Role Of Selected Fimbrial Adheins In Pathogenesis Of Acid-Induced Eneterohemorrhagic Escherichia Coli 0157:H7

10.32920/ryerson.14657628 ◽

2021 ◽

Author(s):

Shahnaz Haque

Keyword(s):

Fatty Acid ◽

Type Strain ◽

Wild Type Strain ◽

Short Chain Fatty Acid ◽

Acid Stress ◽

Chain Fatty Acid ◽

Short Chain ◽

Wild Type ◽

Food Borne

Enterohemorrhagic Escherichia coli (EHEC) 0157:H7 is a food-borne pathogen that causes hemolytic uremic syndrome and hemorrhagic colitis. The mechanisms underlying the adhesion of EHEC 0157:H7 to intestinal epithelial cells are not well understood. Like other food-borne pathogens, ECEC 0157:H7 must survive the acid stress of the gastric juice in the stomach and short chain fatty acid in the intestine in order to colonize the large intestine. We have found that acid stress and short chain fatty acid stress significantly enhance host-adhesion of EHEC 0157:H7 and also upregulates expression of EHEC fimbrial genes, lpfA1, lpfA2 and yagZ, as demonstrated by our DNA microarray. We now report that disruption of the yagZ (also known as the E. coli common pilus A) gene results in loss of the acid-induced and short chain fatty acid-induced adhesion increase seen for the wild type strain. When the yagZ mutant is complemented with yagZ, the sress-induced and short chain fatty acid-induced adhesion increase seen for the wild type strain. When the yagZ mutant is complemented with yagZ, the stress-induced adhesion pehnotype is restored, confirming the role of yagZ in the acid as well as short chain fatty acid induced adhesion to HEp-2 cells. On the other hand, neither disruption in the long polar fimbria genes lpfA1 or lpfA2 in the wild type showed any effect in adherence to HEp-2 cells; rather displaying a hyperadherant phenotype to HEp-2 cells after acid-induced or short chain fatty acid-induced stress. The results also indicate that acid or short chain fatty acid stress, which is a part of the host's natural defense mechanism against pathogens, may regulate virulence factors resulting in enhanced bacteria-host attachment during colonization in the human or bovine host.

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Engineered Fatty Acid Biosynthesis inStreptomyces by Altered Catalytic Function of β-Ketoacyl-Acyl Carrier Protein Synthase III

Journal of Bacteriology ◽

10.1128/jb.183.7.2335-2342.2001 ◽

2001 ◽

Vol 183 (7) ◽

pp. 2335-2342 ◽

Cited By ~ 23

Author(s):

Natalya Smirnova ◽

Kevin A. Reynolds

Keyword(s):

Fatty Acid ◽

Type Strain ◽

Wild Type Strain ◽

Fatty Acid Biosynthesis ◽

Acyl Carrier Protein ◽

Chain Fatty Acid ◽

Wild Type ◽

Acid Biosynthesis ◽

Branched Chain

ABSTRACT The Streptomyces glaucescens β-ketoacyl-acyl carrier protein (ACP) synthase III (KASIII) initiates straight- and branched-chain fatty acid biosynthesis by catalyzing the decarboxylative condensation of malonyl-ACP with different acyl-coenzyme A (CoA) primers. This KASIII has one cysteine residue, which is critical for forming an acyl-enzyme intermediate in the first step of the process. Three mutants (Cys122Ala, Cys122Ser, Cys122Gln) were created by site-directed mutagenesis. Plasmid-based expression of these mutants in S. glaucescens resulted in strains which generated 75 (Cys122Ala) to 500% (Cys122Gln) more straight-chain fatty acids (SCFA) than the corresponding wild-type strain. In contrast, plasmid-based expression of wild-type KASIII had no effect on fatty acid profiles. These observations are attributed to an uncoupling of the condensation and decarboxylation activities in these mutants (malonyl-ACP is thus converted to acetyl-ACP, a SCFA precursor). Incorporation experiments with perdeuterated acetic acid demonstrated that 9% of the palmitate pool of the wild-type strain was generated from an intact D3 acetyl-CoA starter unit, compared to 3% in a strain expressing the Cys122Gln KASIII. These observations support the intermediacy of malonyl-ACP in generating the SCFA precursor in a strain expressing this mutant. To study malonyl-ACP decarboxylase activity in vitro, the KASIII mutants were expressed and purified as His-tagged proteins in Escherichia coli and assayed. In the absence of the acyl-CoA substrate the Cys122Gln mutant and wild-type KASIII were shown to have comparable decarboxylase activities in vitro. The Cys122Ala mutant exhibited higher activity. This activity was inhibited for all enzymes by the presence of high concentrations of isobutyryl-CoA (>100 μM), a branched-chain fatty acid biosynthetic precursor. Under these conditions the mutant enzymes had no activity, while the wild-type enzyme functioned as a ketoacyl synthase. These observations indicate the likely upper and lower limits of isobutyryl-CoA and related acyl-CoA concentrations within S. glaucescens.

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OR31-3 Role of a Novel Short Chain Fatty Acid Receptor OLFR78 in Mediating Gluco-metabolic Hormone Secretion

Journal of the Endocrine Society ◽

10.1210/js.2019-or31-3 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Kristen Lednovich ◽

Medha Priyadarshini ◽

Kumar Kotlo ◽

Kai Xu ◽

Shubha Priyamvada ◽

...

Keyword(s):

Fatty Acid ◽

Short Chain Fatty Acid ◽

Hormone Secretion ◽

Chain Fatty Acid ◽

Short Chain ◽

Acid Receptor ◽

Metabolic Hormone ◽

Fatty Acid Receptor

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Role of Colonic Short-Chain Fatty Acid Transport in Diarrhea

Annual Review of Physiology ◽

10.1146/annurev-physiol-021909-135817 ◽

2010 ◽

Vol 72 (1) ◽

pp. 297-313 ◽

Cited By ~ 146

Author(s):

Henry J. Binder

Keyword(s):

Fatty Acid ◽

Short Chain Fatty Acid ◽

Chain Fatty Acid ◽

Short Chain ◽

Fatty Acid Transport ◽

Acid Transport

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Role of Short Chain Fatty Acid Receptors in Intestinal Physiology and Pathophysiology

Comprehensive Physiology ◽

10.1002/cphy.c170050 ◽

2018 ◽

pp. 1091-1115 ◽

Cited By ~ 22

Author(s):

Medha Priyadarshini ◽

Kumar U. Kotlo ◽

Pradeep K. Dudeja ◽

Brian T. Layden

Keyword(s):

Fatty Acid ◽

Short Chain Fatty Acid ◽

Chain Fatty Acid ◽

Short Chain ◽

Intestinal Physiology

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Short-Chain Fatty Acid Propionate Alleviates Akt2 Knockout-Induced Myocardial Contractile Dysfunction

Experimental Diabetes Research ◽

10.1155/2012/851717 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Linlin Li ◽

Yinan Hua ◽

Jun Ren

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Membrane Potential ◽

Mitochondrial Membrane ◽

Short Chain Fatty Acid ◽

Contractile Function ◽

Short Chain Fatty Acids ◽

Chain Fatty Acid ◽

Short Chain

Background and Aims. Dysregulation of Akt has been implicated in diseases such as cancer and diabetes, although little is known about the role of Akt deficiency on cardiomyocyte contractile function. This study was designed to examine the effect of Akt2 knockout-induced cardiomyocyte contractile response and the effect of dietary supplementation of short-chain fatty acid propionate on Akt2 knockout-induced cardiac dysfunction, if any.Methods and Results. Adult male wild-type (WT) and Akt2 knockout mice were treated with propionate (0.3 g/kg, p.o.) or vehicle for 7 days. Oral glucose tolerance test (OGTT) was performed. Cardiomyocyte contractile function and mitochondrial membrane potential were assessed. Expression of insulin-signaling molecules Akt, PTEN, GSK3β, and eNOS receptors for short-chain fatty acids GPR41, and GPR43 as well as protein phosphatase PP2AA, PP2AB, PP2C were evaluated using Western blot analysis. Our results revealed that Akt2 knockout led to overt glucose intolerance, compromised cardiomyocyte contractile function (reduced peak shortening and maximal velocity of shortening/relengthening as well as prolonged relengthening), loss of mitochondrial membrane potential, decreased GPR41 and elevated GPR43 expression, all of which, with the exception of glucose intolerance and elevated GPR43 level, were significantly attenuated by propionate. Neither Akt2 knockout nor propionate affected the expression of protein phosphatases, eNOS, pan, and phosphorylated PTEN and GSK3β.Conclusions. Taken together, these data depicted that Akt2 knockout may elicit cardiomyocyte contractile and mitochondrial defects and a beneficial role of propionate or short-chain fatty acids against Akt2 deficiency-induced cardiac anomalies.

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The role of rye bran and antibiotics on the digestion, fermentation process and short-chain fatty acid production and absorption in an intact pig model

Food & Function ◽

10.1039/d1fo00213a ◽

2021 ◽

Vol 12 (7) ◽

pp. 2886-2900

Author(s):

Yetong Xu ◽

Anne Katrine Bolvig ◽

Brendan McCarthy-Sinclair ◽

Maria L. Marco ◽

Knud Erik Bach Knudsen ◽

...

Keyword(s):

Fatty Acid ◽

Acid Production ◽

Fermentation Process ◽

Short Chain Fatty Acid ◽

Chain Fatty Acid ◽

Short Chain ◽

Fatty Acid Production ◽

Marginal Effects ◽

Butyrate Production

Rye bran diet induced different DF degradation processes and SCFA profile compared with refined wheat cellulose, while antibiotics had marginal effects on digestibility and DF degradation but hampered butyrate production.

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