Role of Pancreatic Tumour-Derived Exosomes and Their Cargo in Pancreatic Cancer-Related Diabetes

Establishing a new-onset diabetes-related metabolism signature for predicting the prognosis and immune landscape in pancreatic cancer

New-onset diabetes (NOD) is a common condition among patients with pancreatic adenocarcinoma (PAAD) and is related to poor clinical outcomes. The potential impact of NOD on PAAD progression and the tumor microenvironment remains unclear. Here, we revealed that NOD in PAAD was associated with metabolic disorders. Utilizing three machine-learning algorithms, an NOD-related metabolism signature (NRMS) was established. Validated in three independent cohorts, patients with a high NRMS score exhibited a worse prognosis. Moreover, an elevated NRMS score was associated with an immunosuppressive microenvironment and diminished response to immunotherapy. Further experiments demonstrated that ALDH3A1, a key feature in NRMS, was significantly upregulated in tissues from PAAD patients with NOD and played a crucial role in tumor progression and immune suppression. Our findings highlight the potential of NRMS as a prognostic biomarker and an indicator of immunotherapy response for patients with PAAD.

Exosome-Derived Cargos in Immune Microenvironment in Esophageal Carcinoma: A Mini-Review

Esophageal carcinoma, a lethal malignancy with limited treatment options and poor prognosis, necessitates understanding its underlying mechanisms and identifying novel therapeutic targets. Recent studies have highlighted the critical role of the immune microenvironment in esophageal carcinoma, particularly the interplay between tumor cells and immune cells mediated by exosomes and their cargos. Exosomes, small extracellular vesicles secreted by various cells, including tumor cells, facilitate intercellular communication by transferring bioactive molecules such as proteins, nucleic acids, and lipids to recipient cells. In the context of esophageal carcinoma, tumor-derived exosomes have been shown to play a significant role in shaping the immune microenvironment. In esophageal carcinoma, exosomal cargos have been found to modulate immune cell function and impact tumor progression. These cargos can carry immune inhibitory molecules, such as programmed death-ligand 1 (PD-L1), to suppress T-cell activity and promote immune evasion by tumor cells. Furthermore, exosomal cargos can activate antigen- presenting cells, enhancing their ability to present tumor-specific antigens to T cells and thereby promoting anti-tumor immune responses. Additionally, the cargos of exosomes have been implicated in the induction of immune regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) within the esophageal carcinoma microenvironment. These immunosuppressive effectors inhibit the activity of T cells, contributing to tumor immune evasion and resistance to immune therapies. In summary, exosomes and their cargo play a crucial role in the immune microenvironment of esophageal carcinoma. Understanding the mechanisms by which exosomal cargos regulate immune cell function and tumor progression may reveal novel therapeutic targets for this devastating disease.

New Onset Diabetes in Pancreatic Adenocarcinoma Does Not Correlate With Molecular Subtype

BACKGROUND AND OBJECTIVES

Studies show that new onset diabetes mellitus (DM) (NOD) predates the diagnosis of PDAC by up to 2 years. Two tumor-intrinsic molecular subtypes of PDAC that are prognostic and predictive of chemotherapy response have been described and validated. We hypothesize that patients with NOD may have different molecular subtypes and prognoses.

METHODS

This is a single-institution study of patients who underwent resection for PDAC from 2009 to 2022 with de-identified samples available for sequencing. Demographic and clinical factors were examined using bivariate and multivariate analysis.

RESULTS

A total of 97 patients met inclusion criteria: 70 with no history of DM, 11 with longstanding DM (> 2 years), and 16 with NOD. The demographics between groups were overall similar. After controlling for age, sex, race, BMI, and tobacco history, NOD was not a significant predictor of PDAC subtype. There were no survival differences between groups. Transcriptomic analysis suggests the upregulation of inflammatory and immune activation and regulation pathways in NOD.

CONCLUSIONS

As continued interest in NOD and PDAC mounts, we are the first to examine if NOD may be associated with molecular subtypes and outcomes. Further investigation into the underlying pathophysiology of the NOD group is still needed.

A negative regulatory role of β-cell-derived exosomes in the glucose-stimulated insulin secretion of recipient β-cells

Exosomes are extracellular vesicles that play a role in intercellular communication through the transportation of their cargo including mRNAs, microRNAs, proteins, and nucleic acids. Exosomes can also regulate glucose homeostasis and insulin secretion under diabetic conditions. However, the role of exosomes in insulin secretion in islet β-cells under physiological conditions remains to be clarified. The aim of this study was to investigate whether exosomes derived from pancreatic islet β-cells could affect insulin secretion in naïve β-cells. We first confirmed that exosomes derived from the RIN-m5f β-cell line interfered with the glucose-stimulated insulin secretion (GSIS) of recipient β-cells without affecting cell viability. The exosomes significantly reduced the protein expression levels of phosphorylated Akt, phosphorylated GSK3α/β, CaMKII, and GLUT2 (insulin-related signaling molecules), and they increased the protein expression levels of phosphorylated NFκB-p65 and Cox-2 (inflammation-related signaling molecules), as determined by a Western blot analysis. A bioinformatics analysis of Next-Generation Sequencing data suggested that exosome-carried microRNAs, such as miR-1224, -122-5p, -133a-3p, -10b-5p, and -423-5p, may affect GSIS in recipient β-cells. Taken together, these findings suggest that β-cell-derived exosomes may upregulate exosomal microRNA-associated signals to dysregulate glucose-stimulated insulin secretion in naïve β-cells.

Cold Exposure Alleviates T2DM Through Plasma-Derived Extracellular Vesicles

Purpose

Anecdotal reports have praised the benefits of cold exposure, exemplified by activities like winter swimming and cold water immersion. Cold exposure has garnered acclaim for its potential to confer benefits and potentially alleviate diabetes. We posited that systemic cold temperature (CT, 4-8°C) likely influences the organism's blood components through ambient temperature, prompting our investigation into the effects of chronic cold exposure on type 2 diabetic (T2DM) mice and our initial exploration of how cold exposure mitigates the incidence of T2DM.

Methods

The effects of CT (4-8°C) or room temperature (RT, 22-25°C) on T2DM mice were investigated. Mice blood and organ specimens were collected for fully automated biochemical testing, ELISA, HE staining, immunohistochemistry, and immunofluorescence. Glucose uptake was assessed using flow cytometry with 2-NBDG. Changes in potential signaling pathways such as protein kinase B (AKT), phosphorylated AKT (p-AKT), insulin receptor substrates 1 (IRS1), and phosphorylated IRS1 (p-IRS1) were evaluated by Western blot.

Results

CT or CT mice plasma-derived extracellular vesicles (CT-EVs) remarkably reduced blood glucose levels and improved insulin sensitivity in T2DM mice. This treatment enhanced glucose metabolism, systemic insulin sensitivity, and insulin secretion function while promoting glycogen accumulation in the liver and muscle. Additionally, CT-EVs treatment protected against the streptozocin (STZ)-induced destruction of islets in T2DM mice by inhibiting β-cell apoptosis. CT-EVs also shielded islets from destruction and increased the expression of p-IRS1 and p-AKT in adipocytes and hepatocytes. In vitro experiments further confirmed its pro-insulin sensitivity effect.

Conclusion

Our data indicate that cold exposure may have a potentially beneficial effect on the development of T2DM, mainly through the anti-diabetic effect of plasma-derived EVs released during cold stimulation. This phenomenon could significantly contribute to understanding the lower prevalence of diabetes in colder regions.

Remnant Pancreas Volume Affects New-Onset Impaired Glucose Homeostasis Secondary to Pancreatic Cancer

BACKGROUND

New-onset diabetes (NOD) has been identified as a high-risk factor for the early detection of pancreatic ductal adenocarcinoma (PDAC). The role of tumor volume and remnant pancreas volume (RPV) in the progression from normal to NOD in PDAC patients is not fully illustrated yet.

METHODS

In this cross-sectional study, glycemic metabolism traits of 95 PDAC patients before pancreatic surgery were described and compared with chronic pancreatitis and type 2 diabetes mellitus patients based on the oral glucose tolerance test. The remnant RPV and tumor volume, calculated by three-dimensional reconstruction of radiological images, were included in the ordinal logistic regression models.

RESULTS

The prevalence of NOD was high among PDAC patients (38.9%). However, normal glucose tolerance (NGT) or prediabetes mellitus status were present as more than half (24/44) of advanced tumor stage patients. Indexes reflecting beta-cell function but not insulin sensitivity gradually worsened from NGT to NOD patients (all p < 0.05). The remnant pancreas volume (RPV) was identified as a potential protective factor for diabetes secondary to PDAC (odds ratio 0.95, 95% CI [0.92, 0.97], p < 0.001).

CONCLUSIONS

Reduced RPV causing beta-cell dysfunction might be one of the mechanisms of NOD secondary to PDAC. Subjects with sufficient pancreas volume could not be detected earlier when regarding patients with NOD as the population at risk for PDAC.

Immunological Regulation of Gut-Tropic Immune Cells by Extracellular Vesicles

The remarkable diversity of lymphocytes, essential components of the immune system, serves as an ingenious mechanism for maximizing the efficient utilization of limited host defense resources. While cell adhesion molecules, notably in gut-tropic T cells, play a central role in this mechanism, the counterbalancing molecular details have remained elusive. Conversely, we've uncovered the molecular pathways enabling extracellular vesicles secreted by lymphocytes to reach the gut's mucosal tissues, facilitating immunological regulation. This discovery sheds light on immune fine-tuning, offering insights into immune regulation mechanisms.

Analysis of MicroRNA Signature Differentially Expressed in Pancreatic Islet Cells Treated with Pancreatic Cancer-Derived Exosomes

Since the majority of patients with pancreatic cancer (PC) develop insulin resistance and/or diabetes mellitus (DM) prior to PC diagnosis, PC-induced diabetes mellitus (PC-DM) has been a focus for a potential platform for PC detection. In previous studies, the PC-derived exosomes were shown to contain the mediators of PC-DM. In the present study, the response of normal pancreatic islet cells to the PC-derived exosomes was investigated to determine the potential biomarkers for PC-DM, and consequently, for PC. Specifically, changes in microRNA (miRNA) expression were evaluated. The miRNA specimens were prepared from the untreated islet cells as well as the islet cells treated with the PC-derived exosomes (from 50 patients) and the healthy-derived exosomes (from 50 individuals). The specimens were subjected to next-generation sequencing and bioinformatic analysis to determine the differentially expressed miRNAs (DEmiRNAs) only in the specimens treated with the PC-derived exosomes. Consequently, 24 candidate miRNA markers, including IRS1-modulating miRNAs such as hsa-miR-144-5p, hsa-miR-3148, and hsa-miR-3133, were proposed. The proposed miRNAs showed relevance to DM and/or insulin resistance in a literature review and pathway analysis, indicating a potential association with PC-DM. Due to the novel approach used in this study, additional evidence from future studies could corroborate the value of the miRNA markers discovered.