Slc26a3 deficiency is associated with loss of colonic HCO3 (-) secretion, absence of a firm mucus layer and barrier impairment in mice

AIM

Downregulated in adenoma (DRA, Slc26a3) is a member of the solute carrier family 26 (SLC26), family of anion transporters, which is mutated in familial chloride-losing diarrhoea (CLD). Besides Cl(-) -rich diarrhoea, CLD patients also have a higher-than-average incidence of intestinal inflammation. In a search for potential explanations for this clinical finding, we investigated colonic electrolyte transport, the mucus layer and susceptibility against dextran sodium sulphate (DSS)-induced colitis in Slc26a3(-/-) mice.

METHODS

HCO3 (-) secretory (JHCO3 (-) ) and fluid absorptive rates were measured by single-pass perfusion in vivo and in isolated mid-distal colonic mucosa in Ussing chambers in vitro. Colonocyte intracellular pH (pHi ) was assessed fluorometrically, the mucus layer by immunohistochemistry and colitis susceptibility by the addition of DSS to the drinking water.

RESULTS

HCO3 (-) secretory (JHCO3- ) and fluid absorptive rates were strongly reduced in Slc26a3(-/-) mice compared to wild-type (WT) littermates. Despite an increase in sodium/hydrogen exchanger 3 (NHE3) mRNA and protein expression, and intact acid-activation of NHE3, the high colonocyte pH in Slc26a3(-/-) mice prevented Na(+) /H(+) exchange-mediated fluid absorption in vivo. Mucin 2 (MUC2) immunohistochemistry revealed the absence of a firm mucus layer, implying that alkaline secretion and/or an absorptive flux may be necessary for optimal mucus gel formation. Slc26a3(-/-) mice were highly susceptible to DSS damage.

CONCLUSIONS

Deletion of DRA results in severely reduced colonic HCO3 (-) secretory rate, a loss of colonic fluid absorption, a lack of a firmly adherent mucus layer and a severely reduced colonic mucosal resistance to DSS damage. These data provide potential pathophysiological explanations for the increased susceptibility of CLD patients to intestinal inflammation.

Subretinal transplantation of rat MSCs and erythropoietin gene modified rat MSCs for protecting and rescuing degenerative retina in rats

For degenerative retinal diseases, like the acquired form exemplified by age-related macular degeneration (AMD), there is currently no cure. This study was to explore a stem cell therapy and a stem cell based gene therapy for sodium iodate (SI)-induced retinal degeneration in rats. Three cell types, i.e., rat mesenchymal stem cells (rMSCs) alone, erythropoietin (EPO) gene modified rMSCs (EPO-rMSCs) or doxycycline (DOX) inducible EPO expression rMSCs (Tet-on EPO-rMSCs), were transplanted into the subretinal spaces of SI-treated rats. The rMSCs were prepared for transplantation after 3 to 5 passages or modified with EPO gene. During the 8 weeks after the transplantation, the rats treated with rMSCs alone or with two types of EPO-rMSCs were all monitored with fundus examination, fundus fluorescein angiography (FFA) and electroretinogram. The transplantation efficiency of donor cells was examined for their survival, integration and differentiation. Following the transplantation, labeled donor cells were observed in subretinal space and adopted RPE morphology. EPO concentration in vitreous and retina of SI-treated rats which were transplanted with EPO-rMSCs or Tet-on EPO-rMSCs was markedly increased, in parallel with the improvement of retinal morphology and function. These findings suggest that rMSCs transplantation could be a new therapy for degenerative retinal diseases since it can protect and rescue RPE and retinal neurons, while EPO gene modification to rMSCs could be an even better option.

Value of alpha-fetoprotein and clinical characteristics in patients with liver neoplasm

This article aimed to investigate the value of α-fetoprotein (AFP) for the diagnosis of hepatocellular carcinoma (HCC) and to evaluate the relationship between AFP and various clinical variables of HCC comprehensively. A retrospective study of postoperative patients diagnosed with liver neoplasm from two Chinese centers was enrolled in our study.A total of 3050 patients were included. The best cut-off point of AFP for the diagnosis of HCC was 20ng/ml with ideal sensitivity (69.74%), specificity (91.18%), LR (4.12) and YI (0.61). Non-HBV infection patients showed the highest specificity (94.44%) but lowest sensitivity (60.13%). In HBV infection. Patients, HBsAg, HBeAb, and HBcAb positive patients had the highest sensitivity (79.55%) and specificity (58.49%). AFP levels increased significantly in symptomatic patients (p=0.011). Those patients with tumor sizes ≥10cm had much higher serum AFP level compared with smaller tumors ones (p=0.014). AFP levels increased remarkably in patients with vascular invasion (p=0.015). Stepwise logistic regression showed tumor size (≥10cm) was an independent predictor of elevated AFP (OR=2.743, 95%CI: 1.167-6.447, P=0.021). The best discriminating AFP value for the diagnosis of HCC is 20ng/ml; HBsAg, HBeAb and HBcAb positive patients have the optimal sensitivity and specificity; tumor size ≥ 10cm is an independent predictor of elevated AFP.

Genetic variants for type 2 diabetes and new-onset cancer in Chinese with type 2 diabetes

BACKGROUND

Diabetes is associated with an increased risk of cancer. This study aimed to evaluate associations between recently reported type 2 diabetes (T2D) susceptibility genetic variants and cancer risk in a prospective cohort of Chinese patients with T2D.

METHODS

Seven single nucleotide polymorphisms (SNP) in IGF2BP2, CDKAL1, SLC30A8, CDKN2A/B, HHEX and TCF7L2, all identified from genome-wide association studies of T2D, were genotyped in 5900 T2D patients [age mean ± SD = 57 ± 13 years, % males = 46] without any known cancer at baseline. Associations between new-onset of cancer and SNPs were tested by Cox proportional hazard models with adjustment of conventional risk factors.

RESULTS

During the mean follow-up period of 8.5 ± 3.3 years, 429 patients (7.3%) developed cancer. Of the T2D-related SNPs, the G-alleles of HHEX rs7923837 (hazard ratio [HR] (95% C.I.) = 1.34 (1.08-1.65); P = 6.7 ×10(-3) under dominant model) and TCF7L2 rs290481 (HR (95% C.I.) = 1.16 (1.01-1.33); P = 0.040 under additive model) were positively associated with cancer risk, while the G-allele of CDKAL1 rs7756992 was inversely associated (HR (95% C.I.) = 0.80 (0.65-1.00); P = 0.048 under recessive model). The risk alleles of these significant SNPs exhibited combined effect on increasing cancer risk (per-allele HR (95% C.I.) = 1.25 (1.12-1.39); P = 4.8 × 10(-5)). The adjusted cancer risk was 2.41 (95% C.I. 1.23-4.69) for patients with four risk alleles comparing to patients without risk allele.

CONCLUSIONS

T2D-related variants HHEX rs7923837, TCF7L2 rs290481 and CDKAL1 rs7756992 increased cancer risk in patients with diabetes.

IMPACT

Our findings provide novel insights into the pathogenesis of cancer in diabetes.

Effects of common polymorphisms rs2910164 in miR-146a and rs11614913 in miR-196a2 on susceptibility to colorectal cancer: a systematic review meta-analysis

PURPOSE

Emerging evidence has shown that single nucleotide polymorphisms occurred in microRNAs may contribute to the development of colorectal cancer (CRC). rs2910164 in miR-146a and rs11614913 in miR-196a2 are suggested to be associated with the susceptibility to CRC, but individually published studies revealed inconclusive results. To systematically summarize the possible correlationship between these polymorphisms and CRC risk, we performed this meta-analysis.

METHODS

We retrieved the relevant articles of the associations between these two microRNA polymorphisms and susceptibility to CRC for the period up to July 1, 2013. A total of seven articles were identified with 2,143 cases and 2,457 controls for miR-146a rs2910164, 1,594 cases and 2,252 controls for miR-196a2 rs11614913. Odds ratio and 95 % confidence interval were calculated to investigate the strength of the association.

RESULTS

The pooled analysis showed that miR-146a rs2910164 did not reveal any correlation with CRC susceptibility. However, a decreased risk was observed between miR-196a2 rs11614913 and CRC in all genetic models.

CONCLUSION

Our current meta-analysis demonstrates that miR-196a2 rs11614913 most likely contributes to decreased risk of CRC, whereas miR-146a rs2910164 may not be associated with the susceptibility to CRC.

Optimization of in vitro cell labeling methods for human umbilical cord-derived mesenchymal stem cells

BACKGROUND AND OBJECTIVES

Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) are a novel source of seed cells for cell therapy and tissue engineering. However, in vitro labeling methods for hUCMSCs need to be optimized for better detection of transplanted cells.

AIM OF THE STUDY

To identify the most stable and efficient method for labeling hUCMSCs in vitro.

MATERIALS AND METHODS

hUCMSCs were isolated using a modified enzymatic digestion procedure and cultured. hUCMSCs of passage three (P3) were then labeled with BrdU, PKH26, or lentivirus-GFP and passaged further. Cells from the first labeled passage (LP1), the fourth labeled passage (LP4) and later passages were observed using a fluorescence microscope. The differentiation potential of LP4 cells was assessed by induction with adipogenic and osteogenic medium. Flow cytometry was used to measure the percentage of labeled cells and the percentage of apoptotic or dead cells. The labeling efficiencies of the three hUCMSC-labeling methods were compared in vitro.

RESULTS

BrdU, PKH26, and lentivirus-GFP all labeled LP1 cells with high intensity and clarity. However, the BrdU labeling of the LP4 cells was vague and not localized to the cell nuclei; LP9 cells were not detected under a fluorescence microscope. There was also a significant decrease in the fluorescence intensity of PKH26-labeled LP4 cells, and LP11 cells were not detected under a fluorescence microscope. However, the fluorescence of LP4 cells labeled with lentivirus-GFP remained strong, and cells labeled with lentivirus-GFP were detected up to LP14 under a fluorescence microscope. Statistical analyses indicated that percentages of LP1 cells labeled with PKH26 and lentivirus-GFP were significantly higher than that of cells labeled with BrdU (p < 0.05), and that the LP4 cells were more efficiently labeled with lentivirus-GFP than with PKH26 or BrdU (p < 0.05). BrdU-, PKH26-, and lentivirus-GFP labeled LP4 cells were all differentiated to adipocytes or osteoblasts with adipogenic and osteogenic medium. No statistical significance (p > 0.05) was observed between the death rates of labeled and unlabeled cells.

CONCLUSIONS

Lentivirus-GFP is a valid method for long-term in vitro labeling, and it may be used as a long-term hUCMSC tracker following transplantation in vivo.

Therapeutic potential of umbilical cord mesenchymal stem cells with Wnt/β-catenin signaling pathway pre-activated for the treatment of diabetic wounds

The pathogenesis of diabetes mellitus wounds is complicate, and there lacks effective treatment strategies. Mesenchymal stem cells can promote wound healing. Compared with bone marrow mesenchymal stem cells, umbilical cord mesenchymal stem cells have obvious advantages in biological property. Wnts are potent regulatory molecules for stem cell turnover and skin regeneration, while Wnt signaling is not well activated in diabetic wounds. Umbilical cord mesenchymal stem cells with Wnt/β-catenin signaling pathway pre-activated have some potential in the treatment of diabetic wounds. In this paper, we review the research status as well as problems in this field.

Epimorphin-induced differentiation of human umbilical cord mesenchymal stem cells into sweat gland cells

OBJECTIVES

Mesenchymal stem cells (MSCs) have the potential for multi-directional differentiation and can be induced to differentiate into sweat gland cells under certain conditions. Epimorphin (EPM) plays an important role in the promotion of epithelial cell morphogenesis; however, its effect on sweat gland-cell differentiation of MSCs remains unknown. The purpose of this study was to investigate how EPM regulates sweat gland cell differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).

MATERIALS AND METHODS

hUCMSCs were labeled with 5-bromo-2-deoxyuridine (BrdU) before differentiation induction; were cultured in common culture medium, conditioned medium, or EPM-conditioned medium; and then induced to differentiate into sweat gland cells. Five days after induction, the expression rates of the sweat gland-cell antigens cytokeratin 14 (CK14), cytokeratin 19 (CK19), and carcinoembryonic antigen (CEA) in hUCMSCs were detected by flow cytometry, and the messenger ribonucleic acid (mRNA) and protein levels of CK14, CK19, and CEA were determined by reverse transcription polymerase chain reaction (RT-PCR) and western blot, respectively.

RESULTS

hUCMSCs can be induced to differentiate into sweat gland cells in conditioned medium, and expression of CEA was detected by immunofluorescence assay. Flow cytometry results showed that the expression rate of the sweat gland-cell antigens CK14, CK19, and CEA in the conditioned medium were significantly lower than that in the EPM conditioned medium (p < 0.05). RT-PCR and western blot results showed that the mRNA and protein levels of CK14, CK19, and CEA in the conditioned medium were all significantly lower than that in the EPM-conditioned medium (p < 0.01).

CONCLUSIONS

These results suggest that EPM can effectively induce the differentiation of hUCMSCs into sweat gland cells.

An improved dosage regimen of sertraline hydrochloride in the treatment for premature ejaculation: an 8-week, single-blind, randomized controlled study followed by a 4-week, open-label extension study

WHAT IS KNOWN AND OBJECTIVE

This study aimed at evaluating the safety and efficacy of an improved dosage regimen of sertraline in patients with premature ejaculation (PE) and to examine whether the premature ejaculation diagnostic tool (PEDT) can be used as a measure of treatment response in these patients.

METHODS

A total of 218 PE patients were randomized into control (n = 61) and treatment (n = 157) groups to receive mycelium of cordyceps sinensis C4 and sertraline 50 mg daily for 8 weeks, respectively. Following this blinded stage, sixty-three patients chose to take sertraline 100 mg daily for an additional 4-week period, and 80 other patients continued treatment with sertraline 50 mg. Main outcome measures include intravaginal ejaculatory latency time (IELT), PEDT score and Clinical Global Impression of Change (CGIC) score.

RESULTS

At weeks 4 and 8, mean IELT of patients who subsequently chose to take 100 mg of sertraline was significantly lower than that of patients who continued taking 50 mg of sertraline, although the IELT value was comparable between the two groups of patients at baseline. However, with an additional 4-week treatment, the mean IELT increased significantly more in the 100-mg group than in the 50-mg continuation group. Similar results were also obtained in the analyses of the PEDT and CGIC scores. Both regimens were well tolerated, and relapse rate did not differ significantly between the two groups.

WHAT IS NEW AND CONCLUSION

These findings suggest that PE patients not responding to an 8-week treatment with sertraline 50 mg can benefit from an additional 4-week treatment with sertraline 100 mg and that the PEDT may be a valid measure of treatment response in PE patients.

Biomechanical changes in the pharynx and upper esophageal sphincter after modified balloon dilatation in brainstem stroke patients with dysphagia

BACKGROUND

Few studies have investigated the biomechanical changes in the upper esophageal sphincter (UES) and pharyngeal function after successful dilatation therapy for dysphagia. Using high-resolution manometry (HRM), we examined the biomechanical properties of swallowing in brainstem stroke patients with dysphagia following modified balloon dilation therapy.

METHODS

30 brainstem stroke patients with dysphagia were included. Patients in the experimental group received 3 weeks of modified balloon dilatation treatment and regular dysphagia therapy. Patients in the control group received 3 weeks of regular dysphagia therapy only. Efficacy of treatment was evaluated before and following intervention. Functional oral intake was measured using the Functional Oral Intake Scale (FOIS). Pharyngeal maximum pressures and duration, UES residual pressure and duration during swallowing were measured using HRM.

KEY RESULTS

In the experimental group, the feeding tube was able to be removed in 12 of 15 patients, vs 2 of 15 patients in the control group. The experimental group had 4-point median improvement, while control groups only had 1-point improvement in FOIS scores. In the experimental group, posttreatment UES relaxation and pharyngeal propulsion were both significantly improved for the three materials (p < 0.05) and UES resting pressure approximated normal. In the control group, pharyngeal propulsion was improved for water and thick liquids (p < 0.05) but not for paste material; there was no improvement in posttreatment UES relaxation for all three materials (p > 0.05).

CONCLUSIONS & INFERENCES

Dysphagia therapy with modified dilatation improved UES relaxation, strengthened pharyngeal propulsion, restored UES resting pressure and improved functional oral intake to a greater extent than regular therapy alone.

Dog safety in rural China: children's sources of safety information and effect on knowledge, attitudes, and practices

Dog bites are a significant pediatric public health challenge in rural China. This study evaluated the effect of various sources of dog-safety information on children's knowledge, attitudes, beliefs and practices with dogs. A total of 1925 children (grade 3-6) between 6 and 15 years old in four rural regions across China participated between May and September 2012. Results showed that teachers and especially parents were effective information sources for children to learn about dog safety. Learning from peers and children teaching themselves were ineffective education strategies. Multi-source learning (from both parents and teachers) did not differ from single-source learning (from parents but not teachers) but did exceed learning from teachers but not parents or no learning from adults. Older age was associated with greater safety knowledge but also riskier practices with dogs. Girls generally held more safety knowledge, less risky attitudes/beliefs and safer practices than boys. Neither age nor gender interacted with information sources on outcome measures. In conclusion, parents appear to play a major role in educating children in rural China on dog safety. Future dog safety interventions might focus on changing cognition and behavior as well as delivering basic knowledge to youth through teachers and especially parents.

Predicting skin permeability from complex chemical mixtures: incorporation of an expanded QSAR model

Quantitative structure-activity relationship (QSAR) models have been widely used to study the permeability of chemicals or solutes through skin. Among the various QSAR models, Abraham's linear free-energy relationship (LFER) model is often employed. However, when the experimental conditions are complex, it is not always appropriate to use Abraham's LFER model with a single set of regression coefficients. In this paper, we propose an expanded model in which one set of partial slopes is defined for each experimental condition, where conditions are defined according to solvent: water, synthetic oil, semi-synthetic oil, or soluble oil. This model not only accounts for experimental conditions but also improves the ability to conduct rigorous hypothesis testing. To more adequately evaluate the predictive power of the QSAR model, we modified the usual leave-one-out internal validation strategy to employ a leave-one-solute-out strategy and accordingly adjust the Q(2) LOO statistic. Skin permeability was shown to have the rank order: water > synthetic > semi-synthetic > soluble oil. In addition, fitted relationships between permeability and solute characteristics differ according to solvents. We demonstrated that the expanded model (r(2) = 0.70) improved both the model fit and the predictive power when compared with the simple model (r(2) = 0.21).

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near PAX4

AIMS/HYPOTHESIS

Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians.

METHODS

We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations.

RESULTS

We identified CDKN2A/B and four novel type 2 diabetes association signals with p < 1 × 10(-5) from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (p meta = 2.6 × 10(-8); OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (p meta = 2.3 × 10(-10)) and a population of European descent (p = 8.6 × 10(-3)). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians.

CONCLUSIONS/INTERPRETATION

Our study identifies rs10229583 near PAX4 as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.