Cystic fibrosis is characterized in the lungs by neutrophil-dominated inflammation mediated significantly by neutrophil elastase (NE). Previous work has shown that

Lactobacillus plantarum P5 grew aerobically in rich media at the expense of lactate; no growth was observed in the absence of aeration. The oxygen-dependent growth was accompanied by the conversion of lactate to acetate which accumulated in the growth medium. Utilization of oxygen with lactate as substrate was observed in buffered suspensions of washed whole cells and in cell-free extracts. A pathway which accounts for the generation of adenosine triphosphate during aerobic metabolism of lactate to acetate via pyruvate and acetyl phosphate is proposed. Each of the enzyme activities involved, nicotinamide adenine dinucleotide independent lactic dehydrogenase, nicotinamide adenine dinucleotide dependent lactic dehydrogenase, pyruvate oxidase, acetate kinase and NADH oxidase were demonstrated in cell-free extracts. The production of pyruvate, acetyl phosphate and acetate was demonstrated using cell-free extracts and cofactors for the enzymes of the proposed pathway.

A non‐genomic antisecretory role for dexamethasone at low concentrations (0.1 nm to1 μm) is described in monolayers of human bronchial epithelial cells in primary culture and in a continuous cell line (16HBE14o‐ cells). Dexamethasone produced a rapid decrease of [Ca2+]i (measured with fura‐2 spectrofluorescence) to a new steady‐state concentration. After 15 min exposure to dexamethasone (1 nm), [Ca2+]i was reduced by 32 ± 11 nm (n= 7, P < 0.0001) from a basal value of 213 ± 36 nm (n= 7). We have shown previously that aldosterone (1 nm) also produces a rapid fall in [Ca2+]i; however, after the decrease in [Ca2+]i induced by dexamethasone, subsequent addition of aldosterone did not produced any further lowering of [Ca2+]i. The rapid response to dexamethasone was insensitive to pretreatment with cycloheximide and unaffected by the glucocorticoid type II and mineralocorticoid receptor antagonists RU486 and spironolactone, respectively. The rapid [Ca2+]i decrease induced by dexamethasone was inhibited by the Ca2+‐ATPase pump inhibitor thapsigargin (1 μm), the adenylate cyclase inhibitor MDL hydrochloride (500 μm) and the protein kinase A inhibitor Rp‐adenosine 3′,5′‐cyclic monophosphorothioate (200 μm), but was not affected by the protein kinase C inhibitor, chelerythrine chloride (0.1 μm). Treatment of 16HBE14o‐ cell monolayers with dexamethasone (1 nm) inhibited the large and transient [Ca2+]i increase induced by apical exposure to ATP (10−4m). Dexamethasone (1 nm) also reduced by 30 % the Ca2+‐dependant Cl− secretion induced by apical exposure to ATP (measured as the Cl−‐sensitive short‐circuit current across monolayers mounted in Ussing chambers). Our results demonstrate, for the first time, that dexamethasone at low concentrations inhibits Cl− secretion in human bronchial epithelial cells. The rapid inhibition of Cl− secretion induced by the synthetic glucocorticoid is associated with a rapid decrease in [Ca2+]i via a non‐genomic mechanism that does not involve the classical glucocorticoid or mineralocorticoid receptor. Rather, it is a result of rapid non‐genomic stimulation of thapsigargin‐sensitive Ca2+‐ATPase, via adenylate cyclase and protein kinase A signalling.

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S. 1989. Impact of aeration on the metabolic end-products formed from glucose and galactose by Streptococcus lactis. 66,77-84. Compared with cultures grown aerobically in batch culture with glucose, aerated cultures of lactic streptococci had a less homolactic type of metabolism when galactose was the carbohydrate source in batch cultures, or when glucose was limiting in chemostat cultures. Differences in end-products of sugar metabolism between aerated and unaerated cultures were observed. In addition to lactate, formate, acetate and ethanol were produced in anaerobic cultures, whereas acetate and acetoin were formed in aerated cultures. Acetate production in aerated cultures depended on lipoic acid, an essential cofactor of the pyruvate dehydrogenase complex. In a chemically defined medium with glucose as the energy substrate, lipoic acid (or acetate) was an essential growth factor. Formation of acetoin was inversely related to lipoic acid concentration in the growth medium. Although not observed in unaerated cultures, acetoin (and 2,3-butanediol) was produced in unaerated buffered suspensions metabolizing pyruvate. Aeration caused a modest increase in the activities of a-acetolactate synthetase and phosphate acetyl transferase, but it is unlikely that the increases were sufficient to account for the changes in end-products of sugar metabolism observed. Journal of Applied Bacteriology

Bifidobacteria are known to inhibit, compete with and displace the adhesion of pathogens to human intestinal cells. Previously, we demonstrated that goat milk oligosaccharides (GMO) increased the attachment of Bifidobacterium longum subsp. infantis ATCC 15697 to intestinal cells in vitro. In this study, we aimed to exploit this effect as a mechanism for inhibiting pathogen association with intestinal cells. We examined the synergistic effect of GMO-treated B. infantis on preventing the attachment of a highly invasive strain of Campylobacter jejuni to intestinal HT-29 cells. The combination decreased the adherence of C. jejuni to the HT-29 cells by an average of 42% compared to the control (non-GMO treated B. infantis). Increasing the incubation time of the GMO with the Bifidobacterium strain resulted in the strain metabolizing the GMO, correlating with a subsequent 104% increase in growth over a 24 h period when compared to the control. Metabolite analysis in the 24 h period also revealed increased production of acetate, lactate, formate and ethanol by GMO-treated B. infantis. Statistically significant changes in the GMO profile were also demonstrated over the 24 h period, indicating that the strain was digesting certain structures within the pool such as lactose, lacto-N-neotetraose, lacto-N-neohexaose 3 -sialyllactose, 6 -sialyllactose, sialyllacto-N-neotetraose c and disialyllactose. It may be that early exposure to GMO modulates the adhesion of B. infantis while carbohydrate utilisation becomes more important after the bacteria have transiently colonised the host cells in adequate numbers. This study builds a strong case for the use of synbiotics that incorporate oligosaccharides sourced from goat s milk and probiotic bifidobacteria in functional foods, particularly considering the growing popularity of formulas based on goat milk. Foods 2020, 9, 348 2 of 15Listeria monocytogenes, and Clostridium difficile [4][5][6]. Microbe-associated molecular patterns (MAMPs) are recognized by the host s intestinal pattern recognition receptors (PRRs), and these interactions play key roles in the association of pathogens with the intestinal epithelia. Probiotics also express molecular patterns which can recognize the same trans-membrane receptors as the pathogens, thus blocking the sites for pathogenic contact by competitive exclusion and, in some cases, displacing already-attached pathogens [7]. However, the health benefits associated with bifidobacteria are reliant on such strains colonising the host in sufficient numbers [8]. The important step in microbial colonisation of the intestinal epithelium is the attachment of bacterial surface lectins to intestinal sugar structures. Recent studies have suggested that milk oligosaccharides may enhance the specific ability of bifidobacteria to attach to the GI epithelium [9][10][11]. Indeed, our group investigated the ability of goat milk oligosaccharides (GMO) to increase the attachment of Bifidobacterium longum subsp. infantis ATCC 15697 to HT-29 cells. Exposure of the strain ...

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In cystic fibrosis airway epithelia, mutation of the CFTR protein causes a reduced response of Cl(-) secretion to secretagogues acting via cAMP. Using a Ca(2+) imaging system, the hypothesis that CFTR activation may permit ATP release and regulate [Ca(2+)](i) via a receptor-mediated mechanism, is tested in this study. Application of external nucleotides produced a significant increase in [Ca(2+)](i) in normal (16HBE14o(-) cell line and primary lung culture) and in cystic fibrosis (CFTE29o(-) cell line) human airway epithelia. The potency order of nucleotides on [Ca(2+)](i) variation was UTP >> ATP > UDP > ADP > AMP > adenosine in both cell types. The nucleotide [Ca(2+)](i) response could be mimicked by activation of CFTR with forskolin (20 microm) in a temperature-dependent manner. In 16HBE14o(-) cells, the forskolin-induced [Ca(2+)](i) response increased with increasing temperature. In CFTE29o(-) cells, forskolin had no effect on [Ca(2+)](i) at body temperature-forskolin-induced [Ca(2+)](i) response in CF cells could only be observed at low experimental temperature (14 degrees C) or when cells were cultured at 26 degrees C instead of 37 degrees C. Pretreatment with CFTR channel blockers glibenclamide (100 microm) and DPC (100 microm), with hexokinase (0.5 U/mg), and with the purinoceptor antagonist suramin (100 microm), inhibited the forskolin [Ca(2+)](i) response. Together, these results demonstrate that once activated, CFTR regulates [Ca(2+)](i) by mediating nucleotide release and activating cell surface purinoceptors in normal and CF human airway epithelia.