[In vitro study on signal transduction in mice spiral ganglion cell stimulated by multi-wavelength laser based on calcium imaging]

Objective: To research the auditory nerve transduction effects under multi-wavelength pulsed laser stimulations within a safe and acceptable signal range. Methods: The real-time detection of intracellular calcium concentration was adopted by specific fluorescent indicator staining based on calcium imager. The spiral ganglion cells of mice were cultured in vitro. After fluorescent indicating, morphologic observation under optical microscope, Fura-2 calcium ion fluorescence excitation, intact morphology cells selection, fixing the optical fiber, the spiral ganglion cells were irradiated by different wavelength laser, including visible light (450 nm) and near infrared light (808 nm,1 065 nm). The intracellular calcium concentration was monitored by calcium ion imaging. Results: When 450 nm laser stimulated spiral ganglion cells, the intracellular calcium concentration was strongly increased, however, for other wavelength laser stimulation, there was no obvious relative response. And the sensitivity expression of the nerve cells under laser was related with the location of laser fiber. Cells closer to the fiber produced more obvious changes in calcium ion concentration, while for cells farther away from the fiber, the change amplitudes were weaker although the number of changes in calcium ion concentration was consistent. Conclusion: The spiral ganglion cells of mice can induce a signal transduction response under the action of laser, and the response has laser wavelength selectivity.

[Evaluation of the electrode position by CBCT following cochlear implantation]

Objective: To observe the position of the electrode in the cochlea following cochlear implantation by cone beam computed tomography (CBCT). Methods: Twenty-five children who received cochlear implantation and CBCT examinations in the Department of Otorhinolaryngology Head and Neck Surgery from the Second Hospital of Shandong University between January 2016 and December 2017 were selected. There were 15 males (17 ears) and 10 females (10 ears). The age ranged from 0.5 to 7.0 years old, with a median age of 1.6 years. 23 patients with unilateral implantation and two patients with bilateral implantation. The implants were all Med-El standard 12-electrode contact arrays. The CBCT was used to determine the position of the electrode in the cochlea, the distance between the electrode contacts and modiolus, and intracochlear insertion length of the electrode arrays. SPSS Statistics, version 22.0 was used for data processing and statistical analysis. Results: CBCT images could clearly demonstrate the structure of round window, oval window, modiolus, osseous cochlear duct, osseous spiral lamina, and electrodes. The electrode arrays of all the children were fully implanted into the cochlea. 26 of the electrode arrays were located in the scala tympani and one of them was inserted into the scala vestibular. The mean intracochlear insertion length of the electrode arrays was 30.23 (95%CI, 30.04-30.71) mm. The distance between the electrode contacts and modiolus gradually increased at the 1-4th electrode contacts and reached the maximum at the 4th electrode contacts with an average of 1.10 mm (95%CI, 1.02 to 1.18 mm), and then gradually decreased from the 5th electrode contacts. Conclusions: CBCT can clearly show cochlear fine structures and therefore accurately assess the electrode position following cochlear implantation.

Crosstalk between intestinal epithelial cell and adaptive immune cell in intestinal mucosal immunity

Constantly challenged by luminal bacteria, intestinal epithelium forms both a physical and biochemical defense against pathogens. Besides, intestinal epithelium senses dynamic and continuous changes in luminal environment and transmits signals to subjacent immune cells accordingly. It has been long accepted that adaptive immune cells fulfill their roles partly by modulating function of intestinal epithelial cells. Recent studies have brought up the proposal that intestinal epithelial cells also actively participate in the regulation of adaptive immunity, especially CD4+ adaptive T cells, which indicates that there is reciprocal crosstalk between intestinal epithelial cells and adaptive immune cells, and the crosstalk may play important role in intestinal mucosal immunity. This Review makes a comprehensive summary about crosstalk between intestinal epithelial cells and CD4+ adaptive T cells in intestinal immunity. Special attention would be given to their implications in inflammatory bowel disease pathogenesis and potential therapeutic targets.

Exosome in intestinal mucosal immunity

Intercellular communication of immune cells is critical to elicit efficient inflammatory responses. In intestinal mucosa, imbalance in pro-inflammatory and anti-inflammatory mediators, especially cytokines and chemokines, characterizes the underlying immune mechanisms of inflammatory bowel disease. Exosomes, small membrane vesicles secreted into the extracellular environment, are emerging as another important intercellular messenger in immune responses. A major recent breakthrough in this field unveils the capacity of exosomes to mediate the functional transfer of genetic materials (mRNAs and miRNAs) between immune cells. RAB27A and RAB27B are two small GTPases involved in exosome secretion. With respect to intestinal mucosal immunity, increased number of RAB27A-positive immune cells and RAB27B-positive immune cells are demonstrated in the colonic mucosa of patients with active ulcerative colitis as compared with that of healthy controls. This indicates the important role of exosome-mediated immune responses in the pathogenesis of inflammatory bowel disease. Here, we will discuss the immune properties of exosomes and recent advances in their function with a special focus on intestinal mucosal immunity.

Organoids derived from digestive tract, liver, and pancreas

Lgr5 marks stem cells in digestive epithelial tissues by lineage tracing, and in vitro ever-expansion of Lgr5 stem cells form organoids, which can be directed to differentiate into functional somatic cells. Organoids derived from gastrointestinal epithelium even recapitulate the morphologic features of their in vivo counterpart. Culture conditions are also modified to establish cancer organoids from individual patients. With great genetic stability during derivation and expansion, organoids retain either single mutation in patients with inherited disease or multiple mutations of cancer tissues. Together with efficient gene-editing protocol, organoids are emerging as powerful in vitro disease models.

High suppressor of cytokine signaling-3 expression impairs STAT3-dependent protective effects of interleukin-22 in ulcerative colitis in remission

BACKGROUND

High SOCS3 expression in intestinal epithelial cells (IECs) of patients with ulcerative colitis (UC) in remission reflects the shorter time to relapse. We investigated whether high SOCS3 increased risk for relapse through violating STAT3-dependent protective effects of interleukin (IL)-22 during UC remission.

METHODS

Expression of IL-22 and c-Myc in UC remission mucosa was analyzed by immunohistochemistry. Effects of IL-22 on migration and proliferation of IEC cell lines with enforced SOCS3 expression were assessed with wounding assay and CCK-8 assay, respectively. Influence of STAT3 interference and SOCS3 overexpression on IL-22-regulated expression of antimicrobial peptide and proliferation-related molecules, including DMBT1, c-Myc, Survivin, Bcl-2, and Bcl-xL, were performed with quantitative real-time polymerase chain reaction or Western blot.

RESULTS

Patients with UC in remission showed significantly more IL-22-positive immune cells, but no difference of epithelial c-Myc levels, in mucosa compared with healthy controls. Overexpression of SOCS3 nearly abolished IL-22-induced activation of STAT3. By inhibiting STAT3 signaling, SOCS3 influenced IL-22-induced expression of DMBT1, c-Myc, Survivin, and Bcl-2 as well as proliferation and migration processes in cultured IEC cell line.

CONCLUSIONS

SOCS3 overexpression impairs IL-22-mediated epithelial homeostasis and mucosal wound healing, which could be the mechanism for high SOCS3 IEC expression contributed early relapse of mucosal inflammation. Prevention of SOCS3 expression or enhancement of IL-22/STAT3 signaling in IEC seems to be rational therapeutic strategies for UC remission maintenance.

LncRNA DQ786243 affects Treg related CREB and Foxp3 expression in Crohn's disease

BACKGROUND

Long non-coding RNAs (lncRNAs) have different functions in cells. They work as signals, decoys, guides, and scaffolds. Altered lncRNA levels can affect the expression of gene products. There are seldom studies on the role of lncRNAs in inflammatory bowel disease (IBD).

RESULTS

Quantitative RT-PCR showed that DQ786243 was significantly overexpressed in clinical active CD patients compared with clinical inactive CD patients (P = 0.0118) or healthy controls (P = 0.002). CREB was also more highly expressed in active CD than in inactive CD (P = 0.0034) or controls (P = 0.0241). Foxp3 was interestingly lower in inactive CD than in active CD (P = 0.0317) or controls (P = 0.0103), but there were no apparent differences between active CD and controls. CRP was well correlated with DQ786243 (r = 0.489, P = 0.034), CREB (r = 0.500, P = 0.029) and Foxp3 (r = 0.546, P = 0.016). At 48 hours after DQ786243 transfection, qRT-PCR showed both CREB (P = 0.017) and Foxp3 (P = 0.046) had an increased mRNA expression in Jurkat cells. Western blot showed the same pattern. After DQ786243 transfection, CREB phosphorylation ratio (p-CREB/t-CREB) was increased (P = 0.0043).

CONCLUSION

DQ786243 can be related with severity of CD. It can affect the expression of CREB and Foxp3 through which regulates the function of Treg. CREB itself seems not the mediator of DQ786243 to up-regulate Foxp3. The phosphorylation of CREB might play a more important role in the process.

Predictive and prognostic roles of BRAF mutation in patients with metastatic colorectal cancer treated with anti-epidermal growth factor receptor monoclonal antibodies: a meta-analysis

OBJECTIVE

This study aimed to evaluate the predictive and prognostic roles of BRAF mutation in patients with metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MoAbs).

METHODS

Computer searches of the literature on BRAF mutation in mCRC patients were performed. Studies with objective response rate (ORR) to anti-EGFR MoAbs and/or overall survival (OS) and progression-free survival (PFS) with different BRAF gene expression in mCRC patients were eligible.

RESULTS

A total of 19 studies including 2875 patients was enrolled in the meta-analysis. BRAF mutation was detected in 246 patients. The ORR was 18.4% (40/217) in mutant BRAF group and 41.7% (831/1993) in the wild-type BRAF group. The overall risk ratio (RR) for the ORR of BRAF mutation patients compared with wild-type BRAF patients was 0.58 (95% confidence intervals [CI] 0.35-0.94, P = 0.027). The median PFS of patients with BRAF mutation was significantly shorter than that of patients with wild-type BRAF (hazard ratio [HR] 2.98, 95% CI 2.07-4.27, P < 0.001) and the median OS of patients with BRAF mutation was also significantly shorter than that of those with wild-type BRAF (HR 2.85, 95% CI 2.31-3.52, P < 0.001).

CONCLUSION

BRAF mutation is associated with poor response to anti-EGFR MoAbs and it is an adverse prognostic biomarker of the survival of patients with mCRC.