Eriko Nakano

Variants in CPA1 are strongly associated with early onset chronic pancreatitis

Chronic pancreatitis is an inflammatory disorder of the pancreas. We analyzed CPA1, encoding carboxypeptidase A1, in subjects with nonalcoholic chronic pancreatitis (cases) and controls in a German discovery set and three replication sets. Functionally impaired variants were present in 29/944 (3.1%) German cases and 5/3,938 (0.1%) controls (odds ratio (OR) = 24.9, P = 1.5 × 10−16). The association was strongest in subjects aged ≤10 years (9.7%; OR = 84.0, P = 4.1 × 10−24). In the replication sets, defective CPA1 variants were present in 8/600 (1.3%) cases and 9/2,432 (0.4%) controls from Europe (P = 0.01), 5/230 (2.2%) cases and 0/264 controls from India (P = 0.02) and 5/247 (2.0%) cases and 0/341 controls from Japan (P = 0.013). The mechanism by which CPA1 variants confer increased pancreatitis risk may involve misfolding-induced endoplasmic reticulum stress rather than elevated trypsin activity, as is seen with other genetic risk factors for this disease.

miR-210 regulates the interaction between pancreatic cancer cells and stellate cells

There is accumulating evidence that pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. microRNAs (miRNAs) are small non-coding RNAs acting as negative regulators of gene expression at the post-transcriptional level. This study aimed to clarify the role of miRNAs in the interaction between PSCs and pancreatic cancer cells. Pancreatic cancer cells were mono-cultured or indirectly co-cultured with PSCs. miRNAs were prepared, and Agilents miRNA microarray containing probes for 904 human miRNAs was used to identify differentially expressed miRNAs. miR-210 was identified as an upregulated miRNA by co-culture with PSCs. Conditioned media of PSCs activated ERK and Akt, but not hypoxia-inducible factor-1α pathway. PSCs-induced miR-210 upregulation was inhibited by inhibitors of ERK and PI3K/Akt pathways. Inhibition of miR-210 expression decreased migration, decreased the expression of vimentin and snai-1, and increased the membrane-associated expression of β-catenin in Panc-1 cells co-cultured with PSCs. In conclusion, our results suggest a novel role of miR-210 in the interaction between PSCs and pancreatic cancer cells.

The angiotensin II type I receptor blocker olmesartan inhibits the growth of pancreatic cancer by targeting stellate cell activities in mice

Abstract There is accumulating evidence that pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, promote the progression of pancreatic cancer. The interactions between PSCs and pancreatic cancer have attracted substantial attention as a novel therapeutic target for the treatment of pancreatic cancer. We examined here the effects of olmesartan, an angiotensin II type I receptor blocker, on pancreatic cancer-associated fibrosis using a subcutaneous tumor model developed by co-injection of pancreatic cancer cells with PSCs in nude mice. Co-injection of pancreatic cancer cells AsPC-1 with PSCs increased the size of tumors compared with AsPC-1 cells alone. Olmesartan administrated at 10 mg/kg in drinking water inhibited the growth of subcutaneous tumors derived from the co-injection, but not those derived from mono-injection. This effect was accompanied by decreased expression of α-smooth muscle actin (a marker of activated PSCs) and collagen deposition. The inhibitory effect of olmesartan was also observed even if it was administrated after significant development of subcutaneous tumors. In addition, olmesartan decreased cell growth and type I collagen production in PSCs in vitro. These results suggest that olmesartan inhibited the growth of tumors by targeting stellate cell activities, and that olmesartan might be useful as an anti-fibrosis therapy in pancreatic cancer.

Pancreatic stellate cells reduce insulin expression and induce apoptosis in pancreatic β-cells.

Islet fibrosis, pancreatic β-cell dysfunction, and β-cell apoptosis are features of pancreatic diabetes and type 2 diabetes; however, the underlying mechanisms remain largely unknown. We hypothesized that pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, might affect the phenotype of pancreatic β-cells. α-Smooth muscle actin (a marker of activated PSC)-positive cells were found within and around the fibrotic islets. Indirect co-culture with PSCs reduced insulin expression and induced apoptosis in RIN-5F pancreatic β-cells. Induction of β-cell apoptosis was associated with activation of the caspase pathway and mitochondrial depolarization. Diphenylene iodonium, an inhibitor of PSC activation, inhibited islet fibrosis and protected islets in vivo. Our findings suggest a novel mechanism linking PSCs, islet fibrosis, and diabetes mellitus.

Identification of novel missense CTRC variants in Japanese patients with chronic pancreatitis

We read with great interest the article by Paliwal et al 1 reporting the identification of novel missense variants in the chymotrypsin C ( CTRC ) gene in patients with tropical pancreatitis and idiopathic chronic pancreatitis (CP) in India. Because there might be geographical differences in the genetics of pancreatitis, we conducted screening of the CTRC gene in Japanese patients with CP. All the eight exons in the CTRC gene were directly sequenced in 506 patients with CP (244 alcoholic, 206 idiopathic, 35 hereditary and 21 familial) and 274 healthy controls as previously described.1 This study was approved by the ethics committee of Tohoku University School of Medicine (article #2012-1-158). We identified five missense variants in patients with CP and one in controls (table 1 …

Common variants at PRSS1–PRSS2 and CLDN2–MORC4 loci associate with chronic pancreatitis in Japan

To the Editor, We read with great interest the article by Derikx et al 1 reporting a replication study of the association between common variants at the PRSS1 – PRSS2 and CLDN2 – MORC4 loci and chronic pancreatitis (CP). In agreement with the results originally reported by Whitcomb et al ,2 they showed that the rs10273639 T allele at the PRSS1–PRSS2 locus protected against CP, whereas the rs7057398 C allele in RIPPLY1 and rs12688220 T allele in MORC4 at the CLDN2–MORC4 locus increased disease susceptibility.1 It has been recognised that geographical differences exist in the genetics of pancreatitis.3 Because the previous studies1 ,2 employed subjects of European ancestry only, we aimed to refine the association in Japanese patients with CP. The three variants were genotyped by direct sequencing in 272 patients (men, n=245) with alcoholic CP (ACP), 197 patients …

PRSS1 c.623G>C (p.G208A) variant is associated with pancreatitis in Japan

We read with great interest the article by Schnur et al 1 reporting the functional effects of 13 serine protease 1 ( PRSS1 ) variants found in sporadic chronic pancreatitis (CP). They reported that five mutants, including p.G208A, showed reduced secretion, suggesting that these variants might increase the risk of pancreatitis related to mutation-induced misfolding and consequent endoplasmic reticulum stress. The pathological role of these variants might be strengthened by their association with pancreatitis cohorts, but such information is scarce. Interestingly, the c.623G>C (p.G208A) variant has been reported only in Asian subjects: a 12-year-old Asian man with CP, a Korean child with recurrent pancreatitis and a 7-year-old Korean child with necrotising acute pancreatitis.2 ,3 We therefore conducted screening of the PRSS1 p.G208A variant in Japanese patients with CP. All of the exons and the flanking regions in …

Pancreatic duct drainage using EUS-guided rendezvous technique for stenotic pancreaticojejunostomy

The patient was a 30-year-old female who had undergone excision of the extrahepatic bile duct and Roux-en-Y hepaticojejunostomy for congenital biliary dilatation at the age of 7. Thereafter, she suffered from recurrent acute pancreatitis due to pancreaticobiliary maljunction and received subtotal stomach-preserving pancreaticoduodenectomy. She developed a pancreatic fistula and an intra-abdominal abscess after the operation. These complications were improved by percutaneous abscess drainage and antibiotic therapy. However, upper abdominal discomfort and the elevation of serum pancreatic enzymes persisted due to stenosis from the pancreaticojejunostomy. Because we could not accomplish dilation of the stenosis by endoscopic retrograde cholangiopancreatography, we tried an endoscopic ultrasonography (EUS) guided rendezvous technique for pancreatic duct drainage. After transgastric puncture of the pancreatic duct using an EUS-fine needle aspiration needle, the guidewire was inserted into the pancreatic duct and finally reached to the jejunum through the stenotic anastomosis. We changed the echoendoscope to an oblique-viewing endoscope, then grasped the guidewire and withdrew it through the scope. The stenosis of the pancreaticojejunostomy was dilated up to 4 mm, and a pancreatic stent was put in place. Though the pancreatic stent was removed after three months, the patient remained symptom-free. Pancreatic duct drainage using an EUS-guided rendezvous technique was useful for the treatment of a stenotic pancreaticojejunostomy after pancreaticoduodenectomy.

Nationwide epidemiological survey of early chronic pancreatitis in Japan

BackgroundThe world’s first diagnostic criteria for early CP were proposed in 2009 in Japan. This study aimed to clarify the clinico-epidemiological features of early CP in Japan.MethodsPatients with early CP who were diagnosed according to the diagnostic criteria for early CP and had visited the selected hospitals in 2011 were surveyed. The study consisted of two-stage surveys: the number of patients with early CP was estimated by the first questionnaire and their clinical features were assessed by the second questionnaire.ResultsThe estimated number of early CP patients was 5410 (95% confidence interval 3675–6945), with an overall prevalence of 4.2 per 100,000 persons. The number of patients who were newly diagnosed with early CP was estimated to be 1330 (95% confidence interval 1058–1602), with an annual incidence of 1.0 per 100,000 persons. Detailed clinical information was obtained in 151 patients in the second survey. The male-to-female sex ratio was 1.32:1. The mean age was 60.4 and the mean age at disease onset was 55.4. Idiopathic (47.7%) and alcoholic (45.0%) were the two most common etiologies. Proportions of female and idiopathic cases were higher in early CP than in definite CP. Hyperechoic foci without shadowing and stranding were the most common findings on endoscopic ultrasonography. The clinical profiles of early CP patients who showed lobularity with honeycombing on endoscopic ultrasonography or previous episodes of acute pancreatitis were similar to those of definite CP patients.ConclusionsWe clarified the current status of early CP in Japan.

Variants in pancreatic carboxypeptidase genes CPA2 and CPB1 are not associated with chronic pancreatitis

Genetic alterations in the carboxypeptidase A1 gene (CPA1) are associated with early onset chronic pancreatitis (CP). Besides CPA1, there are two other human pancreatic carboxypeptidases (CPA2 and CPB1). Here we examined whether CPA2 and CPB1 alterations are associated with CP in Japan and Germany. All exons and flanking introns of CPA2 and CPB1 were sequenced in 477 Japanese patients with CP (234 alcoholic, 243 nonalcoholic) and in 497 German patients with nonalcoholic CP by targeted next-generation sequencing and/or Sanger sequencing. Secretion and enzymatic activity of CPA2 and CPB1 variants were determined after transfection into HEK 293T cells. We identified six nonsynonymous CPA2 variants (p.V67I, p.G166R, p.D168E, p.D173H, p.R237W, and p.G388S), eight nonsynonymous CPB1 alterations (p.S65G, p.N120S, p.D172E, p.R195H, p.D208N, p.F232L, p.A317V, and p.D364Y), and one splice-site variant (c.687+1G>T) in CPB1. Functional analysis revealed essentially complete loss of function in CPA2 variants p.R237W and p.G388S and CPB1 variants p.R110H and p.D364Y. None of the CPA2 or CPB1 variants, including those resulting in a marked loss of function, were overrepresented in patients with CP. In conclusion, CPA2 and CPB1 variants are not associated with CP.