Hydrolysates and peptide fractions from pork and chicken skin collagen as pancreatic lipase inhibitors.

The objective of this work was to obtain hydrolysates and peptide fractions from pork (PSC) and chicken (CSC) skin collagen extracts and to evaluate their ability as pancreatic lipase inhibitors. Collagen extracts were hydrolyzed with collagenase or a protease from Bacillus licheniformis (MPRO NX®) at 6, 12, and 24 h. After 24 h incubation, the highest degree of hydrolysis of PSC (p < 0.05) was obtained with collagenase (72.58%), while in CSC was obtained with MPRO NX® (64.45%). Hydrolysates obtained at 24 h had the highest inhibitory activity of lipase (p < 0.05). CSC/collagenase hydrolysates (10 mg/mL) presented the highest inhibitory activity (75.53%) (p < 0.05). Ultrafiltrated fractions >5 kDa from CSC/collagenase and PSC/MPRO NX® hydrolysates were the most bioactive fractions (IC50: 4.33 mg/mL). The highest were obtained by CSC peptides (IC50s: 6.30 and 6.08 mg/mL). These results may be considered as a novel approach to use collagen hydrolysates, or their peptide fractions, as promising natural inhibitors of pancreatic lipase.

Genetic Variants and Tumor Immune Microenvironment: Clues for Targeted Therapies in Inflammatory Breast Cancer (IBC).

To better understand the etiology of inflammatory breast cancer (IBC) and identify potential therapies, we studied genomic alterations in IBC patients. Targeted, next-generation sequencing (NGS) was performed on cell-free DNA (cfDNA) (n = 33) and paired DNA from tumor tissues (n = 29) from 32 IBC patients. We confirmed complementarity between cfDNA and tumor tissue genetic profiles. We found a high incidence of germline variants in IBC patients that could be associated with an increased risk of developing the disease. Furthermore, 31% of IBC patients showed deficiencies in the homologous recombination repair (HRR) pathway (BRCA1, BRCA2, PALB2, RAD51C, ATM, BARD1) making them sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. We also characterized the tumor-infiltrating lymphocytes (TILs) in tumor tissue biopsies by studying several markers (CD4, CD8, FoxP3, CD20, PD-1, and PD-L1) through immunohistochemistry (IHC) staining. In 7 of 24 (29%) patients, tumor biopsies were positive for PD-L1 and PD-1 expression on TILs, making them sensitive to PD-1/PD-L1 blocking therapies. Our results provide a rationale for considering PARP inhibitors and PD-1/PDL1 blocking immunotherapy in qualifying IBC patients.

V-Type ATPase Mediates Airway Surface Liquid Acidification in Pig Small Airway Epithelial Cells.

In a newborn pig cystic fibrosis (CF) model, the ability of gland-containing airways to fight infection was affected by at least two major host-defense defects: impaired mucociliary transport and a lower airway surface liquid (ASL) pH. In the gland-containing airways, the ASL pH is balanced by CFTR (CF transmembrane conductance regulator) and ATP12A, which, respectively, control HCO3- transport and proton secretion. We found that, although porcine small airway tissue expressed lower amounts of ATP12A, the ASL of epithelial cultures from CF distal small airways (diameter < 200 µm) were nevertheless more acidic (compared with non-CF airways). Therefore, we hypothesized that gland-containing airways and small airways control acidification using distinct mechanisms. Our microarray data suggested that small airway epithelia mediate proton secretion via ATP6V0D2, an isoform of the V0 d subunit of the H+-translocating plasma membrane V-type ATPase. Immunofluorescence of small airways verified the expression of the V0 d2 subunit isoform at the apical surface of Muc5B+ secretory cells, but not ciliated cells. Inhibiting the V-type ATPase with bafilomycin A1 elevated the ASL pH of small airway cultures, in the presence or absence of HCO3-, and decreased ASL viscosity. These data suggest that, unlike large airways, which are acidified by ATP12A activity, small airways are acidified by V-type ATPase, thus identifying V-type ATPase as a novel therapeutic target for small airway diseases.

In Vitro Digestibility and Quality of an Emulsified Meat Product Formulated With Animal Fat Encapsulated With Pectin.

Animal fat plays a key role in the structure, quality, and acceptability of emulsified meat products. However, a high consumption of saturated fat has been related to several health problems. Fat encapsulation with a nondigestible carbohydrate, such as pectin, may offer a promising alternative to reduce fat intake from a meat product, by preventing its digestion and absorption. The objective of this study was to develop a meat sausage with pectin-encapsulated-fat (PEF) to decrease its lipid digestibility, without compromising its acceptability. Pork fat particles encapsulation by emulsification with a 4% pectin solution, and also stability during meat processing and cooking, was confirmed by confocal microscopy. No changes (P > 0.05) compared to Control (C) were found on thermal stability and composition of sausages formulated with direct addition of pectin (T1) and with incorporation of PEF (T2). However, in comparison with C, pH, color, and texture of T1 and T2 samples were affected (P < 0.05). Nevertheless, these changes had no influence (P > 0.05) on sensory acceptability of treated samples, and actually improved (P < 0.05) their texture acceptance. In vitro digestive degradation of triacylglycerols was decreased (P < 0.05) by 20% on T2 samples compared to control and it was superior (P < 0.05) to T1 (8%). Confocal images confirmed lipid digestibility reduction of T2 samples. Incorporation of PEF in a meat sausage offers a better protection against the hydrolytic action of lipases over triaclyglycerides, than a direct addition of pectin, without affecting its sensory acceptability. Therefore, it can be a potential strategy to reduce fat intake from meat products. PRACTICAL APPLICATION: Reduction or replacement strategies tested to modify or decrease fat content in meat products usually leads to nondesirable sensory attributes. However, decreasing lipid digestibility by encapsulating animal fat with nondigestible pectin offers a new approach to reduce fat intake from full-animal-fat meat products, without affecting their sensory acceptability.

Indoor Particulate Matter From Smoker Homes Induces Bacterial Growth, Biofilm Formation, and Impairs Airway Antimicrobial Activity. A Pilot Study.

Background: Particulate matter (PM) air pollution causes deleterious health effects; however, less is known about health effects of indoor air particulate matter (IAP). Objective: To understand whether IAP influences distinct mechanisms in the development of respiratory tract infections, including bacterial growth, biofilm formation, and innate immunity. Additionally, we tested whether IAP from Iowa houses of subjects with and without recent respiratory exacerbations recapitulated the National Institute of Standards and Technology (NIST) IAP findings. Methods: To test the effect of NIST and Iowa IAP on bacterial growth and biofilm formation, we assessed Staphylococcus aureus growth and Pseudomonas aeruginosa biofilm formation with and without the presence of IAP. To assess the effect of IAP on innate immunity, we exposed primary human airway surface liquid (ASL) to NIST, and Iowa IAP. Lastly, we tested whether specific metals may be responsible for effects on airway innate immunity. Results: NIST and Iowa IAP significantly enhanced bacterial growth and biofilm formation. NIST IAP (whole particle and the soluble portion) impaired ASL antimicrobial activity. IAP from one Iowa home significantly impaired ASL antimicrobial activity (p < 0.05), and five other homes demonstrated a trend (p ≤ 0.18) of impaired ASL antimicrobial activity. IAP from homes of subjects with a recent history of respiratory exacerbation tended (p = 0.09) to impair ASL antimicrobial activity more than IAP from homes of those without a history respiratory exacerbation. Aluminum and Magnesium impaired ASL antimicrobial activity, while copper was bactericidal. Combining metals varied their effect on ASL antimicrobial activity. Conclusions: NIST IAP and Iowa IAP enhanced bacterial growth and biofilm formation. ASL antimicrobial activity was impaired by NIST IAP, and Iowa house IAP from subjects with recent respiratory exacerbation tended to impair ASL antimicrobial activity. Individual metals may explain impaired ASL antimicrobial activity; however, antimicrobial activity in the presence of multiple metals warrants further study.

Airway surface liquid from smokers promotes bacterial growth and biofilm formation via iron-lactoferrin imbalance.

BACKGROUND: Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance. METHODS: We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation. RESULTS: BAL from smokers had increased bacterial growth and biofilm formation compared to non-smokers after both S. aureus and P. aeruginosa challenge. In addition, we found that samples from smokers had a higher iron to lactoferrin ratio. Supplementing the BAL of non-smokers with cigarette smoke extract and ferric chloride increased bacterial growth. Conversely, supplementing the BAL of smokers with lactoferrin had a concentration-dependent decrease in bacterial growth and biofilm formation. CONCLUSION: Cigarette smoking produces factors which increase bacterial growth and biofilm formation in the BAL. We propose that smoking disrupts the iron-to-lactoferrin in the airways. This finding offers a new avenue for potential therapeutic interventions to prevent respiratory infections in smokers.