the genome structures of 29 unclassified nodule bacteria isolated from the root nodules of leguminous trees, Robinia sp., Dalbergia spp., and A lbizia spp. and 7 rhizobial reference strains by I-CeuI cleavage, then clustered these bacteria phylogenetically based on their genome structures and compared these clusters with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Eleven phylogenetic clusters were obtained. The clusters were in large part consistent with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Also there are inconsistent clusters based on the above three methods. But results are completely consistent with 16S rRNA clusters. This suggested that the genome structure clustering method can be used to fastly identify root nodule isolates and detect their phylogenetic relationships. The credibility and repeatability of the results, together with the simplicity and possibility to analyze a large number of strains in a short time of the method, indicates the broad potential application of genome structure as phylogenetic marker to categorize rhizobial isolates and should in the future facilitate biodiversity studies.