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Journal of Clinical Medicine Feb 2024The pancreas has two main functions: to produce and secrete digestive enzymes (exocrine function) and to produce hormones that regulate blood glucose and splanchnic... (Review)
Review
The pancreas has two main functions: to produce and secrete digestive enzymes (exocrine function) and to produce hormones that regulate blood glucose and splanchnic secretion (endocrine function). The endocrine and exocrine portions of the pancreas are central regulators in digestion and metabolism, with continuous crosstalk between their deeply interconnected components, which plays a role in disease. Pancreatic neoplasms, inflammation, trauma, and surgery can lead to the development of type 3c diabetes when an insult simultaneously damages both acini and islets, leading to exocrine and endocrine dysfunction. In diabetes mellitus patients, pancreatic exocrine insufficiency is highly prevalent, yet little is known about the associations between diabetes mellitus and pancreatic exocrine function. This review aims to provide an overview of the physiology of the pancreas, summarize the pathophysiology and diagnostic work-up of pancreatic exocrine insufficiency, and explore the relationships between exocrine pancreatic insufficiency and diabetes mellitus.
PubMed: 38398492
DOI: 10.3390/jcm13041179 -
Journal of Experimental & Clinical... Aug 2023Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant...
BACKGROUND
Gemcitabine resistance has brought great challenges to the treatment of pancreatic cancer. The N6-methyladenosine (m6A) mutation has been shown to have a significant regulatory role in chemosensitivity; however, it is not apparent whether gemcitabine resistance can be regulated by fat mass and obesity-associated protein (FTO).
METHODS
Cells with established gemcitabine resistance and tissues from pancreatic cancer patients were used to evaluate FTO expression. The biological mechanisms of the effects of FTO on gemcitabine resistant cells were investigated using CCK-8, colony formation assay, flow cytometry, and inhibitory concentration 50. Immunoprecipitation/mass spectrometry, MeRIP-seq, RNA sequencing and RIP assays, RNA stability, luciferase reporter, and RNA pull down assays were employed to examine the mechanism of FTO affecting gemcitabine resistant pancreatic cancer cells.
RESULTS
The results revealed that FTO was substantially expressed in cells and tissues that were resistant to gemcitabine. Functionally, the gemcitabine resistance of pancreatic cancer could be enhanced by FTO, while its depletion inhibited the growth of gemcitabine resistant tumor cells in vivo. Immunoprecipitation/mass spectrometry showed that the FTO protein can be bound to USP7 and deubiquitinated by USP7, leading to the upregulation of FTO. At the same time, FTO knockdown significantly decreased the expression level of NEDD4 in an m6A-dependent manner. RNA pull down and RNA immunoprecipitation verified YTHDF2 as the reader of NEDD4, which promoted the chemoresistance of gemcitabine resistant cells. FTO knockdown markedly increased the PTEN expression level in an NEDD4-dependent manner and influenced the chemosensitivity to gemcitabine through the PI3K/AKT pathway in pancreatic cancer cells.
CONCLUSION
In conclusion, we found that gemcitabine resistance in pancreatic cancer can be influenced by FTO that demethylates NEDD4 RNA in a m6A-dependent manner, which then influences the PTEN expression level and thereby affects the PI3K/AKT pathway. We also identified that the FTO level can be upregulated by USP7.
Topics: Humans; Gemcitabine; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Ubiquitin-Specific Peptidase 7; RNA Stability; Pancreatic Neoplasms; PTEN Phosphohydrolase; Alpha-Ketoglutarate-Dependent Dioxygenase FTO
PubMed: 37605223
DOI: 10.1186/s13046-023-02792-0 -
Current Gastroenterology Reports Oct 2023Immune checkpoint inhibitors (ICI) have revolutionized cancer care and work primarily by blocking CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), and/or PD-1... (Review)
Review
PURPOSE OF REVIEW
Immune checkpoint inhibitors (ICI) have revolutionized cancer care and work primarily by blocking CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), and/or PD-1 (programmed cell death protein 1), and/or PD-L1 (programmed death-ligand 1), thereby providing highly efficacious anti-tumor activity. However, this unmitigated immune response can also trigger immune related adverse events (irAEs) in multiple organs, with pancreatic irAEs (now referred to as type 3 Autoimmune pancreatitis (AIP) being infrequent.
RECENT FINDINGS
Type 3 AIP is a drug-induced, immune mediated progressive inflammatory disease of the pancreas that may have variable clinical presentations viz., an asymptomatic pancreatic enzyme elevation, incidental imaging evidence of pancreatitis, painful pancreatitis, or any combination of these subtypes. Management is largely supportive with intravenous fluid hydration, pain control and holding the inciting medication. Steroids have not been shown to demonstrate a clear benefit in acute management. A rapid development pancreatic atrophy is observed on imaging as early as 1 year post initial injury. Type 3 AIP is a chronic inflammatory disease of the pancreas that though predominantly asymptomatic and mild in severity can lead to rapid organ volume loss regardless of type of clinical presentation and despite steroid therapy.
Topics: Humans; Autoimmune Pancreatitis; Immune Checkpoint Inhibitors; Neoplasms; Pancreas; Pancreatitis
PubMed: 37845557
DOI: 10.1007/s11894-023-00885-6 -
Current Opinion in Gastroenterology Sep 2023The diagnosis and management of exocrine pancreatic dysfunction (EPD) can be challenging. EPD classically results from conditions that cause loss of pancreatic acinar... (Review)
Review
PURPOSE OF REVIEW
The diagnosis and management of exocrine pancreatic dysfunction (EPD) can be challenging. EPD classically results from conditions that cause loss of pancreatic acinar cell function and decreased digestive enzyme production. However, several conditions may contribute to signs or symptoms of EPD with otherwise normal pancreatic exocrine function. A thoughtful approach to considering these conditions, along with their specific therapies, can guide a tailored management approach.
RECENT FINDINGS
An EPD severity classification schema has been proposed, which emphasizes a shift towards a more restrictive prescription of pancreas enzyme replacement therapy (PERT) for patients with milder EPD. In contrast, PERT use has been associated with a measurable survival benefit among individuals with EPD and pancreatic cancer, so the prescription of PERT may be more liberal in this population. Recent publications in the cystic fibrosis population offer pearls guiding the titration and optimization of PERT.
SUMMARY
Among individuals with severe EPD, PERT is an effective therapy. Among individuals with milder EPD, although PERT is effective, there may be opportunities to provide additional and potentially more effective therapies.
Topics: Humans; Exocrine Pancreatic Insufficiency; Pancreas; Pancreatic Neoplasms; Gastrointestinal Agents
PubMed: 37530731
DOI: 10.1097/MOG.0000000000000951 -
Minerva Surgery Dec 2023Being an underdiagnosed and under or insufficiently treated condition, surgical pancreatic exocrine insufficiency (PSP) is the condition in which pancreatic enzymes are...
Being an underdiagnosed and under or insufficiently treated condition, surgical pancreatic exocrine insufficiency (PSP) is the condition in which pancreatic enzymes are insufficient for digestion because of gastrointestinal (GI) surgery involving the upper GI tract, biliary ducts, or the pancreas, and and leading to potential malnutrition and deterioration in quality of life. Age, obesity, history of tobacco use, family history of diabetes, surgery due to a malignant tumor, presence of steatorrhea, jaundice, weight loss, and intraoperative findings of hard pancreatic texture have been associated with a higher risk of PSP. Pancreatoduodectomy (PD) has demonstrated an increased risk of developing PSP, with a prevalence between 19-100%. Distal pancreatectomy (DP) and central pancreatectomy (CenP) are associated with less risk of PSP, with a prevalence of 0-82% and 3.66-8.7%, respectively. In patients with chronic pancreatitis (CP), PSP was associated with 80% in Partington-Rochelle procedure, 86% in Frey procedure, 80% in duodenum preserving pancreatic head procedure, >60% in PD and 27.5-63% in DP. Fecal elastase-1 (FE-1) is a generally accepted tool for diagnosis. Treatment is recommended to start as soon as a diagnosis is achieved, or clinical suspicion is high. Pancreatic enzyme replacement therapy improves symptoms of malabsorption, facilitates weight gain, and ultimately improves patients' quality of life. Starting dosage is between 10,000-50,000 units in snacks and 50,000-75,000 units in main meals, administered throughout food intake, though further data specifically on PSP are needed. Follow-up in PSP is recommended on an on-demand basis, where malnutrition should be assessed.
Topics: Humans; Quality of Life; Exocrine Pancreatic Insufficiency; Pancreas; Pancreatectomy; Malnutrition
PubMed: 38059441
DOI: 10.23736/S2724-5691.23.10125-0 -
Diabetologia Nov 2023Increased circulating levels of incompletely processed insulin (i.e. proinsulin) are observed clinically in type 1 and type 2 diabetes. Previous studies have suggested...
AIMS/HYPOTHESIS
Increased circulating levels of incompletely processed insulin (i.e. proinsulin) are observed clinically in type 1 and type 2 diabetes. Previous studies have suggested that Ca signalling within beta cells regulates insulin processing and secretion; however, the mechanisms that link impaired Ca signalling with defective insulin maturation remain incompletely understood.
METHODS
We generated mice with beta cell-specific sarcoendoplasmic reticulum Ca ATPase-2 (SERCA2) deletion (βS2KO mice) and used an INS-1 cell line model of SERCA2 deficiency. Whole-body metabolic phenotyping, Ca imaging, RNA-seq and protein processing assays were used to determine how loss of SERCA2 impacts beta cell function. To test key findings in human model systems, cadaveric islets were treated with diabetogenic stressors and prohormone convertase expression patterns were characterised.
RESULTS
βS2KO mice exhibited age-dependent glucose intolerance and increased plasma and pancreatic levels of proinsulin, while endoplasmic reticulum (ER) Ca levels and glucose-stimulated Ca synchronicity were reduced in βS2KO islets. Islets isolated from βS2KO mice and SERCA2-deficient INS-1 cells showed decreased expression of the active forms of the proinsulin processing enzymes PC1/3 and PC2. Additionally, immunofluorescence staining revealed mis-location and abnormal accumulation of proinsulin and proPC2 in the intermediate region between the ER and the Golgi (i.e. the ERGIC) and in the cis-Golgi in beta cells of βS2KO mice. Treatment of islets from human donors without diabetes with high glucose and palmitate concentrations led to reduced expression of the active forms of the proinsulin processing enzymes, thus phenocopying the findings observed in βS2KO islets and SERCA2-deficient INS-1 cells. Similar findings were observed in wild-type mouse islets treated with brefeldin A, a compound that perturbs ER-to-Golgi trafficking.
CONCLUSIONS/INTERPRETATION
Taken together, these data highlight an important link between ER Ca homeostasis and proinsulin processing in beta cells. Our findings suggest a model whereby chronic ER Ca depletion due to SERCA2 deficiency impairs the spatial regulation of prohormone trafficking, processing and maturation within the secretory pathway.
DATA AVAILABILITY
RNA-seq data have been deposited in the Gene Expression Omnibus (GEO; accession no.: GSE207498).
Topics: Mice; Humans; Animals; Proinsulin; Insulin-Secreting Cells; Diabetes Mellitus, Type 2; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Insulin; Glucose; Islets of Langerhans
PubMed: 37537395
DOI: 10.1007/s00125-023-05979-4 -
Cancer Letters Oct 2023Pancreatic ductal adenocarcinoma (PDAC) is a highly life-threatening tumour with a low early-detection rate, rapid progression and a tendency to develop resistance to... (Review)
Review
Pancreatic ductal adenocarcinoma (PDAC) is a highly life-threatening tumour with a low early-detection rate, rapid progression and a tendency to develop resistance to chemotherapy. Therefore, understanding the regulatory mechanisms underlying the initiation, development and metastasis of pancreatic cancer is necessary for enhancing therapeutic effectiveness. In this review, we summarised single-gene mutations (including KRAS, CDKN2A, TP53, SMAD4 and some other less prevalent mutations), epigenetic changes (including DNA methylation, histone modifications and RNA interference) and large chromosome alterations (such as copy number variations, chromosome rearrangements and chromothripsis) associated with PDAC. In addition, we discussed variations in signalling pathways that act as intermediate oncogenic factors in PDAC, including PI3K/AKT, MAPK/ERK, Hippo and TGF-β signalling pathways. The focus of this review was to investigate alterations in the microenvironment of PDAC, particularly the role of immunosuppressive cells, cancer-associated fibroblasts, lymphocytes, other para-cancerous cells and tumour extracellular matrix in tumour progression. Peripheral axons innervating the pancreas have been reported to play a crucial role in the development of cancer. In addition, tumour cells can influence the behaviour of neighbouring non-tumour cells by secreting certain factors, both locally and at a distance. In this review, we elucidated the alterations in intracellular molecules and the extracellular environment that occur during the progression of PDAC. Altogether, this review may enhance the understanding of the biological characteristics of PDAC and guide the development of more precise treatment strategies.
Topics: Humans; DNA Copy Number Variations; Phosphatidylinositol 3-Kinases; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Tumor Microenvironment
PubMed: 37714257
DOI: 10.1016/j.canlet.2023.216391 -
The EMBO Journal Jul 2023How pancreatic cancer cells acquire tumor initiating capacities remains poorly understood. A recent study by Yamazaki et al (2023) uncovers a crucial, targetable role...
How pancreatic cancer cells acquire tumor initiating capacities remains poorly understood. A recent study by Yamazaki et al (2023) uncovers a crucial, targetable role of tyrosine kinase-like orphan receptor (ROR1) in PDAC tumor formation and progression.
Topics: Humans; Pancreatic Neoplasms; Pancreas; Cell Line, Tumor; Receptor Tyrosine Kinase-like Orphan Receptors
PubMed: 37312634
DOI: 10.15252/embj.2023114282 -
The Journal of Organic Chemistry Oct 2023Enantioselective synthesis of nabscessin C (), an aminocyclitol amide with antimicrobial activity, is reported. Starting from -inositol, (+)-nabscessin C was synthesized...
Enantioselective synthesis of nabscessin C (), an aminocyclitol amide with antimicrobial activity, is reported. Starting from -inositol, (+)-nabscessin C was synthesized in 12 isolation steps. Desymmetrization of 2-deoxygenated 4,6-dibenzylinositol was achieved using lipase from porcine pancreas (PPL), and the stereochemistry was established by X-ray crystallography. This method has the potential for synthesizing other cyclitol-derived compounds.
Topics: Animals; Swine; Cyclitols; Stereoisomerism; Lipase; Inositol
PubMed: 37681712
DOI: 10.1021/acs.joc.3c01064