Introduction

Rare early onset cases of diabetes stem from single gene mutations, whereas frequent gene variants can also contribute to multifactorial diabetes, indicating shared disease mechanisms. Our recent study has identified ONECUT1 as a gene implicated in both monogenic and multifactorial diabetes, establishing it as crucial target for investigating fundamental signaling pathways in diabetes pathology [1,2]. However, numerous diabetic characteristics remain unexplained by typical genetic alterations, highlighting the underestimated significance of the non-coding genome. We have identified a neonatal diabetes patient carrying a heterozygous ONECUT1 truncating variant. Remarkably, the patient exhibited a phenotype akin to individuals with homozygous ONECUT1 truncating mutations. Upon further examination, we detected an additional heterozygous deletion in the non-coding genome, leading us to hypothesize that it could impact the regulation of the remaining ONECUT1 allele. Consequently, the dysregulation of the ONECUT1-dependent transcriptional machinery crucial for proper beta-cell development occurs, ultimately leading to the severe diabetic phenotype observed in the patient.

Aims & Methods

Following deletion of specific genomic regions in human embryonic stem cells, we initiated their differentiation into the pancreatic endocrine lineage and meticulously characterized the developmental stages.

Results

Importantly, we successfully replicated the patient’s diabetic phenotype, elucidating deficiencies in both pancreatic development and beta-cell functionality. The differentiation of pancreatic progenitors was notably hindered by the loss of the regulatory region associated with nearly complete ablation of ONECUT1. Moreover, the stem cell-derived islets exhibited a reduced number of beta-cells as well as impaired insulin secretion, even in heterozygous knockouts.

Conclusion

Altogether, our ongoing comprehensive mechanistic characterization provides insights into the precise role of the identified regulatory element in pancreatic beta-cell development and diabetes pathophysiology, emphasizing the significance of the non-coding genome. By unveiling unknown molecular pathomechanisms linked to alterations in regulatory sequences, we contribute to a deeper understanding of the pancreatic transcriptional network and establish the foundation for personalized diabetes treatment.

References

[1] Philippi, A., Heller, S., Costa, I.G. et al. Mutations and variants of ONECUT1 in diabetes. Nat Med 27, 1928–1940 (2021). https://doi.org/10.1038/s41591-021-01502-7
[2] Heller, S., Li, Z., Lin, Q. et al. Transcriptional changes and the role of ONECUT1 in hPSC pancreatic differentiation. Commun Biol 4, 1298 (2021). https://doi.org/10.1038/s42003-021-02818-3

Introduction

Splanchnic vein thrombosis (SVT) presents as a common complication of cirrhosis due to modification in hemodynamics and hemostatic balance, and it also frequently associated with solid cancers, myeloproliferative neoplasms and less often with pregnancy, abdominal infections, pancreatitis, or surgery.

Aims & Methods

The SVT registry is an ongoing registry of consecutive patients diagnosed with, treated, and/or followed up for SVT at our Center since January 2005. Baseline and follow-up data, including demographics, clinical features, risk factors, diagnostic procedures, classification of SVT, and treatment were collected during hospitalization, and at scheduled outpatient visits. The aim of this study was to describe patients with SVT and management in a single center, with focus on the differences between cirrhotic and non-cirrhotic patients.

Results

From January 2005 to December 2022, 320 patients were eligible SVT-registry, including 228 patients (71.2 %) with liver disease. Among the latter, 126 (55.3%) had isolated portal thrombosis, 18 (7.9%) isolated mesenteric thrombosis and the remaining multiple site venous thrombosis. Among isolated portal thrombosis, 61 (48.4 %) of patients experienced a complete thrombosis, 47 (37.3 %) a partial thrombosis. Therefore, there is a difference in the site of thrombosis and the extent of portal thrombosis between the two groups (p = 0.046 and p = 0.001, respectively). Ninety-three patients (40.7 %) experienced solid cancer and 45 (19.7 %) had HCC. Patients with liver disease developed a higher rate of portal hypertension-related complications, such as ascites and esophageal varices, than the other population (p < 0.0001). Most patients (77.6%) received an anticoagulation therapy and those with cirrhosis were preferably treated with low molecular weight heparin/heparin related agents (64.5%; p < 0.0001). Only patients treated with anticoagulants experienced a major complication such as bleeding (n=23, 10.1%), which in no case led to the patient’s death. Seventy-seven patients (33.8 %) experienced resolution of SVT with a median time of 8.4 months and no differences were found between the two groups, with 20.8% spontaneous resolution-rate. A lower rate of recanalization is shown in patients presenting with portal hypertension complications (p = 0.0431) such as esophageal varices (p = 0.0299) at the time of SVT diagnosis, regardless of therapeutic approach. Following recanalization, 7 patients with liver disease (9.1%) had a recurrence of venous thromboembolism earlier than the other group. Presence of HCC diagnosis and not long-term use of VKA have been found to be associated with an increased risk of SVT recurrence (p= 0.0099 and p= 0.037, respectively).

Conclusion

SVT-registry is a relatively large ongoing population-based registry of SVT patients, with high-quality data representing a valuable source of real-world data on the management and outcomes of SVT.
Our data show that there are differences in the presentation and course of SVTs between patients with and without liver disease, which may therefore require specific management.

Introduction

By 2030, pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related death. Due to its resistance to conventional therapies and heterogeneous mutational landscape, molecular stratification and the development of targeted therapeutic options are essential for improving survival of PDAC patients. Previous work from our group investigated loss-of-function mouse models for the ATM serine/threonine kinase causing homologous recombination deficiency (HRD) in PDAC. Specifically, ATM loss was reported to accelerate tumorigenesis, support metastatic burden, and coincide with oncogenic programs, including epithelial-mesenchymal transition (EMT). Interestingly, ATM-deficient tumors accumulated EZH2, suggesting that ATM status contributes to rewiring the epigenetic landscape of pancreatic tumors, subsequently supporting oncogenic features.

Aims & Methods

To investigate whether and how EZH2 impacts ATM-deficient PDAC pathogenesis, we generated conditional double ATM and EZH2 knockouts in Kras^G12D/+; Ptf1a^Cre/+ mice. In vitro approaches were conducted using primary cell lines isolated from murine endpoint tumors. Additionally, CRISPR/Cas9 strategy was implemented on ATM-deficient cell lines to decipher the ATM-EZH2 molecular axis.

Results

Double-null mice showed extended mouse survival and decreased undifferentiated malignant cell features. Strikingly, interrogation of publicly available human datasets (TCGA, PanCancer Atlas) revealed a significant extended progression-free survival of ATM^neg EZH2^neg PDAC patients compared to ATM^neg EZH2^pos PDAC cases. Furthermore, we identified the histone-methyltransferase EZH2 as a direct ATM substrate impacting the mesenchymal phenotype of ATM-depleted tumors. Interestingly, RNA-seq analysis of ATM-deficient pancreatic cancer cells revealed upregulation of a transcriptomic program associated with cell differentiation upon EZH2 depletion by CRISPR/Cas9 strategy. In line, EZH2 depletion restored differentiated tumor features ex vivo. Further in vitro investigations revealed that ATM status significantly impacts EZH2 activity via a post-translational regulation axis, leading to a fostered tumor supporting EZH2 activity during pancreatic carcinogenesis. Specifically, the ATM kinase activity results in EZH2 ubiquitination and degradation by promoting Cullin1 E3-ubiquitin ligase recruitment. Finally, we demonstrated that a combinatorial therapy involving a potent EZH2 inhibitor promotes genomic instability and exacerbates the cytotoxic effects of PARP interference in ATM-deficient HRD PDAC.

Conclusion

Overall, we show that ATM deficiency significantly impacts EZH2 epigenetic functions and highlight the molecular stratification according to ATM status prior to pharmacological EZH2 interference in PDAC therapies as a valuable approach to target ATM-deficient HRD tumors.

Introduction

Gene regulatory networks play a vital role in pancreatic development and function. However, pathomechanisms associated with the non-coding genome are just starting to be discovered. Our recent work demonstrated that mutations in the ONECUT1 gene are responsible for a new neonatal diabetes syndrome in homozygous patients, whereas heterozygous carriers develop early-onset diabetes. Stage-specific characterization of in vitro differentiated human embryonic stem cells (hESC) revealed that ONECUT1 plays an important role in transcriptional regulation during pancreatic progenitor formation and the initiation of the endocrine developmental program. Nonetheless, the complex regulation is only partly uncovered. While investigating the ONECUT1 locus, we found a variant most strongly associated with T2D (rs2440374). This variant is located within the lncRNA RP11-209K10.2 (further lncRNA-RP11), 11 kbp distant to ONECUT1. GTEx Portal database shows decreased lncRNA-RP11 expression in the pancreas in the presence of the T2D-associated allele. Also, this SNP disrupts a binding motif for transcription factor NKX2.2 essential for endocrine pancreas development and pancreatic islet-cell fate. Since promoters of lncRNAs can also act as enhancer elements stimulating the regulation of neighboring genes, we hypothesize that the lncRNA-RP11 locus plays an important role in regulating ONECUT1 and that disturbance of this transcriptional network promotes diabetes onset.

Aims & Methods

After deletion of lncRNA-RP11, hESC were differentiated into the pancreatic endocrine lineage followed by characterization of the developmental stages.

Results

Although differentiation of pancreatic progenitors is not impaired by the loss of the regulatory region, stem cell-derived islets further generated from these progenitors exhibit reduced number and function of beta-cells supporting an involvement during pancreas differentiation. The transcript of lncRNA-RP11 with main localization in the nucleus follows similar stage-specific dynamics as ONECUT1 allowing for several modes of action.

Conclusion

Next, a comprehensive mechanistic characterization will provide insights into the exact function of lncRNA-RP11 in pancreatic endocrine development and pathophysiology. Thus, identifying novel molecular mechanisms involved in diabetes will improve our understanding of the transcriptional landscape and lay the groundwork for personalized diabetes treatment.

References

Philippi, A., Heller, S., Costa, I.G. et al. Mutations and variants of ONECUT1 in diabetes. Nat Med 27, 1928–1940 (2021). https://doi.org/10.1038/s41591-021-01502-7

Introduction

96-98% of patients survive acute pancreatitis (AP), but in the post-AP phase, patients are at high risk of morbidity and mortality. It has been shown that pancreatic exocrine insufficiency can occur after AP.

Aims & Methods

We aimed to investigate the rate, risk factors, and the effect of pancreatic enzyme replacement therapy (PERT) for PEI in patients with AP. The study protocol was registered on PROSPERO (CRD42024516403). We conducted a systematic search on 5 February 2024 in three databases (PubMed, EMBASE, and CENTRAL). We included in the analysis studies reporting on risk factors and PERT efficacy in PEI associated with AP. Pooled proportion and odds ratios (OR) with a 95% confidence interval (CI) were calculated using a random effect model.

Results

Fifty-six articles were included in our meta-analysis. Among 17896 patients with AP, the pooled proportion of PEI was 20 % ([CI]: 15–26). The odds of PEI development were two-fold higher in severe acute pancreatitis (OR=2.44, [CI]: 0.98–6.11) compared with mild or moderate AP and three times higher after necrosectomy compared to patients without necrosectomy (OR=3.26, [CI]: 1.6–6.64). There was no significant difference between the odds of PEI among AP patients with necrosis (OR=1.43, [CI]: 0.32–6.45) and those without necrosis. However, the odds of PEI were twice as high in patients with infected necrosis (OR=2.13, [CI]: 0.93–4.87) than in patients with sterile necrosis. Pancreatic enzyme replacement therapy was prescribed for 22% ([CI]: 16–30) of patients after AP.

Conclusion

One in five patients with AP develops PEI. The rate is higher in patients with severe AP, infected necrosis, or who need necrosectomy. Patients with AP should be screened for PEI to allow timely PERT administration.