Renal Threshold for Glucose Re-Absorption in Patients with Latent Autoimmune Diabetes of Adults is Similar to That of Patients with Type 1 Diabetes Mellitus but Lower than That of Patients with Type 2 Diabetes Mellitus

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Akt2 phosphorylates Synip to regulate docking and fusion of GLUT4-containing vesicles

We have identified an unusual potential dual Akt/protein kinase B consensus phosphorylation motif in the protein Synip (RxKxRS97xS99). Surprisingly, serine 97 is not appreciably phosphorylated, whereas serine 99 is only a specific substrate for Akt2 but not Akt1 or Akt3. Although wild-type Synip (WT-Synip) undergoes an insulin-stimulated dissociation from Syntaxin4, the Synip serine 99 to phenylalanine mutant (S99F-Synip) is resistant to Akt2 phosphorylation and fails to display insulin-stimulated Syntaxin4 dissociation. Furthermore, overexpression of WT-Synip in 3T3L1 adipocytes had no effect on insulin-stimulated recruitment of glucose transporter 4 (GLUT4) to the plasma membrane, whereas overexpression of S99F-Synip functioned in a dominant-interfering manner by preventing insulin-stimulated GLUT4 recruitment and plasma membrane fusion. These data demonstrate that insulin activation of Akt2 specifically regulates the docking/fusion step of GLUT4-containing vesicles at the plasma membrane through the regulation of Synip phosphorylation and Synip–Syntaxin4 interaction

Fyn phosphorylates AMPK to inhibit AMPK activity and AMP-dependent activation of autophagy

We previously demonstrated that proto-oncogene Fyn decreased energy expenditure and increased metabolic phenotypes. Also Fyn decreased autophagy-mediated muscle mass by directly inhibiting LKB1 and stimulating STAT3 activities, respectively. AMPK, a downstream target of LKB1, was recently identified as a key molecule controlling autophagy. Here we identified that Fyn phosphorylates the α subunit of AMPK on Y436 and inhibits AMPK enzymatic activity without altering the assembly state of the AMPK heterotrimeric complex. As pro-inflammatory mediators are reported modulators of the autophagy processes, treatment with the pro-inflammatory cytokine TNFα resulted in 1) increased Fyn activity 2) stimulated Fyn-dependent AMPKα tyrosine phosphorylation and 3) decreased AICAR-dependent AMPK activation. Importantly, TNFα induced inhibition of autophagy was not observed when AMPKα was mutated on Y436. 4) These data demonstrate that Fyn plays an important role in relaying the effects of TNFα on autophagy and apoptosis via phosphorylation and inhibition of AMPK

Outcomes of endoscopic treatment for malignant biliary obstruction in patients with surgically altered anatomy: analysis of risk factors for clinical failure

Background To evaluate the outcomes of endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO) using short-type double-balloon enteroscope (sDBE) in patients with surgically altered anatomy. Methods A total of 45 patients with surgically altered anatomy underwent ERCP using sDBE for the treatment of MBO between April 2011 and March 2019. We retrospectively evaluated the clinical and technical success (insertion and biliary intervention success), adverse events, and risk factors for clinical failure. Results The scope was successfully inserted in the target site in 82.2% of patients (37/45), and among them, biliary intervention success was achieved in 86.4% (32/37). The overall technical success rate was 71.1% (32/45) and clinical success rate was 68.9% (31/45), with an adverse event rate of 11.1%. In multivariate analysis, the presence of peritoneal dissemination (odds ratio, 7.3; 95% confidence interval, 1.5–43.5, p = 0.02) was as an independent risk factor for clinical failure. The clinical success rate was 38.5% in patients with peritoneal dissemination and 81.3% in those without peritoneal dissemination. Conclusion Endoscopic treatment using sDBE in patients without peritoneal dissemination provided favorable outcomes, and it can be an initial treatment for MBO in patients with surgically altered anatomy. Endoscopic biliary stent placement with endoscopic retrograde cholangiography (ERCP) for the treatment of malignant biliary obstruction (MBO) has been widely accepted as an effective drainage method because it is less invasive and safe and has a high success rate (1–3). However, MBO is treated using percutaneous transhepatic biliary drainage (PTBD) or surgical bypass because of difficulties related to endoscopic access to the bile duct following gastrointestinal reconstruction. However, these methods are associated with marked adverse event (AE) rates [1,2,3]. Recently, balloon-assisted endoscopy (BAE) facilitates ERCP in patients with surgically altered anatomy. As for a double-balloon enteroscope (DBE), a short-type DBE (sDBE) is especially useful because it allows the use of many standard ERCP accessories. The success rates of reaching the target site and ERCP-related interventions associated using these endoscopes range from 73–100% and 85–100%, respectively [4, 5]. We previously reported that the success rate of reaching the target site and biliary intervention was 93.8% and 95.7%, respectively, in patients with benign hepaticojejunostomy (HJ) anastomotic stricture [6]. However, inaccessibility of the target site may occur due to severe postoperative adhesions or a long insertion time (i.e., > 60 min). Furthermore, previous reports have shown that the success rate of BAE in MBO cases was significantly lower than that in benign biliary diseases [7, 8]. Few reports have investigated the outcome of BAE for MBO in patients with surgically altered anatomy. Additionally, the risk factors for clinical failure are not well-established. Thus, we retrospectively evaluated the outcomes of endoscopic treatment for MBO using sDBE in patients with surgically altered anatomy and identified risk factors for clinical failure

Efficacy of low dose rectal diclofenac for preventing post‐endoscopic retrograde cholangiopancreatography pancreatitis: Propensity score‐matched analysis

Background Acute pancreatitis is a major adverse event of endoscopic retrograde cholangiopancreatography (ERCP). Rectal administration of non‐steroidal anti‐inflammatory drugs (NSAIDs) decreases the incidence of post‐ERCP pancreatitis (PEP). However, the efficacy of low dose rectal NSAIDs for preventing PEP remains controversial. Methods We performed a retrospective study of 301 patients with native papilla and a body weight of Results A total of 66 pairs of patients in each group were selected. The patients and procedural‐related factors were similar in both groups. In total, 15 patients (11.4%) developed PEP: 12.1% (8/66) in the NSAIDs group and 10.6% (7/66) in the control group (Odds ratio (OR) 1.2; 95% confidence interval (CI) 0.4–3.5; P = 0.78). There was no significant difference in incidence of other adverse events related to ERCP between the two groups. Conclusions Prophylactic administration of a 25 mg dose of rectal diclofenac did not reduce the incidence of PEP in patients with a native papilla and a body weight of <50 kg in this study and a certain dose of rectal NSAIDs, such as a 100‐mg dose, should be administered regardless of body weight to prevent PEP

Fyn Phosphorylates Transglutaminase 2 (Tgm2) and modulates autophagy and p53 expression in the development of diabetic kidney disease

Autophagy is involved in the development of diabetic kidney disease (DKD), the leading cause of end-stage renal disease. The Fyn tyrosine kinase (Fyn) suppresses autophagy in the muscle. However, its role in kidney autophagic processes is unclear. Here, we examined the role of Fyn kinase in autophagy in proximal renal tubules both in vivo and in vitro. Phospho-proteomic analysis revealed that transglutaminase 2 (Tgm2), a protein involved in the degradation of p53 in the autophagosome, is phosphorylated on tyrosine 369 (Y369) by Fyn. Interestingly, we found that Fyn-dependent phosphorylation of Tgm2 regulates autophagy in proximal renal tubules in vitro, and that p53 expression is decreased upon autophagy in Tgm2-knockdown proximal renal tubule cell models. Using streptozocin (STZ)-induced hyperglycemic mice, we confirmed that Fyn regulated autophagy and mediated p53 expression via Tgm2. Taken together, these data provide a molecular basis for the role of the Fyn–Tgm2–p53 axis in the development of DKD

MicroRNA-451a inhibits gemcitabine-refractory biliary tract cancer progression by suppressing the MIF-mediated PI3K/AKT pathway

Gemcitabine is an effective chemotherapeutic agent for biliary tract cancers (BTCs), including gallbladder cancer (GBC) and cholangiocarcinoma (CCA). However, few other effective agents are currently available, particularly for GEM-refractory BTCs. We previously identified microRNA-451a (miR-451a) as a potential therapeutic target in GBC. To elucidate the antineoplastic effects of miR-451a and its underlying mechanisms, we transfected miR-451a into GBC, gemcitabine-resistant GBC (GR-GBC), and gemcitabine-resistant CCA (GR-CCA) cell lines. Furthermore, mimicking in vivo conditions, tumorigenic GBC organoids and three-dimensional (3D) cell culture systems were employed to investigate the anti-proliferative effects of miR-451a on BTCs, and its effect on stem cell properties. We found that miR-451a significantly inhibited cell proliferation, induced apoptosis, and reduced chemoresistant phenotypes, such as epithelial-mesenchymal transition, in both GBC and GR-GBC. The principal mechanism is probably the negative regulation of the phosphatidylinositol 3-kinase/AKT pathway, partially accomplished by directly downregulating macrophage migration inhibitory factor. The Gene Expression Omnibus database revealed that miR-451a was the most significantly downregulated microRNA in CCA tissues. The introduction of miR-451a resulted in similar antineoplastic effects in GR-CCA. Furthermore, miR-451a reduced cell viability in 3D spheroid models and tumorigenic GBC organoids. These findings suggest that the supplementation of miR-451a is a potential treatment strategy for GEM-refractory BTCs

A Functional SNP in BNC2 Is Associated with Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity. We previously conducted a genome-wide association study (GWAS) and detected two loci associated with AIS. To identify additional loci, we extended our GWAS by increasing the number of cohorts (2,109 affected subjects and 11,140 control subjects in total) and conducting a whole-genome imputation. Through the extended GWAS and replication studies using independent Japanese and Chinese populations, we identified a susceptibility locus on chromosome 9p22.2 (p = 2.46 × 10−13; odds ratio = 1.21). The most significantly associated SNPs were in intron 3 of BNC2, which encodes a zinc finger transcription factor, basonuclin-2. Expression quantitative trait loci data suggested that the associated SNPs have the potential to regulate the BNC2 transcriptional activity and that the susceptibility alleles increase BNC2 expression. We identified a functional SNP, rs10738445 in BNC2, whose susceptibility allele showed both higher binding to a transcription factor, YY1 (yin and yang 1), and higher BNC2 enhancer activity than the non-susceptibility allele. BNC2 overexpression produced body curvature in developing zebrafish in a gene-dosage-dependent manner. Our results suggest that increased BNC2 expression is implicated in the etiology of AIS

Evidence of causality of low body mass index on risk of adolescent idiopathic scoliosis: a Mendelian randomization study

IntroductionAdolescent idiopathic scoliosis (AIS) is a disorder with a three-dimensional spinal deformity and is a common disease affecting 1-5% of adolescents. AIS is also known as a complex disease involved in environmental and genetic factors. A relation between AIS and body mass index (BMI) has been epidemiologically and genetically suggested. However, the causal relationship between AIS and BMI remains to be elucidated.Material and methodsMendelian randomization (MR) analysis was performed using summary statistics from genome-wide association studies (GWASs) of AIS (Japanese cohort, 5,327 cases, 73,884 controls; US cohort: 1,468 cases, 20,158 controls) and BMI (Biobank Japan: 173430 individual; meta-analysis of genetic investigation of anthropometric traits and UK Biobank: 806334 individuals; European Children cohort: 39620 individuals; Population Architecture using Genomics and Epidemiology: 49335 individuals). In MR analyses evaluating the effect of BMI on AIS, the association between BMI and AIS summary statistics was evaluated using the inverse-variance weighted (IVW) method, weighted median method, and Egger regression (MR-Egger) methods in Japanese.ResultsSignificant causality of genetically decreased BMI on risk of AIS was estimated: IVW method (Estimate (beta) [SE] = -0.56 [0.16], p = 1.8 × 10-3), weighted median method (beta = -0.56 [0.18], p = 8.5 × 10-3) and MR-Egger method (beta = -1.50 [0.43], p = 4.7 × 10-3), respectively. Consistent results were also observed when using the US AIS summary statistic in three MR methods; however, no significant causality was observed when evaluating the effect of AIS on BMI.ConclusionsOur Mendelian randomization analysis using large studies of AIS and GWAS for BMI summary statistics revealed that genetic variants contributing to low BMI have a causal effect on the onset of AIS. This result was consistent with those of epidemiological studies and would contribute to the early detection of AIS