Iodine Promotes Glucose Uptake through Akt Phosphorylation and Glut-4 in Adipocytes, but Higher Doses Induce Cytotoxic Effects in Pancreatic Beta Cells

BACKGROUND

Epidemiological clinical reports have shown an association between iodine excess with diabetes mellitus type 2 and higher blood glucose. However, the relationship between iodine, the pancreas, adipose tissue, and glucose transport is unclear. The goal of this study was to analyze the effect of iodine concentrations (in Lugol solution) on glucose transport, insulin secretion, and its cytotoxic effects in mature 3T3-L1 adipocytes and pancreatic beta-TC-6 cells.

METHODS

Fibroblast 3T3-L1, mature adipocytes, and pancreatic beta-TC-6 cells were treated with 1 to 1000 µM of Lugol (molecular iodine dissolved in potassium iodide) for 30 min to 24 h for an MTT proliferation assay. Then, glucose uptake was measured with the fluorescent analog 2-NBDG, insulin receptor, Akt protein, p-Akt (ser-473), PPAR-gamma, and Glut4 by immunoblot; furthermore, insulin, alpha-amylase, oxidative stress, and caspase-3 activation were measured by colorimetric methods and the expression of markers of the apoptotic pathway at the RNAm level by real-time PCR.

RESULTS

Low concentrations of Lugol significantly induce insulin secretion and glucose uptake in pancreatic beta-TC-6 cells, and in adipose cells, iodine-induced glucose uptake depends on the serine-473 phosphorylation of Akt (p-Akt) and Glut4. Higher doses of Lugol lead to cell growth inhibition, oxidative stress, and cellular apoptosis dependent on PPAR-gamma, Bax mRNA expression, and caspase-3 activation in pancreatic beta-TC-6 cells.

CONCLUSIONS

Iodine could influence glucose metabolism in mature adipocytes and insulin secretion in pancreatic beta cells, but excessive levels may cause cytotoxic damage to pancreatic beta cells.

Fullerene C60 protects against 7,12-dimethylbenz [a] anthracene (DMBA) induced-pancreatic damage via NF-κB and Nrf-2/HO-1 axis in rats

The objective of this investigation was to investigate the protective effects of fullerene C60 nanoparticle against pancreatic damage experimentally induced by 7,12-dimethylbenz [a] anthracene (DMBA) in female rats. Fullerene C60 nanoparticle was administered to rats 5 times a week by oral gavage (o.g) at 1.7 mg/kg bw 7 days after DMBA administration. 60 Wistar albino female rats divided to four groups; Groups: (1) Control group: Fed with standard diet; (2) Fullerene C60 group: Fullerene C60 (1.7 mg/kg bw); (3) DMBA group: DMBA (45 mg/kg bw); (4) Fullerene C60 + DMBA group: Fullerene C60 (1.7 mg/kg bw) and DMBA (45 mg/kg bw). Lipid peroxidation malondialdehyde (MDA), catalase activity (CAT) and glutathione (GSH) levels in pancreatic tissue were determined by spectrophotometer. Protein expression levels of p53, HO-1, p38-α (MAPK), Nrf-2, NF-κB and COX-2 in pancreatic tissue were determined by western blotting technique. In our findings, compared to the group given DMBA, MDA levels and p38-α, NF-κB and COX-2 levels decreased, CAT activity, GSH level, total protein density and p53, HO-1, Nrf-2 levels in the groups given fullerene C60 nanoparticle an increase in expression levels was observed. Our results showed that fullerene C60 nanoparticle may be more beneficial in preventing pancreatic damage.

Drug-Induced Acute Pancreatitis in Hospitalized COVID-19 Patients

Coronavirus disease-19 (COVID-19), caused by SARS-CoV-2, is a systemic disease that affects not only the respiratory system, but also other systems, including gastrointestinal. A great number of different drugs have been used on hospitalized patients for the management of COVID-19, and acute pancreatitis (AP) has been reported as a complication or side effect of these drugs. The development of drug-induced acute pancreatitis (DIAP) follows a complex of pathophysiological mechanisms, and particular risk factors play a key role. Diagnosis of DIAP depends on specific criteria, and based on these, a drug may be characterized as having a definite, probable or possible connection with AP. The aim of this review is to present the medications that are used for COVID-19 management and are associated with AP in hospitalized patients. The list of these drugs mainly includes corticosteroids, glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), antiviral agents, antibiotics, monoclonal antibodies, estrogens and anesthetic agents. Moreover, the prevention of the development of DIAP is vital, especially for critically ill patients who may receive multiple drugs. DIAP management is mainly non-invasive and the first step concerns the exception of the suspicious drug from patients therapy.

Modeling type 2 diabetes in rats by administering tacrolimus

The prevalence of diabetes is rapidly increasing. The current number of diagnosed cases is ~422 million, expected to reach ~640 million by 2040. Type 2 diabetes, which constitutes ~95% of the cases, is characterized by insulin resistance and a progressive loss of β-cell function. Despite intense research efforts, no treatments are yet able to cure the disease or halt its progression. Since all existing animal models of type 2 diabetes have serious drawbacks, one is needed that represents the complete pathogenesis, is low cost and non-obese, and can be developed relatively quickly. The aim of this study was to evaluate a low-cost, non-obese model of type 2 diabetes engendered by administering a daily high dose of tacrolimus (an immunosuppressant) to Wistar rats for 4 weeks. The biochemical and antioxidant markers were measured at basal and after the 4-week tacrolimus treatment. At week 4, the values of these parameters closely resembled those observed in human type 2 diabetes, including fasting blood glucose at 141.5 mg/dL, blood glucose greater than 200 mg/dL at 120 min of the glucose tolerance test, blood glucose at varied levels in the insulin tolerance test, and elevated levels of cholesterol and triglyceride. The tacrolimus treatment produced hypoinsulinemia and sustained hyperglycemia, probably explained by the alteration found in pancreatic β-cell function and morphology. This model should certainly be instrumental for evaluating possible type 2 diabetes treatments, and for designing new immunosuppressants that do not cause pancreatic damage, type 2 diabetes, or new-onset diabetes after transplantation (NODAT).

Phytochemicals with protective effects against acute pancreatitis: a review of recent literature

CONTEXT

Acute pancreatitis (AP) is an acute abdominal inflammatory disease with episodes ranging from mild to fulminant symptoms which could include necrosis, systemic inflammation and multiple organ dysfunction. Increasing experimental evidence demonstrates that specific bioactive ingredients from natural plants have a favourable therapeutic effect on AP.

OBJECTIVE

The objective of this review is to summarize the protective effects and potential mechanisms of action of phytochemicals on the attenuation of AP.

METHODS

Experimental studies in vivo or in vitro between January 2016 and June 2021 were sought in PubMed and Web of Science using the following search terms: ('phytochemicals' OR 'medicinal plant' OR 'traditional medicine') AND ('pancreatitis' OR 'pancreatic damage' OR 'pancreatic injury'). Data concerning the basic characteristics of phytochemicals, therapeutic dose and potential molecular mechanisms related to AP were extracted in this study.

RESULTS

A total of 30 phytochemicals with potential therapeutic effects were reviewed and summarized systematically. According to their molecular pathways in AP, the underlying mechanisms of the phytochemicals were illustrated in detail.

DISCUSSION AND CONCLUSIONS

The phytochemicals with anti-inflammatory and antioxidant abilities may be efficient candidate drugs for AP treatment. Importantly, more preclinical investigations are needed to illustrate the efficacy of future phytochemicals.

Effect of Anti-TNFα Therapy by Infliximab against Pancreatic Tissue Damage in Severe Acute Necrotizing Pancreatitis

Nowadays, it is difficult to find a more complicated inflammatory disease of the abdominal organs in its pathogenesis than acute pancreatitis (AP). The application of antimediatory drugs and antimetabolites is the most promising direction in the correction of inflammatory pathological processes. The study of possible applications of a new group of drugs (monoclonal antibodies) that may trigger inflammation is also of great interest. The present study aimed to study the effect of infliximab on the lethality, volume, and nature of pancreatic lesions in severe necrotizing ductal pancreatic necrosis. The study was conducted on female Wistar rats (n=30) of similar age in the weight range of 200-250g. All manipulations were performed under general anesthesia by intraperitoneal injection of zoletil at a dose of 60 mg/kg, as well as chloral hydrate at a dose of 125 mg/kg. Model of severe acute necrotizing pancreatitis was performed through the injection of 0.5 ml of a buffer solution containing a bile acid salt-sodium taurocholate introductory. The animals were divided into the following groups: Group A (n=6): normal values; Group B (n=6): the mortality study was conducted in acute destructive pancreatitis in a period of 24 h; Group C (n=6): the simulation of acute severe necrotic pancreatitis was performed in this group along with the study of the volume of pancreatic lesions for a period of 6 h from the moment of modeling; Group D (n=6): in this group, the effect of infliximab (at a dose of 60 mkg/kg) was studied on mortality in severe destructive pancreatitis for a period of 24 h from the moment of modeling; Group E (n=6): in this group, the effect of infliximab (at a dose of 120 mkg/kg) was studied on the volume of pancreatic lesions in severe destructive pancreatitis for a period of 6 h from the moment of modeling. During the assessment of pancreatic damage, the mean±SD volume of pancreatic lesions was determined to be 34.8%±1.2% in a period of 6 h after modeling. Assessment of pancreatic damage in group E and the protective effect of infliximab at a dose of 60 mg/kg showed that the total volume of the necrotic pancreatic lesion was determined to be 21.3%±1.4% after a period of 6 h from the moment of AP modeling. In the course of this study, it was revealed that the application of infliximab at a dose of 60 mcg/kg led to a pronounced positive effect on the pancreatic lesion, manifested by up to 50% decrease in mortality for one day in group D. Infliximab had a definite protective effect in AP, decreasing the volume of the injury, as well as the mortality rate by half for 24 h. Therapy with anti-tumor necrosis factor with infliximab could significantly reduce the volume of pancreatic lesions in severe forms of pancreatic necrosis, which contributed to a pronounced decrease in mortality for 1 day from the moment of pathology reproduction.

Comparison of Pancreatic Damage in Rats for Two Methods of Paraquat Administration

It is noted that elevated serum amylase levels suggesting pancreatic damage has an association with prognosis in PQ patients. This study aimed to determine whether PQ can cause pancreatic damage. The two conventional models (intragastric infusion (iG) and intraperitoneal injection (iP)) may exhibit different effects on the pancreas depending on whether or not they pass through the digestive tract. In this study, the rats were divided into four groups: the intragastric infusion group (PQ-iG, n = 45), intraperitoneal injection group (PQ-iP, n = 53), normal control group 1 (NC-iG, n = 6) and normal control group 2 (NC-iP, n = 6). Pancreatic damage was compared between groups using serum amylase activity assay, hematoxylin and eosin (H&E) staining, TUNEL assay, and transmission electron microscopy (TEM). Serum amylase levels in group PQ-iG were significantly higher than in group PQ-iP (p < 0.05). Examination of the H&E sections showed damage to the pancreas. Both experimental groups were displayed inflammatory infiltration within 9 h of PQ treatment. After 9 h, patchy necrosis was observed in group PQ-iP, when inflammatory infiltration was still the dominant pathology. Necrosis appeared and gradually worsened in group PQ-iG, in which necrosis was the dominant pathology. The TUNEL assay showed significantly higher numbers of apoptotic cells in the pancreas of PQ-groups than in the control NC- groups (p < 0.05). TEM showed expansive endoplasmic reticulum lumens and mitochondria swelling in the pancreas of the PQ-groups. It is concluded that both methods of modeling could cause pancreatic damage and the type and degree of damage would change over time. Note that pancreatic damage in group PQ-iG was more severe than that in group PQ-iP. Therefore, clinical practitioners should pay close attention to pancreatic damage caused by PQ, especially when the route of PQ administration was oral.

Oxidized Pork Induces Disorders of Glucose Metabolism in Mice

SCOPE

Consumption of red meat, particularly processed red meat, has been reported to be associated with type 2 diabetes risk, and oxidized proteins and amino acids may be involved in this process. This study explores the effects of pork with varying degrees of oxidative injury caused by cooking on glucose metabolism in mice.

METHODS AND RESULTS

Cooked pork is freeze-dried to prepare animal feed. Mice are fed either a control diet (CON), a low- (LOP), or a high-oxidative injury pork diet (HOP) for 12 weeks. Intake of HOP causes hyperglycemia, hypoinsulinemia, and impaired glucose tolerance, indicating a glucose metabolism disorder. Accumulation of oxidation products increases oxidative stress and inflammatory response, which impairs pancreatic islet β cells function and reduces insulin secretion. Moreover, HOP-mediated hyperglycemia can be partly attributed to elevated hepatic glucose output, as indicated by increased gluconeogenesis and glycogenolysis, and decreased glycolysis and glycogen content. Changes in these processes may be regulated by reduced insulin levels and suppression of the insulin receptor substrate-1 (IRS-1)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and its downstream signaling molecules.

CONCLUSION

HOP intake induces disorders of glucose metabolism by impairing pancreatic insulin secretion and increasing hepatic glucose output. Protein oxidation plays a key role in abnormal glucose metabolism induced by HOP.

Can topical epinephrine application to the papilla prevent pancreatitis after endoscopic retrograde cholangiopancreatography? Results from a double blind, multicentre, placebo controlled, randomised clinical trial

Background and study aims

Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is a complication associated with important morbidity, occasional mortality and high costs. Preventive strategies are suboptimal as PEP continues to affect 4% to 9% of patients. Spraying epinephrine on the papilla may decrease oedema and prevent PEP. This study aimed to compare rectal indomethacin plus epinephrine (EI) versus rectal indomethacin plus sterile water (WI) for the prevention of PEP.

Patients and methods

This multicentre randomised controlled trial included patients aged >18 years with an indication for ERCP and naive major papilla. All patients received 100 mg of rectal indomethacin and 10 mL of sterile water or a 1:10 000 epinephrine dilution. Patients were asked about PEP symptoms via telephone 24 hours and 7 days after the procedure. The trial was stopped half way through after a new publication reported an increased incidence of PEP among patients receiving epinephrine.

Results

Of the 3602 patients deemed eligible, 3054 were excluded after screening. The remaining 548 patients were randomised to EI group (n=275) or WI group (n=273). The EI and WI groups had similar baseline characteristics. Patients in the EI group had a similar incidence of PEP to those in the WI group (3.6% (10/275) vs 5.12% (14/273), p=0.41). Pancreatic duct guidewire insertion was identified as a risk factor for PEP (OR 4.38, 95% CI (1.44 to 13.29), p=0.009).

Conclusion

Spraying epinephrine on the papilla was no more effective than rectal indomethacin alone for the prevention of PEP.

Trial registration number

This study was registered with ClinicalTrials.gov (NCT02959112).

Reduction of hepatorenal and pancreatic damage by Ferula elaeochytris extract in STZ induced diabetic rats

The therapeutic potential and antioxidant capacity of Ferula elaeochytris extract (FE) in the liver, kidney and pancreas of rats with diabetes induced by streptozotocin (STZ) was assessed using biochemistry, histopathology and immunohistochemistry. Forty adult Wistar albino male rats were divided randomly into five groups of eight rats each. The normal control (NC) group was untreated. The diabetes control (DC) group was treated with STZ to induce diabetes. The diabetes + acarbose group (DAC) was treated with STZ, then with acarbose daily for 28 days. The diabetes + FE (DFE) group was treated with STZ, then FE daily for 28 days. DC rats had inflammatory cell infiltration, hydropic degeneration and necrosis, whereas the DFE rats exhibited nearly normal histology. Insulin immunostaining in the pancreatic beta cells was decreased in the DC group compared to the NC group, whereas the DFE group was similar to the NC group. Many serum biomarkers of damage to liver, kidneys or pancreas were elevated in the DC group compared to the NC group; these biomarkers were decreased in the DFE group. The DC group exhibited increased malondialdehyde levels and decreased levels of the antioxidant defense system constituents compared to the NC group. The level of biomarkers the DFE group was close to the NC group. FE exhibited a protective effect against tissue damage owing to its antioxidant activities and to its ability to effect regeneration of β-cells in STZ induced diabetic rats.

Protective Role of Melatonin in Streptozotocin Induced Pancreatic Damages in Diabetic Wistar Rat

BACKGROUND AND OBJECTIVE

Hyperglycemia is a representative hallmark and risk factor for diabetes and is closely linked to diabetes associated complications. The aim of the present study was to evaluate the therapeutic potential of exogenous melatonin against the streptozotocin induced pancreatic damages in rats.

MATERIALS AND METHODS

Streptozotocin was injected for consecutive 6 days. Diabetes was confirmed by blood glucose measurement after 72 h and on 7th day after injection. Animals having blood glucose level above 250 mg dL-1 were considered as diabetic and were administered exogenous melatonin for 4 weeks. Animals were euthanized after last dose, pancreas were dissected out, weighed and fixed in Bouin's fixative for histology and further tissues were kept at -20°C for biochemistry.

RESULTS

Diabetic rats displayed significant increase in lipid peroxidation, but pancreatic weight index, antioxidant system (GSH, SOD and CAT) showed decrease. Melatonin treatment to diabetic rats restored the alteration in physiological and biochemical markers. Results were supported by the histopathological observations, STZ treated pancreas showed damage in islets of langerhans, while as melatonin treated diabetic rats recovered the cellular architecture which inturn normalize the function of the pancreas.

CONCLUSION

Therefore, melatonin might be considered as a molecule to protect the pancreatic damages.

Resveratrol increases stem cell function in the treatment of damaged pancreas

Pancreatic damage results in insufficient insulin secretion, leading to type 1 diabetes. Stem cell-based therapy has recently shown potential in the treatment of type 1 diabetes. Resveratrol supplementation has demonstrated a beneficial effect in treating diabetes. This study investigates if adipose-derived stem cells (ADSC), preconditioned with resveratrol, show better effects on experimental diabetic animals. Wistar rats were randomly divided into four groups including sham (normal rats), DM (diabetic rats induced by SZT injection), DM+ADSC (DM rats with receiving autologous ADSC transplantation) and DM+R-ADSC (DM rats receiving resveratrol preconditioned ADSC). The experimental results show that SZT induced pancreatic damage (DM group), including reduction of islet size, fibrosis pathway activation, survival signaling suppression, and apoptotic pathway expression, lead to serum glucose elevation. Autologous ADSC (DM+ADSC group) transplantation shows improvement in the above observations in DM rats. Furthermore, ADSC precondition with resveratrol (DM+R-ADSC group) reveals significant improvement in the above pathological observations over both DM and DM+ADSC groups. We found that ADSC precondition with resveratrol increases the survival marker p-Akt expression, leading to enhanced ADSC viability. This study suggests that ADSC precondition with resveratrol shows potential in the treatment of patients with type 1 DM.

Leea macrophylla root extract upregulates the mRNA expression for antioxidative enzymes and repairs the necrosis of pancreatic β-cell and kidney tissues in fructose-fed Type 2 diabetic rats

This research investigated the functional food effect of Leea macrophylla (Roxb.) ex Hornem root extract on pancreatic necrosis in Streptozotocin-induced type-2 diabetes. Prior to animal intervention, Leea macrophylla root extract (LMR) was subjected to GC-MS analysis. Across a three-week intervention of fructose-fed albino model with LMR50, LMR100 and LMR200, the fluid & food intake, body weight changes, weekly blood glucose concentrations and oral glucose tolerance (OGT) were recorded. The animals were sacrificed after intervention and serum was analyzed for insulin, ALT, AST, LDH, CK-MB, creatinine, uric acid and lipid profile and liver section was used for glycogen estimation. Changes of pancreas and kidney architecture were evaluated by histopathology. Relative mRNA for superoxide dismutase 1 (SOD1), glutathione peroxidase (GPx) and catalase (CAT) were quantitated using assay kits. Results showed that fluid and food intake, weekly blood glucose level, ALT, AST, LDH, CK-MB level were significantly (p < 0.05) decreased in LMR50 group. Conversely, the glucose tolerance ability, liver glycogen level, serum insulin, organ weight and pancreatic morphology were improved significantly in this group. Diameter of islet of Langerhans (μm), area occupied by β-cell/ islet of Langerhans (μm²) and number of β-cells/islet of Langerhans were amazingly improved to the NC animals. Expressions of mRNA for SOD1 and CAT from liver tissue have been found to be increased multifold while GPx was remained unchanged. The data suggests that L. macrophylla root extract could be very potential as functional food to modulate pancreatic action.

Treatment with Evasin-3 abrogates neutrophil-mediated inflammation in mouse acute pancreatitis

BACKGROUND

Acute pancreatitis is characterized by inflammatory processes affecting not only the pancreas, but also the lung. Here, we investigated timing of leucocyte infiltration and chemokine expression within lung and pancreas during pancreatitis and whether treatments selectively inhibiting chemokines (using Evasins) could improve organ injury.

MATERIAL AND METHODS

C57Bl/6 mice were submitted in vivo to 10-h intraperitoneal injections of cerulein and followed for up to 168 h. Five minutes after the first cerulein injection, a single intraperitoneal injection of 10 μg Evasin-3, 1 μg Evasin-4 or an equal volume of vehicle (PBS) was performed. Leucocytes, reactive oxygen species (ROS), necrosis and chemokine/cytokine mRNA expression were assessed in different organs by immunohistology and real-time RT-PCR, respectively.

RESULTS

In the lung, neutrophil infiltration and macrophage infiltration peaked at 12 h and were accompanied by increased CXCL2 mRNA expression. CCL2, CXCL1 and TNF-alpha significantly increased after 24 h as compared to baseline. No increase in CCL3 and CCL5 was observed. In the pancreas, neutrophil infiltration peaked at 6 h, while macrophages increased only after 72 h. Treatment with Evasin-3 decreased neutrophil infiltration, ROS production and apoptosis in the lung and reduced neutrophils, macrophages apoptosis and necrosis in the pancreas. Evasin-4 only reduced macrophage content in the lung and did not provide any benefit at the pancreas level.

CONCLUSION

Chemokine production and leucocyte infiltration are timely regulated in lung and pancreas during pancreatitis. CXC chemokine inhibition with Evasin-3 improved neutrophil inflammation and injury, potentially interfering with damages in acute pancreatitis and related pulmonary complications.

Comparison of the chronic effects of ribavirin and caffeic acid phenethyl ester (CAPE) on pancreatic damage and hepatotoxicity

This study was aimed to comparison of the effects of the chronic use of the Ribavirin and caffeic acid phenethyl ester (CAPE) on the pancreatic damage and hepatotoxicity in rats.

METHODS

The rats were given orally 30 mg/kg/day doses of Ribavirin for 30 days, and intraperitoneally 10 μmol/kg doses of CAPE. The 37 rats were divided into 4 groups: (I) Control (n=7), (II) Ribavirin (R) (n=10), (III) CAPE (n=10), and (IV) R+CAPE (n=10).

RESULTS

Ribavirin and CAPE yielded similar results in terms of Serum, total antioxidant status (TAS), total oxidant status (TOS), amylase, lipase, and insulin compared to the control group. However, while Ribavirin provided similar results with the control group in terms of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes, the CAPE group had elevated AST and ALT levels compared to the control group. Histopathologic evaluations revealed that CAPE or Ribavirin had no degenerative effects on both the pancreas and liver tissues. In this way, the biochemical results were confirmed by the histopathologic results.

CONCLUSION

It can be concluded that Ribavirin does not lead to any pancreatic damage and hepatotoxicity, and has more beneficial effects than CAPE on especially liver tissue.

Claudin-4-targeted optical imaging detects pancreatic cancer and its precursor lesions

OBJECTIVES

Novel imaging methods based on specific molecular targets to detect both established neoplasms and their precursor lesions are highly desirable in cancer medicine. Previously, we identified claudin-4, an integral constituent of tight junctions, as highly expressed in various gastrointestinal tumours including pancreatic cancer. Here, we investigate the potential of targeting claudin-4 with a naturally occurring ligand to visualise pancreatic cancer and its precursor lesions in vitro and in vivo by near-infrared imaging approaches.

DESIGN

A non-toxic C-terminal fragment of the claudin-4 ligand Clostridium perfringens enterotoxin (C-CPE) was labelled with a cyanine dye (Cy5.5). Binding of the optical tracer was analysed on claudin-4 positive and negative cells in vitro, and tumour xenografts in vivo. In addition, two genetically engineered mouse models for pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer were used for in vivo validation. Optical imaging studies were conducted using 2D planar fluorescence reflectance imaging (FRI) technology and 3D fluorescence-mediated tomography (FMT).

RESULTS

In vitro, the peptide-dye conjugate showed high binding affinity to claudin-4 positive CAPAN1 cells, while claudin-4 negative HT1080 cells revealed little or no fluorescence. In vivo, claudin-4 positive tumour xenografts, endogenous pancreatic tumours, hepatic metastases, as well as preinvasive PanIN lesions, were visualised by FRI and FMT up to 48 h after injection showing a significantly higher average of fluorochrome concentration as compared with claudin-4 negative xenografts and normal pancreatic tissue.

CONCLUSIONS

C-CPE-Cy5.5 combined with novel optical imaging methods enables non-invasive visualisation of claudin-4 positive murine pancreatic tumours and their precursor lesions, representing a promising modality for early diagnostic imaging.