The plastid-encoded protein Orf2971 is required for protein translocation and chloroplast quality control.

Photosynthesis and the biosynthesis of many important metabolites occur in chloroplasts. In these semi-autonomous organelles, the chloroplast genome encodes approximately 100 proteins. The remaining chloroplast proteins, close to 3,000, are encoded by nuclear genes whose products are translated in the cytosol and imported into chloroplasts. However, there is still no consensus on the composition of the protein import machinery including its motor proteins and on how newly imported chloroplast proteins are refolded. In this study, we have examined the function of orf2971, the largest chloroplast gene of Chlamydomonas reinhardtii. The depletion of Orf2971 causes the accumulation of protein precursors, partial proteolysis and aggregation of proteins, increased expression of chaperones and proteases, and autophagy. Orf2971 interacts with the TIC (translocon at the inner chloroplast envelope) complex, catalyzes ATP (adenosine triphosphate) hydrolysis, and associates with chaperones and chaperonins. We propose that Orf2971 is intimately connected to the protein import machinery and plays an important role in chloroplast protein quality control.

Loss of EphA7 Expression in Basal Cell Carcinoma by Hypermethylation of CpG Islands in the Promoter Region.

Basal cell carcinoma (BCC) is the most common malignancy worldwide, with increasing incidence. BCCs present low mortality but high morbidity, and its pathogenesis remains unclear. Eph receptors have been implicated in tumorigenesis. EphA7 plays a role as a tumor suppressor in certain cancers. We checked EphA7 expression levels and methylation status in a set of BCCs, benign skin diseases, and compound nevus tissue samples using immunohistochemistry. EphA7 protein was positively expressed in normal basal cells, benign skin diseases, and compound nevus cells, but lost in areas of BCC tissues. We detected hypermethylation in BCC tissue samples with reduced expression of EphA7. There is a significant relationship between the expression level of EphA7 receptor protein and the methylation status of CpG islands in the EphA7 promoter region (P < 0.001). To our knowledge, this is the first study to report the EphA7 expression profile and hypermethylation of EphA7 in BCC. The role of the EphA7 gene and the status of hypermethylation in tumorigenesis and treatment of BCC warrant further investigation.

The Effects of Sidt2 on the Inflammatory Pathway in Mouse Mesangial Cells.

In patients with chronic kidney disease, the abnormal activation of inflammatory pathways is usually an important factor leading to renal fibrosis and further deterioration of renal function. Finding effective intervention targets of the inflammatory signaling pathway is an important way to treat chronic kidney disease. As a newly discovered lysosomal membrane protein, the correlation between SID1 transmembrane family member 2 (Sidt2) and the inflammatory signaling pathway has not been reported. The aim of this study was to investigate the effect of Sidt2 on inflammation by inhibiting the expression of the Sidt2 gene in a mouse mesangial cell line mediated by a lentiviral CRISPR/Cas9 vector. Hematoxylin and eosin staining and microscopy found that the mesangial cells lost their normal morphology after inhibiting the expression of Sidt2, showing that the cell body became smaller, the edge between the cells was unclear, and part of the nucleus was pyknotic and fragmented, appearing blue-black. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the NF-κB pathway of the Sidt2 -/- group were higher than those of the Sidt2 +/+ group. p-Jak2 and IL6 increased in the Jak/Stat pathway, and p-ERK and p-P38 increased in the MAPK pathway. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the NF-κB pathway of the Sidt2 +/++LPS group were significantly higher than those in the Sidt2 +/+ group. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. In the Jak/Stat pathway, the protein expressions of p-Jak2 and IL6 in the Sidt2 +/++LPS group were higher than those in the Sidt2 +/+ group. The expressions of p-Jak2 and IL6 in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-Jak2 and IL6 in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the MAPK pathway in the Sidt2 +/++LPS group were higher than those in the Sidt2 +/+ group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. These data suggested that deletion of the Sidt2 gene changed the three inflammatory signal pathways, eventually leading to the damage of glomerular mesangial cells in mice.

Variation in arsenic accumulation and translocation among 74 main rice cultivars in Jiangsu Province, China.

Arsenic (As) is a ubiquitous carcinogen and environmental toxin. In China, rice consumption is a major dietary source of inorganic As. Thus, the development of strategies to decrease As accumulation in rice is of considerable importance. In this study, we investigated variation in As accumulation and translocation among 74 hydroponically grown rice cultivars in Jiangsu Province, China. We also examined the relationships between As accumulation and translocation, and the uptake of elements such as silicon (Si), phosphorus (P), iron (Fe), and manganese (Mn). Our results showed 3.43-, 2.7-, and 6.34-fold variations in shoot As concentration, root As concentration, and root-to-shoot As translocation factors (TFs), respectively, among 74 cultivars, indicating that cultivar genotype significantly affected As accumulation and translocation. Redundancy analysis revealed that As uptake and transport were more closely related to P and Mn uptake than to Si and Fe uptake, for all 74 rice genotypes. In addition, the 20 cultivars that accumulated the least shoot As (low-As), and those that accumulated the most shoot As (high-As), exhibited different strategies in response to As exposure. The As TFs were key factors influencing shoot As concentrations in high-As cultivars, but this was not the case in low-As cultivars. In the latter, more accumulated As were sequestered in roots, which restricted As translocation to shoots, thus leading to lower shoot As concentrations. In addition, the shoot As concentrations of various rice cultivars and their parents differed. The low-As rice cultivar YJ2 exhibited a significantly lower shoot As concentration than its parents, suggesting that it is possible to breed low-As rice cultivars from parents that also exhibit low-As characteristics.

Genotypic Variation in Nickel Accumulation and Translocation and Its Relationships with Silicon, Phosphorus, Iron, and Manganese among 72 Major Rice Cultivars from Jiangsu Province, China.

Nickel (Ni) is a ubiquitous environmental toxicant and carcinogen, and rice is a major dietary source of Ni for the Chinese population. Recently, strategies to decrease Ni accumulation in rice have received considerable attention. This study investigated the variation in Ni accumulation and translocation, and also multi-element (silicon (Si), phosphorus (P), iron (Fe), and manganese (Mn)) uptake and transport among 72 rice cultivars from Jiangsu Province, China, that were grown under hydroponic conditions. Our results showed a 2.2-, 4.2-, and 5.3-fold variation in shoot Ni concentrations, root Ni concentrations, and translocation factors (TFs) among cultivars, respectively. This suggests that Ni accumulation and translocation are significantly influenced by the genotypes of the different rice cultivars. Redundancy analysis of the 72 cultivars revealed that the uptake and transport of Ni were more similar to those of Si and Fe than to those of P and Mn. The Ni TFs of high-Ni cultivars were significantly greater than those of low-Ni cultivars (p < 0.001). However, there were no significant differences in root Ni concentrations of low-Ni and high-Ni cultivars, suggesting that high-Ni cultivars could translocate Ni to shoots more effectively than low-Ni cultivars. In addition, the cultivars HD8 and YD8 exhibited significantly lower levels of Ni accumulation than their parents (p < 0.05). Our results suggest that breeding can be an effective strategy for mitigating excessive Ni accumulation in rice grown in Ni-contaminated environments.

Radiofrequency ablation combined with esophageal stent in the treatment of malignant esophageal stenosis: A single-center prospective study.

The purpose of this study was to investigate the efficacy of radiofrequency ablation (RFA) combined with esophageal stent in treating malignant esophageal stenosis. Seventy patients with malignant esophageal obstruction treated in Department of Gastroenterology from April 2013 to April 2015 in China-Japan Union Hospital of Jilin University were enrolled. They were randomly assigned into the treatment group (radiofrequency ablation combined with esophageal stent) and control group (esophageal stent). To observe the degree of dysphagia, esophageal stenosis diameter, readmission time, adverse events and complications. There was no significant differences in dysphagia and esophageal diameter between the treatment group and the control group within 1-3 months after operation (P>0.05), and the degree of dysphagia and esophageal diameter in the treatment group at postoperative 6 months were better than those in the control group (P=0.018 and 0.038, respectively). The readmission time of the treatment group was also better than that of the control group (P=0.021). The adverse events and complications included hemorrhage, perforation and esophageal stent displacement. No significant differences in adverse events and complications between the treatment group and the control group were observed. All patients were successfully treated during hospitalization. Effect of radiofrequency ablation combined with esophageal stent implantation was better than esophageal stent implantation in the treatment of malignant esophageal stenosis, but it had no effect on the survival time.

MiR-22-3p Regulates Cell Proliferation and Inhibits Cell Apoptosis through Targeting the eIF4EBP3 Gene in Human Cervical Squamous Carcinoma Cells.

Background: MicroRNAs (miRNAs) are non-coding small RNAs that function as negative regulators of gene expression and are involved in tumour biology. The eIF4E-binding proteins (eIF4EBPs) play essential roles in preventing translation initiation and inhibiting protein synthesis at a global or message-specific level in a variety of tumours. Methods: According to comparative miRNA profiles of clinical cervical cancer and non-cancerous cervical tissue specimens, several miRNAs were aberrantly expressed in the cervical cancer samples. C33a and SiHa cell proliferation and apoptosis were detected using methyl thiazolyl tetrazolium (MTT) and flow cytometry assays, respectively. Results: Among the aberrantly expressed miRNAs, miR-22-3p was significantly differentially expressed in cervical cancer tissues and was highly associated with cervical cancer cell growth regulation. In addition, bioinformatic predictions and experimental validation were used to identify whether eIF4E-binding protein 3 (eIF4EBP3) was a direct target of miR-22-3p; eIF4EBP3 protein levels were generally low in the cervical cancer tissues. Furthermore, functional studies revealed that either a miR-22-3p inhibitor or eIF4EBP3 overexpression could induce apoptosis in cervical cancer cells in vitro. Importantly, we found that eIF4EBP3 accumulation could significantly attenuate cervical cancer cell proliferation triggered by a miR-22-3p mimic as well as enhance apoptosis in cervical cancer cells. Conclusion: Taken together, our data provide primary proof that miR-22-3p can induce cervical cancer cell growth at least in part by up-regulating its expression to decrease eIF4EBP3 expression levels; miR-22-3p thus holds promise as a prognostic biomarker and potential therapeutic target for treating cervical cancer.

The role of the globular heads of the C1q receptor in paclitaxel-induced human ovarian cancer cells apoptosis by a mitochondria-dependent pathway.

As a mitochondrial membrane protein, globular C1q receptor (gC1qR) can mediate a variety of biological responses. Our study aims to investigate the role of gC1qR in paclitaxel-induced apoptosis of human ovarian cancer cells and to elucidate its potential molecular mechanism. The level of gC1qR was examined using real-time PCR and western blot analyses. Human ovarian cancer cells viability, migration, and proliferation were detected using the water-soluble tetrazolium salt (WST-1) assay, the transwell assay, and H-thymidine incorporation into DNA (H-TdR) assay, respectively. Apoptosis in cells was assessed using flow cytometric analysis. The intracellular reactive oxygen species was estimated by the fluorescence of H2DCFDA and the mitochondrial membrane potential was tested using a JC-1 probe. The expression of the gC1qR gene decreased significantly in human ovarian cancer tissues relative to the surrounding non-neoplastic ovarian tissues. Cells treated with paclitaxel showed increased gC1qR gene expression, cell apoptosis, and mitochondria dysfunction, and the effects on these cells could be abrogated by the addition of gC1qR small-interfering RNA or α-lipoic acid that was used to protect the mitochondria function. In summary, these data support a mechanism that gC1qR-induced mitochondria dysfunction was involved in the paclitaxel-mediated apoptosis of ovarian cancer cells.