Search Results (94)

Although the digestion of dietary and endogenous proteins by the exocrine pancreatic proteases and peptidases in the small intestine luminal fluid is highly efficient for most proteins, it has been roughly approximated that between 3 and 11 g of alimentary proteins and peptides are moving from the small intestine to the large intestine in humans. Here, this nitrogenous material is degraded by the bacterial protease and peptidase activities, releasing amino acids. These amino acids are utilized by the abundant population of bacteria, notably amino acids that the bacteria are unable to synthesize, and which can thus be considered as indispensable for these microorganisms. The anabolism of amino acids by colonic bacteria is related to the synthesis of proteins while some specific amino acids are used for the synthesis of the purine and pyrimidine rings in DNA and RNA. Catabolism of specific amino acids allows for ATP synthesis and results in the production of metabolites with documented roles in the metabolism and physiology of commensal and pathogenic microorganisms among the intestinal microbiota. In the present narrative review, we examine the recycling of the undigested host’s proteins by large intestine bacteria and the metabolism of released amino acids. In addition, we describe how these metabolic pathways are involved in bacterial growth and communication, as well as in bacterial physiology in terms of virulence, resistance to detrimental environmental conditions, and capacity to form biofilms. Full article

Although the pancreas is the organ that produces the most critical digestive enzymes, there are other important contributors to the cleavage of food into absorbable units. Pre-pancreatic digestion of carbohydrates occurs through the action of salivary amylase. Pre-pancreatic digestion of fats is mediated by lingual and gastric lipases, and their action may be important as a signal for coordinated digestion. Pepsin, which is present in the stomach, initiates the digestion of dietary proteins into peptides and amplifies distal proteolysis. The major post-pancreatic intestinal carbohydrate-digesting enzymes are sucrase-isomaltase, maltase-glucoamylase and lactase-phlorizin hydrolase. There are no post-pancreatic mucosal enzymes that act on dietary triglycerides; however, the complete digestion of phospholipids depends on several brush border phospholipases. Intestinal processing is an important contributor to digestion of proteins, although mucosal proteases may serve as signaling proteins rather than as primary adjuncts to dietary protein digestion and absorption. This review describes the role of these non-pancreatic digestive enzymes in supporting nutritional health. Full article

The serine protease kazal-type inhibitor (SPINK) family is central to the regulation of proteolytic function, the establishment of physiological homeostasis, and the development of many disease states, including cancer. Emerging research has identified that members of the SPINK family are commonly overexpressed in most malignancies and are deeply implicated in pivotal oncogenic pathways like cell growth, epithelial-to-mesenchymal transition (EMT), metastasis, and drug resistance. This review provides an in-depth examination of structural and functional characteristics of SPINK proteins and their involvement in the onset and development of multiple cancers, which include prostrate, pancreatic, and colorectal carcinomas. Significantly, SPINK proteins regulate major signalling pathways, including EGFR, NF-κB, and MAPK, highlighting their role as prognostic biomarkers and therapeutic targets. The review underscores the most recent advancements in therapeutic strategies for SPINK-related pathways and outlines the bottlenecks that have restricted their use in the clinic. By integrating current evidence, this work signals the potential of SPINK proteins as good precision oncology candidates with novel options for cancer prognosis, treatment, and management. Full article

Background/Objectives: Cadherin-6 (CDH6), also known as K-cadherin, is a type II classic cadherin molecule that plays an important role in the embryonic development of the kidney but has very limited expression in adult tissues. It is overexpressed in several human malignancies, primarily in ovarian cancer, renal cell carcinoma, as well as, less frequently, cholangiocarcinoma, uterine serous carcinoma, glioma, lung, pancreatic and thyroid cancers. The characteristic of limited expression in normal tissues, high expression in tumor tissues, and rapid internalization upon antibody binding makes CDH6 a well-suited antibody-drug conjugate (ADC) target. Methods: We developed a novel CDH6-targeting ADC, CUSP06, consisting of a proprietary humanized antibody selective for CDH6, a protease cleavable linker, and an exatecan payload, with a drug-to-antibody ratio (DAR) of 8. We further characterized the pharmacological activities of CUSP06 in multiple in vitro and in vivo models. Results: CUSP06 was selectively bound to cell surface CDH6 and was efficiently internalized into CDH6-positive ovarian cancer cells, and led to the induction of DNA damage and apoptosis of CDH6-positive cancer cells. CUSP06 exhibited strong antiproliferative activity against several CDH6-positive cancer cell lines and demonstrated strong bystander cell killing effect in the cell mixing experiments in vitro. CUSP06 exhibits excellent in vivo antitumor efficacy in CDH6-high or -low cell line-derived xenograft (CDX) or patient-derived xenograft (PDX) models from human ovarian, renal and uterine cancers, as well as cholangiocarcinoma. CUSP06 demonstrated a favorable safety profile in GLP-compliant toxicology studies in Sprague Dawley rats and cynomolgus monkeys. Conclusions: The preclinical data highlighted the therapeutic potential of CUSP06 in multiple CDH6-positive human cancers. Full article

The extraction of enzyme preparations from bovine pancreas is a key step in the production of pancreatin used for pharmaceutical and food industry applications. However, conventional methods (CMs) often fail to preserve enzymatic activity (EA) during processing, particularly under variable temperature and pH conditions. This study investigates the potential of ultrasound-assisted extraction (UAM) as an alternative to CMs for improving the recovery, stability, and performance of two essential pancreatic enzymes—α-amylase (AA) and protease (PA). EA was assessed over a broad temperature range (10–50 °C) and pH spectrum (5.5–8.0), with both methods evaluated under identical conditions. UAM consistently yielded higher EA across all tested parameters, with optimal AA and PA observed at pH 6.0 and 38 °C. Notably, UAM-extracted enzymes retained significant activity even at elevated temperatures (46–50 °C), whereas CM-derived samples showed a marked loss of function. These findings demonstrate that UAM enhances enzyme release and thermal resilience by minimizing denaturation and structural degradation during extraction. UAM showed improved apparent thermal tolerance under the tested conditions, which may indicate enhanced applicability in temperature-sensitive processing environments. Full article

Mussels are nutrient-rich but perishable, resulting in substantial resource loss. A protease-producing strain (Bacillus velezensis Z-1, Mytilus edulis) isolated from marine sludge was used to hydrolyze mussels, producing Y-1, a hydrolysate with antioxidant activity. In this study, ultrafiltration, gel chromatography, and LC-MS/MS were employed to isolate and identify bioactive peptides from the hydrolysate. The results revealed that the hydrolysate exhibited antioxidant activity, pancreatic cholesterol esterase inhibitory activity, pancreatic lipase inhibitory activity, and α-glucosidase inhibitory activity. Molecular docking using AutoDock Tools 1.5.6 was performed to analyze the interactions of peptides with CD38 and Keap1, leading to the identification of five potentially bioactive peptides: VPPFY, IMLFP, LPFLF, FLPF, and FPRIM. These peptides formed hydrogen bonds and hydrophobic interactions with CD38 and Keap1, demonstrating strong DPPH radical scavenging and superoxide anion radical scavenging capacities. This study highlights the multifunctional bioactive potential of these peptides, offering insights into their therapeutic applications. The findings provide a novel approach for the effective utilization of mussel resources and highlight their potential application value in the development of functional foods. Full article

Tumor cell heterogeneity, e.g., in stroma-rich pancreatic ductal adenocarcinoma (PDAC), includes a differential metabolism of lactate. While being secreted as waste product by most cancer cells characterized by the glycolytic Warburg metabolism, it is utilized by a subset of highly malignant cancer cells running the reverse Warburg metabolism. Key drivers of lactate transport are the carrier proteins SLC16A1 (import/export) and SLC16A3 (export). Expression and function of both carriers are controlled by the chaperone Basigin (BSG), which itself is functionally controlled by the transmembrane protease serine 11B (TMPRSS11B). In this study we explored the impact of TMPRSS11B on the phenotype of PDAC cells under reverse Warburg conditions. Amongst a panel of PDAC cell lines, Panc1 and BxPc3 cells were identified to express TMPRSS11B at a high level, whilst other cell lines such as T3M4 did not. ShRNA-mediated TMPRSS11B knock-down in Panc1 and BxPc3 cells enhanced lactate import through SLC16A1, as shown by GFP/iLACCO1 lactate uptake assay, whereas TMPRSS1B overexpression in T3M4 dampened SLC16A1-driven lactate uptake. Moreover, knock-down and overexpression of TMPRSS11B differentially impacted proliferation and chemoresistance under reverse Warburg conditions in Panc1 or BxPc3 and T3M4 cells, respectively, as well as their stemness properties indicated by altered colony formation rates and expression of the stem cell markers Nanog, Sox2, KLF4 and Oct4. These effects of TMPRSS11B depended on both SLC16A1 and BSG as shown by gene silencing. Immunohistochemical analysis revealed a reciprocal expression of TMPRSS11B and BSG together with SLC16A1 in some areas of tumor tissues from PDAC patients. Those regions exhibiting low or no TMPRSS11B expression but concomitant high expression of SLC16A1 and BSG revealed greater amounts of KLF4. In contrast, other tumor areas exhibiting high expression of TMPRSS11B together with BSG and SLC16A1 were largely negative for KLF4 expression. Thus, the differential expression of TMPRSS11B adds to metabolic heterogeneity in PDAC and its absence supports the reverse Warburg metabolism in PDAC cells by the enhancement of BSG-supported lactate uptake through SLC16A1 and subsequent phenotype alterations towards greater stemness. Full article

Insulin-degrading enzyme is a zinc metalloprotease that degrades low-molecular-weight substrates, including insulin. Ubiquitous expression, high evolutionary conservation, upregulation of Ide in stress situations, and literature findings suggest a broader function of Ide in cell physiology and protein homeostasis that remains to be elucidated. We used proteomics and transcriptomics approaches to search for leads related to a broader role of Ide in protein homeostasis. We combined an analysis of the proteome and single-cell transcriptome of Ide^+/+ and Ide^−/− pancreatic islet cells with an examination of the interactome of human cytosolic Ide using proximity biotinylation. We observe an upregulation of pathways related to RNA processing, translation and splicing in Ide^+/+ relative to Ide^−/− islet cells. Corroborating these results and providing a potential mechanistic explanation, proximity biotinylation reveals interaction of Ide with several subunits of CCR4-NOT, a key mRNA deadenylase regulating gene expression “from birth to death”. We propose a speculative model in which human and murine Ide cooperate with CCR4-NOT to control protein expression in proteotoxic and metabolic stress situations through cooperation between their deadenylase and protease functions. Full article

Objectives: Ferulic acid is a natural and safe herbal feed additive. This study aims to evaluate the effects of ferulic acid on the growth performance, anti-inflammatory and antioxidant capacities, immune function, and intestinal microbiota of broiler chickens. Methods: A total of 320 broiler chickens, aged 14 days, were randomly divided into four groups: a blank control group (MA group), a low-concentration ferulic acid group (BM group, 10 mg/kg), a medium-concentration ferulic acid group (CM group, 30 mg/kg), and a high-concentration ferulic acid group (DM group, 90 mg/kg) after a 14-day acclimatization period. The experiment lasted for 28 days, and the chickens were dissected on day 29. Results: The results showed that compared to the MA group, the feed-to-meat ratio in the CM and DM groups was significantly reduced. The activity of duodenal trypsin in the CM and DM groups was significantly enhanced, and the activity of pancreatic protease in the DM group was significantly increased. The serum levels of urea nitrogen, creatinine, and triglycerides were significantly elevated in the CM and DM groups. The serum malondialdehyde (MDA) levels in the BM, CM, and DM groups were significantly reduced, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly increased in the CM and DM groups. The serum interleukin-2 (IL-2) levels in the BM group were significantly decreased, while interferon-gamma (IFN-γ) levels in the CM group and complement component 3 (C-3) levels in the DM group were significantly increased. The mRNA expression levels of TLR4, MyD88, NF-κB, TNF-α, NLRP3, IL-1β, and IL-18 in the jejunum of the DM group were significantly reduced. The diversity of cecal microbiota in the ferulic acid groups changed, with a certain degree of increase in the relative abundance of Spirulina and Ruminococcus. The relative abundance of Escherichia coli in the DM group significantly increased, altering the metabolic function of the cecal microbiota in broiler chickens. Conclusions: The above results indicate that ferulic acid, as a novel feed additive for broiler chickens, has an impact on the growth performance, anti-inflammatory and antioxidant capacity, immune function, and intestinal microbiota of broiler chickens. Full article

Fibroblast activation protein (FAP) is a serine protease selectively expressed in cancer-associated fibroblasts (CAFs), fibrotic tissues, and areas of active tissue remodeling, making it an attractive target for diagnostic imaging across a spectrum of disease. FAP inhibitors (FAPIs) labeled with PET tracers have rapidly advanced as a novel imaging modality with broad clinical applications that offers several advantages, including rapid tumor accumulation, low background uptake, and high tumor-to-background ratios. In oncology, FAPI PET has demonstrated excellent performance in visualizing a wide range of malignancies, including those with low glycolytic activity, such as pancreatic cancer, cholangiocarcinoma, and certain sarcomas. Its high sensitivity and specificity for the stromal component enables improved tumor delineation, staging, and response assessment. Additionally, the potential to guide theranostic approaches, where the same tracer can be labeled with therapeutic radionuclides, positions FAPI as a key player in precision oncology. Beyond oncology, FAPI PET has shown promise in imaging conditions characterized by fibrotic and inflammatory processes. In the cardiovascular field, FAPI PET imaging is being investigated for its ability to detect myocardial fibrosis and active cardiac remodeling, crucial in conditions like heart failure, post-myocardial infarction remodeling, and hypertrophic cardiomyopathy. This review highlights the expanding clinical applications of FAPI-based PET imaging across oncology, inflammation, and cardiovascular disease. While the current data are promising, further large-scale studies and multicenter trials are essential to validate these findings and establish standardized protocols. The versatility and broad applicability of FAPI PET underscore its potential as a transformative tool in precision medicine. Full article

Acute pancreatitis (AP) an inflammatory condition caused by the premature activation of pancreatic proteases, leads to organ damage, systemic inflammation, and multi-organ failure. Severe acute pancreatitis (SAP) has high morbidity and mortality, affecting the liver, kidneys, and lungs. Autophagy maintains pancreatic homeostasis, with VMP1-mediated selective autophagy (zymophagy) preventing intracellular zymogen activation and acinar cell death. This study examines the protective role of VMP1 (Vacuole Membrane Protein 1)-induced autophagy using ElaI-VMP1 transgenic mice in a necrohemorrhagic SAP model (Hartwig’s model). ElaI-VMP1 mice show significantly reduced pancreatic injury, including lower necrosis, edema, and inflammation, compared to wild-type (WT) mice. Biochemical markers (lactate dehydrogenase-LDH-, amylase, and lipase) and histopathology confirm that VMP1 expression mitigates pancreatic damage. Increased zymophagy negatively correlates with acinar necrosis, reinforcing its protective role. Beyond the pancreas, ElaI-VMP1 mice exhibit preserved liver, kidney, and lung histology, indicating reduced systemic organ damage. The liver maintains normal architecture, kidneys show minimal tubular necrosis, and lung inflammation features are reduced compared to WT mice. Our results confirm that zymophagy functions as a protective pathophysiological mechanism against pancreatic and extrapancreatic tissue injury in SAP. Further studies on the mechanism of VMP1-mediated selective autophagy in AP are necessary to determine its relevance and possible modulation to prevent the severity of AP. Full article

Background/Objectives: Radiotheranostics of neurotensin subtype 1 receptor (NTS₁R)-expressing tumors, like pancreatic, gastrointestinal, or prostate cancer, has attracted considerable attention in recent years. Still, the fast degradation of neurotensin (NT)-based radioligands, by angiotensin-converting enzyme (ACE), neprilysin (NEP), and other proteases, has considerably compromised their efficacy. The recently introduced [^99mTc]Tc-DT11 (DT11, N₄-Lys(MPBA-PEG4)-Arg-Arg-Pro-Tyr-Ile-Leu-OH; N₄, 6-(carboxy)-1,4,8,11-tetraazaundecane) has displayed promising uptake in NTS₁R-positive tumors in mice and enhanced resistance to both ACE and NEP by virtue of the lateral MPBA-PEG4 (MPBA, 4-(4-methylphenyl)butyric acid; PEG4, 14-amino-3,6,9,12-tetraoxatetradecan-1-oic acid) chain attached to the ε-NH₂ of Lys⁷. We were next interested in investigating whether these qualities could be retained in DT14D, likewise modified at Lys⁷ but carrying the universal chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) via a (βAla)₃ spacer at the α-NH₂ of Lys⁷. This chelator switch enables the labeling of DT14D with a wide range of trivalent radiometals suitable for true theranostic applications, not restricted to the diagnostic imaging of NTS₁R-positive lesions only by single-photon emission computed tomography (SPECT). Methods: DT14D was labeled with Ga-67 (a surrogate for the positron emission tomography radionuclide Ga-68), In-111 (for SPECT), and Lu-177 (applied in radiotherapy). The resulting radioligands were tested in NTS₁R-expressing pancreatic cancer AsPC-1 cells and mice models. Results: [⁶⁷Ga]Ga/[¹¹¹In]In/[¹⁷⁷Lu]Lu-DT14D displayed high affinity for human NTS₁R and internalization in AsPC-1 cells. They remained >70% intact 5 min after entering the mice’s circulation, displaying NTS₁R-specific uptake in AsPC-1 xenografts. Conclusions: Suitably side-chain modified NT analogs show enhanced metabolic stability and hence better prospects for radiotheranostic application in NTS₁R-positive cancer. Full article

It was found that the serine protease inhibitors BmSPI38 and BmSPI39 in silkworm can strongly inhibit the activity of porcine pancreatic elastase, which has potential applicational value in the drug research and development of lung diseases, inflammatory diseases, and skin aging caused by the excessive release of elastase. Previous studies have shown that homotypic multimers obtained by tandem expression can significantly enhance the antifungal activity and structural homogeneity of BmSPI38 and BmSPI39, while the effect of the tandem expression of these two inhibitors, with different combinations, on the total activity and expression levels of multimers remains unclear. The aim of this study is to explore whether it is possible to obtain the combination of BmSPI38 and BmSPI39 with strong total expression activity by protein engineering. In this study, 40 tandem multimer expression vectors with different combinatorial forms of BmSPI38 and BmSPI39 were constructed by the isocaudomer method, and recombinant proteins were obtained by the prokaryotic expression system. The target proteins were separated by SDS-PAGE to analyze the expression levels of multimer proteins with different combinatorial forms. The total activity of the recombinant expression products with different tandem forms was investigated using the in-gel activity staining technique of protease inhibitors. The SDS-PAGE results show that the expression levels of tandem multimers containing the BmSPI39 module at the carboxyl terminus were generally higher in the Escherichia coli supernatant than that of the tandem multimers containing the BmSPI38 module at the carboxyl terminus. The activity staining results indicate that compared with BmSPI38 and BmSPI39 homotypic multimers, the total activity of some recombinant expression products with different tandem forms was stronger. Furthermore, the total activity level was relatively higher when the carboxyl terminus of the multimer was a BmSPI39 module, such as the tandem dimers SPIAB and SPIaB and the tandem trimers SPIabB, SPIaaB, and SPIbaB. In this study, the expression of tandem fusion proteins with different combinations of the silkworm protease inhibitors BmSPI38 and BmSPI39 in E. coli was successfully achieved. It was confirmed that the tandem of different combinatorial forms, based on protein engineering, was an effective way to enhance the total activity of the fusion proteins of BmSPI38 and BmSPI39 and to improve their expression levels. Additionally, a number of multimer proteins with strong total activity and high exogenous expression levels were also screened, for example, SPIbaA, SPIbbA, SPIbbB, SPIabB, SPIaaB, and SPIbaB. This study not only lays the foundation for the exogenous production and development of BmSPI38 and BmSPI39 but also provides a reference for the construction of tandem and multimerization exploration of other protease inhibitors. Full article

Background: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer, able to thrive in a challenging tumor microenvironment. Current standard therapies, including surgery, radiation, chemotherapy, and chemoradiation, have shown a dismal survival prognosis, resulting in less than a year of life in the metastatic setting. Methods: The pressing need to find better therapeutic methods brought about the discovery of new targeted therapies against the infamous KRAS mutations, the major oncological drivers of PDAC. Results: The most common KRAS mutation is KRAS^G12D, which causes a conformational change in the protein that constitutively activates downstream signaling pathways driving cancer hallmarks. Novel anti-KRAS^G12D therapies have been developed for solid-organ tumors, including small compounds, pan-RAS inhibitors, protease inhibitors, chimeric T cell receptors, and therapeutic vaccines. Conclusions: This comprehensive review summarizes current knowledge on the biology of KRAS-driven PDAC, the latest therapeutic options that have been experimentally validated, and developments in ongoing clinical trials. Full article

In this work, the hypolipidemic and antioxidative capacity of FSGLR (S7) and GIEWA (S10) from miiuy croaker swim bladders was explored systematically in an oleic acid (OA)-induced nonalcoholic fatty liver disease (NAFLD) model of HepG2 cells. Moreover, the hypolipidemic activity of S7 and S10 and their antioxidative abilities were preliminarily investigated in combination with molecular docking technology. The results indicated that S7 and S10 could decrease the amount of lipid accumulation and the content of triglycerides (TG) and total cholesterol (TC) in the OA-induced NAFLD cell model in a dose-dependent manner. In addition, S7 and S10 exhibited better bile salt binding, pancreatic lipase (PL) inhibition, and cholesterol esterase (CE) inhibition capacities. The hypolipidemic mechanisms of S7 and S10 were connected with the downregulation of the mRNA expression levels of adipogenic factors, including sterol-regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), sterol-regulatory element-binding protein (SREBP)-2, hydroxymethylglutaryl-CoA reductase (HMGR), and fatty acid synthase (FAS) (p < 0.01), and the upregulation of the mRNA expression of β-oxidation-related factors, including carnitine palmitoyltransferase 1 (CPT-1), acyl-CoA oxidase 1 (ACOX-1), and peroxisome proliferator-activated receptor α (PPARα). Moreover, FSGLR (S7) and GIEWA (S10) could significantly protect HepG2 cells against OA-induced oxidative damage, and their antioxidant mechanisms were related to the increased activity of intracellular antioxidant proteases (superoxide dismutase, SOD; glutathione peroxidase, GSH-PX; catalase, CAT) to remove excess reactive oxygen species (ROS) and decrease the production of malondialdehyde (MDA). The presented findings indicate that the hypolipidemic and antioxidant functions and mechanisms of S7 and S10 could make them potential hypolipidemic and antioxidant candidates for the treatment of NAFLD. Full article