Value of next‑generation sequencing in inherited arrhythmia syndromes

Background@#Genetic studies are clinically recommended in some cases of inherited arrhythmia syndromes. Nextgeneration sequencing (NGS) would be helpful because of its high analytical throughput and relative speed. This study aimed to assess the mutation-detection yield obtained by NGS compared with conventional Sanger sequencing method. @*Methods@#Patients with aborted sudden cardiac death and their families who underwent gene sequencing tests for inherited arrhythmia syndromes were retrospectively and enrolled in this study from 2017 to 2022 at Chonnam National University Hospital. We evaluated NGS study results of 17 patients (NGS group) and Sanger study results of 19 patients (Sanger group). @*Results@#64.7% of NGS and 94.7% of Sanger group were probands. Type 1 Brugada pattern ECG was more frequent in NGS group (64.7% vs. 21.1%; p = 0.007). BrS was the most common disorder in NGS group (76.5%), and idiopathic ventricular fibrillation was the most common one in Sanger group (63.2%). Mutations with uncertain significance were the most common ones in NGS group (89.5%), and pathogenic or likely pathogenic mutations were the most common ones in Sanger group (45.7%). When positive yield was defined as the ratio of pathogenic or likely pathogenic mutations that were detected by sequencing, the yields were 10.5% and 45.7% in NGS and Sanger groups, respectively. The NGS arrhythmia panel did not cover two inherited arrhythmia-related mutations (RYR1, APOA5) that were detected by the Sanger method. The extended NGS arrhythmia panel was able to detect 84.8% of inherited arrhythmia-related mutations that were detected in Sanger group. @*Conclusions@#NGS study has some limitations in obtaining the full genetic data of probands. Well-designed NGS panels are needed to increase the efficiency of the NGS study. With the well-designed panels, large-scale gene sequencing can efficiently and rapidly be applied in real clinical practices, especially in inherited fatal arrhythmia syndromes that have a high detection yield in genetic analyses.

12-O-Tetradecanoylphorbol-13-Acetate Induces Keratin 8 Phosphorylation and Reorganization via Expression of Transglutaminase-2

The stiffness of cancer cells is attributable to intermediate filaments such as keratin. Perinuclear reorganization via phosphorylation of specific serine residue in keratin is implicated in the deformability of metastatic cancer cells including the human pancreatic carcinoma cell line (PANC-1). 12-O-Tetradecanoylphorbol-13-acetate (TPA) is a potent tumor promoter and protein kinase C (PKC) activator. However, its effects on phosphorylation and reorganization of keratin 8 (K8) are not well known. Therefore, we examined the underlying mechanism and effect of TPA on K8 phosphorylation and reorganization. TPA induced phosphorylation and reorganization of K8 and transglutaminase-2 (Tgase-2) expression in a time- and dose-dependent manner in PANC-1 cells. These effects peaked after 45 min and 100 nM of TPA treatment. We next investigated, using cystamine (CTM), Tgase inhibitor, and Tgase-2 gene silencing, Tgase-2's possible involvement in TPA-induced K8 phosphorylation and reorganization. We found that Tgase-2 gene silencing inhibited K8 phosphorylation and reorganization in PANC-1 cells. Tgase-2 gene silencing, we additionally discovered, suppressed TPA-induced migration of PANC-1 cells and Tgase-2 overexpression induced migration of PANC-1 cells. Overall, these results suggested that TPA induced K8 phosphorylation and reorganization via Tgase-2 expression in PANC-1 cells.

Ethacrynic Acid Inhibits Sphingosylphosphorylcholine-Induced Keratin 8 Phosphorylation and Reorganization via Transglutaminase-2 Inhibition

Sphingosylphosphorylcholine (SPC) is significantly increased in the malicious ascites of tumor patients and induces perinuclear reorganization of keratin 8 (K8) filaments in PANC-1 cells. The reorganization contributes to the viscoelasticity of metastatic cancer cells resulting in increased migration. Recently, we reported that transglutaminase-2 (Tgase-2) is involved in SPC-induced K8 phosphorylation and reorganization. However, effects of Tgase-2 inhibitors on SPC-induced K8 phosphorylation and reorganization were not clearly studied. We found that ethacrynic acid (ECA) concentration-dependently inhibited Tgase-2. Therefore, we examined the effects of ECA on SPC-induced K8 phosphorylation and reorganization. ECA concentration-dependently suppressed the SPC-induced phosphorylation and perinuclear reorganization of K8. ECA also suppressed the SPC-induced migration and invasion. SPC induced JNK activation through Tgase-2 expression and ECA suppressed the activation and expression of JNK in PANC-1 cells. These results suggested that ECA might be useful to control Tgase-2 dependent metastasis of cancer cells such as pancreatic cancer and lung cancers.

Glomerular Filtration Rate Difference between Renal Cyst Group and Control Group / 가정의학회지

BACKGROUND: The simple renal cyst is the most prevalent cystic deformation in adults and is most of them are incidentally found during medical examination. In this study, the clinical differences were compared between simple renal cyst and control groups diagnosed by abdominal ultrasonography during periodic medical examination. METHODS: We randomly selected 2,277 persons who took medical examination in one general hospital health promotion center. Among them, analysis was conducted for 188 subjects with simple renal cyst and 188 subjects without renal cyst whose sex, age, and body mass index were matched. Renal cyst subjects were compared with control group to search for their relationship with hypertension, renal function and microscopic hematuria, past medical history, social history, results of other abdominal ultrasonography findings, urine test, and blood test. RESULTS: Among 2,213 subjects, simple renal cyst was found in 188 subjects (8.5%). The subjects who had more than three simple renal cysts were significant older (P = 0.05) and the oldest age was 70's. Also, higher hypertension prevalence (P = 0.05), more microscopic hematuria, higher serum creatinine (P = 0.02), and lower glomerular filtration rate (P < 0.01) were observed in simple renal cyst group. CONCLUSION: It is needed to survey size, shape and change of simple renal cyst using abdominal ultrasonography as well as how its progression may be related to developing hypertension, decreased renal function and microscopic hematuria.