REDOX SIGNALLING IN THE PANCREAS IN HEALTH AND DISEASE.

This review addresses oxidative stress and redox signaling in the pancreas under physiological conditions as well as in acute pancreatitis, chronic pancreatitis, pancreatic cancer, and diabetes. Physiological redox homeodynamics is maintained mainly by NRF2/KEAP1, NF-κB, protein tyrosine phosphatases, peroxisome proliferator-activated receptor-γ co-activator 1α (PGC1α), and normal autophagy. Depletion of reduced glutathione in the pancreas is a hallmark of acute pancreatitis and is initially accompanied by disulfide stress, which is characterized by protein cysteinylation without increased glutathione oxidation. A cross-talk between oxidative stress, MAPKs, and NF-κB amplifies the inflammatory cascade, acting PP2A and PGC1α as key redox regulatory nodes. In acute pancreatitis, nitration of cystathionine-ß synthase causes blockade of the trans-sulfuration pathway leading to increased homocysteine levels, whereas p53 triggers necroptosis in the pancreas through downregulation of sulfiredoxin, PGC1α, and peroxiredoxin 3. Chronic pancreatitis exhibits oxidative distress mediated by NADPH oxidase 1 and/or CYP2E1, which promotes cell death, fibrosis, and inflammation. Oxidative stress cooperates with mutant KRAS to initiate and promote pancreatic adenocarcinoma. Mutant KRAS increases mitochondrial ROS, which trigger acinar-to-ductal metaplasia and progression to PanIN. ROS are maintained at sufficient level to promote cell proliferation, whilst avoiding cell death or senescence through formation of NADPH and GSH, and activation of NRF-2, HIF-1/2α, and CREB. Redox signalling also plays a fundamental role in differentiation, proliferation, and insulin secretion of ß-cells. However, ROS overproduction promotes ß-cell dysfunction and apoptosis in type 1 and type 2 diabetes.

Very-low-density lipoprotein receptor-enhanced lipid metabolism in pancreatic stellate cells promotes pancreatic fibrosis.

Lipoprotein disorder is a common feature of chronic pancreatitis (CP); however, the relationship between lipoprotein disorder and pancreatic fibrotic environment is unclear. Here, we investigated the occurrence and mechanism of pancreatic stellate cell (PSC) activation by lipoprotein metabolites and the subsequent regulation of type 2 immune responses, as well as the driving force of fibrotic aggressiveness in CP. Single-cell RNA sequencing revealed the heterogeneity of PSCs and identified very-low-density lipoprotein receptor (VLDLR)+ PSCs that were characterized by a higher lipid metabolism. VLDLR promoted intracellular lipid accumulation, followed by interleukin-33 (IL-33) expression and release in PSCs. PSC-derived IL-33 strongly induced pancreatic group 2 innate lymphoid cells (ILC2s) to trigger a type 2 immune response accompanied by the activation of PSCs, eventually leading to fibrosis during pancreatitis. Our findings indicate that VLDLR-enhanced lipoprotein metabolism in PSCs promotes pancreatic fibrosis and highlight a dominant role of IL-33 in this pro-fibrotic cascade.

Combining full-length gene assay and SpliceAI to interpret the splicing impact of all possible SPINK1 coding variants.

BACKGROUND: Single-nucleotide variants (SNVs) within gene coding sequences can significantly impact pre-mRNA splicing, bearing profound implications for pathogenic mechanisms and precision medicine. In this study, we aim to harness the well-established full-length gene splicing assay (FLGSA) in conjunction with SpliceAI to prospectively interpret the splicing effects of all potential coding SNVs within the four-exon SPINK1 gene, a gene associated with chronic pancreatitis. RESULTS: Our study began with a retrospective analysis of 27 SPINK1 coding SNVs previously assessed using FLGSA, proceeded with a prospective analysis of 35 new FLGSA-tested SPINK1 coding SNVs, followed by data extrapolation, and ended with further validation. In total, we analyzed 67 SPINK1 coding SNVs, which account for 9.3% of the 720 possible coding SNVs. Among these 67 FLGSA-analyzed SNVs, 12 were found to impact splicing. Through detailed comparison of FLGSA results and SpliceAI predictions, we inferred that the remaining 653 untested coding SNVs in the SPINK1 gene are unlikely to significantly affect splicing. Of the 12 splice-altering events, nine produced both normally spliced and aberrantly spliced transcripts, while the remaining three only generated aberrantly spliced transcripts. These splice-impacting SNVs were found solely in exons 1 and 2, notably at the first and/or last coding nucleotides of these exons. Among the 12 splice-altering events, 11 were missense variants (2.17% of 506 potential missense variants), and one was synonymous (0.61% of 164 potential synonymous variants). Notably, adjusting the SpliceAI cut-off to 0.30 instead of the conventional 0.20 would improve specificity without reducing sensitivity. CONCLUSIONS: By integrating FLGSA with SpliceAI, we have determined that less than 2% (1.67%) of all possible coding SNVs in SPINK1 significantly influence splicing outcomes. Our findings emphasize the critical importance of conducting splicing analysis within the broader genomic sequence context of the study gene and highlight the inherent uncertainties associated with intermediate SpliceAI scores (0.20 to 0.80). This study contributes to the field by being the first to prospectively interpret all potential coding SNVs in a disease-associated gene with a high degree of accuracy, representing a meaningful attempt at shifting from retrospective to prospective variant analysis in the era of exome and genome sequencing.

Meflin is a marker of pancreatic stellate cells involved in fibrosis and epithelial regeneration in the pancreas.

Pancreatic stellate cells (PSCs) are stromal cells in the pancreas that play an important role in pancreatic pathology. In chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC), PSCs are known to get activated to form myofibroblasts or cancer-associated fibroblasts (CAFs) that promote stromal fibroinflammatory reactions. However, previous studies on PSCs were mainly based on the findings obtained using ex vivo expanded PSCs, with few studies that addressed the significance of in situ tissue-resident PSCs using animal models. Their contributions to fibrotic reactions in CP and PDAC are also lesser-known. These limitations in our understanding of PSC biology have been attributed to the lack of specific molecular markers of PSCs. Herein, we established Meflin (Islr), a glycosylphosphatidylinositol-anchored membrane protein, as a PSC-specific marker in both mouse and human by using human pancreatic tissue samples and Meflin reporter mice. Meflin-positive (Meflin+ ) cells contain lipid droplets and express the conventional PSC marker Desmin in normal mouse pancreas, with some cells also positive for Gli1, the marker of pancreatic tissue-resident fibroblasts. Three-dimensional analysis of the cleared pancreas of Meflin reporter mice showed that Meflin+ PSCs have long and thin cytoplasmic protrusions, and are localised on the abluminal side of vessels in the normal pancreas. Lineage tracing experiments revealed that Meflin+ PSCs constitute one of the origins of fibroblasts and CAFs in CP and PDAC, respectively. In these diseases, Meflin+ PSC-derived fibroblasts showed a distinctive morphology and distribution from Meflin+ PSCs in the normal pancreas. Furthermore, we showed that the genetic depletion of Meflin+ PSCs accelerated fibrosis and attenuated epithelial regeneration and stromal R-spondin 3 expression, thereby implying that Meflin+ PSCs and their lineage cells may support tissue recovery and Wnt/R-spondin signalling after pancreatic injury and PDAC development. Together, these data indicate that Meflin may be a marker specific to tissue-resident PSCs and useful for studying their biology in both health and disease. © 2023 The Pathological Society of Great Britain and Ireland.

Optimized rAAV8 targeting acinar KLF4 ameliorates fibrosis in chronic pancreatitis via exosomes-enriched let-7s suppressing pancreatic stellate cells activation.

Chronic pancreatitis (CP) is marked by progressive fibrosis and the activation of pancreatic stellate cells (PSCs), accompanied by the destruction of pancreatic parenchyma, leading to the loss of acinar cells (ACs). Few research studies have explored the mechanism by which damaged ACs (DACs) contribute to PSCs activation and pancreatic fibrosis. Currently, there are no effective drugs for curing CP or limiting the progression of pancreatic fibrosis. In this research, co-culture with intact acinar cells (IACs) suppressed PSC activation, while co-culture with DACs did the opposite. Krüppel-like factor 4 (KLF4) was significantly upregulated in DACs and was established as the key molecule that switches ACs from PSCs-suppressor to PSCs-activator. We revealed the exosomes of IACs contributed to the anti-activated function of IACs-CS on PSCs. MiRNome profiling showed that let-7 family is significantly enriched in IAC-derived exosomes (>30% miRNome), which partially mediates IACs' suppressive impacts on PSCs. Furthermore, it has been observed that the enrichment of let-7 in exosomes was influenced by the expression level of KLF4. Mechanistic studies demonstrated that KLF4 in ACs upregulated Lin28A, thereby decreasing let-7 levels in AC-derived exosomes, and thus promoting PSCs activation. We utilized an adeno-associated virus specifically targeting KLF4 in ACs (shKLF4-pAAV) to suppress PSCs activation in CP, resulting in reduced pancreatic fibrosis. IAC-derived exosomes hold potential as potent weapons against PSCs activation via let-7s, while activated KLF4/Lin28A signaling in DACs diminished such functions. ShKLF4-pAAV holds promise as a novel therapeutic approach for CP.

Pancreas-directed AAV8-hSPINK1 gene therapy safely and effectively protects against pancreatitis in mice.

OBJECTIVE: Currently, there is no cure for chronic pancreatitis (CP). Germline loss-of-function variants in SPINK1 (encoding trypsin inhibitor) are common in patients with CP and are associated with acute attacks and progression of the disease. This preclinical study was conducted to explore the potential of adeno-associated virus type 8 (AAV8)-mediated overexpression of human SPINK1 (hSPINK1) for pancreatitis therapy in mice. DESIGN: A capsid-optimised AAV8-mediated hSPINK1 expression vector (AAV8-hSPINK1) to target the pancreas was constructed. Mice were treated with AAV8-hSPINK1 by intraperitoneal injection. Pancreatic transduction efficiency and safety of AAV8-hSPINK1 were dynamically evaluated in infected mice. The effectiveness of AAV8-hSPINK1 on pancreatitis prevention and treatment was studied in three mouse models (caerulein-induced pancreatitis, pancreatic duct ligation and Spink1 c.194+2T>C mouse models). RESULTS: The constructed AAV8-hSPINK1 vector specifically and safely targeted the pancreas, had low organ tropism for the heart, lungs, spleen, liver and kidneys and had a high transduction efficiency (the optimal expression dose was 2×1011 vg/animal). The expression and efficacy of hSPINK1 peaked at 4 weeks after injection and remained at significant level for up to at least 8 weeks. In all three mouse models, a single dose of AAV8-hSPINK1 before disease onset significantly alleviated the severity of pancreatitis, reduced the progression of fibrosis, decreased the levels of apoptosis and autophagy in the pancreas and accelerated the pancreatitis recovery process. CONCLUSION: One-time injection of AAV8-hSPINK1 safely targets the pancreas with high transduction efficiency and effectively ameliorates pancreatitis phenotypes in mice. This approach is promising for the prevention and treatment of CP.

Dysfunctional astrocyte glutamate uptake in the hypothalamic paraventricular nucleus contributes to visceral pain and anxiety-like behavior in mice with chronic pancreatitis.

Abdominal visceral pain is a predominant symptom in patients with chronic pancreatitis (CP); however, the underlying mechanism of pain in CP remains elusive. We hypothesized that astrocytes in the hypothalamic paraventricular nucleus (PVH) contribute to CP pain pathogenesis. A mouse model of CP was established by repeated intraperitoneal administration of caerulein to induce abdominal visceral pain. Abdominal mechanical stimulation, open field and elevated plus maze tests were performed to assess visceral pain and anxiety-like behavior. Fiber photometry, brain slice Ca2+ imaging, electrophysiology, and immunohistochemistry were used to investigate the underlying mechanisms. Mice with CP displayed long-term abdominal mechanical allodynia and comorbid anxiety, which was accompanied by astrocyte glial fibrillary acidic protein reactivity, elevated Ca2+ signaling, and astroglial glutamate transporter-1 (GLT-1) deficits in the PVH. Specifically, reducing astrocyte Ca2+ signaling in the PVH via chemogenetics significantly rescued GLT-1 deficits and alleviated mechanical allodynia and anxiety in mice with CP. Furthermore, we found that GLT-1 deficits directly contributed to the hyperexcitability of VGLUT2PVH neurons in mice with CP, and that pharmacological activation of GLT-1 alleviated the hyperexcitability of VGLUT2PVH neurons, abdominal visceral pain, and anxiety in these mice. Taken together, our data suggest that dysfunctional astrocyte glutamate uptake in the PVH contributes to visceral pain and anxiety in mice with CP, highlighting GLT-1 as a potential therapeutic target for chronic pain in patients experiencing CP.

Pancreatic Schwann cell reprogramming supports cancer-associated neuronal remodeling.

The peripheral nervous system is a key regulator of cancer progression. In pancreatic ductal adenocarcinoma (PDAC), the sympathetic branch of the autonomic nervous system inhibits cancer development. This inhibition is associated with extensive sympathetic nerve sprouting in early pancreatic cancer precursor lesions. However, the underlying mechanisms behind this process remain unclear. This study aimed to investigate the roles of pancreatic Schwann cells in the structural plasticity of sympathetic neurons. We examined the changes in the number and distribution of Schwann cells in a transgenic mouse model of PDAC and in a model of metaplastic pancreatic lesions induced by chronic inflammation. Schwann cells proliferated and expanded simultaneously with new sympathetic nerve sprouts in metaplastic/neoplastic pancreatic lesions. Sparse genetic labeling showed that individual Schwann cells in these lesions had a more elongated and branched structure than those under physiological conditions. Schwann cells overexpressed neurotrophic factors, including glial cell-derived neurotrophic factor (GDNF). Sympathetic neurons upregulated the GDNF receptors and exhibited enhanced neurite growth in response to GDNF in vitro. Selective genetic deletion of Gdnf in Schwann cells completely blocked sympathetic nerve sprouting in metaplastic pancreatic lesions in vivo. This study demonstrated that pancreatic Schwann cells underwent adaptive reprogramming during early cancer development, supporting a protective antitumor neuronal response. These finding could help to develop new strategies to modulate cancer associated neural plasticity.

Secretagogue-induced pancreatitis in mice devoid of chymotrypsin.

The serine protease chymotrypsin protects the pancreas against pancreatitis by degrading trypsinogen, the precursor to the digestive protease trypsin. Taking advantage of previously generated mouse models with either the Ctrb1 gene (encoding chymotrypsin B1) or the Ctrl gene (encoding chymotrypsin-like protease) disrupted, here we generated the novel Ctrb1-del × Ctrl-KO strain in the C57BL/6N genetic background, which harbors a naturally inactivated Ctrc gene (encoding chymotrypsin C). The newly created mice are devoid of chymotrypsin, yet the animals develop normally, breed well, and show no spontaneous phenotype, indicating that chymotrypsin is dispensable under laboratory conditions. When given cerulein, the Ctrb1-del × Ctrl-KO strain exhibited markedly increased intrapancreatic trypsin activation and more severe acute pancreatitis, relative to wild-type C57BL/6N mice. After the acute episode, Ctrb1-del × Ctrl-KO mice spontaneously progressed to chronic pancreatitis, whereas C57BL/6N mice recovered rapidly. The cerulein-induced pancreas pathology in Ctrb1-del × Ctrl-KO mice was highly similar to that previously observed in Ctrb1-del mice; however, trypsin activation was more robust and pancreatitis severity was increased. Taken together, the results confirm and extend prior observations demonstrating that chymotrypsin safeguards the pancreas against pancreatitis by limiting pathologic trypsin activity. In mice, the CTRB1 isoform, which constitutes about 90% of the total chymotrypsin content, is responsible primarily for the anti-trypsin defenses and protection against pancreatitis; however, the minor isoform CTRL also contributes to an appreciable extent.NEW & NOTEWORTHY Chymotrypsins defend the pancreas against the inflammatory disorder pancreatitis by degrading harmful trypsinogen. This study demonstrates that mice devoid of pancreatic chymotrypsins are phenotypically normal but become sensitized to secretagogue hyperstimulation and exhibit increased intrapancreatic trypsin activation, more severe acute pancreatitis, and rapid progression to chronic pancreatitis. The observations confirm and extend the essential role of chymotrypsins in pancreas health.

Metabolic Sequelae: The Pancreatitis Zeitgeist of the 21st Century.

Holistic management of pancreatitis means that gastroenterologists in the 21st Century should think beyond improving in-hospital outcomes of pancreatitis alone. In particular, there is considerable room for optimizing the management of new-onset diabetes, exocrine pancreatic insufficiency, and other metabolic sequelae of pancreatitis. The present article provides state-of-the-art information on classification, terminology, and burden of the common sequelae of pancreatitis. A high-risk group of patients with pancreatitis is identified, which is positioned to benefit the most from the metabolic sequelae surveillance program introduced in this article. The program involves continuous follow-up after pancreatitis diagnosis, with the focus on early identification of new-onset diabetes after pancreatitis and exocrine pancreatic insufficiency. The metabolic sequelae surveillance program is scalable and has the potential to reduce the burden of pancreatitis through tertiary prevention in the decades to come.

Multiparametric MRI Scoring System of the Pancreas for the Diagnosis of Chronic Pancreatitis.

BACKGROUND: Ductal features alone may not offer high diagnostic sensitivity or most accurate disease severity of chronic pancreatitis (CP). PURPOSE: Diagnose CP based on multiparametric MRI and MRCP features. STUDY TYPE: Prospective. POPULATION: Between February 2019 and May 2021, 46 control (23 males, 49.3 ± 14.1 years), 45 suspected (20 males, 48.7 ± 12.5 years), and 46 definite (20 males, 53.7 ± 14.6 years) CP patients were enrolled at seven hospitals enrolled in the MINIMAP study. CP classification was based on imaging findings and clinical presentation. FIELD STRENGTH AND SEQUENCES: 1.5 T. T1-weighted (T1W) spoiled gradient echo, T1 map with variable flip angle, dual-echo Dixon, secretin-enhanced MRCP before and after secretin infusion. ASSESSMENT: Dual-echo fat fraction (FF), T1 relaxation time, extracellular volume (ECV), T1 signal intensity ratio of the pancreas to the spleen (T1 score), arterial-to-venous enhancement ratio (AVR), pancreatic tail diameter (PTD), pancreas volume, late gadolinium enhancement, pancreatic ductal elasticity (PDE), and duodenal filling grade of secretin-enhanced MRCP were measured. STATISTICAL TESTS: Logistic regression analysis generated CP-MRI and secretin-enhanced CP-SMRI scores. Receiver operating characteristics analysis was used to differentiate definite CP from control. Interobserver agreement was assessed using Lin's concordance correlation coefficient. RESULTS: Compared to control, definite CP cohort showed significantly higher dual-echo FF (7% vs. 11%), lower AVR (1.35 vs. 0.85), smaller PTD (2.5 cm vs. 1.95 cm), higher ECV (28% vs. 38%), and higher incidence of PDE loss (6.5% vs. 50%). With the cut-off of >2.5 CP-MRI score (dual-echo FF, AVR, and PTD) and CP-SMRI score (dual-echo FF, AVR, PTD, and PDE) had cross-validated area under the curves of 0.84 (sensitivity 87%, specificity 68%) and 0.86 (sensitivity 89%, specificity 67%), respectively. Interobserver agreement for both CP-MRI and CP-SMRI scores was 0.74. CONCLUSION: The CP-MRI and CP-SMRI scores yielded acceptable performance and interobserver agreement for the diagnosis of CP. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Circulating immune signatures in chronic pancreatitis with and without preceding acute pancreatitis: A pilot study.

OBJECTIVE: To investigate profiles of circulating immune signatures in healthy controls and chronic pancreatitis patients (CP) with and without a preceding history of acute pancreatitis (AP). METHODS: We performed a phase 1, cross-sectional analysis of prospectively collected serum samples from the PROspective Evaluation of Chronic Pancreatitis for EpidEmiologic and Translation StuDies (PROCEED) study. All samples were collected during a clinically quiescent phase. CP subjects were categorized into two subgroups based on preceding episode(s) of AP. Healthy controls were included for comparison. Blinded samples were analyzed using an 80-plex Luminex assay of cytokines, chemokines, and adhesion molecules. Group and pairwise comparisons of analytes were performed between the subgroups. RESULTS: In total, 133 patients with CP (111 with AP and 22 without AP) and 50 healthy controls were included. Among the 80 analytes studied, CP patients with a history of AP had significantly higher serum levels of pro-inflammatory cytokines (interleukin (IL)-6, IL-8, IL-1 receptor antagonist, IL-15) and chemokines (Cutaneous T-Cell Attracting Chemokine (CTACK), Monokine induced Gamma Interferon (MIG), Macrophage-derived Chemokine (MDC), Monocyte Chemoattractant Protein-1 (MCP-1)) compared to CP without preceding AP and controls. In contrast, CP patients without AP had immune profiles characterized by low systemic inflammation and downregulation of anti-inflammatory mediators, including IL-10. CONCLUSION: CP patients with a preceding history of AP have signs of systemic inflammatory activity even during a clinically quiescent phase. In contrast, CP patients without a history of AP have low systemic inflammatory activity. These findings suggest the presence of two immunologically diverse subtypes of CP.

Increased kidney stone risk following total pancreatectomy with islet autotransplantation.

BACKGROUND/OBJECTIVES: Chronic pancreatitis (CP) is associated with increased risk of calcium-oxalate kidney stones, likely due to enteric hyperoxaluria. However, the risk of kidney stones for patients with CP after total pancreatectomy with islet autotransplantation (TPIAT) is unknown. We aimed to evaluate kidney stone risk in patients with CP after TPIAT. METHODS: A retrospective analysis of 629 patients who underwent TPIAT was conducted to identify patients who developed kidney stones post-TPIAT. Kaplan-Meier analysis estimated time to first event. An Anderson-Gill proportional-hazards analysis of all kidney stone events described key clinical associations. RESULTS: Mean age at TPIAT was 33 years (SD 15.3, range 3-69); 69.8 % (n = 439) were female. The estimated chance of any kidney stone episodes by 5 years post-TPIAT was 12.8 % (95 % CI: 8.8-16.6 %); by 10 years, 23.2 % (CI: 17.5-28.6 %); by 15 years, 29.4 % (CI: 21.8-36.2 %). Significant associations with kidney stones post-TPIAT included older age (HR 1.25 per 10 years), smoking history (HR 1.72), mild chronic kidney disease (HR 1.96), renal cysts (HR 3.67), pre-TPIAT kidney stones (HR 4.06), family history of kidney stones (HR 4.10), and Roux-en-Y reconstruction (HR 2.68). Of the 77 patients who developed kidney stones, 34 (44.1 %) had recurrent episodes. Of 143 total kidney stone events, 35 (24.5 %) required stone removal, 79 (55.2 %) resolved spontaneously, and 29 (20.3 %) were missing this data. CONCLUSIONS: Patients with CP post-TPIAT commonly have kidney stones: nearly 3 in 10 have ≥1 kidney stone episodes within 15 years. Clinicians should be aware of this risk and counsel patients on prevention.

Pancreatitis pain quality changes at year 1 follow-up, but GP130 remains a biomarker for pain.

BACKGROUND/OBJECTIVES: Debilitating abdominal pain is a common symptom affecting patients with chronic pancreatitis (CP). CP pain is dynamic due to multiple underlying mechanisms. The objective of this study was to 1) evaluate changes in pain phenotype at one year follow-up and 2) validate putative pain biomarkers in a prospective cohort study. METHODS: The Neuropathic and Nociceptive PROMIS-PQ questionnaires were used to classify pain for participants with in the PROCEED study. Putative serum biomarkers were measured via immunoassay. RESULTS: At enrollment, 17.6 % (120/681) subjects with CP reported no pain in the previous year. Of those, 29 % experienced pain during the 1 yr follow-up whereas 18 % of those with pain prior to enrollment reported no pain during the 1 yr follow-up period. Of the 393 subjects with PROMIS-PQ data at enrollment, 212 also had follow-up data at 1 yr. Approximately half (53.3 %) of those individuals changed pain phenotype between baseline and follow-up. At 1 yr, serum TGFß1 level was negatively correlated with nociceptive T-scores (p = 0.006). GP130 was significantly correlated with both nociceptive (p = 0.012) and neuropathic T-scores (p = 0.043) at 1 yr, which is consistent with the previously published findings. CONCLUSIONS: The positive association between TGFß1 and pain is not maintained over time, suggesting it is a poor pain biomarker. However, serum GP130 is a consistent biomarker for mixed-type pain in CP. Preclinical studies show that targeting TGFß1 or IL-6 (ligand for GP130) is sufficient to inhibit CP pain supporting further investigation of this as a potential therapeutic target.

Heterozygous Spink1 c.194+2T>C mutation promotes chronic pancreatitis after acute attack in mice.

BACKGROUND & AIMS: Mutations in genes, including serine protease inhibitor Kazal-type 1 (SPINK1), influence disease progression following sentinel acute pancreatitis event (SAPE) attacks. SPINK1 c.194+2T > C intron mutation is one of the main mutants of SPINK1，which leads to the impairment of SPINK1 function by causing skipping of exon 3. Research on the pathogenesis of SAPE attacks would contribute to the understanding of the outcomes of acute pancreatitis. Therefore, the aim of the study was to clarify the role of SPINK1 c.194+2T > C mutation in the CP progression after an AP attack. METHODS: SAPE attacks were induced in wildtype and SPINK mutant (Spink1 c.194+2T > C) mice by cerulein injection. The mice were sacrificed at 24 h, 14 d, 28 d, and 42 d post-SAPE. Data-independent acquisition (DIA) proteomic analysis was performed for the identification of differentially expressed protein in the pancreatic tissues. Functional analyses were performed using THP-1 and HPSCs. RESULTS: Following SAPE attack, the Spink1 c.194+2T > C mutant mice exhibited a more severe acute pancreatitis phenotype within 24 h. In the chronic phase, the chronic pancreatitis phenotype was more severe in the Spink1 c.194+2T > C mutant mice after SAPE. Proteomic analysis revealed elevated IL-33 level in Spink1 c.194+2T > C mutant mice. Further in vitro analyses revealed that IL-33 induced M2 polarization of macrophages and activation of pancreatic stellate cells. CONCLUSION: Spink1 c.194+2T > C mutation plays an important role in the prognosis of patients following SAPE. Heterozygous Spink1 c.194+2T > C mutation promotes the development of chronic pancreatitis after an acute attack in mice through elevated IL-33 level and the induction of M2 polarization in coordination with pancreatic stellate cell activation.

Novel chymotrypsin C (CTRC) variants from real-world genetic testing of pediatric chronic pancreatitis cases.

BACKGROUND: Chymotrypsin C (CTRC) protects the pancreas against unwanted intrapancreatic trypsin activity through degradation of trypsinogen. Loss-of-function CTRC variants increase the risk for chronic pancreatitis (CP). The aim of the present study was to characterize novel CTRC variants found during genetic testing of CP cases at a pediatric pancreatitis center. METHODS: We used next-generation sequencing to screen patients. We analyzed the functional effects of CTRC variants in HEK 293T cells and using purified enzymes. RESULTS: In 5 separate cases, we detected 5 novel heterozygous CTRC variants: c.407C>T (p.Thr136Ile), c.550G>A (p.Ala184Thr), c.627Cdup (p.Ser210Leufs∗?, where the naming indicates a frame shift with no stop codon), c.628T>C (p.Ser210Pro), and c.779A>G (p.Asp260Gly). Functional studies revealed that with the exception of p.Ser210Leufs∗?, the CTRC variants were secreted normally from transfected cells. Enzyme activity of purified variants p.Thr136Ile, p.Ala184Thr, and p.Asp260Gly was similar to that of wild-type CTRC, whereas variant p.Ser210Pro was inactive. The frame-shift variant p.Ser210Leufs∗? was not secreted but accumulated intracellularly, and induced endoplasmic reticulum stress, as judged by elevated mRNA levels of HSPA5 and DDIT3, and increased mRNA splicing of XBP1. CONCLUSIONS: CTRC variants p.Ser210Pro and p.Ser210Leufs∗? abolish CTRC function and should be classified as pathogenic. Mechanistically, variant p.Ser210Pro directly affects the amino acid at the bottom of the substrate-binding pocket while the frame-shift variant promotes misfolding and thereby blocks enzyme secretion. Importantly, 3 of the 5 novel CTRC variants proved to be benign, indicating that functional analysis is indispensable for reliable determination of pathogenicity and the correct interpretation of genetic test results.

Correlation between endoscopic ultrasound features and exocrine pancreatic function in chronic pancreatitis.

BACKGROUND: Endoscopic ultrasound (EUS) is the most sensitive method for diagnosing chronic pancreatitis (CP) in its early stages, and Rosemont Classification (RC) is used for its evaluation. Data on the correlation between EUS features and pancreatic exocrine insufficiency (PEI) are limited. We investigated the correlation between the EUS findings and PEI. METHODS: This was a retrospective, monocentric cohort study involving patients prospectively enrolled from 2018 to 2022, with definite or probable CP according to the M-ANNHEIM criteria. All the patients underwent EUS and exocrine function investigations within 12 months of diagnosis. PEI was diagnosed using fecal elastase (FE) or when overt steatorrhea was reversed by pancreatic enzyme replacement therapy. Logistic regression analyses, rank correlation, ROC curve, and area under the curve (AUROC) were performed to evaluate the association between EUS features and PEI, and the accuracy of RC in predicting PEI. RESULTS: Among 128 patients examined (63.3 % male; mean age, 47 years), 69.5 % were diagnosed with PEI. In multivariate logistic regression among all the RC criteria, only lithiasis in the main pancreatic duct (MPD) was associated with increased risk of PEI (OR 2.92, 95 % CI 1.29-6.61; p = 0.01). Rank analysis showed a weak inverse correlation between RC and FE (Spearman's rho = -0.02; p = 0.03). The accuracy of RC was moderate (AUROC 0.62, p = 0.014). CONCLUSIONS: Among RC EUS features, lithiasis in the MPD is helpful for predicting the risk of PEI, while other findings are of limited utility in evaluating exocrine function.

"Quality of life is impaired in children with chronic pancreatitis: A multicenter study".

BACKGROUND AND OBJECTIVES: The impact of chronic pancreatitis (CP) on quality of life (QOL) of children is not well established. Our objective was to evaluate the QOL, identify contributing factors, and determine the prevalence of anxiety and depression in children with CP in India. METHODS: Children (8-18y old) with CP were prospectively enrolled across three pediatric gastroenterology centres in India. QOL was assessed using the pediatric QOL inventory (PedsQL 4.0) scale, administered to both children and their parents. Anxiety and depression was studied using the Revised Children's Anxiety and Depression Scale (RCADS 25). Contributing factors were identified using binary logistic regression analysis. The data was compared against published QOL data in healthy Indian children. RESULTS: 121 children with CP (boys-57.9 %, age at QOL-14 ± 3.2years) were enrolled. A majority (82.7 %) had pain and advanced disease (Cambridge grade IV- 63.6 %). Children with CP had poorer QOL compared to controls (total score 74.6 ± 16 vs. 87.5 ± 11.1, p < 0.0001). QOL scores were similar across centres. Older children were similar to younger ones, except for a poorer emotional QOL. Taking QOL < -2 standard deviation (SD) of controls, ∼35 % had poor physical (50.9 ± 11.9) and 20 % had poor psychosocial (PS) QOL score (52.1 ± 7.2). On analysis, presence of pain and lower socio-economic status (SES) adversely affected both physical and PS-QOL. Additionally, girls had poorer PS-QOL than boys (Odds ratio 3.1, 95%CI:1.23-7.31). Anxiety and depression were uncommon (2,1.6 %). CONCLUSIONS: Patients with CP had impaired physical and psycho-social QOL. Presence of pain and lower SES adversely affected QOL. Psychiatric comorbidities were uncommon.

The burden of recurrence acute pancreatitis and annual event rates are underestimated because of high rates of home self-management.

BACKGROUND/OBJECTIVES: The event-rate of recurrent acute pancreatitis (RAP) in patient populations is critical for powering research studies. We hypothesize that some patients manage RAP attacks at home, reducing event rate estimations based on counting emergency department (ED) visits and hospitalizations only. The aim of this study was to determine the rates of home self-management of recurrent acute pancreatitis compared to ED visits and hospitalizations. METHODS: An anonymous 8-question survey was sent to 1825 individuals on an email list of individuals with a history of acute pancreatitis (AP) or chronic pancreatitis or interest in pancreatic diseases. Question were designed to identify subjects with RAP within the past 2 years and to subdivide patients based on having a chronic pain syndrome or not. RESULTS: After an initial email request and one reminder a total of 194 subjects responded with 98 RAP subjects suitable for analysis. Annual AP events included an average of 1.44 hospitalizations, 1.37 ED visits, 2.46 disrupted work/school/social engagements, and 3.95 pancreatitis-like pain attacks per year. Patients with RAP average 6.8 RAP events per year with 58.4 % managed at home. CONCLUSIONS: The burden of disease in patients with RAP is significantly underestimated, especially for patients with chronic pain. Future studies should include measures to capture RAP events managed at home and utilize methods of documenting RAP events.

Prevalence and risk factors of fatigue and its association with quality of life among patients with chronic pancreatitis: A cross-sectional study.

BACKGROUND: Fatigue is a debilitating symptom found in various chronic diseases and is associated with more severe symptoms and worse quality of life (QoL). However, this symptom has not been adequately addressed in chronic pancreatitis (CP), and there have been no studies on fatigue in patients with CP. METHODS: This cross-sectional study was conducted at the Changhai Hospital in Shanghai, China. Data on the patients' sociodemographic, disease, and therapeutic characteristics were collected. Fatigue was assessed using the Multidimensional Fatigue Inventory-20. QoL was assessed utilizing the European Organization for the Research and Treatment of Cancer of QoL questionnaire (EORTC-QLQ-C30). Sleep quality, anxiety and depression, and pain was assessed using Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, and the Brief Pain Inventory, respectively. RESULTS: The prevalence of fatigue among Chinese patients with CP was 35.51 % (87/245). Multivariate analysis showed that steatorrhea (OR = 2.638, 95 % CI: 1.117-6.234), history of smoking (OR = 4.627, 95 % CI: 1.202-17.802), history of endoscopic treatment (OR = 0.419, 95 % CI: 0.185-0.950), depression (OR = 5.924, 95 % CI: 2.462-14.255), and sleep disorder (OR = 6.184, 95 % CI: 2.543-15.034) were influencing factors for the presence of fatigue. The scores for global health and all functional dimensions in the EORTC-QLQ-C30 significantly decreased, whereas the scores for all symptom dimensions significantly increased in patients with fatigue. CONCLUSIONS: This study indicated that Fatigue is a common symptom and has a negative impact on the QoL of patients with CP. Steatorrhea, smoking history, endoscopic treatment, depression, and sleep disorders were associated with fatigue.