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Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal malignancy characterized by dysregulated energy and stromal metabolism. It is strongly supported by activated pancreatic stellate cells (PSC) which drive excessive desmoplasia and tumor growth via metabolic crosstalk. Herein, a programmed nanosystem is designed to dual rectify the metabolism abnormalities of the PDAC cells, which overexpress glucose transporter 1(GLUT1) and CD71, and the PSC for oncotherapy. The nanosystem is based on a tumor microenvironment-responsive liposome encapsulating an NF-κB inhibitor (TPCA-1) and a CD71 aptamer-linked Glut1 siRNA. TPCA-1 reverses the activated PSC to quiescence, which hampers metabolic support of the PSC to PDAC cells and bolsters the PDAC cell-targeting delivery of the siRNA. Aerobic glycolysis and the following enhancement of oxidative phosphorylation are restrained by the nano-modulation so as to amplify anti-PDAC efficacy in an orthotopic xenograft mouse model, which implies more personalized PDAC treatment based on different energy metabolic profiles., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Pancreatic cancer (PC) is characterized by abnormally fibrotic mesenchyme, which notably influences on the effectiveness of immunotherapy. Low-dose arsenic trioxide (ATO, 1.0 μM) can inhibit the activation of pancreatic stellate cells (PSCs) and affect fibrosis, which is a potential strategy for enhancing the sensitivity to immunotherapy., Methods: Extracellular matrix (ECM) models were employed to assess the regulatory effects of ATO on ECM and peripheral blood mononuclear cells. Orthotopic C57BL/6J models were utilized to evaluate the influence of ATO on CD8 + T cell infiltration and immunotherapy in PC. Additionally, nanomaterials loaded with ATO designed to specifically target PSCs (scAbFAP-α-HMSNs-PAA-ATO) were produced to enhance targeting effects of ATO., Results: Low-dose ATO (1.0 μM) suppressed PSCs activation, exhibiting potential for synergistic immunotherapy. Under low-dose ATO intervention, ECM underwent remodeling, leading to increases in CD8 + T cell infiltration, thereby enhancing anti-PD-L1 therapy effect. We further demonstrated that low-dose ATO remodeled ECM by regulating the expression of LOXL3 in PSCs. scAbFAP-α-HMSNs-PAA-ATO exhibited improved targeting capabilities, and enhanced capacity to inhibit fibrosis and sensitize immunotherapy., Conclusions: Our research reveals that low-dose ATO, by regulating LOXL3, remodels the ECM and enhances CD8 + T cell infiltration, thus sensitizing the efficacy of immunotherapy, which provides a novel strategy for comprehensive treatment to PC., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The use of human samples was approved by Sun Yat-sen Memorial Hospital Ethics Committee and the informed consent from all participants were obtained (SYSKY-2023-116-01). All methods involved in this study were carried out in accordance with relevant guidelines and regulations. All animals care and experimental procedures were conducted according to the National Research Council’s Guidelines for the Care and Use of Laboratory Animals, and were approved by the Institutional Animal Care and Use Committee of Sun Yat-sen University Cancer Center (L102012022040E)., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Pancreatic fibrosis is the main pathological feature of chronic pancreatitis. There is a lack of medications that effectively alleviate or reverse pancreatic fibrosis and thus cure chronic pancreatitis., Methods: We screened drugs that could alleviate pancreatic fibrosis from 80 traditional Chinese medicine monomers and verified their efficacy and mechanisms., Results: We preliminarily identified corynoline as an antifibrotic candidate by drug screening among 80 compounds. In vitro, corynoline dose-dependently reduces collagen I synthesis in pancreatic stellate cells induced by TGF-β1 and inhibits its activation. Furthermore, we found that corynoline could alleviate the morphological disruption, such as acinar cell atrophy, collagen deposition etc., as well as reduced pancreatic weight in mice with chronic pancreatitis. We further validated the antifibrotic effect of corynoline in mRNA and protein levels. We also found that corynoline could inhibit NF-κB signaling pathway in vitro and in vivo. Next, we identified PSMA2 as the binding protein of corynoline by Lip-SMap and validated it using DARTS. Moreover, the siRNA of PSMA2 disrupts the anti-fibrotic effect of corynoline., Conclusion: In conclusion, corynoline is a promising agent for the treatment of pancreatic fibrosis and chronic pancreatitis., (© 2024. Japanese Society of Gastroenterology.)

Background: Mesenchymal stromal cells (MSCs) are recognized for their potential in regenerative medicine, attributed to their multipotent differentiation capabilities and immunomodulatory properties. Despite this potential, the classification and detailed characterization of MSCs, especially those derived from specific tissues like the pancreas, remains challenging leading to a proliferation of terminology in the literature. This study aims to address these challenges by providing a thorough characterization of human pancreatic islets-derived mesenchymal stromal cells (hPD-MSCs)., Methods: hPD-MSCs were isolated from donor islets using enzymatic digestion, immortalized through lentiviral transduction of human telomerase reverse transcriptase (hTERT). Cells were characterized by immunostaining, flow cytometry and multilineage differentiation potential into adipogenic and osteogenic lineages. Further a transcriptomic analysis was done to compare the gene expression profiles of hPD-MSCs with other mesenchymal cells., Results: We show that hPD-MSCs express the classical MSC features, including morphological characteristics, surface markers expression (CD90, CD73, CD105, CD44, and CD106) and the ability to differentiate into both adipogenic and osteogenic lineages. Furthermore, transcriptomic analysis revealed distinct gene expression profiles, showing notable similarities between hPD-MSCs and pancreatic stellate cells (PSCs). The study also identified specific genes that distinguish hPD-MSCs from MSCs of other origins, including genes associated with pancreatic function (e.g., ISL1) and neural development (e.g., NPTX1, ZNF804A). A novel gene with an unknown function (ENSG00000286190) was also discovered., Conclusions: This study enhances the understanding of hPD-MSCs, demonstrating their unique characteristics and potential applications in therapeutic strategies. The identification of specific gene expression profiles differentiates hPD-MSCs from other mesenchymal cells and opens new avenues for research into their role in pancreatic function and neural development., (© 2024. The Author(s).)

RUNX1 with CBFβ functions as an activator or repressor of critical mediators regulating cellular function. The aims of this study were to clarify the role of RUNX1 on regulating TGF-β1-induced COL1 synthesis and the mechanism of calcipotriol (Cal) on antagonizing COL1 synthesis in PSCs. RT-qPCR and Western Blot for determining the mRNAs and proteins of RUNX1 and COL1A1/1A2 in rat PSC line (RP-2 cell). Luciferase activities driven by RUNX1 or COL1A1 or COL1A2 promoter, co-immunoprecipitation and immunoblotting for pSmad3/RUNX1 or CBFβ/RUNX1, and knockdown or upregulation of Smad3 and RUNX1 were used. RUNX1 production was regulated by TGF-β1/pSmad3 signaling pathway in RP-2 cells. RUNX1 formed a coactivator with CBFβ in TGF-β1-treated RP-2 cells to regulate the transcriptions of COL1A1/1A2 mRNAs under a fashion of pSmad3/RUNX1/CBFβ complex. However, Cal effectively abrogated the levels of COL1A1/1A2 transcripts in TGF-β1-treated RP-2 cells by downregulating RUNX1 production and hindering the formation of pSmad3/RUNX1/CBFβ complexes. This study suggests that RUNX1 may be a promising antifibrotic target for the treatment of chronic pancreatitis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

In healthy pancreas, pancreatic stellate cells (PaSCs) synthesize the basement membrane, which is mainly composed of type IV collagen and laminin. In chronic pancreatitis (CP), PaSCs are responsible for the production of a rigid extracellular matrix (ECM) that is mainly composed of fibronectin and type I/III collagen. Reactive oxygen species evoke the formation of the rigid ECM by PaSCs. One source of reactive oxygen species is NADPH oxidase (Nox) enzymes. Nox1 up-regulates the expression of Twist1 and matrix metalloproteinase-9 (MMP-9) in PaSCs from mice with CP. This study determined the functional relationship between Twist1 and MMP-9, and other PaSC-produced proteins, and the extent to which Twist1 regulates digestion of ECM proteins in CP. Twist1 induced the expression of MMP-9 in mouse PaSCs. The action of Twist1 was not selective to MMP-9 because Twist1 induced the expression of types I and IV collagen, fibronectin, transforming growth factor, and α-smooth muscle actin. Luciferase assay indicated that Twist1 in human primary PaSCs increased the expression of MMP-9 at the transcriptional level in an NF-κB dependent manner. The digestion of type I/III collagen by MMP-9 secreted by PaSCs from mice with CP depended on Twist1. Thus, Twist1 in PaSCs from mice with CP induced rigid ECM production and MMP-9 transcription in an NF-κB-dependent mechanism that selectively displayed proteolytic activity toward type I/III collagen., Competing Interests: Disclosure Statement None declared., (Copyright © 2024 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Our knowledge of the origins, heterogeneity, and functions of cancer-associated fibroblasts (CAF) in pancreatic ductal adenocarcinoma (PDAC) has exponentially increased over the last two decades. This has been facilitated by the implementation of new models and single-cell technologies. However, a few key studies preceded the current exciting times in CAF research and were fundamental in initiating the investigation of CAFs and of their roles in PDAC. With their study published in Cancer Research in 2008, Hwang and colleagues have been first to successfully isolate and immortalize human pancreatic stellate cells (HPSC) from PDAC tissues. This new tool allowed them to probe the roles of CAFs in PDAC as never done before. By performing complementary in vitro and in vivo analyses, the authors demonstrated the involvement of HPSCs in PDAC malignant cell proliferation, invasion, and therapy resistance. Here, we leverage that seminal study as a framework to discuss the advances made over the last 16 years in understanding the complexity and central roles of CAFs in PDAC progression. See related article by Hwang and colleagues, Cancer Res 2008;68:918-26., (©2024 American Association for Cancer Research.)

Interactions between tumor and stromal cells are well known to play prominent roles in progression of pancreatic ductal adenocarcinoma (PDAC). As knowledge of stromal crosstalk in PDAC has evolved, it has become clear that cancer associated fibroblasts can play both tumor promoting and tumor suppressive roles through a combination of paracrine crosstalk and juxtacrine interactions involving direct physical contact. Another major contributor to dismal survival statistics for PDAC is development of resistance to chemotherapy drugs, though less is known about how the acquisition of chemoresistance impacts upon tumor-stromal crosstalk. Here, we use time lapse imaging and image analysis to study how co-culture geometry impacts interactions between epithelial and stromal cells. We show that extracellular matrix (ECM) overlay cultures in which stromal cells (pancreatic stellate cells, or normal human fibroblasts) are placed adjacent to PDAC cells (PANC1) result in direct heterotypic cell adhesions accompanied by dramatic fibroblast contractility. We analyze these interactions in co-cultures using particle image velocimetry (PIV) analysis to quantify cell velocities over the course of time lapse movie sequences. We further contrast co-cultures of PANC1 with those containing a drug resistant subline (PANC1-OR) previously established in our lab and find that heterotypic cell-cell interactions are suppressed in the latter relative to the parental line. We use RNA-seq and bioinformatics analysis to identify differential gene expression in PANC1 and PANC1-OR, which shows that negative regulation of cell adhesion molecules, consistent with increased epithelial mesenchymal transition (EMT), is also correlated with reduction in the hetrotypic cell-cell contact necessary for the contractile behavior observed in drug naïve cultures. Overall these findings elucidate the role of drug-resistance in inhibiting an avenue of stromal crosstalk which is associated with tumor suppression and also help to establish cell culture conditions useful for further mechanistic investigation., (© 2024. The Author(s).)

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive form of cancer with a low survival rate. A successful treatment strategy should not be limited to targeting cancer cells alone, but should adopt a more comprehensive approach, taking into account other influential factors. These include the extracellular matrix (ECM) and immune microenvironment, both of which are integral components of the tumor microenvironment. The present review describes the roles of pancreatic stellate cells, differentiated cancer‑associated fibroblasts and the interleukin family, either independently or in combination, in the progression of precursor lesions in pancreatic intraepithelial neoplasia and PDAC. These elements contribute to ECM deposition and immunosuppression in PDAC. Therapeutic strategies that integrate interleukin and/or stromal blockade for PDAC immunomodulation and fibrogenesis have yielded inconsistent results. A deeper comprehension of the intricate interplay between fibrosis, and immune responses could pave the way for more effective treatment targets, by elucidating the mechanisms and causes of ECM fibrosis during PDAC progression.

Purpose: To evaluate the effect and mechanism of 1,25(OH) 2 D 3 on pancreatic stellate cells (PSCs) in type 2 diabetes mellitus (T2DM)., Methods: A mouse model of T2DM was successfully established by high-fat diet (HFD) /streptozotocin (STZ) and administered 1,25(OH) 2 D 3 for 3 weeks. Fasting blood glucose (FBG), glycated hemoglobin A1c (GHbA1c), insulin (INS) and glucose tolerance were measured. Histopathology changes and fibrosis of pancreas were examined by hematoxylin and eosin staining and Masson staining. Mouse PSCs were extracted, co-cultured with mouse insulinoma β cells (MIN6 cells) and treated with 1,25(OH) 2 D 3 . ELISA detection of inflammatory factor expression. Tissue reactive oxygen species (ROS) levels were also measured. Immunofluorescence or Western blotting were used to measure fibrosis and inflammation-related protein expression., Results: PSCs activation and islets fibrosis in T2DM mice. Elevated blood glucose was accompanied by significant increases in serum inflammatory cytokines and tissue ROS levels. 1,25(OH) 2 D 3 attenuated islet fibrosis by reducing hyperglycemia, ROS levels, and inflammatory factors expression. Additionally, the co-culture system confirmed that 1,25(OH) 2 D 3 inhibited PSCs activation, reduced the secretion of pro-inflammatory cytokines, down-regulated the expression of fibrosis and inflammation-related proteins, and promoted insulin secretion., Conclusion: Our findings identify that PSCs activation contributes to islet fibrosis and β-cell dysfunction. 1,25(OH) 2 D 3 exerts beneficial effects on T2DM potentially by inhibiting PSCs activation and inflammatory response, highlighting promising control strategies of T2DM by vitamin D., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease that is almost entirely resistant to conventional chemotherapy and radiation therapy. A significant factor in this resistance appears to be the dense desmoplastic stroma, which contains various cancer-associated fibroblast (CAF) populations. However, our understanding of the communication between tumor cells and CAFs that contributes to this aggressive malignancy is still developing. Recently, we used an advanced three-dimensional heterospecies, heterospheroid co-culture model to investigate the signaling between human pancreatic tumor Panc1 cells and mouse pancreatic stellate cells (mPSCs) through global expression profiling. Upon discovering that CCN1 was significantly upregulated in Panc1 cells during co-culture, we decided to explore the role of CCN1 using CRISPR-Cas9 knockout technology. Panc1 cells lacking CCN1 showed reduced differentiation and decreased sensitivity to gemcitabine, primarily due to lower expression of genes involved in gemcitabine transport and metabolism. Additionally, we observed that stimulation with TGF-β1 and lysophosphatidic acid increased CCN1 expression in Panc1 cells and induced a shift in mPSCs towards a more myofibroblastic CAF-like phenotype.

Background: Pancreatic fibrosis is an early diagnostic feature of the common inherited disorder cystic fibrosis (CF). Many people with CF (pwCF) are pancreatic insufficient from birth and the replacement of acinar tissue with cystic lesions and fibrosis is a progressive phenotype that may later lead to diabetes. Little is known about the initiating events in the fibrotic process though it may be a sequela of inflammation in the pancreatic ducts resulting from loss of CFTR impairing normal fluid secretion. Here we use a sheep model of CF (CFTR -/- ) to examine the evolution of pancreatic disease through gestation., Methods: Fetal pancreas was collected at six time points from 50-days of gestation through to term, which is equivalent to ~ 13 weeks to term in human. RNA was extracted from tissue for bulk RNA-seq and single cells were prepared from 80-day, 120-day and term samples for scRNA-seq. Data were validated by immunochemistry., Results: Transcriptomic evidence from bulk RNA-seq showed alterations in the CFTR -/- pancreas by 65-days of gestation, which are accompanied by marked pathological changes by 80-days of gestation. These include a fibrotic response, confirmed by immunostaining for COL1A1, αSMA and SPARC, together with acinar loss. Moreover, using scRNA-seq we identify a unique cell population that is significantly overrepresented in the CFTR -/- animals at 80- and 120-days gestation, as are stellate cells at term., Conclusion: The transcriptomic changes and cellular imbalance that we observe likely have pivotal roles in the evolution of CF pancreatic disease and may provide therapeutic opportunities to delay or prevent pancreatic destruction in CF., (© 2024. The Author(s).)

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., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024. Published by Elsevier Inc.)

Pancreatic cancer remains a formidable challenge in oncology due to its aggressive nature and limited treatment options. The dense stroma surrounding pancreatic tumors not only provides structural support but also presents a formidable barrier to effective therapy, hindering drug penetration and immune cell infiltration. This review delves into the intricate interplay between stromal components and cancer cells, highlighting their impact on treatment resistance and prognosis. Strategies for stromal remodeling, including modulation of cancer-associated fibroblasts (CAFs), pancreatic stellate cells (PSCs) activation states, and targeting extracellular matrix (ECM) components, are examined for their potential to enhance drug penetration and improve therapeutic efficacy. Integration of stromal remodeling with conventional therapies, such as chemotherapy and immunotherapy, is discussed along with the emerging field of intelligent nanosystems for targeted drug delivery. This comprehensive overview underscores the importance of stromal remodeling in pancreatic cancer treatment and offers insights into promising avenues for future research and clinical translation.

Pancreatic stellate cells (PSC) are one source of cancer-associated fibroblasts (CAF) and play, therefore, an essential role in pancreatic ductal adenocarcinoma (PDA). Paracrine signalling between PDA cells and CAF has been widely studied, yet external influences on paracrine crosstalk are poorly understood. This study aimed to gain a deeper insight into the communication of PSC and cancer cells under different co-culture conditions via analysis of PSC gene expression profiles. Two contactless co-culture models with tumor cells from the p48-Cre; lox-stop-lox-Kras G12D/+ ; lox-stop-lox-Trp53 R172H/+ mouse model (KPC) and murine PSC separated through a microporous membrane and grown in different compartments (standard co-culture) or on different sides of the same membrane (inverse co-culture), were established. RNA-Sequencing analysis of PSC mRNA was performed 24 h and 72 h after co-culture with KPC cells. For selected genes, results were confirmed by quantitative RT-PCR and immunocytochemistry. Standard co-culture displayed 19 differentially expressed genes (DEG) at 24 h and 52 DEG at 72 h. In inverse co-culture, 800 DEG at 24 h and 2213 DEG at 72 h were enriched. PSC showed great heterogeneity in their gene expression profiles; however, mutually regulated genes of both co-cultures, such as VCAN and CHST11, could be identified. VCAN-protein-protein interaction-network analysis revealed several shared genes between co-culture models, such as SDC4 and FN1. In conclusion, PSC show a varying susceptibility to cancer cell signals depending on the co-culture method, with intensified transcriptome changes with closer proximity., (© 2024. The Author(s).)

Integrin β6 (ITGB6) is upregulated in multiple tumor types and elevated ITGB6 levels have been detected in patients with chronic pancreatitis. However, the role of ITGB6 in pancreatic fibrosis and cancer remains to be elucidated. In the present study, ITGB6 expression was assessed using western blotting and qRT-PCR. Besides, cell proliferation, cycling, migration, and invasion were evaluated using CCK-8, flow cytometry, wound healing, and transwell assays, respectively. The expression of fibrosis and JAK2/STAT3 signaling markers was detected by western blotting and immunofluorescence analysis. Moreover, nude mice were subcutaneously injected with co-cultured cell suspensions to establish an in vivo model. The results showed that ITGB6 was highly expressed in pancreatic cancer tissues and TGF-β-induced pancreatic stellate cells (PSCs). Inhibition of ITGB6 expression in PSCs resulted in clear inhibition of activated PSC proliferation, migration, and fibrogenesis. Additionally, reduced ITGB6 expression inhibits the JAK2/STAT3 signaling pathway. Interestingly, activators of the JAK2/STAT3 signaling pathway reversed the effects of ITGB6 disruption on PSCs. Activated PSCs notably promoted the proliferation, invasion, and migration of pancreatic cancer cells in a co-culture assay. In contrast, activated PSCs with low ITGB6 expression failed to significantly affect the malignancy of pancreatic cancer cells. Moreover, in vivo results showed that interference with ITGB6 inhibited the activation of PSCs and promoted the development of pancreatic cancer. Silencing ITGB6 inhibited the proliferation, migration, and fibrosis-like effects of activated PSCs and indirectly inhibited the metastasis and malignant process of pancreatic cancer by inhibiting the JAK2/STAT3 signaling pathway. Therefore, ITGB6 is a potential candidate target for pancreatic cancer prevention and treatment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pancreatic cancer remains one of the most lethal malignant diseases. Gemcitabine-based chemotherapy is still one of the first-line systemic treatments, but chemoresistance occurs in the majority of patients. Recently, accumulated evidence has demonstrated the role of the tumour microenvironment in promoting chemoresistance. In the tumour microenvironment, pancreatic stellate cells (PSCs) are among the main cellular components, and extracellular vesicles (EVs) are common mediators of cell‒cell communication. In this study, we showed that SP1-transcribed miR-31-5p not only targeted LATS2 in pancreatic cancer cells but also regulated the Hippo pathway in PSCs through EV transfer. Consequently, PSCs synthesized and secreted protein acidic and rich in cysteins (SPARC), which was preferentially expressed in stromal cells, stimulating Extracellular Signal regulated kinase (ERK) signalling in pancreatic cancer cells. Therefore, pancreatic cancer cell survival and chemoresistance were improved due to both the intrinsic Hippo pathway regulated by miR-31-5p and external SPARC-induced ERK signalling. In mouse models, miR-31-5p overexpression in pancreatic cancer cells promoted the chemoresistance of coinjected xenografts. In a tissue microarray, pancreatic cancer patients with higher miR-31-5p expression had shorter overall survival. Therefore, miR-31-5p regulates the Hippo pathway in multiple cell types within the tumour microenvironment via EVs, ultimately contributing to the chemoresistance of pancreatic cancer cells., (© 2024 The Author(s). Journal of Extracellular Vesicles published by Wiley Periodicals LLC on behalf of International Society for Extracellular Vesicles.)

As a pluripotent cell, activated pancreatic stellate cells (PSCs) can differentiate into various pancreatic parenchymal cells and participate in the secretion of extracellular matrix and the repair of pancreatic damage. Additionally, PSCs characteristics allow them to contribute to pancreatic inflammation and carcinogenesis. Moreover, a detailed study of the pathogenesis of activated PSCs in pancreatic disease can offer promise for the development of innovative therapeutic strategies and improved patient prognoses. Therefore, the present study review aimed to examine the involvement of activated PSCs in pancreatic diseases and elucidate the underlying mechanisms to provide a viable therapeutic strategy for the management of pancreas‑related diseases.

Background: Pancreatic fibrosis is one of the most important pathological features of chronic pancreatitis (CP) and pancreatic stellate cells (PSCs) are the key cells of fibrosis. As an extracellular matrix (ECM) glycoprotein, cartilage oligomeric matrix protein (COMP) is critical for collagen assembly and ECM stability and recent studies showed that COMP exert promoting fibrosis effect in the skin, lungs and liver. However, the role of COMP in activation of PSCs and pancreatic fibrosis remain unclear. We aimed to investigate the role and specific mechanisms of COMP in regulating the profibrotic phenotype of PSCs and pancreatic fibrosis., Methods: ELISA method was used to determine serum COMP in patients with CP. Mice model of CP was established by repeated intraperitoneal injection of cerulein and pancreatic fibrosis was evaluated by Hematoxylin-Eosin staining (H&E) and Sirius red staining. Immunohistochemical staining was used to detect the expression changes of COMP and fibrosis marker such as α-SMA and Fibronectin in pancreatic tissue of mice. Cell Counting Kit-8, Wound Healing and Transwell assessed the proliferation and migration of human pancreatic stellate cells (HPSCs). Western blotting, qRT-PCR and immunofluorescence staining were performed to detect the expression of fibrosis marker, AKT and MAPK family proteins in HPSCs. RNA-seq omics analysis as well as small interfering RNA of COMP, recombinant human COMP (rCOMP), MEK inhibitors and PI3K inhibitors were used to study the effect and mechanism of COMP on activation of HPSCs., Results: ELISA showed that the expression of COMP significantly increased in the serum of CP patients. H&E and Sirius red staining analysis showed that there was a large amount of collagen deposition in the mice in the CP model group and high expression of COMP, α-SMA, Fibronectin and Vimentin were observed in fibrotic tissues. TGF-β1 stimulates the activation of HPSCs and increases the expression of COMP. Knockdown of COMP inhibited proliferation and migration of HPSCs. Further, RNA-seq omics analysis and validation experiments in vitro showed that rCOMP could significantly promote the proliferation and activation of HPSCs, which may be due to promoting the phosphorylation of ERK and AKT through membrane protein receptor CD36. rCOMP simultaneously increased the expression of α-SMA, Fibronectin and Collagen I in HPSCs., Conclusion: In conclusion, this study showed that COMP was up-regulated in CP fibrotic tissues and COMP induced the activation, proliferation and migration of PSCs through the CD36-ERK/AKT signaling pathway. COMP may be a potential therapeutic candidate for the treatment of CP. Interfering with the expression of COMP or the communication between COMP and CD36 on PSCs may be the next direction for therapeutic research., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Aims: Evidence is accumulating of the therapeutic benefits of mesenchymal stromal cells (MSCs) in diabetes-related conditions. We have identified a novel population of stromal cells within islets of Langerhans - islet stellate cells (ISCs) - which have a similar morphology to MSCs. In this study we characterize mouse ISCs and compare their morphology and function to MSCs to determine whether ISCs may also have therapeutic potential in diabetes., Methods: ISCs isolated from mouse islets were compared to mouse bone marrow MSCs by analysis of cell morphology; expression of cell-surface markers and extracellular matrix (ECM) components; proliferation; apoptosis; paracrine activity; and differentiation into adipocytes, chondrocytes and osteocytes. We also assessed the effects of co-culture with ISCs or MSCs on the insulin secretory capacity of islet beta cells., Results: Although morphological similar, ISCs were functionally distinct from MSCs. Thus, ISCs were less proliferative and more apoptotic; they had different expression levels of important paracrine factors; and they were less efficient at differentiation down multiple lineages. Co-culture of mouse islets with ISCs enhanced glucose induced insulin secretion more effectively than co-culture with MSCs., Conclusions: ISCs are a specific sub-type of islet-derived stromal cells that possess biological behaviors distinct from MSCs. The enhanced beneficial effects of ISCs on islet beta cell function suggests that they may offer a therapeutic target for enhancing beta cell functional survival in diabetes., (© 2024 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.)

Small extracellular vesicles (sEVs) are cell-derived vesicles evolving as important elements involved in all stages of cancers. sEVs bear unique protein signatures that may serve as biomarkers. Pancreatic cancer (PC) records a very poor survival rate owing to its late diagnosis and several cancer cell-derived proteins have been reported as candidate biomarkers. However, given the pivotal role played by stellate cells (PSCs, which produce the collagenous stroma in PC), it is essential to also assess PSC-sEV cargo in biomarker discovery. Thus, this study aimed to isolate and characterise sEVs from mouse PC cells and PSCs cultured alone or as co-cultures and performed proteomic profiling and pathway analysis. Proteomics confirmed the enrichment of specific markers in the sEVs compared to their cells of origin as well as the proteins that are known to express in each of the culture types. Most importantly, for the first time it was revealed that PSC-sEVs are enriched in proteins (including G6PI, PGAM1, ENO1, ENO3, and LDHA) that mediate pathways related to development of diabetes, such as glucose metabolism and gluconeogenesis revealing a potential role of PSCs in pancreatic cancer-related diabetes (PCRD). PCRD is now considered a harbinger of PC and further research will enable to identify the role of these components in PCRD and may develop as novel candidate biomarkers of PC., (© 2024 The Authors. PROTEOMICS published by Wiley‐VCH GmbH.)

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignancy worldwide owing to its complex tumour microenvironment and dense physical barriers. Stromal-derived factor-1 (SDF-1), which is abundantly secreted by tumour stromal cells, plays a pivotal role in promoting PDAC growth and metastasis. In this study, we investigated the impact and molecular mechanisms of the anti-PD-L1&CXCR4 bispecific nanobody on the TME and their consequent interference with PDAC progression. We found that blocking the SDF-1/CXCR4 signalling pathway delayed the epithelial-mesenchymal transition in pancreatic cancer cells. Anti-PD-L1&CXCR4 bispecific nanobody effectively suppress the secretion of SDF-1 by pancreatic stellate cells and downregulate the expression of smooth muscle actin alpha(α-SMA), thereby preventing the activation of cancer-associated fibroblasts by downregulating the PI3K/AKT signaling pathway. This improves the pancreatic tumour microenvironment, favouring the infiltration of T cells into the tumour tissue. In conclusion, our results suggest that the anti-PD-L1&CXCR4 bispecific nanobody exerts an antitumor immune response by changing the pancreatic tumour microenvironment. Hence, the anti-PD-L1&CXCR4 bispecific nanobody is a potential candidate for pancreatic cancer treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic cancer is characterized by desmoplasia; crosstalk between pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) leads to the deposition of extracellular matrix proteins in the tumor environment resulting in poor vascularity. Targeting either PCCs or PSCs individually has produced mixed results, and there is currently no effective strategy to target both cell types simultaneously. Previously, we demonstrated, through in vitro cell culture experiments, that a specific gold nanoparticle-based nanoformulation containing the anti-EGFR antibody cetuximab (C225) as a targeting agent and gemcitabine as a chemotherapeutic agent effectively targets both PCCs and PSCs simultaneously. Herein, we extend our studies to test the ability of these in vitro tested nano formulations to inhibit tumor growth in an orthotopic co-implantation model of pancreatic cancer in vivo. Orthotopic tumors were established by co-implantation of equal numbers of PCCs and PSCs in the mouse pancreas. Among the various formulations tested, 5 nm gold nanoparticles coated with gemcitabine, cetuximab and poly-ethylene glycol (PEG) of molecular weight 1000 Da, which we named ACGP441000, demonstrated optimal efficacy in inhibiting tumor growth. The current study reveals an opportunity to target PCCs and PSCs simultaneously, by exploiting their overexpression of EGFR as a target, in order to inhibit pancreatic cancer growth., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic cancer is characterized by a densely fibrotic stroma. The fibrotic stroma hinders the intratumoral penetration of nanomedicine and diminishes therapeutic efficacy. Fibrosis is characterized by an abnormal organization of extracellular matrix (ECM) components, namely the abnormal deposition and/or orientation of collagen and fibronectin. Abnormal ECM organization is chiefly driven by pathological signaling in pancreatic stellate cells (PSCs), the main cell type involved in fibrogenesis. However, whether targeting signaling pathways involved in abnormal ECM organization improves the intratumoral penetration of nanomedicines is unknown. Here, we show that targeting transforming growth factor-β (TGFβ)/Rho-associated kinase (ROCK) 1/2 signaling in PSCs normalizes ECM organization and concomitantly improves macromolecular permeability of the fibrotic stroma. Using a 3-dimensional cell culture model of the fibrotic pancreatic cancer microenvironment, we found that pharmacological inhibition of TGFβ or ROCK1/2 improves the permeation of various macromolecules. By using an isoform-specific pharmacological inhibitor and siRNAs, we show that targeting ROCK2, but not ROCK1, alone is sufficient to normalize ECM organization and improve macromolecular permeability. Moreover, we found that ROCK2 inhibition/knockdown attenuates Yes-associated protein (YAP) nuclear localization in fibroblasts co-cultured with pancreatic cancer cells in 3D. Finally, pharmacological inhibition or siRNA-mediated knockdown of YAP normalized ECM organization and improved macromolecular permeability. Our results together suggest that the TGFβ/ROCK2/YAP signaling axis may be therapeutically targeted to normalize ECM organization and improve macromolecular permeability to augment therapeutic efficacy of nanomedicines in pancreatic cancer., Competing Interests: Declaration of competing interest Takuya Miyazaki is the CEO and Horacio Cabral is the co-founder and the head of drug discovery of Red Arrow Therapeutics, Inc. All other authors declare no conflict of interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic fibrosis (PF) is primarily characterized by aberrant production and degradation modes of extracellular matrix (ECM) components, resulting from the activation of pancreatic stellate cells (PSCs) and the pathological cross-linking of ECM mediated by lysyl oxidase (LOX) family members. The excessively deposited ECM increases matrix stiffness, and the over-accumulated reactive oxygen species (ROS) induces oxidative stress, which further stimulates the continuous activation of PSCs and advancing PF; challenging the strategy toward normalizing ECM homeostasis for the regression of PF. Herein, ROS-responsive and Vitamin A (VA) decorated micelles (named LR-SSVA) to reverse the imbalanced ECM homeostasis for ameliorating PF are designed and synthesized. Specifically, LR-SSVA selectively targets PSCs via VA, thereby effectively delivering siLOXL1 and resveratrol (RES) into the pancreas. The ROS-responsive released RES inhibits the overproduction of ECM by eliminating ROS and inactivating PSCs, meanwhile, the decreased expression of LOXL1 ameliorates the cross-linked collagen for easier degradation by collagenase which jointly normalizes ECM homeostasis and alleviates PF. This research shows that LR-SSVA is a safe and efficient ROS-response and PSC-targeted drug-delivery system for ECM normalization, which will propose an innovative and ideal platform for the reversal of PF., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

The effect of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a persistent environmental pollutant commonly used as a flame retardant in various consumer products, on pancreatitis has not been clearly elucidated, although it has been reported to be toxic to the liver, nervous system, and reproductive system. Acute pancreatitis (AP) and chronic pancreatitis (CP) models were induced in this study by intraperitoneal injection of caerulein. The aim was to investigate the impact of BDE-47 on pancreatitis by exposing the animals to acute (1 week) or chronic (8 weeks) doses of BDE-47 (30 mg/kg in the low-concentration group and 100 mg/kg in the high-concentration group). Additionally, BDE-47 was utilized to stimulate mouse bone marrow-derived macrophages, pancreatic primary stellate cells, and acinar cells in order to investigate the impact of BDE-47 on pancreatitis. In vivo experiments conducted on mice revealed that chronic exposure to BDE-47, rather than acute exposure, exacerbated the histopathological damage of AP and CP, leading to elevated fibrosis in pancreatic tissue and increased infiltration of inflammatory cells in the pancreas. In vitro experiments showed that BDE-47 can promote the expression of the inflammatory cytokines Tnf-α and Il-6 in M1 macrophages, as well as promote acinar cell apoptosis through the activation of the PERK and JNK pathways via endoplasmic reticulum stress. The findings of this study imply chronic exposure to BDE-47 may exacerbate the progression of both AP and CP by inducing acinar cell apoptosis and dysregulating inflammatory responses., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Chronic pancreatitis (CP) is a persistent, recurrent, and progressive disorder that is characterized by chronic inflammation and irreversible fibrosis of the pancreas. It is associated with severe morbidity, resulting in intense abdominal pain, diabetes, exocrine and endocrine dysfunction, and an increased risk of pancreatic cancer. The etiological factors are diverse and the major risk factors include smoking, chronic alcoholism, as well as other environmental and genetic factors. The treatment and management of CP is challenging, and no definitive curative therapy is currently available., Areas Covered: This review paper aims to provide an overview of the different cell types in the pancreas that is known to mediate disease progression and outline potential novel therapeutic approaches and drug targets that may be effective in treating and managing CP. The information presented in this review was obtained by conducting a NCBI PubMed database search, using relevant keywords., Expert Opinion: In recent years, there has been an increased interest in the development of novel therapeutics for CP. A collaborative multi-disciplinary approach coupled with a consistent funding for research can expedite progress of translating the findings from bench to bedside.

One major obstacle in the drug treatment of pancreatic ductal adenocarcinoma (PDAC) is its highly fibrotic tumor microenvironment, which is replete with activated pancreatic stellate cells (a-PSCs). These a-PSCs generate abundant extracellular matrix and secrete various cytokines to form biophysical and biochemical barriers, impeding drug access to tumor tissues. Therefore, it is imperative to develop a strategy for reversing PSC activation and thereby removing the barriers to facilitate PDAC drug treatment. Herein, by integrating chromatin immunoprecipitation (ChIP)-seq, Assays for Transposase-Accessible Chromatin (ATAC)-seq, and RNA-seq techniques, this work reveals that super-enhancers (SEs) promote the expression of various genes involved in PSC activation. Disruption of SE-associated transcription with JQ1 reverses the activated phenotype of a-PSCs and decreases stromal fibrosis in both orthotopic and patient-derived xenograft (PDX) models. More importantly, disruption of SEs by JQ1 treatments promotes vascularization, facilitates drug delivery, and alters the immune landscape in PDAC, thereby improving the efficacies of both chemotherapy (with gemcitabine) and immunotherapy (with IL-12). In summary, this study not only elucidates the contribution of SEs of a-PSCs in shaping the PDAC tumor microenvironment but also highlights that targeting SEs in a-PSCs may become a gate-opening strategy that benefits PDAC drug therapy by removing stromal barriers., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

In the realm of fibroinflammatory conditions, chronic pancreatitis (CP) stands out as a particularly challenging ailment, lacking a dedicated, approved treatment. The potential of Pirfenidone (PFD), a drug originally used for treating idiopathic pulmonary fibrosis (IPF), in addressing CP's fibrotic aspects has sparked new interest. This investigation focused on the role of PFD in diminishing fibrosis and immune response in CP, using a mouse model induced by caerulein. The research extended to in vitro studies examining the influence of PFD on pancreatic stellate cells' (PSCs) behavior and the polarization of macrophages into M1 and M2 types. Advanced techniques like RNA sequencing and comprehensive data analyses were employed to decode the molecular interactions of PFD with PSCs. Supplementary experiments using techniques such as quantitative real-time PCR, western blotting, and immunofluorescence were also implemented. Results showed a notable reduction in pancreatic damage in PFD-treated mice, manifested through decreased acinar cell atrophy, lower collagen deposition, and a reduction in macrophage presence. Further investigation revealed PFD's capacity to hinder PSCs' migration, growth, and activation, alongside a reduction in the production and secretion of extracellular matrix proteins. This effect is primarily achieved by interfering with signaling pathways such as TGF-β/Smad, Wnt/β-catenin, and JAK/STAT. Additionally, PFD selectively hampers M1 macrophage polarization through the STAT3 pathway, without impacting M2 polarization. These outcomes highlight PFD's dual mechanism in moderating PSC activity and M1 macrophage polarization, positioning it as a promising candidate for CP therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Pancreatic stellate cells (PSCs) are activated following loss of cytoplasmic vitamin A (retinol)-containing lipid droplets, which is a key event in the process of fibrogenesis of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDCA). PSCs are the major source of cancer-associated fibroblasts (CAFs) that produce stroma to induce PDAC cancer cell growth, invasion, and metastasis. As an active metabolite of retinol, retinoic acid (RA) can regulate target gene expression in PSCs through its nuclear receptor complex (RAR/RXR or RXR/RXR) or transcriptional intermediary factor. Additionally, RA also has extranuclear and non-transcriptional effects. In vitro studies have shown that RA induces PSC deactivation which reduces extracellular matrix production through multiple modes of action, such as inhibiting TβRⅡ, PDGFRβ, β-catenin and Wnt production, downregulating ERK1/2 and JNK phosphorylation and suppressing active TGF-β1 release. RA alone or in combination with other reagents have been demonstrated to have an effective anti-fibrotic effect on cerulein-induced mouse CP models in vivo studies. Clinical trial data have shown that repurposing all-trans retinoic acid (ATRA) as a stromal-targeting agent for human pancreatic cancer is safe and tolerable, suggesting the possibility of using RA for the treatment of CP and PDCA in humans. This review focuses on RA signaling pathways in PSCs and the effects and mechanisms of RA in PSC-mediated fibrogenesis as well as the anti-fibrotic and anti-tumor effects of RA targeting PSCs or CAFs in vitro and in vivo, highlighting the potential therapies of RA against CP and PDAC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Pancreatic stellate cells (PSC) have been defined to be the key players in pancreatic fibrogenesis and carcinogenesis. They undergo myofibroblast-like differentiation, express α-smooth muscle actin (α-SMA), and play a crucial role in injury and inflammation sites. This study aims to evaluate the relationship between α-SMA expression and histopathological parameters of pancreatic ductal adenocarcinoma (PDAC), and investigate their association with prognosis., Material and Methods: Eighty-one consecutive pancreatectomies diagnosed as usual pancreatic ductal adenocarcinoma were included. The stromal density was scored as loose, moderate, or dense, and α-SMA expression was evaluated immunohistochemically., Results and Conclusion: Mean survival was 19.6 months. Male gender, larger tumor diameter ( > 3.7 cm), and older age ( > 64 years) were identified as independent poor prognostic factors. Perineural invasion significantly effected survival. A statistically significant correlation was found between high α-SMA expression and the presence of angioinvasion (p=0.01). Stromal α-SMA expression in PDAC may help determine the risk of angioinvasion.

Activation of pancreatic stellate cells (PSCs) to cancer-associated fibroblasts (CAFs) is responsible for the extensive desmoplastic reaction observed in PDAC stroma: a key driver of pancreatic ductal adenocarcinoma (PDAC) chemoresistance leading to poor prognosis. Specialized pro-resolving mediators (SPMs) are prime modulators of inflammation and its resolution, traditionally thought to be produced by immune cells. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based lipid mediator profiling PSCs as well as primary human CAFs express enzymes and receptors to produce and respond to SPMs. Human PSC/CAF SPM secretion profile can be modulated by rendering these cells activated [transforming growth factor beta (TGF-β)] or quiescent [all- trans retinoic acid (ATRA)]. ATRA-induced nuclear translocation of arachidonate-15-lipoxygenase (ALOX15) was linked to increased production of n-3 docosapentaenoic acid-derived Resolvin D5 (RvD5 n-3 DPA ), among other SPMs. Inhibition of RvD5 n-3 DPA formation increases cancer cell invasion, whereas addback of this molecule reduced activated PSC-mediated cancer cell invasion. We also observed that circulating concentrations of RvD5 n-3 DPA levels were decreased in peripheral blood of metastatic PDAC patients when compared with those measured in plasma of non-metastatic PDAC patients. Together, these findings indicate that RvD5 n-3 DPA may regulate cancer-stroma cross-talk and invasion., Competing Interests: Author JD is an inventor on patents related to the composition of matter and/or use of pro-resolving mediators, some of which are licensed by Brigham and Women’s Hospital or Queen Mary University of London for clinical development. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Aguirre, Goulart, Barts Pancreas Tissue Bank, Dalli and Kocher.)

Pancreatic ductal adenocarcinoma (PDAC), a highly malignant neoplasm, is classified as one of the most severe and devastating types of cancer. PDAC is a notable malignancy that exhibits a discouraging prognosis and a rising occurrence. The interplay between diabetes and pancreatic cancer exhibits a reciprocal causation. The identified metabolic disorder has been observed to possess noteworthy consequences on health outcomes, resulting in elevated rates of morbidity. The principal mechanisms involve the suppression of the immune system, the activation of pancreatic stellate cells (PSCs), and the onset of systemic metabolic disease caused by dysfunction of the islets. From this point forward, it is important to recognize that pancreatic-cancer-related diabetes (PCRD) has the ability to increase the likelihood of developing pancreatic cancer. This highlights the complex relationship that exists between these two physiological states. Therefore, we investigated into the complex domain of PSCs, elucidating their intricate signaling pathways and the profound influence of chemokines on their behavior and final outcome. In order to surmount the obstacle of drug resistance and eliminate PDAC, researchers have undertaken extensive efforts to explore and cultivate novel natural compounds of the next generation. Additional investigation is necessary in order to comprehensively comprehend the effect of PCRD-mediated apoptosis on the progression and onset of PDAC through the utilization of natural compounds. This study aims to examine the potential anticancer properties of natural compounds in individuals with diabetes who are undergoing chemotherapy, targeted therapy, or immunotherapy. It is anticipated that these compounds will exhibit increased potency and possess enhanced pharmacological benefits. According to our research findings, it is indicated that naturally derived chemical compounds hold potential in the development of PDAC therapies that are both safe and efficacious.

Pancreatic stellate cells (PSCs) that can co-metastasize with cancer cells shape the tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDAC) by producing an excessive amount of extracellular matrix. This leads to a TME characterized by increased tissue pressure, hypoxia, and acidity. Moreover, cells within the tumor secrete growth factors. The stimuli of the TME trigger Ca 2+ signaling and cellular Na + loading. The Na + /Ca 2+ exchanger (NCX) connects the cellular Ca 2+ and Na + homeostasis. The NCX is an electrogenic transporter, which shuffles 1 Ca 2+ against 3 Na + ions over the plasma membrane in a forward or reverse mode. Here, we studied how the impact of NCX activity on PSC migration is modulated by cues from the TME. NCX expression was revealed with qPCR and Western blot. [Ca 2+ ] i , [Na + ] i , and the cell membrane potential were determined with the fluorescent indicators Fura-2, Asante NaTRIUM Green-2, and DiBAC 4 (3), respectively. PSC migration was quantified with live-cell imaging. To mimic the TME, PSCs were exposed to hypoxia, pressure, acidic pH (pH 6.6), and PDGF. NCX-dependent signaling was determined with Western blot analyses. PSCs express NCX1.3 and NCX1.9. [Ca 2+ ] i , [Na + ] i , and the cell membrane potential are 94.4 nmol/l, 7.4 mmol/l, and - 39.8 mV, respectively. Thus, NCX1 usually operates in the forward (Ca 2+ export) mode. NCX1 plays a differential role in translating cues from the TME into an altered migratory behavior. When NCX1 is operating in the forward mode, its inhibition accelerates PSC migration. Thus, NCX1-mediated extrusion of Ca 2+ contributes to a slow mode of migration of PSCs., (© 2023. The Author(s).)

The pancreatic stellate cells (PSCs) play an important role in the development of pancreatic cancer (PC) through mechanisms that remain unclear. Exosomes secreted from PSCs act as mediators for communication in PC. This study aimed to explore the role of PSC-derived exosomal small RNAs derived from tRNAs (tDRs) in PC cells. Exosomes from PSCs were extracted and used to detect their effects on PC cell proliferation, migration and invasion. Exosomal tDRs profiling was performed to identify PSC-derived exosomal tDRs. ISH and qRT-PCR were used to examine the tRF-19-PNR8YPJZ levels and clinical value in clinical samples. The biological function of exosomal tRF-19-PNR8YPJZ was determined using the CCK-8, clone formation, wound healing and transwell assays, subcutaneous tumour formation and lung metastatic models. The relationship between the selected exosomal tRF-19-PNR8YPJZ and AXIN2 was determined by RNA sequencing, luciferase reporter assay. PSC-derived exosomes promoted the proliferation, migration, and invasion of PC cells. Novel and abundant tDRs are found to be differentially expressed in PANC-1 cells after treatment with PSC-derived exosomes, such as tRF-19-PNR8YPJZ. PC tissue samples showed markedly higher levels of tRF-19-PNR8YPJZ than normal controls. Patients with PC exhibiting high tRF-19-PNR8YPJZ expression had a highly lymph node invasion, metastasis, perineural invasion, advanced clinical stage and poor overall survival. Exosomal tRF-19-PNR8YPJZ from PSCs targeted AXIN2 in PC cells and decreased its expression, thus activating the Wnt pathway and promoting proliferation and metastasis. Exosomal tRF-19-PNR8YPJZ from PSCs promoted proliferation and metastasis in PC cells via AXIN2., (© 2023 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Pancreatic fibrosis is characterized by the activation of pancreatic stellate cells leading to the expression of smooth muscle actin (α-SMA). Normal pancreatic tissue has predominantly quiescent stellate cells in periductal and perivascular locations, which do not express α-SMA. We aimed at studying the immunohistochemistry (IHC) expression pattern of α-SMA, platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGF-β) in the resected specimen of chronic pancreatitis. Twenty biopsies from resected specimens of patients with chronic pancreatitis were included. The expression was measured in comparison to positive control biopsies (breast carcinoma for PDGF-BB and TGF-β and appendicular tissue for α-SMA) and scored based on a semi-quantitative system based on staining intensity. The percentage of positive cells was used for objective scoring, which ranged from 0 to 15. The scoring was done separately for acini, ducts, stroma and islet cell. All patients had undergone surgery for refractory pain and the median duration of symptoms was 48 months. On IHC, α-SMA was not expressed in the acini, ducts or islets, but had high expression in the stromal regions (vs. acini, ducts and islet, p < 0.05), TGF-β1 was also expressed maximally in islet cells; however, the distribution among all locations was statistically similar. α-SMA expression in the pancreatic stroma is an indicator of the concentration of activated stellate cells in the stroma, a site for genesis of fibrosis under the influence of growth factors in the local milieu., (© 2023. Indian Society of Gastroenterology.)

Chronic pancreatitis (CP) is a disease characterized by the inflammation and destruction of pancreatic tissue, leading to the replacement of functional tissue with fibrotic tissue. The regenerating gene (Reg) family proteins have recently been implicated in the repair and regeneration of inflamed pancreatic tissue, though the exact mechanisms of their involvement in the pathogenesis of CP are not yet fully understood. To investigate the role of Reg family proteins in CP, we generated global knockout mice (Reg -/- ) for Reg1-3 (Reg1,2,3a,3b,3d,3g) genes using the CRISPR/Cas9 system. We then investigated the effect of Reg family protein deficiency in a genetic model of CP (X-SPINK1) mice by knocking out Reg1-3 genes. We examined pancreatic morphology, inflammatory cytokines expression, and activation of pancreatic stellate cells (PSCs) at different ages. Reg -/- mice showed no abnormalities in general growth and pancreas development. Deficiency of Reg1-3 in CP mice led to a reduction in pancreatic parenchymal loss, decreased deposition of collagen, and reduced expression of proinflammatory cytokines. Additionally, Reg proteins were found to stimulate PSCs activation. Overall, our study suggests that Reg1-3 deficiency can lead to the remission of CP and Reg family proteins could be a potential therapeutic target for the treatment of CP., (© 2023. The Author(s).)

Hypoxia in pancreatic islets (islet hypoxia) can occur in type 2 diabetes mellitus. Previously, our in vitro experiments demonstrated that pancreatic stellate cells (PSCs) within the islet are activated in hypoxia, promoting pancreatic β-cell death. Here, we aimed to demonstrate the in vivo activation of intra-islet PSCs and investigate the mechanism of PSC-induced β-cell death in hypoxia. A novel in vivo model of islet hypoxia was established by injecting fluorescent microspheres into a carotid artery of Balb/c mice (Microsphere mice). The intraperitoneal glucose tolerance (IPGTT) was performed, and pancreatic tissues were stained for insulin expression after tissue clearing. Pimonidazole staining was also performed in the pancreas to detect the presence of hypoxia in islets. Next, primary PSCs were isolated and cultured from Balb/c mice. Exosomes were isolated from culture media from PSCs cultured in hypoxia (1% oxygen). MicroRNAs (miRNAs) were prepared from exosomes from PSCs, and miRNA expression profiles were analyzed by miRNA sequencing. Several miRNAs were overexpressed in islets using miRNA mimics. Two weeks after injection of microspheres, the Microsphere mice showed worsening of glucose tolerance in IPGTT. Later, cataracts were developed in the eyes of the mice. The pancreas showed that the areas, perimeters, and diameters of insulin-positive cells decreased in Microsphere mice. Pimonidazole adducts were detected in the islets of these mice, indicating the presence of islet hypoxia. In addition, α-smooth muscle actin-positive cell numbers per islet were higher in Microsphere mice, confirming the in vivo activation of intra-islet PSCs in hypoxia. Mouse islets incubated with exosomes isolated from PSCs cultured in hypoxia showed a decrease in cell viability. The exosomes contained a variety of miRNAs, of which miR-23a-3p was found to notably increase β-cell death through apoptosis. Together, our in vivo and in vitro data provide evidence to support that PSCs within the islets are activated in hypoxia and promote β-cell death through exosomal miRNA transfer, which may contribute to the progression of type 2 diabetes mellitus., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Ki-Ho Song reports financial support was provided by National Research Foundation of Korea., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Since the prognosis of patients with pancreatic cancer is very poor and there is a lack of treatment methods, this study is performed to investigate the function of PITX2 in pancreatic stellate cells (PSCs) in the progression of pancreatic cancer. Scientific hypotheses are proposed according to bioinformatics analysis and tissue microarray analysis. Stable knockdown of PITX2 in PSCs is achieved through lentiviral infection. The relative expressions of PITX2, α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are measured in wild-type PSCs and PITX2 -knockdown PSCs. Proliferative capacity is measured by EdU assay. After coculture with PSCs, the proliferation, invasion and migration capacity of pancreatic cancer cells are tested. EMT and Wnt/β-catenin downstream genes of pancreatic cancer cells are investigated to reveal the potential mechanism. Bioinformatics analysis reveals that the PITX2 gene is highly expressed in stromal cells in pancreatic cancer and is correlated with squamous-type PDAC. Analysis of PDAC tissue microarray further demonstrates that high PITX2 level in stromal cells is correlated with poor prognosis in PDAC. After stable knockdown of PITX2 in PSCs, the relative protein levels of α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are decreased, and the proliferative capacity of PSCs is also decreased. After coculture with PSCs, in which PITX2 expression is downregulated, the proliferation, invasion and migration capacities of pancreatic cancer cells are inhibited. Thus, our results show that PITX2 -silenced PSCs inhibit the growth, migration and invasion of pancreatic cancer cells via reduced EMT and Wnt/β-catenin signaling.

The acidic tumor microenvironment (TME) of pancreatic cancer affects the physiological function of pancreatic stellate cells (PSCs), which in turn promotes cancer progression. Acid-sensing ion channel 1a (ASIC1a) is responsible for acidosis-related physiopathological processes. In this study, we investigated the effect of acid exposure on the activation and autophagy of PSCs, and the role of ASIC1a in these events. The results showed that acidic medium upregulated the expression of ASIC1a, induced PSCs activation and autophagy, which can be suppressed by inhibiting ASIC1a using PcTx1 or ASIC1a knockdown, suggesting that ASIC1a involves these two processes. In addition, the acid-induced activation of PSCs was impaired after the application of autophagy inhibitor alone or in combination with ASIC1a siRNA, meaning a connection between autophagy and activation. Collectively, our study provides evidence for the involvement of ASIC1a in the acid-caused PSCs activation, which may be associated with autophagy induction.

Pancreatic stellate cells (PSCs) are crucial for metabolism and disease progression in pancreatic ductal adenocarcinoma (PDAC). However, detailed mechanisms of PSCs in glutamine (Gln) metabolism and tumor-stromal metabolic interactions have not been well clarified. Here we showed that tumor tissues displayed Gln deficiency in orthotopic PDAC models. Single-cell RNA sequencing analysis revealed metabolic heterogeneity in PDAC, with significantly higher expression of Gln catabolism pathway in stromal cells. Significantly higher glutamine synthetase (GS) protein expression was further validated in human tissues and cells. Elevated GS levels in tumor and stroma were independently prognostic of poorer prognosis in PDAC patients. Gln secreted by PSCs increased basal oxygen consumption rate in PCCs. Depletion of GS in PSCs significantly decreased PCCs proliferation in vitro and in vivo. Mechanistically, activation of Wnt signaling induced directly binding of β-catenin/TCF7 complex to GS promoter region and upregulated GS expression. Rescue experiments testified that GS overexpression recovered β-catenin knockdown-mediated function on Gln synthesis and tumor-promoting ability of PSCs. Overall, these findings identify the Wnt/β-catenin/TCF7/GS-mediated growth-promoting effect of PSCs and provide new insights into stromal Gln metabolism, which may offer novel therapeutic strategies for PDAC., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Pancreatic stellate cell (PSC) activation is a major cause of chronic pancreatitis and pancreatic cancer, yet the mechanisms by which PSCs switch from quiescent to activated state are poorly studied. In this study, we identified JUN, a key transcription factor that maintains the quiescent state of PSCs, by integrating single-cell sequencing data from multiple pancreatic tissues and using WGCNA and SCENIC algorithms, and demonstrated that the expression and activity of JUN is a major regulator of the quiescent state of PSCs through cellular experiments and multiple pancreatic-related disease bulk RNAseq data. This study explores the main mechanism of PSC activation and provides a theoretical basis for the treatment of multiple pancreatic injury-related diseases caused by PSCs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Human pancreatic stellate cells (HPSCs) are an essential stromal component and mediators of pancreatic ductal adenocarcinoma (PDAC) progression. Small extracellular vesicles (sEVs) are membrane-enclosed nanoparticles involved in cell-to-cell communications and are released from stromal cells within PDAC. A detailed comparison of sEVs from normal pancreatic stellate cells (HPaStec) and from PDAC-associated stellate cells (HPSCs) remains a gap in our current knowledge regarding stellate cells and PDAC. We hypothesized there would be differences in sEVs secretion and protein expression that might contribute to PDAC biology. To test this hypothesis, we isolated sEVs using ultracentrifugation followed by characterization by electron microscopy and Nanoparticle Tracking Analysis. We report here our initial observations. First, HPSC cells derived from PDAC tumors secrete a higher volume of sEVs when compared to normal pancreatic stellate cells (HPaStec). Although our data revealed that both normal and tumor-derived sEVs demonstrated no significant biological effect on cancer cells, we observed efficient uptake of sEVs by both normal and cancer epithelial cells. Additionally, intact membrane-associated proteins on sEVs were essential for efficient uptake. We then compared sEV proteins isolated from HPSCs and HPaStecs cells using liquid chromatography-tandem mass spectrometry. Most of the 1481 protein groups identified were shared with the exosome database, ExoCarta. Eighty-seven protein groups were differentially expressed (selected by 2-fold difference and adjusted p value ≤0.05) between HPSC and HPaStec sEVs. Of note, HPSC sEVs contained dramatically more CSE1L (chromosome segregation 1-like protein), a described marker of poor prognosis in patients with pancreatic cancer. Based on our results, we have demonstrated unique populations of sEVs originating from stromal cells with PDAC and suggest that these are significant to cancer biology. Further studies should be undertaken to gain a deeper understanding that could drive novel therapy., Competing Interests: Conflict of Interest Dr John M. Koomen is partially funded by BMS for a different project unrelated to this work. Dr Jason B. Fleming is a scientific advisor/consultant in the following companies: Glycosbio Food Sciences, Inc, Biopath Holdings Inc, Natera, Panther Therapeutics Inc, and an independent contractor in MyCareGorithm. Other authors have no conflict of interests with the contents of the article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Epidermal growth factor receptor (EGFR) is an essential target for cancer treatment. However, EGFR inhibitor erlotinib showed limited clinical benefit in pancreatic cancer therapy. Here, we showed the underlying mechanism of tumor microenvironment suppressing the sensitivity of EGFR inhibitor through the pancreatic stellate cell (PSC)., Methods: The expression of alpha-smooth muscle actin (α-SMA) and hypoxia marker in human pancreatic cancer tissues were detected by immunohistochemistry, and their correlation with overall survival was evaluated. Human immortalized PSC was constructed and used to investigate the potential effect on pancreatic cancer cell lines in hypoxia and normoxia. Luciferase reporter assay and Chromatin immunoprecipitation were performed to explore the potential mechanisms in vitro. The combined inhibition of EGFR and Met was evaluated in an orthotopic xenograft mouse model of pancreatic cancer., Findings: We found that high expression levels of α-SMA and hypoxia markers are associated with poor prognosis of pancreatic cancer patients. Mechanistically, we demonstrated that hypoxia induced the expression and secretion of HGF in PSC via transcription factor HIF-1α. PSC-derived HGF activates Met, the HGF receptor, suppressing the sensitivity of pancreatic cancer cells to EGFR inhibitor in a KRAS-independent manner by activating the PI3K-AKT pathway. Furthermore, we found that the combination of EGFR inhibitor and Met inhibitor significantly suppressed tumor growth in an orthotopic xenograft mouse model., Interpretation: Our study revealed a previously uncharacterized HIF1α-HGF-Met-PI3K-AKT signaling axis between PSC and cancer cells and indicated that EGFR inhibition plus Met inhibition might be a promising strategy for pancreatic cancer treatment., Funding: This study was supported by The National Natural Science Foundation of China., Competing Interests: Declaration of interests The authors declare that they have no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Pancreatic stellate cells (PSCs) foster the progression of pancreatic adenocarcinoma and chronic pancreatitis (CP) by producing a dense fibrotic stroma. However, the incomplete knowledge of PSCs biology hampers the exploration of antifibrotic therapies. Here, we explored the role of the Hippo pathway in the context of PSCs activation and experimental CP., Methods: CP model was created in rats with the tail vein injection of dibutyltin dichloride (DBTC). The expression of Yes-associated protein (YAP) in CP tissue was assessed. Primary and immortalized rats PSCs were treated with the YAP-inhibitor verteporfin. Furthermore, YAP siRNA was employed. Subsequently, DNA synthesis, cell survival, levels of α-smooth muscle actin (α-SMA) protein, presence of lipid droplets and PSCs gene expression were evaluated. Upstream regulators of YAP signaling were studied by reporter gene assays., Results: In DBTC-induced CP, pronounced expression of YAP in areas of tubular structures and periductal fibrosis was observed. Verteporfin diminished DNA replication in PSCs in a dose-dependent fashion. Knockdown of YAP reduced cell proliferation. Primary cultures of PSCs were characterized by a decrease of lipid droplets and increased synthesis of α-SMA protein. Both processes were not affected by verteporfin. At the non-cytotoxic concentration of 100 nmol/L, verteporfin significantly reduced mRNA levels of transforming growth factor-β1 (Tgf-β1) and Ccn family member 1 (Ccn1). YAP signaling was activated by TGF-β1, but repressed by interferon-γ., Conclusions: Activated YAP enhanced PSCs proliferation. The antifibrotic potential of Hippo pathway inhibitors warrants further investigation., (Copyright © 2022. Published by Elsevier B.V.)

Background: Desmoplastic stroma, a feature of pancreatic ductal adenocarcinoma (PDAC), contains abundant activated pancreatic stellate cells (PSCs). How PSCs promote PDAC progression remains incompletely understood., Methods: Effect of epithelium-specific E-twenty six factor 3 (ESE3)-positive PSCs on PDAC fibrosis and chemoresistance was examined by western blot, RT-PCR, immunofluorescence, flow cytometry assay, chromatin immunoprecipitation, luciferase assay, immunohistochemistry and subcutaneous pancreatic cancer mouse model., Results: ESE3 expression increased in PSCs in PDAC tissues compared with those in normal PSCs. Clinical data showed that ESE3 upregulation in PSCs was positively correlated with tumour size, pTNM stage, CA19-9, carcinoembryonic antigen and serum CA242 level. ESE3 overexpression in PSCs was an independent negative prognostic factor for disease-free survival and overall survival amongst patients with PDAC. Mechanistically, the conditional medium from the loss and gain of ESE3-expressing PSCs influenced PDAC chemoresistance and tumour growth. ESE3 directly induced the transcription of α-SMA, collagen-I and IL-1β by binding to ESE3-binding sites on their promoters to activate PSCs. IL-1β upregulated ESE3 in PSCs through NF-κB activation, and ESE3 was required for PSC activation by tumour cell-derived IL-1β., Conclusion: Inhibiting the IL-1β/ESE3 (PSCs)/IL-1β-positive feedback loop is a promising therapeutic strategy to reduce tumour fibrosis and increase chemotherapeutic efficacy in PDAC., (© 2022. The Author(s).)

Pancreatic stellate cells (PSCs) constitute the fibrotic tumor microenvironment composed of the stroma matrix, which blocks the penetration of gemcitabine (GEM) in pancreatic adenocarcinoma (PDAC) and results in chemoresistance. We analyzed the expression of α-SMA, collagen type I, and fibronectin by immunohistochemistry of pancreatic cancer tissues and demonstrated that the abundant interstitial stroma is associated with dismal survival. Two desmoplastic pancreatic tumor models are treated with arsenic trioxide (ATO) and GEM to confirm the sensitizing effect of ATO on GEM. RNA-seq was performed to analyze the potential fibrotic genes regulated by ATO. Western blotting, CCK-8 methods, colony formation, and wound healing and transwell assays were utilized to verify that ATO attenuates the tumor-promoting ability of PSCs by inhibiting its activation and decreasing matrix secretion via the PI3K/AKT/AP4/galectin-1 pathway. Furthermore, we developed targeted ATO-loaded nanoparticles self-assembled by poly (D,L-lactide) and poly(ethylene glycol) (PEG-PDLLA) and modified by the single-chain antibody of FAP-α (scAb FAP-α ) (scAb-ATO-NPs) to promote the delivery efficiency of ATO to PSCs and enhance anti-tumor effects with gemcitabine. Herein, we elucidate the mechanism of how ATO inhibits the activation of PSCs and enhances the therapeutic effect of GEM. We propose a novel cocktail therapy including scAb-ATO-NPs and GEM, indicating a new perspective in the treatment of PDAC.

Pancreatic stellate cell (PSC) activation is a major event occurring during pancreatic ductal adenocarcinoma (PDAC) development. Up to now mechanisms underlying their activation by mechanical cues such as the elevated tissue pressure in PDAC remain poorly understood. Here we investigate the role of one potential mechano-transducer, TRPC1 ion channel, in PSC activation. Using pre-activated human siTRPC1 and murine TRPC1-KO PSCs, we show that TRPC1 promotes αSMA (α-smooth muscle actin) expression, the main activation marker, in cooperation with the phosphorylated SMAD2, under normal and elevated pressure. Functional studies following TRPC1 silencing demonstrate the dual role of TRPC1 in the modulation of PSC proliferation and IL-6 secretion through the activation of ERK1/2 and SMAD2 pathways. Moreover, pressurization changes the mechanical behavior of PSCs by increasing their cellular stiffness and emitted traction forces in a TRPC1-dependent manner. In summary, these results point to a role of TRPC1 channels in sensing and transducing the characteristic mechanical properties of the PDAC microenvironment in PSCs., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Obesity plays a major role in type II diabetes (T2DM) progression because it applies metabolic and oxidative stress resulting in dysfunctional beta-cells and activation of intra-islet pancreatic stellate cells (PaSCs) which cause islet fibrosis. Administration of antioxidant N-acetyl-L-cysteine (NAC) in vivo improves metabolic outcomes in diet-induced obese diabetic mice, and in vitro inhibits PaSCs activation. However, the effects of NAC on diabetic islets in vivo are unknown. This study examined if dosage and length of NAC treatment in HFD-induced diabetic mice effect metabolic outcomes associated with maintaining healthy beta-cells and quiescent PaSCs, in vivo . Male C57BL/6N mice were fed normal chow (ND) or high-fat (HFD) diet up to 30 weeks. NAC was administered in drinking water to HFD mice in preventative treatment (HFD pNAC ) for 23 weeks or intervention treatment for 10 (HFD iNAC ) or 18 (HFD iNAC+) weeks, respectively. HFD pNAC and HFD iNAC+ , but not HFD iNAC , mice showed significantly improved glucose tolerance and insulin sensitivity. Hyperinsulinemia led by beta-cell overcompensation in HFD mice was significantly rescued in NAC treated mice. A reduction of beta-cell nuclear Pdx-1 localization in HFD mice was significantly improved in NAC treated islets along with significantly reduced beta-cell oxidative stress. HFD-induced intra-islet PaSCs activation, labeled by αSMA, was significantly diminished in NAC treated mice along with lesser intra-islet collagen deposition. This study determined that efficiency of NAC treatment is beneficial at maintaining healthy beta-cells and quiescent intra-islet PaSCs in HFD-induced obese T2DM mouse model. These findings highlight an adjuvant therapeutic potential in NAC for controlling T2DM progression in humans., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Schuurman, Wallace, Sahi, Barillaro, Zhang, Rahman, Sawyez, Borradaile and Wang.)