The exocyst complex and intracellular vesicles mediate soluble protein trafficking to the primary cilium

The efficient transport of proteins into the primary cilium is a crucial step for many signaling pathways. Dysfunction of this process can lead to the disruption of signaling cascades or cilium assembly, resulting in developmental disorders and cancer. Previous studies on the protein delivery to the cilium were mostly focused on the membrane-embedded receptors. In contrast, how soluble proteins are delivered into the cilium is poorly understood. In our work, we identify the exocyst complex as a key player in the ciliary trafficking of soluble Gli transcription factors. In line with the known function of the exocyst in intracellular vesicle transport, we demonstrate that soluble proteins, including Gli2/3 and Lkb1, can use the endosome recycling machinery for their delivery to the primary cilium. Finally, we identify GTPases: Rab14, Rab18, Rab23, and Arf4 that are involved in vesicle-mediated Gli protein ciliary trafficking. Our data pave the way for a better understanding of ciliary transport and uncover transport mechanisms inside the cell.

MRCKα/β positively regulates Gli protein activity

Posttranslational modifications (PTMs) are key regulatory events for the majority of signaling pathways. Transcription factors are often phosphorylated on multiple residues, which regulates their trafficking, stability, or transcriptional activity. Gli proteins, transcription factors that respond to the Hedgehog pathway, are regulated by phosphorylation, but the sites and the kinases involved have been only partially described. We identified three novel kinases: MRCKα, MRCKβ, and MAP4K5 which physically interact with Gli proteins and directly phosphorylate Gli2 on multiple sites. We established that MRCKα/β kinases regulate Gli proteins, which impacts the transcriptional output of the Hedgehog pathway. We showed that double knockout of MRCKα/β affects Gli2 ciliary and nuclear localization and reduces Gli2 binding to the Gli1 promoter. Our research fills a critical gap in our understanding of the regulation of Gli proteins by describing their activation mechanisms through phosphorylation.

Mucocutaneous Manifestations and Associated Factors in Patients with Crohn's Disease

BACKGROUND

One-third of all extraintestinal manifestations are mucocutaneous findings in patients with Crohn's disease and there is a relationship between some risk factors. Our aim is to evaluate factors associated with mucocutaneous manifestations in our cohort of patients with Crohn's disease with a follow-up duration of up to 25 years.

METHODS

In the study, 336 patients with Crohn's disease who were followed up between March 1986 and October 2011 were included. The demographic characteristics, Crohn's disease-related data, and accompanying mucocutaneous manifestations were recorded. The cumulative probability of mucocutaneous extraintestinal manifestations and possible risk factors were analyzed.

RESULTS

Oral and skin involvement were detected in 109 (32%) and 31 (9.2%) patients, respectively. The cumulative probability of developing oral and skin manifestations were 43.2% and 20.3%, respectively. Cox regression analysis showed that female gender (odds ratio: 3.28, 95% CI: 1.51-7.14, P = .003) and corticosteroid use (odds ratio: 7.88, 95% CI: 1.07-57.97, P = .043) are independently associated with the development of skin manifestations, while family history (odds ratio: 3.59, 95% CI: 2.18-5.93, P < .001) and inflammatory-type disease (odds ratio: 1.776, 95% CI: 1.21-2.61, P = .004) were independently associated with the development of oral ulcers.

CONCLUSION

Mucocutaneous extraintestinal manifestations are associated with female gender, corticosteroid use, family history, and disease type in a large cohort of patients with Crohn's disease. Defining the specific relationships of immune-mediated diseases will help to better understand the pathogenesis of Crohn's disease and associated mucocutaneous manifestations and to use more effective treatments.

Optimizing the Personalized Care for the Management of Rectal Cancer: A Consensus Statement

Colorectal cancer is the third most common cancer in Turkey. The current guidelines do not provide sufficient information to cover all aspects of the management of rectal cancer. Although treatment has been standardized in terms of the basic principles of neoadjuvant, surgical, and adjuvant therapy, uncertainties in the management of rectal cancer may lead to significant differences in clinical practice. In order to clarify these uncertainties, a consensus program was constructed with the participation of the physicians from the Acıbadem Mehmet Ali Aydınlar and Koç Universities. This program included the physicians from the departments of general surgery, gastroenterology, pathology, radiology, nuclear medicine, medical oncology, radiation oncology, and medical genetics. The gray zones in the management of rectal cancer were determined by reviewing the evidence-based data and current guidelines before the meeting. Topics to be discussed consisted of diagnosis, staging, surgical treatment for the primary disease, use of neoadjuvant and adjuvant treatment, management of recurrent disease, screening, follow-up, and genetic counseling. All those topics were discussed under supervision of a presenter and a chair with active participation of related physicians. The consensus text was structured by centralizing the decisions based on the existing data.

Cyclosporine Therapy as a Rescue Treatment in Steroid Refractory Acute Severe Ulcerative Colitis: A Real Life Data From a Tertiary Center

BACKGROUND

Cyclosporine is a rescue treatment alternative to avoid colectomy in corticosteroid refractory acute severe ulcerative colitis. In this study, we aimed to evaluate the long-term efficacy and safety of cyclosporine therapy in acute severe ulcerative colitis patients.

METHODS

Acute severe ulcerative colitis (basal Lichtiger score > 10) patients who did not respond to 40 mg intravenous methylpredniso- lone therapy after 3-5 days were included in the study. The presence of clinical response and remission was assessed at 1st week, 1st, 6th, and 12th month according to the Lichtiger index.

RESULTS

In this study, 40 patients, whose steroid refractory acute severe ulcerative colitis and basal Lichtiger score > 10 points were enrolled. The median disease duration was 49.3 months (2-204). All patients received cyclosporine for 132 ± 78 days (7-270). Clinical response was obtained on seventh day in 82.5%. The clinical response rates of the first and sixth months were 72.5% and 62.5%, respectively. A total of 17/40 (42.5%) patients underwent colectomy within 1 year. In the patients who underwent colectomy, the basal LS (14.2 ± 1.9 vs 12.3 ± 1.7) (P = .002) was higher and the basal hemoglobin value (11.8 ± 2.3 vs 10.1 ± 1.5) (P = .037) was lower than those who did not undergo colectomy.

CONCLUSION

Our findings suggest that cyclosporine treatment may be successfully and safely used in steroid refractory acute severe ulcerative colitis patients. Cyclosporine is a drug that has recently started to come up again with the introduction of new maintenance treatments. Especially in patients who develop a loss of response to infliximab therapy, or where infliximab therapy is contraindicated, or who have azathioprine intolerance, or are unresponsive.

Cryptogenic liver cirrhosis and hepatitis E virus (HEV): Are they related?

INTRODUCTION AND OBJECTIVES

Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis. In recent years, its role in the development of chronic hepatitis and cirrhosis especially in immunosuppressed patients and its wide range of extrahepatic involvement have increased the amount of research on HEV. In this study we aimed to investigate the presence of HEV infection in individuals with cryptogenic cirrhosis.

MATERIALS AND METHODS

HEV antibodies were analysed using the Anti HEV enzyme-linked immunosorbent assay (ELISA) kit (anti-HEV ELISA; Diapro Prodiagnostic Bioprobes, Milan, Italy). HEV RNA was isolated with using QIAMP Viral RNA mini kit (QIAGEN, Hilden, Germany). The HEV RNA titre was detected with the Rotor Gene 3000 real time polymerase chain reaction (PCR) system using GenoSen's HEV (Rotor Gene) Quantitative Real Time PCR Kit (Genome Diagnostics Private Limited, the Netherlands).

RESULTS

Our study included 21 healthy volunteers (12 males) and 35 cryptogenic cirrhosis patients (19 males). The ages of the patients and the controls were similar (46±12.1 vs. 37.5±9.7years). The mean Child-Pugh score was 8±2.5. The anti HEV immunoglobulin G(IgG) positivity rate was 9.5% and 25.7% in the control and patient groups respectively (p>0.05). HEV RNA positivity was not detected in the control group, but 3 cases (8.6%) in the patient group were positive (p>0.05). The HEV RNA, aspartate aminotransferase (AST) and alanine aminotransferase(ALT) levels for these 3 cases were 326.461copies/mL, 91IU/L and 67IU/L; 480copies/mL, 68IU/L and 36IU/L and 72copies/mL, 42IU/L and 24IU/L respectively. There were positive correlations between HEV RNA levels and AST and ALT levels (p<0.05).

CONCLUSIONS

Anti HEVIgG and HEV RNA positivity rates are high in cryptogenic cirrhosis although it is not statistically significant and there is a positive correlation between HEV RNA and aminotransferases.

Does the number of mucosal immune cells differ in irritable bowel syndrome and its subtypes?

BACKGROUND/AIMS

Recently, mucosal inflammation has been proposed to be one of the mechanisms underlying the pathophysiology of irritable bowel syndrome (IBS); however, there are controversial results regarding this hypotheses. Our aim was to evaluate immune cell infiltration in rectal and ileal biopsy specimens of patients with IBS and to compare it with those of healthy controls.

MATERIALS AND METHODS

In total, 36 patients with IBS (15 with diarrhea and 21 with constipation) and 16 healthy volunteers were enrolled. Ileocolonoscopy and ileal/rectal biopsies were performed. Rectal and terminal ileal biopsy specimens were evaluated for mucosal immune cell infiltration using immunohistochemical analysis. Serotonin positivity as well as counts of intraepithelial lymphocytes (IEL) and CD4+, CD8+, CD20+, and CD3+ cells were determined by a single pathologist who is an expert in the gastrointestinal system.

RESULTS

CD3+ and CD4+ cell counts in rectal and terminal ileal biopsy specimens were lower in the IBS group than in the controls. Conversely, there was no statistically significant difference between the IBS and control groups in terms of serotonin positivity as well as counts of IEL and CD20+ and CD8+ cells. Comparison between the IBS subgroups revealed a higher number of IEL in rectal biopsy specimens of the diarrhea dominant group. In the IBS subgroups, immune cell counts in terminal ileal and rectal biopsy specimens showed a positive correlation.

CONCLUSION

IBS and its subgroups showed lower immune cell counts than the controls in our study. These results indicate that there is no significant mucosal inflammation in homogeneous groups of patients with IBS. Rectal biopsies may be sufficient for the evaluation of inflammation in IBS.

Can Helicobacter pylori be eradicated with high-dose proton pump inhibitor in extensive metabolizers with the CYP2C19 genotypic polymorphism?

Proton pump inhibitors (PPI) metabolism and pharmacokinetics are regulated by cytochrome P450 enzymes in the liver. Cytochrome P450 2C19 (CYP2C19) polymorphism plays an import role in the metabolism of PPIs. The three possible genotypes for CYP2C19 each has a distinct effect on the pharmacodynamics of PPIs. Homozygote extensive metabolizers (HomEM) are the most frequent genotype and have two wild-types (non-mutant) (*1/*1) alleles. HomEM is associated with increased enzyme activity, which increases the rate of PPI metabolism. Intragastric pH, which is required for eradication, is lowest in HomEM. In HomEMs, an insufficient increase in intragastric pH results in decreased anti-Helicobacter pylori (HP) efficacy of the antibiotics and, therefore, lower eradication rates. We determined whether the HP eradication rate would increase after high-dose PPI treatment of extensive PPI metabolizers who had been treated unsuccessfully with a standard PPI dose. In our report, increasing the PPI dosage in patients with genotype polymorphisms may be effective on eradication rates. Eradication rates are directly affected by CYP2C19 polymorphisms, and eradication treatments should be planned considering such genotypic polymorphisms. Hence, CYP2C19 genotyping prior to treatment may facilitate determination of the optimum PPI dose to improve the therapeutic outcome. However, further researches are required to confirm this hypothesis.

Steroid-refractory inflammatory bowel disease is a risk factor for CMV infection

OBJECTIVE

Patients with inflammatory bowel disease (IBD) show increased the prevalence of cytomegalovirus (CMV) infection due to the severity of the disease and the immunosuppressive treatments they receive. The aim of this study was to determine the prevalence of CMV infection in IBD patients and identify the risk factors for CMV infection with different demographic characteristics in IBD patients.

PATIENTS AND METHODS

We enrolled 85 patients diagnosed with IBD (43 with ulcerative colitis (UC) and 42 with Crohn's disease (CD)) in this prospective study. The clinical disease activities of UC and CD were assessed using Truelove-Witts and Crohn's disease activity index (CDAI). CMV infection was assessed by detection of DNA using real-time polymerase chain reaction (PCR) in blood samples and quantitative PCR in colonic biopsy specimens and by detection of inclusion bodies using hematoxylin-eosin staining.

RESULTS

Thirteen patients with IBD exhibited concomitant CMV infection. CMV infection was not detected in any of the patients in remission. Viral loads measured in the colonic mucosa of infected patients ranged from 800-7000 genome copies/mL total extracted DNA. The mean serum CMV DNA level was 1694 ± 910 copies/mL (range: 800-3800). The rate of steroid resistance in CMV-positive cases was significantly higher than that in CMV-negative cases (p = 0.001). CD with acute exacerbation was a risk factor for CMV disease (p = 0.04). All of the CMV-positive patients received immunosuppressive treatments.

CONCLUSIONS

CMV infection should be suspected in steroid-resistant UC and CD. Antiviral treatment improved the clinical outcome in steroid-resistant IBD cases with serum CMV DNA levels above 1000 copies/mL.

Effect of cytochrome P450 2C19 polymorphisms on the Helicobacter pylori eradication rate following two-week triple therapy with pantoprazole or rabeprazole

OBJECTIVE

Cytochrome P450 2C19 (CYP2C19) polymorphisms play an important role in the metabolism of proton pump inhibitors. Rabeprazole is primarily metabolized via non-enzymatic pathways. In this study, we determined whether rabeprazole- and pantoprazole-based eradication treatments were influenced by CYP2C19 polymorphisms.

PATIENTS AND METHODS

A total of 200 patients infected with Helicobacter pylori were treated with either 40 mg of pantoprazole or 20 mg of rabeprazole plus 500 mg of clarithromycin, 1000 mg of amoxicillin twice daily for 2 weeks. CYP2C19 genotype status was determined by Polymerase Chain Reaction (PCR)-restriction-fragment-length polymorphism. The genotypes of cytochrome P450 2C19 were classified as homozigote extensive metabolizer (HomEM), heterozigote metabolizer (HetEM) and poor metabolizer (PM). The CYP2C19 genotype of all patients, the effectiveness of the treatment, the effect of the genotypic polymorphism on the treatment were assessed.

RESULTS

The frequencies of HotEM, HetEM, PM were 78%, 19.5% and 2.5%, respectively. 48% (n = 96) of the patients received treatment with rabeprazole and 52% (n = 104) with pantoprazole. The eradication rate was 64.7% for HomEM, 79.4% for HetEM, 100% for PM (p = 0.06). In HetEM, PM, are considered as a single group, the eradication rates were higher in patients with the HetEM and PM (HetEM+PM) genotypes than in those with the wild-type genotype (81.8 vs. 64.7% p = 0.031). Among the patients treated with rabeprazole, the eradication rates were significantly lower in those with the HomEM genotype than in those with the HetEM+PM genotypes (60% vs. 85.7% p = 0.023).

CONCLUSIONS

The genotypic polymorphism is effective on the rate of eradication. Eradication treatment rate with rabeprazole is influenced by CYP2C19 genotype.

Infliximab in inflammatory bowel disease: attention to adverse events

OBJECTIVE

To assess the efficacy and adverse effects of infliximab in patients with Crohn's disease and ulcerative colitis who are resistant to conventional therapy or having fistulising type Crohn's disease.

PATIENTS AND METHODS

The patients with a diagnosis of inflammatory bowel disease received infliximab between 2007 and 2009 were followed-up prospectively. Infliximab 5 mg/kg was given at week 0, 2, 6, and every 8 weeks thereafter. Early and late adverse events occurring during the treatment were recorded for each patient.

RESULTS

There were 36 patients [mean age 35±12, 17 male] included in the study. Thirty-two (88%) patients were receiving concomitant long-term immunosuppressive therapy. Complete or partial response was obtained in 75% of all patients. At least one adverse event was observed in 10 (28%) patients. Anaphylaxis was seen in 2 (6%) patients, mild acute infusion reaction in 2 (6%) patients, hypotension in 2 (6%) patients, respiratory distress in 2 (6%) patients, skin rash and eruptions in 2 (6%) patients, one hypertension (3%) and one (3%) tightness in the chest. Treatment was continued in all except patients with anaphylaxis. No infection, tumour or cases of death were observed.

CONCLUSIONS

Several adverse events might be observed in patients who receive infliximab. Care should be given to patients whom treatment was restarted after a break in regard to anaphylaxis. No serious adverse event was observed during infliximab treatment except allergic events.

Efficacy of tenofovir in adefovir-experienced patients compared with treatment-naive patients with chronic hepatitis B

BACKGROUND

Tenofovir (TDF) has similar antiviral efficacy in both treatment-naive and lamivudine-resistant chronic hepatitis B (CHB) patients. Data on TDF use in patients with adefovir (ADV) resistance is inconsistent. The aim of our study was to assess antiviral efficacy of TDF against nucleoside analogue-naive (NN) and ADV-resistant (ADV-R) CHB and suboptimal responders to ADV (ADV-S).

METHODS

A database of 135 CHB patients treated with TDF was analysed. A total of 37 patients with incomplete data were excluded and analysis was performed in 98 (44 NN, 30 ADV-R and 24 ADV-S). Patients with primary ADV-R mutations had either A181T/V or N236T mutations or both. HBV DNA was measured at 3-month intervals until month 24. Primary outcome measures were comparison of the decline of HBV DNA between the three treatment groups.

RESULTS

NN patients had higher baseline HBV DNA compared with ADV-R and ADV-S patients (6.08 log10 IU/ml versus 5.53 and 4.88, respectively; P=0.002). By exponential regression analysis, HBV DNA decline kinetics differed between the three groups. HBV DNA decline was faster in NN patients compared to ADV-R and ADV-S CHB patients (P=0.002 and P=0.004, respectively). Undetectable HBV DNA was achieved in 77.2%, 60% and 75% of NN, ADV-R and ADV-S CHB patients, respectively, at month 12 (P= not significant).

CONCLUSIONS

HBV DNA decline is slower in ADV-experienced patients compared with treatment-naive patients. The clinical significance of this slow response may be important in patients with critical liver reserve and high viral load. Optimal combination treatment (TDF+ entecavir) could be considered in these patients.

Treatment failure may lead to accelerated fibrosis progression in patients with chronic hepatitis C

Chronic hepatitis C (CHC) patients with treatment failure (TF) remain at risk of continuing fibrosis progression. However, it has not been investigated whether there is an increased risk of accelerated fibrosis progression after failed interferon-based therapy. We aimed to investigate long-term influence of TF on fibrosis progression compared with untreated patients with CHC. We studied 125 patients with CHC who underwent paired liver biopsies from 1994 to 2012. Patients with advanced fibrosis were excluded from the analysis. Sixty-three patients had TF, and 62 patients were treatment-naïve (TN). Annual fibrosis progression rate (FPR) was calculated, and significant fibrosis progression (SFP) was defined as ≥ 2 stage increase in fibrosis during follow-up. Multiple regression analyses were performed to find out independent predictors of FPR and SFP. Demographic characteristics and duration between paired liver biopsies were similar in TF and TN groups. Baseline alanine aminotransferase and gamma-glutamyl transferase (GGT) levels (71 ± 31 vs 47 ± 22, P < 0.001 and 49 ± 39 vs 36 ± 28, P = 0.027, respectively), baseline mean fibrosis stage (2.2 ± 0.7 vs 1.9 ± 0.7, P = 0.018) and histologic activity index (6.3 ± 1.9 vs 4.3 ± 1.6, P < 0.001) were higher in the TF group compared with the TN group. In regression analyses, the strongest independent predictor of fibrosis progression was the GGT level (OR: 1.03, 95%CI 1.01-1.5, P < 0.001). Treatment experience (OR: 5.97, 95%CI 1.81-19.7, P = 0.003) also appeared as an independent predictor of both FPR and SFP. Failed interferon-based CHC treatment may lead to accelerated FPR in the long-term compared with the natural course.

Apolipoprotein E-e4, processing speed, and white matter volume in a genetically enriched sample of midlife adults

Healthy midlife children of a parent with Alzheimer's disease ([AD] N = 23; 9 male) participated in neuropsychological testing, and magnetic resonance imaging (MRI) of brain volumetrics were obtained. In all, 35% of the sample were apolipoprotein E (ApoE)-e4 positive (n = 8; 5 male). The ApoE-e4 group exhibited significantly slower performances on an executive function and processing speed measure and had less white matter volume than the non-ApoE-e4 group. Lesser white matter volume was significantly correlated with slower processing speed. Processing speed and changes in white matter volume might be indicators of preclinical decline in AD.

Phenotype ? genotype correlation in eight Polish patients with inherited Factor XIII deficiency: identification of three novel mutations

Inherited factor XIII (FXIII) deficiency is known as one of the most rare blood coagulation disorder in humans. In the present study, phenotype and genotype of eight FXIII deficient Polish patients from five unrelated families were compared. The patients presented with a severe phenotype demonstrated by a high incidence of intracerebral haemorrhages (seven of eight patients), haemarthrosis (six patients) and bleeding due to trauma (five patients). Introduction of regular substitution with FXIII concentrate prevented spontaneous bleeding in seven patients. In all patients, mutations within the F13A gene have been identified revealing four missense mutations (Arg77Cys, Arg260Cys, Ala378Pro, Gly420Ser), one nonsense mutation (Arg661X), one splice site mutation (IVS5-1 G>A) and one small deletion (c.499-512del). One homozygous large deletion involving exon 15 was detected by failure of PCR product. The corresponding mutations resulted in severely reduced FXIII activity and FXIII A-subunit antigen concentration, while FXIII B-subunit antigen remained normal or mildly decreased. Structural analysis demonstrated that the novel Ala378Pro mutation may cause a disruption of the FXIII catalytic triad leading to a non-functional protein which presumably undergoes premature degradation. In conclusion, the severe phenotype with high incidence of intracranial bleeding and haemarthrosis was in accordance with laboratory findings on FXIII and with severe molecular defects of the F13A gene.

[Predictive values of peak expiratory flow measured with mechanical meters for Polish children and adolescents between 7-19 years of age]

The aim of this study was to evaluate the predicted values of pack expiratory flow for the Polish children and youth by means of measures Mini Wright and Personal Best. The accounts were based on a group of 86 boys and 110 girls. It was established that it was necessary to state different predicted values for different measures and that an optimum model of regression for counting of predicted values of PEFR in relation to body height for the Polish children and youth was an exponential model. Model indices for both measures were set up separately for boys and girls.

[The transfer of hepatitis B virus (HBV) from HBsAg(+) mothers to their babies]

In this study, Hepatitis B surface antigen (HBsAg) was detected in 3.1% (19/602) of mothers just after delivery. HBsAg positivity was detected in 31% (6/19) in cord blood of newborn infants born from HBsAg positive mothers. Six months later, 15 of the HBsAg positive mothers and their children were screened serologically. HBsAg positivity persisted in only one child (1/15, 6.6%).