SCN5A encodes the α-subunit of the voltage-gated sodium channel NaV1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We ...investigated whether patients with IBS have SCN5A variants that affect the function of NaV1.5.
We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls.
Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted NaV1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-NaV1.5 had the greatest effect in reducing NaV1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS.
About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt NaV1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
Abstract
Background
Peripheral arterial disease caused mainly by atherosclerosis portent significant morbidity, adverse prognosis and mortality, with localized treatment approaches aiming at symptom ...alleviation and improvement of circulation. Recently, scientific interest has been shifted towards epigenomics, with microRNAs appearing as a future therapeutic target in ischemic cardiovascular diseases due to their potential in regulating angiogenesis.
Purpose
We investigated the pro-angiogenic effect of miRNA-126 mimic in an in vivo model of hind limb ischemia.
Methods
Ten-week-old male C57Bl/6 mice (n=20) were subjected to left femoral artery ligation and were treated with microRNA-126 mimic at a dose of 5mg/kg (Group A, n=10) or 0.2ml normal saline (Group B, n=10) on days 1, 3 and 7. Laser Doppler imaging was performed to verify successful ligation on day 0 and to evaluate differences in the ischemic-to-normal (I/N) hind limb perfusion ratio on day 7 and 28. Muscle tissue expression of microRNA-126 and vascular endothelial growth factor (VEGF) was determined via PCR.
Results
Following microRNA-126 mimic administration in Group A subjects, we noted a qualitative and quantitative stepwise increase in I/N hind limb perfusion ratio Day 0: 0.354 (0.276, 0.455) vs. Day 8: 0.775 (0.700, 0.844) vs. Day 28: 0.681 (0.660, 0.896), p=0.001 (Figure 1, Panels A and B). In Group B a stepwise increase of lesser magnitude was observed in I/N hind limb perfusion ratio Day 0: 0.267 (0.164, 0.383) vs. Day 8: 0.400 (0.338, 0.418) vs. Day 28: 0.539 (0.483, 0.603), p=0.074. Importantly, over time changes of I/N hind limb perfusion ratio were significantly higher in group A compared to group B (p for interaction=0.005) (Figure 1, Panel B). Muscle tissue expression of microRNA-126 in the ischemic hind limb of Group A was 350-fold lower compared to the ischemic hind limb of Group B (p<0.001) (Figure 1, Panel C). A higher expression (14.2-fold) of VEGF in the ischemic hind limb of microRNA-126-treated mice compared to that of control group was detected (p<0.001) (Figure 1, Panel C). A statistically significant negative correlation was noted between microRNA-126 and VEGF tissue expression levels in the ischemic limbs of both Group A and B subjects whereas no correlation between microRNA-126 and VEGF was observed in the non-ischemic hind limbs of the entire study population (Figure 1, Panel D).
Conclusion
MicroRNA-126 mimic delivery in the ischemic hind limb of mice can accelerate vascular perfusion recovery via angiogenesis, which is mediated by VEGF expression.
Funding Acknowledgement
Type of funding sources: None. Figure 1
Abstract
Background
Therapeutic drug monitoring (TDM) of adalimumab trough levels (ADA-TLs) and antibodies to adalimumab (ADA-Abs) in patients with inflammatory bowel disease (IBD) is usually ...performed in a reactive setting when the disease flares. There is not enough evidence in favor of proactive TDM in these patients.
Methods
We aimed to evaluate the role of proactive measurement of ADA-TLs and ADA-Abs in IBD patients under treatment with adalimumab. Consecutive IBD patients on maintenance treatment with ADA, were included. ADA-TLs and Abs were measured using ELISA (Immunoguide, Aybayteche, Turkey) on serum samples drawn before ADA administration. At the same time serum biomarkers Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cells (WBC), hemoglobin (Hgb), platelets (PLT) as well as home-based fecal calprotectin (FC) ±3 months from blood sampling were assessed. After the measurements patients were followed and treatment changes made were recorded.
Results
A total of 52 patients receiving ADA maintenance therapy 48 CD, 4 UC, 31 males, mean age (±SD) 42.1±12.6 years, 8 on combination therapy with immunomodulators (IMMs), 23 under intensified dose (either 40mg/w or 80mg/2w) were included. Median (IQR) time since ADA initiation was 31 (17.5–38.5) months and median value (IQR) of serum ADA-TLs was 8.24 μg/ml (3.32–10.02). Five out 52 (9.6%) were positive for ATIs (>3 AU/ml). Patients with positive Abs had median (IQR) ADA-TLs 0.41 μg/ml (0.10–0.71) statistically lower compared to those with negative Abs 8.86μg/ml (5.6–10.0) (p=0.0004). The correlations of ADA-TLs with disease characteristics, treatment and biomarkers in IBD patients are presented in Table 1. Elevated CRP was negatively associated with ADA-TLs. No other significant correlations were observed except a trend towards significance for body mass index (BMI) and ADA treatment duration (both p=0.09). After a median (IQR) follow up of 15 (11.5–16) months treatment optimization became necessary in 4 patients (8%) adalimumab dose intensification in 2, change to a clinical trial medication in 1 and 1 underwent surgery who initially had significantly lower ADA-TLs than the rest patients median (IQR) ADA-TLs 0.51μg/ml (0.26-5.09-10.04) vs 8.62 (4.48–10.04); p=0.0362.
Conclusion
Proactive measurement of ADA-TLs and Abs in patients under maintenance treatment with adalimumab may be worth using along with other parameters in the management of IBD patients. Additional long term research in larger populations focused on the optimal use of proactive TDM is needed.
To evaluate the antitumor efficacy of Ag
Au
Trp
NPs in a SCID mouse cancer model, with respect to their effect on tumor growth, on tumor's metastatic potential and the underlying molecular mechanism.
...Ag
Au
Trp
NPs were radiolabeled with Gallium-68 and the biodistribution was studied in Swiss mice without tumors and in SCID mice bearing tumors. SCID mice received intratumoral Ag
Au
Trp
NPs and tumor size was measured using calipers. Lung and liver tissues were extracted and studied microscopically for the detection of any metastatic sites. Changes in the Caspase-3 and TNF-related apoptosis-inducing ligand (TRAIL) were also investigated using real-time PCR and Western blot techniques, respectively.
In the 4T1 tumor-bearing SCID mice, Ag
Au
Trp
NPs showed quick passive accumulation at tumor sites at 30 mins post-injection. Mice that received the highest dose of NPs (5.6mg/mL) demonstrated a 1.9-fold lower tumor volume compared to that of the control group at 11 days post-injection, while mice that did not receive NPs showed metastatic sites in liver and lung. Extracted tumor tissue of treated mice revealed increased Casp-3 mRNA levels as well as elevated TRAIL protein levels.
Based on our results, Ag
Au
Trp
NPs express anti-tumor and anti-metastatic effects in vivo. Ag
Au
Trp
NPs also reach tumor site via the enhancement and retention effect which results in the apoptotic death of cancerous cells selectively via the extrinsic TRAIL-dependent pathway.
Colorectal cancer (CRC) is the third most common cancer and fourth-leading cause of cancer death worldwide. Lifetime risk in Western European and North American populations is around 5%. Both genetic ...and environmental factors contribute to disease etiology, with about one-third of disease variance attributed to inherited genetic factors. For complex diseases, such as CRC, genetics research in human populations, remarkable progress has been made in recent times with the publication of a number of genome-wide association scans (GWAS) and subsequent statistical replications. These studies have identified new genes and pathways implicated in disease, many of which were not known before. Until very recently, the defined genetic contribution to CRC comprised rare, high-penetrance variants in a few genes (DNA mismatch repair genes, APC, SMAD4, BMPR1A and MUTYH). In a genome-wide association study to identify loci associated with CRC, 555,510 single nucleotide polymorphisms were genotyped in different populations including 747 Greek CRC cases and 850 controls. The GWAS studies revealed that common genetic variations in the 8q23.3, 8q24, 10p14, 11p23, 15p13, and 18q21 (SMAD7) regions also contribute to CRC risk. As well as providing risk estimates for population groups, identification of CRC risk loci provides new insights into disease causation. Studies of the mechanisms by which these genetic associations impact CRC risk could lead to the development of small molecule interventions for chemoprevention and chemotherapy.
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