Low testosterone state inhibits erectile function by downregulating the expression of GIT1 in rat penile corpus cavernosum.

Background: The mechanism of erectile dysfunction (ED) caused by a low androgen level is still not clear. Aim: To explore the influence of the low testosterone state on G protein-coupled receptor kinase interactor 1 (GIT1) and its contact to erectile function. Methods: Thirty male Sprague-Dawley rats aged 8 weeks were distributed at random into 5 groups: control (sham operated), castration, testosterone supplement after castration, castration + vacant lentiviral transfection, and castration + lentiviral transfection. The testis and epididymis were removed through a scrotal incision to develop castrated rats. Four weeks after castration, a lentivirus carrying the GIT1 gene was injected into the middle of rat penile corpus cavernosum. One week after transfection, maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP), serum testosterone, nitric oxide, GIT1, endothelial nitric oxide synthase (eNOS), phospho-eNOS (p-eNOS), p-eNOS/eNOS, and the interaction between eNOS and GIT1 were assessed in the rats. Outcomes: The levels of GIT1 in the penile cavernous tissue of castrated rats are significantly lower than that of controls. Results: GIT1 was expressed in the cytoplasm and cell membrane of vascular endothelial cells and smooth muscle cells in rat penile tissue. In comparison with normal rats, the castrated rats showed lower levels of GIT1 expression, GIT1 and eNOS interaction, p-eNOS/eNOS, nitric oxide, and ICPmax/MAP (P < .01). Overexpression of GIT1 can intensively enhance the expression level of GIT1, the interaction between GIT1 and eNOS, p-eNOS/eNOS, nitric oxide, and ICPmax/MAP in rats (P < .01). Clinical Translation: Modulating the interaction between eNOS and GIT1 might be a novel method of treating ED caused by a low androgen level. Strengths and Limitations: The impact of GIT1 phosphorylation on the activity of eNOS and its possible mechanisms affecting erectile function require further study. Conclusion: A low testosterone state inhibits erectile function in rats by reducing the expression of GIT1 and the protein interaction between GIT1 and eNOS.

Homogeneous preparation of water-soluble products from chitin under alkaline conditions and their cell proliferation in vitro.

The purpose of this study was to prepare water-soluble products by homogeneous depolymerization of chitin with H2O2 under alkaline conditions and investigate their potential application in wound healing. For the first time, water-soluble products were successfully prepared using a chitin-NaOH/urea solution; the products were chitosans with molecular weights (Mw) of 3.48-33.5 kDa and degrees of deacetylation (DD) > 0.5. Their Mw, DD and yield were affected by the reaction temperature, reaction time, concentration of H2O2 and chitin DD. The deacetylation and depolymerization of chitin were achieved simultaneously. The depolymerization of chitin was caused by hydrogen abstraction of HO, whereas the deacetylation resulted from the cleavage of amide bonds by HO- and HO2-, although the latter played a more important role. All water-soluble chitosans markedly promoted the proliferation of human skin fibroblast (HSF) cells, but they inhibited the proliferation of human keratinocyte cells. For the proliferation of HSF, a low concentration of chitosans was important. In addition, water-soluble chitosans with an Mw of 3.48-16.4 kDa markedly stimulated the expression of growth factors such as PDGF and TGF-ß by macrophages. Water-soluble chitosans could be used as a potential active component in wound dressings.

Colorectal cancer cell-derived exosomes containing miR-10b regulate fibroblast cells via the PI3K/Akt pathway.

BACKGROUND: Cancer-associated fibroblasts (CAFs) contribute to the proliferation of colorectal cancer(CRC) cells. However, the mechanism by which CAFs develop in the tumor microenvironment remains unknown. Exosomes may be involved in activating CAFs. METHODS: Using a miRNA expression profiling array, we determined the miRNA expression profile of secretory exosomes in CRC cells and then identified potential miRNAs with significant differential expression compared to normal cells via enrichment analysis. Predicted targets of candidate miRNAs were then assessed via bioinformatics analysis. Realtime qPCR, western blot, and cell cycle analyses were performed to evaluate the role of candidate exosomal miRNAs. Luciferase reporter assays were applied to confirm whether candidate exosomal miRNAs control target pathway expression. A CRC xenograft mouse model was constructed to evaluate tumor growth in vivo. RESULTS: Exosomes from CRC cells contained significantly higher levels of miR-10b than did exosomes from normal colorectal epithelial cells. Moreover, exosomes containing miR-10b were transferred to fibroblasts. Bioinformatics analysis identified PIK3CA, as a potential target of miR-10b. Luciferase reporter assays confirmed that miR-10b directly inhibited PIK3CA expression. Co-culturing fibroblasts with exosomes containing miR-10b significantly suppressed PIK3CA expression and decreased PI3K/Akt/mTOR pathway activity. Finally, exosomes containing miR-10b reduced fibroblast proliferation but promoted expression of TGF-ß and SM α-actin, suggesting that exosomal miR-10b may activate fibroblasts to become CAFs that express myofibroblast markers. These activated fibroblasts were able to promote CRC growth in vitro and in vivo. CONCLUSION: CRC-derived exosomes actively promote disease progression by modulating surrounding stromal cells, which subsequently acquire features of CAFs.

Downregulation of Annexin A11 (ANXA11) Inhibits Cell Proliferation, Invasion, and Migration via the AKT/GSK-3ß Pathway in Gastric Cancer.

BACKGROUND Gastric cancer (GC) is one of the most common malignant tumors in the world and in China the incidence and mortality rates of gastric cancer are the second highest among all forms of cancer. Annexin A11 (ANXA11) is a member of the annexins family. Previous studies have shown that ANXA11 participates in many cellular functions and has significant influence on ovarian, breast, liver, and colorectal cancer. However, the expression and biological functions of ANXA11 in GC are still unknown. MATERIAL AND METHODS A total of 63 paired gastric cancer tissues and matched adjacent mucosa were used to measure the ANXA11 levels and its correlation with clinical characteristics. We carried out the biological functions and underlying mechanism study using SGC-7901and AGS cell lines. RESULTS The expression of ANXA11 in cancer tissues was higher than in adjacent mucosa at mRNA and protein levels. In clinicopathological analysis, we found that increased expression of ANXA11 was significantly associated with tumor size, tumor infiltration, local lymph node metastasis, TNM staging, and vascular invasion. Small interfering RNA (siRNA) silencing of ANXA11 inhibits cell proliferation, colony formation, migration, and invasion through the AKT/GSK-3ß pathway. CONCLUSIONS ANXA11 plays a critical role in regulating GC proliferation, migration, and invasion via the AKT/GSK-3ß pathway, and can potentially be used as a prognostic factor and therapeutic target for gastric cancer patients.

Identification of aberrantly expressed long non-coding RNAs in stomach adenocarcinoma.

AIM: Stomach adenocarcinoma (STAD) is a common malignancy worldwide. This study aimed to identify the aberrantly expressed long non-coding RNAs (lncRNAs) in STAD. RESULTS: Total of 74 DElncRNAs and 449 DEmRNAs were identified in STAD compared with paired non-tumor tissues. The DElncRNA/DEmRNA co-expression network was constructed, which covered 519 nodes and 2993 edges. The qRT-PCR validation results of DElncRNAs were consistent with our bioinformatics analysis based on RNA-sequencing. The DEmRNAs co-expressed with DElncRNAs were significantly enriched in gastric acid secretion, complement and coagulation cascades, pancreatic secretion, cytokine-cytokine receptor interaction and Jak-STAT signaling pathway. The expression levels of the nine candidate DElncRNAs in TCGA database were compatible with our RNA-sequencing. FEZF1-AS1, HOTAIR and LINC01234 had the potential diagnosis value for STAD. MATERIALS AND METHODS: The lncRNA and mRNA expression profile of 3 STAD tissues and 3 matched adjacent non-tumor tissues was obtained through high-throughput RNA-sequencing. Differentially expressed lncRNAs/mRNAs (DElncRNAs/DEmRNAs) were identified in STAD. DElncRNA/DEmRNA co-expression network construction, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to predict the biological functions of DElncRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was subjected to validate the expression levels of DEmRNAs and DElncRNAs. Moreover, the expression of DElncRNAs was validated through The Cancer Genome Atlas (TCGA) database. The diagnosis value of candidate DElncRNAs was accessed by receiver operating characteristic (ROC) analysis. CONCLUSIONS: Our work might provide useful information for exploring the tumorigenesis mechanism of STAD and pave the road for identification of diagnostic biomarkers in STAD.