Role of the fatty pancreatic infiltration in pancreatic oncogenesis.

Although pancreatic precancerous lesions are known to be related to obesity and fatty pancreatic infiltration, the mechanisms remain unclear. We assessed the role of fatty infiltration in the process of pancreatic oncogenesis and obesity. A combined transcriptomic, lipidomic and pathological approach was used to explore neoplastic transformations. Intralobular (ILF) and extralobular (ELF) lipidomic profiles were analyzed to search for lipids associated with pancreatic intraepithelial neoplasia (PanINs) and obesity; the effect of ILF and ELF on acinar tissue and the histopathological aspects of pancreatic parenchyma changes in obese (OB) and non-obese patients. This study showed that the lipid composition of ILF was different from that of ELF. ILF was related to obesity and ELF-specific lipids were correlated to PanINs. Acinar cells were shown to have different phenotypes depending on the presence and proximity to ILF in OB patients. Several lipid metabolic pathways, oxidative stress and inflammatory pathways were upregulated in acinar tissue during ILF infiltration in OB patients. Early acinar transformations, called acinar nodules (AN) were linked to obesity but not ELF or ILF suggesting that they are the first reversible precancerous pancreatic lesions to occur in OB patients. On the other hand, the number of PanINs was higher in OB patients and was positively correlated to ILF and ELF scores as well as to fibrosis. Our study suggests that two types of fat infiltration must be distinguished, ELF and ILF. ILF plays a major role in acinar modifications and the development of precancerous lesions associated with obesity, while ELF may play a role in the progression of PDAC.

Benefits of Circulating Human Metabolites from Fish Cartilage Hydrolysate on Primary Human Dermal Fibroblasts, an Ex Vivo Clinical Investigation for Skin Health Applications.

Due to its significant exposure to stressful environmental factors, the skin undergoes a high remodeling rate over time, which alters not only its appearance but also its functionality. This alteration of the skin, namely photoaging, is characterized by dryness and a loss of elasticity that mainly originates from the dysregulation of dermal fibroblast activities. In order to overcome such tissue outcome, cosmetic products have evolved toward nutricosmetics, thus promoting beauty from within. Among bio-actives of interest, bio-peptides deriving from plant or animal sources may exert various biological activities beyond their nutritional value. However, studies remain mostly descriptive and the mode of action at the cellular level in clinic remains a concern. In a recent clinical trial, it was showed that supplementation with a fish cartilage hydrolysate (FCH) improved signs of chronological and photoaging-induced skin changes in healthy women. Here, using an original ex vivo clinical approach adapted to nutricosmetic purpose, we further demonstrated that this fish cartilage hydrolysate was absorbed and that the circulating metabolites produced in humans following FCH intake stimulate human dermal fibroblast growth, promote specific hyaluronan production, up-regulate elastin synthesis and inhibit MMP-1 and 3 expression along with the enhancement of TGF-ß release. Altogether, these data provide clues on the mechanisms likely contributing to the beneficial impact of FCH on human skin functionality by supporting hydration, elasticity and limiting the expression of catabolic factors involved in photoaging onset.

Fish Hydrolysate Supplementation Prevents Stress-Induced Dysregulation of Hippocampal Proteins Relative to Mitochondrial Metabolism and the Neuronal Network in Mice.

Over the past several decades, stress has dramatically increased in occidental societies. The use of natural resources, such as fish hydrolysates, may be an attractive strategy to improve stress management. Our previous study demonstrated the anxiolytic effects of fish hydrolysate supplementation in mice exposed to acute mild stress by limiting stress-induced corticosterone release and modulating the expression of a number of stress-responsive genes. Here, we explore hippocampal protein modulation induced by fish hydrolysate supplementation in mice submitted to acute mild stress, with the aim of better elucidating the underlying mechanisms. Hippocampi from the same cohort of Balb/c mice supplemented with fish hydrolysate (300 mg·kg-1 body weight) or vehicle daily for seven days before being submitted or not to an acute mild stress protocol (four groups, n = 8/group) were subjected to label-free quantitative proteomics analysis combined with gene ontology data mining. Our results show that fish hydrolysate supplementation prevented the observed stress-induced dysregulation of proteins relative to mitochondrial pathways and the neuronal network. These findings suggest that fish hydrolysate represents an innovative strategy to prevent the adverse effects of stress and participate in stress management.

Variation of fetuin-A in maternal and fetal serum during human parturition.

BACKGROUND: parturition involves multiple signalling pathways and most advances in research underline the importance of fetal development and maturation in the timing of labour, especially the fetal pituitary-adrenal axis. But, there is currently no consensual hypothesis on all the physiological processes responsible for human parturition. METHODS: sixty low-risk pregnant women were enrolled in a prospective cohort. Maternal blood was sampled regularly during consultations each week in last trimester, at delivery and at postnatal consultation. Cord blood was collected at delivery. We used proteomic analysis to identify maternal blood biomarkers of potential interest, focusing on serum proteins from 39 W G in pregnancies to delivery and postpartum. RESULTS: among 56 peaks we identified variation in the N-terminal part of fetuin-A in maternal serum. Fetuin-A is a natural antagonist of TGF-beta and is able to bind calcium. We found a significant decrease in maternal serum fetuin-A in the days preceding delivery, independently of the mode of delivery. Also, there does not appear to be significant influence of the different fetal parameters (sex, Z-score) on maternal serum variations at delivery. CONCLUSION: fetuin-A is described by the literature as a potential biomarker for organ dysfunction and metabolic syndrome disorders. The protein mineral homeostasis would be an interesting pathway to explore during pregnancy and particularly parturition.

Proteomic Landscape of Cholangiocarcinomas Reveals Three Different Subgroups According to Their Localization and the Aspect of Non-Tumor Liver.

PURPOSE: Cholangiocarcinomas (CCs) define a heterogeneous entity based upon their anatomic localization (intra versus extrahepatic) and, for the intrahepatic CCs, the aspect of background liver (normal versus cirrhosis). The aim of the study was to characterize the molecular heterogeneity of CCs by a global proteomic approach. EXPERIMENTAL DESIGN: Thirty-three tumor samples from 17 intrahepatic CCs (iCC) (9 developed on normal (iCCN ) and 8 developed in cirrhotic liver (iCCC )); 5 hilar CCs (CCH ); 5 pancreatic CCs (CCP ) and 6 hepatocellular carcinomas (HCC), were submitted to label-free quantitative proteomic analysis. Differential proteins were analyzed by immunohistochemistry in a validation set of 30 CCs. RESULTS: Unsupervised analysis revealed two main clusters: cluster 1 contained most of the iCCC while cluster 2 was divided in 2 subgroups, one containing most of the iCCN and the other regrouping CCH and CCP . Compared to iCCN , iCCC displayed upregulation of molecules involved in cell adhesion, motility and angiogenesis. Epithelial markers associated with secretory pathway and fibroblast markers were overexpressed in CCH compared to iCCN CONCLUSION AND CLINICAL RELEVANCE: This study demonstrated that iCCC is a specific entity, suggesting a major impact of the background liver on tumor biology, and confirmed that extrahepatic CCs define a homogeneous subgroup.

Progression from cirrhosis to cancer is associated with early ubiquitin post-translational modifications: identification of new biomarkers of cirrhosis at risk of malignancy.

Cirrhosis is a lesion at risk of hepatocellular carcinoma (HCC). Identifying mechanisms associated with the transition from cirrhosis to HCC and characterizing biomarkers of cirrhosis at high risk of developing into cancer are crucial for improving early diagnosis and prognosis of HCC. We used MALDI imaging to compare mass spectra obtained from tissue sections of cirrhosis without HCC, cirrhosis with HCC, and HCC, and a top-down proteomics approach to characterize differential biomarkers. We identified a truncated form of monomeric ubiquitin lacking the two C-terminal glycine residues, Ubi(1-74), the level of which increased progressively, from cirrhosis without HCC to cirrhosis with HCC to HCC. We showed that kallikrein-related peptidase 6 (KLK6) catalysed the production of Ubi(1-74) from monomeric ubiquitin. Furthermore, we demonstrated that KLK6 was induced de novo in cirrhosis and increased in HCC in parallel with accumulation of Ubi(1-74). We investigated in vitro the possible consequences of Ubi(1-74) accumulation and demonstrated that Ubi(1-74) interferes with the normal ubiquitination machinery in what is likely to be a kinetic process. Our data suggest that de novo KLK6 expression during early liver carcinogenesis may induce production of Ubi(1-74) by post-translational modification of ubiquitin. Given the deleterious effect of Ubi(1-74) on protein ubiquitination and the major role of ubiquitin machinery in maintenance of cell homeostasis, Ubi(1-74) might severely impact a number of critical cellular functions during transition from cirrhosis to cancer. Ubi(1-74) and KLK6 may serve as markers of cancer risk in patients with cirrhosis.

In situ proteomic analysis by MALDI imaging identifies ubiquitin and thymosin-ß4 as markers of malignant intraductal pancreatic mucinous neoplasms.

PURPOSE: Intraductal pancreatic mucinous neoplasms (IPMN) are precancerous cystic lesions. The aim was to investigate the in situ IPMN proteome using MALDI (Matrix-Assisted Laser Desorption/Ionisation) imaging and to characterize biomarkers associated with the grade of dysplasia. EXPERIMENTAL DESIGN: Frozen human Branch duct -IPMN sections were selected according to dysplasia and proteomic analyses were performed by MALDI imaging to obtain mass spectra distribution. The most discriminating peaks were identified using tissue extraction and nanoLC-ESI-MS/MS. Identified peaks were validated in independent series of IPMN by immunochemistry on surgical specimens (tissue-microarrays (TMA), n = 45) and endoscopic ultrasound fine-needle aspiration (EUS FNA) samples (n = 25). RESULTS: BD-IPMN samples with low (n = 10) and high (n = 10) grades of dysplasia were analyzed. Differential spectra of proteins were found in the two groups with significantly different intensities (n = 15). The two peaks (intense in high grade IPMN) (m/z 8565 and 4747) were characterized as the monomeric ubiquitin (Mascot score = 319.22) and an acetylated fragment of thymosin-ß4 (2-42) (Omssa score = 1.37 E-9). Validation on TMA and EUS FNA samples confirmed that ubiquitin was overexpressed in high grade dysplasia (p = 0.04 and p = 0.0004). Thymosin-ß4 expression was confirmed on TMA by immunohistochemistry on high grade IPMN (p = 0.011). CONCLUSION: Ubiquitin and thymosin-ß4 are overexpressed in IPMN with high grade dysplasia. Positive immunochemical staining on EUS-FNA material is a major argument in support of preventive resection.

Tumoral heterogeneity of hepatic cholangiocarcinomas revealed by MALDI imaging mass spectrometry.

Cholangiocarcinoma (CC) is the second most common primary malignancy of the liver. Although all CC derive from biliary epithelial cells, two main subtypes, hilar (H), and peripheral (P) CC are described. The objective of the study was to compare, using MALDI imaging mass spectrometry (MALDI IMS), in situ proteomic profiles of H- and P-CC in order to assess whether these subtypes may express different markers and to describe their respective localizations. Twenty-seven CC (16 P-CC and 11 H-CC) were subjected to MALDI IMS. Proteomic data were submitted to a dedicated cross-classification comparative design, enabling comparison of the entire generated spectra. Immunohistochemistry was performed for validation. Comparative analysis yielded a list of 19 differential protein peaks for the two subtypes, 14 of which were overexpressed in H-CC and five in P-CC. Among H-CC protein markers, most discriminant were human neutrophil peptides 1-3 that were expressed mainly by tumor cells and S100 proteins (A6 and A11) that were restricted to the stromal area. In P-CC, thymosin ß4 was diffusely overexpressed. These results highlight the potential of MALDI IMS to discover new relevant biomarkers of CC and to characterize the heterogeneity of the two different subtypes.

Imaging mass spectrometry reveals modified forms of histone H4 as new biomarkers of microvascular invasion in hepatocellular carcinomas.

UNLABELLED: Microvascular invasion (MiVI) is a major risk factor in postoperative tumor recurrence and mortality in hepatocellular carcinoma (HCC). Unfortunately, this histological feature is usually missed by liver biopsy because of limited sampling, and MiVI is commonly detected only after surgery and examination of the full resected specimen. To date, there exists no reliable tool for identifying MiVI prior to surgical procedures. This study aimed to compare the proteome of HCC with and without MiVI in order to identify surrogate biomarkers of MiVI. A training cohort comprising surgically resected primary HCC with MiVI (n = 30) and without MiVI (n = 26) was subjected to matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI IMS). Comparative analysis of acquired mass spectra of the two groups yielded 30 differential protein peaks, among which 28 were more strongly expressed in HCC with MiVI. Among these, two peaks were identified as N-term acetylated histone H4 dimethylated at lysine (K) 20, and N-term acetylated histone H4 dimethylated at K20 and acetylated at K16. Both peaks were validated in the training cohort and in an independent validation cohort (n = 23) by immunohistochemistry and western blot. CONCLUSION: These results demonstrate the potential of MALDI IMS for uncovering new relevant biomarkers of MiVI in HCC, and highlight the role of epigenetic modifications in the prognosis of HCC. Preoperative detection of modified forms of histone H4 expression in tumor biopsies would be helpful in management of patients with HCC.

Imaging mass spectrometry provides fingerprints for distinguishing hepatocellular carcinoma from cirrhosis.

MALDI imaging mass spectrometry (MALDI IMS) is a powerful tool for comprehending the spectrum of peptides/proteins expressed in tissue sections. The aim of the present study was to investigate, using MALDI IMS, the proteome of hepatocellular carcinomas (HCC) and to compare it with peritumoral cirrhosis so as to characterize new biomarkers of HCC. Frozen liver tissues corresponding to HCC and background cirrhosis (n = 30) were selected and subjected to MALDI IMS. We found a set of proteins/peptides with a differential intensity level that most accurately delineated cancer from adjacent cirrhotic tissue. Using a support vector machine algorithm, we generated a classification model in the train set that enabled segmenting images from the independent validation set and that in most cases matched histologic analysis. The most discriminating peak (m/z 8565) more intense in HCC was characterized as the monomeric ubiquitin. An immunohistochemical study in a large series of HCC/cirrhosis sampled on tissue microarray supported that ubiquitin was overexpressed in HCC. We demonstrated also that this increase was not related to an upregulation of ubiquitin gene transcription in HCC, thus suggesting a post-transcriptional mechanism. This approach might provide a new tool for diagnosis of difficult HCC cases and an opportunity for identifying candidate biomarkers.

Abnormal presence of the matrix extracellular phosphoglycoprotein-derived acidic serine- and aspartate-rich motif peptide in human hypophosphatemic dentin.

Severe dental troubles are associated with X-linked hypophosphatemic rickets and are mainly related to impaired dentin mineralization. In dentin matrix, matrix extracellular phosphoglycoprotein (MEPE) may be protected from proteolysis by a specific interaction with PHEX (phosphate regulating gene with homologies to endopeptidases on the X chromosome). The objective of our work was to determine whether PHEX impairment induces MEPE cleavage in dentin and the subsequent release of the C-terminal acidic serine- and aspartate-rich motif (ASARM) peptide, which is known to inhibit mineralization. By Western blot analysis, we explored dentin extracts from seven hypophosphatemic patients with mutations of the PHEX gene. A proteomic approach combining immunoprecipitation, surface-enhanced laser desorption/ionization-time of flight-mass spectrometry and matrix-assisted laser desorption ionization-time of flight analysis of the samples completed this exploration. This study shows a 4.1-kDa peptide containing the MEPE-derived ASARM peptide in hypophosphatemic samples. The presence of ASARM was less marked in patients treated with 1-hydroxylated vitamin D and phosphate during growth. Moreover, recombinant ASARM implanted in a rat pulp injury model disturbed the formation of the reparative dentin bridge. These results suggest that abnormal MEPE cleavage occurs when PHEX activity is deficient in humans, the ASARM peptide may be involved in the mineralization defects and the PHEX-MEPE interaction may be indirect, as ensuring a better phosphate and vitamin D environment to the mineralizing dentin prevents MEPE cleavage.