title: Pyrroloquinoline quinone (PQQ) producing Escherichia coli Nissle 1917 (EcN) alleviates age associated oxidative stress and hyperlipidemia, and improves mitochondrial function in ageing rats.
abstract: BACKGROUND
  Ageing involves oxidative stress mediated by Reactive Oxygen Species (ROS) and mitochondrial dysfunction. The present work demonstrates the protective effect of PQQ producing EcN against rotenone induced mitochondrial oxidative stress and consequence of mitochondrial and cellular dysfunction in naturally ageing rat model. PQQ is a potent antioxidant molecule also known to stimulate mitochondrial biogenesis and function in mammals.
  
  
  METHODS
  Firstly, adult rats (16-18 weeks old) were treated with rotenone (2.5 mg/kg body weight; i.p.) daily for 28 days along with PQQ (10 mg/kg diet, daily) and modified probiotic EcN strains (10(8) CFU twice weekly). Secondly, ageing rats (48-50 weeks old) were gavaged with probiotic EcN strains (10(8)CFU twice weekly) and PQQ (10 mg/kg diet, daily) for 8 months.
  
  
  RESULTS
  PQQ producing EcN-5 treatment prevented rotenone induced hepatic oxidative stress and mitochondrial damage in rats as assessed by reduced lipid peroxidation (29%), elevated glutathione (GSH) content (43%), increased catalase (52%) and superoxide dismutase (52%) activities when compared to only rotenone treatment. Moreover, increased hepatic mitochondrial content (41%), peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) mRNA (25%) and mitochondrial Superoxide Dismutase (Mit-SOD) activity (94%) were also observed in EcN-5 treated rats. Rotenone treated rats did not exhibit gain in body weight, whereas rats co-treated with EcN-5 showed significant restoration in body weight gain. Furthermore, weekly administration of EcN-5 to naturally ageing rats for eight months resulted in significant reduction of oxidative stress in hepatic and colonic tissues (assessed by lipid peroxidation, GSH content and catalase and SOD enzyme activities) along with increase in hepatic mitochondrial enzyme activities (Mit-SOD and succinate dehydrogenase) and biogenesis, when compared to untreated rats. Additionally, these rats also exhibited reduced expression of fatty acid synthase (50%) and increased expression of acyl coenzyme oxidase (225%) genes in liver in contrast to untreated rats resulting in lowered triglyceride (13% & 13.5%) and cholesterol (21% & 27%) levels in plasma and liver, respectively. Increased levels of butyrate (93%), propionate (45%) and acetate (18%) were also found in colonic content of these rats. PQQ administered daily (supplemented in diet) exhibited more or less similar effect as weekly gavaged EcN-5 in both the experiments, which substantiate that these effects are mediated by PQQ.
  
  
  CONCLUSIONS
  These results suggest that genetically modified EcN-5 can be used as a nutritional supplement which can reduce age related oxidative stress and hyperlipidemia. Furthermore, it also rejuvenates healthy mitochondria by stimulating mitochondrial biogenesis and metabolism.
authors.affiliation: Molecular Microbial Biochemistry Lab, Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India. Electronic address: singhashish1186@gmail.com.
authors.forename: Ashish Kumar
authors.initials: AK
authors.lastname: Singh
authors.affiliation: Molecular Microbial Biochemistry Lab, Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India. Electronic address: sumitkumarpandey2@gmail.com.
authors.forename: Sumeet Kumar
authors.initials: SK
authors.lastname: Pandey
authors.affiliation: Molecular Microbial Biochemistry Lab, Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India. Electronic address: gourav.saha@gmail.com.
authors.forename: Gourav
authors.initials: G
authors.lastname: Saha
authors.affiliation: Molecular Microbial Biochemistry Lab, Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India. Electronic address: gnaresh_k@yahoo.co.in.
authors.forename: Naresh Kumar
authors.initials: NK
authors.lastname: Gattupalli
mesh_terms: D000375:Aging / Q000187:drug effects; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D004926:Escherichia coli / Q000235:genetics*; D005978:Glutathione / Q000378:metabolism; D006949:Hyperlipidemias / Q000188:drug therapy*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D045542:PQQ Cofactor / Q000008:administration & dosage* / Q000235:genetics; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D012402:Rotenone / Q000008:administration & dosage*; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D000099156:Superoxide Dismutase 2
chemical_list: D000975:Antioxidants; D005978:Glutathione; D045542:PQQ Cofactor; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D017382:Reactive Oxygen Species; D012402:Rotenone; D013385:Succinate Dehydrogenase; D013482:Superoxide Dismutase; D014157:Transcription Factors; D000099156:Superoxide Dismutase 2; C501429:Ppargc1a protein, rat
keywords: Ageing; Escherichia coli Nissle 1917; Healthy mitochondria; Hyperlipidemia; Pyrroloquinoline quinone; ROS