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Mabry S, Bradshaw JL, Gardner JJ, Wilson EN, Cunningham RL. Sex-dependent effects of chronic intermittent hypoxia: implication for obstructive sleep apnea. Biol Sex Differ 2024; 15:38. [PMID: 38664845 PMCID: PMC11044342 DOI: 10.1186/s13293-024-00613-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS). METHODS Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-6, IL-10, TNF-α), circulating steroid hormones, circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). Rats were implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype. RESULTS Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex. CONCLUSIONS Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.
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Affiliation(s)
- Steve Mabry
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Jessica L Bradshaw
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Jennifer J Gardner
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - E Nicole Wilson
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX, 76107-2699, USA.
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2
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Mabry S, Bradshaw JL, Gardner JJ, Wilson EN, Cunningham R. Sex-dependent effects of chronic intermittent hypoxia: Implication for obstructive sleep apnea. RESEARCH SQUARE 2024:rs.3.rs-3898670. [PMID: 38352622 PMCID: PMC10862974 DOI: 10.21203/rs.3.rs-3898670/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Background Obstructive sleep apnea (OSA) affects 10-26% of adults in the United States with known sex differences in prevalence and severity. OSA is characterized by elevated inflammation, oxidative stress (OS), and cognitive dysfunction. However, there is a paucity of data regarding the role of sex in the OSA phenotype. Prior findings suggest women exhibit different OSA phenotypes than men, which could result in under-reported OSA prevalence in women. To examine the relationship between OSA and sex, we used chronic intermittent hypoxia (CIH) to model OSA in rats. We hypothesized that CIH would produce sex-dependent phenotypes of inflammation, OS, and cognitive dysfunction, and these sex differences would be dependent on mitochondrial oxidative stress (mtOS). Methods Adult male and female Sprague Dawley rats were exposed to CIH or normoxia for 14 days to examine the impact of sex on CIH-associated circulating inflammation (IL-1β, IL-4, IL-6, IL-10, TNF-α), circulating OS, and behavior (recollective and spatial memory; gross and fine motor function; anxiety-like behaviors; and compulsive behaviors). A subset of rats was implanted with osmotic minipumps containing either a mitochondria-targeting antioxidant (MitoTEMPOL) or saline vehicle 1 week prior to CIH initiation to examine how inhibiting mtOS would affect the CIH phenotype. Results Sex-specific differences in CIH-induced inflammation, OS, motor function, and compulsive behavior were observed. In female rats, CIH increased inflammation (plasma IL-6 and IL-6/IL-10 ratio) and impaired fine motor function. Conversely, CIH elevated circulating OS and compulsivity in males. These sex-dependent effects of CIH were blocked by inhibiting mtOS. Interestingly, CIH impaired recollective memory in both sexes but these effects were not mediated by mtOS. No effects of CIH were observed on spatial memory, gross motor function, or anxiety-like behavior, regardless of sex. Conclusions Our results indicate that the impact of CIH is dependent on sex, such as an inflammatory response and OS response in females and males, respectively, that are mediated by mtOS. Interestingly, there was no effect of sex or mtOS in CIH-induced impairment of recollective memory. These results indicate that mtOS is involved in the sex differences observed in CIH, but a different mechanism underlies CIH-induced memory impairments.
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3
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Wu WL, Adame MD, Liou CW, Barlow JT, Lai TT, Sharon G, Schretter CE, Needham BD, Wang MI, Tang W, Ousey J, Lin YY, Yao TH, Abdel-Haq R, Beadle K, Gradinaru V, Ismagilov RF, Mazmanian SK. Microbiota regulate social behaviour via stress response neurons in the brain. Nature 2021; 595:409-414. [PMID: 34194038 DOI: 10.1038/s41586-021-03669-y] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/25/2021] [Indexed: 02/07/2023]
Abstract
Social interactions among animals mediate essential behaviours, including mating, nurturing, and defence1,2. The gut microbiota contribute to social activity in mice3,4, but the gut-brain connections that regulate this complex behaviour and its underlying neural basis are unclear5,6. Here we show that the microbiome modulates neuronal activity in specific brain regions of male mice to regulate canonical stress responses and social behaviours. Social deviation in germ-free and antibiotic-treated mice is associated with elevated levels of the stress hormone corticosterone, which is primarily produced by activation of the hypothalamus-pituitary-adrenal (HPA) axis. Adrenalectomy, antagonism of glucocorticoid receptors, or pharmacological inhibition of corticosterone synthesis effectively corrects social deficits following microbiome depletion. Genetic ablation of glucocorticoid receptors in specific brain regions or chemogenetic inactivation of neurons in the paraventricular nucleus of the hypothalamus that produce corticotrophin-releasing hormone (CRH) reverse social impairments in antibiotic-treated mice. Conversely, specific activation of CRH-expressing neurons in the paraventricular nucleus induces social deficits in mice with a normal microbiome. Via microbiome profiling and in vivo selection, we identify a bacterial species, Enterococcus faecalis, that promotes social activity and reduces corticosterone levels in mice following social stress. These studies suggest that specific gut bacteria can restrain the activation of the HPA axis, and show that the microbiome can affect social behaviours through discrete neuronal circuits that mediate stress responses in the brain.
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Affiliation(s)
- Wei-Li Wu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. .,Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
| | - Mark D Adame
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chia-Wei Liou
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jacob T Barlow
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tzu-Ting Lai
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Gil Sharon
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Catherine E Schretter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Brittany D Needham
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Madelyn I Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Weiyi Tang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - James Ousey
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yuan-Yuan Lin
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tzu-Hsuan Yao
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Reem Abdel-Haq
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Keith Beadle
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Rustem F Ismagilov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sarkis K Mazmanian
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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4
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Philippe C, Szabo de Edelenyi F, Naudon L, Druesne-Pecollo N, Hercberg S, Kesse-Guyot E, Latino-Martel P, Galan P, Rabot S. Relation between Mood and the Host-Microbiome Co-Metabolite 3-Indoxylsulfate: Results from the Observational Prospective NutriNet-Santé Study. Microorganisms 2021; 9:microorganisms9040716. [PMID: 33807160 PMCID: PMC8065611 DOI: 10.3390/microorganisms9040716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 11/29/2022] Open
Abstract
Gut microbiota metabolizes tryptophan into indole, which can influence brain and behavior. Indeed, some oxidized derivatives of indole, formed in the liver, have neuroactive properties, and indole overproduction by the gut microbiota induces an anxio-depressive phenotype in rodents. The aim of this study was to investigate in humans whether there was a relationship between recurrent depressive symptoms and indole production by the gut microbiota. A case-control study was conducted in 45–65-year-old women, who were participants in the observational prospective NutriNet-Santé Study. Cases were defined as having two Center for Epidemiological Studies-Depression Scales (CES-D) scores ≥ 23 at a two-year interval (recurrent depressive symptoms, n = 87). Each case was matched with two controls (two CES-D <23; n = 174). Urinary excretion of 3-indoxylsulfate, the major final metabolite of indole, was used as a biomarker of indole production by the gut microbiota. Conditional logistic regression models for paired data showed a positive association between urinary 3-indoxylsulfate concentrations, grouped in tertiles, and recurrent depressive symptoms (odds ratio = 2.46, p for trend = 0.0264 in the final model adjusted for confounding factors). This association suggested that indole production by the gut microbiota may play a role in the onset of mood disorders in humans.
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Affiliation(s)
- Catherine Philippe
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
- Correspondence: (C.P.); (F.S.d.E.); (P.G.); (S.R.)
| | - Fabien Szabo de Edelenyi
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
- Correspondence: (C.P.); (F.S.d.E.); (P.G.); (S.R.)
| | - Laurent Naudon
- INRAE, AgroParisTech, CNRS, Micalis Institute, Université Paris-Saclay, 78350 Jouy-en-Josas, France;
| | - Nathalie Druesne-Pecollo
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
| | - Serge Hercberg
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
| | - Emmanuelle Kesse-Guyot
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
| | - Paule Latino-Martel
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
| | - Pilar Galan
- Sorbonne Paris Nord, Epidemiology and Statistics Research Center (CRESS), Inserm U1153, INRAE U1125, Cnam, Paris 13 University, Nutritional Epidemiology Research Team (EREN), 93017 Bobigny, France; (N.D.-P.); (S.H.); (E.K.-G.); (P.L.-M.)
- Correspondence: (C.P.); (F.S.d.E.); (P.G.); (S.R.)
| | - Sylvie Rabot
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
- Correspondence: (C.P.); (F.S.d.E.); (P.G.); (S.R.)
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5
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Sarkar A, Harty S, Johnson KVA, Moeller AH, Carmody RN, Lehto SM, Erdman SE, Dunbar RIM, Burnet PWJ. The role of the microbiome in the neurobiology of social behaviour. Biol Rev Camb Philos Soc 2020; 95:1131-1166. [PMID: 32383208 PMCID: PMC10040264 DOI: 10.1111/brv.12603] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
Microbes colonise all multicellular life, and the gut microbiome has been shown to influence a range of host physiological and behavioural phenotypes. One of the most intriguing and least understood of these influences lies in the domain of the microbiome's interactions with host social behaviour, with new evidence revealing that the gut microbiome makes important contributions to animal sociality. However, little is known about the biological processes through which the microbiome might influence host social behaviour. Here, we synthesise evidence of the gut microbiome's interactions with various aspects of host sociality, including sociability, social cognition, social stress, and autism. We discuss evidence of microbial associations with the most likely physiological mediators of animal social interaction. These include the structure and function of regions of the 'social' brain (the amygdala, the prefrontal cortex, and the hippocampus) and the regulation of 'social' signalling molecules (glucocorticoids including corticosterone and cortisol, sex hormones including testosterone, oestrogens, and progestogens, neuropeptide hormones such as oxytocin and arginine vasopressin, and monoamine neurotransmitters such as serotonin and dopamine). We also discuss microbiome-associated host genetic and epigenetic processes relevant to social behaviour. We then review research on microbial interactions with olfaction in insects and mammals, which contribute to social signalling and communication. Following these discussions, we examine evidence of microbial associations with emotion and social behaviour in humans, focussing on psychobiotic studies, microbe-depression correlations, early human development, autism, and issues of statistical power, replication, and causality. We analyse how the putative physiological mediators of the microbiome-sociality connection may be investigated, and discuss issues relating to the interpretation of results. We also suggest that other candidate molecules should be studied, insofar as they exert effects on social behaviour and are known to interact with the microbiome. Finally, we consider different models of the sequence of microbial effects on host physiological development, and how these may contribute to host social behaviour.
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Affiliation(s)
- Amar Sarkar
- Trinity College, Trinity Street, University of Cambridge, Cambridge, CB2 1TQ, U.K.,Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, U.K
| | - Siobhán Harty
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Dublin, Ireland.,School of Psychology, Trinity College Dublin, Dublin 2, Dublin, Ireland
| | - Katerina V-A Johnson
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K.,Pembroke College, University of Oxford, Oxford, OX1 1DW, U.K.,Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
| | - Andrew H Moeller
- Department of Ecology and Evolutionary Biology, Corson Hall, Tower Road, Cornell University, Ithaca, NY, 14853, U.S.A
| | - Rachel N Carmody
- Department of Human Evolutionary Biology, Harvard University, Peabody Museum, 11 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
| | - Soili M Lehto
- Psychiatry, University of Helsinki and Helsinki University Hospital, PL 590, FI-00029, Helsinki, Finland.,Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, P.O. Box 6, FI-00014, Helsinki, Finland.,Institute of Clinical Medicine/Psychiatry, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Susan E Erdman
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, MA, 02139, U.S.A
| | - Robin I M Dunbar
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K
| | - Philip W J Burnet
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
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6
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Odour conditioning of positive affective states: Rats can learn to associate an odour with being tickled. PLoS One 2019; 14:e0212829. [PMID: 31188832 PMCID: PMC6561538 DOI: 10.1371/journal.pone.0212829] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 04/30/2019] [Indexed: 12/03/2022] Open
Abstract
Most associative learning tests in rodents use negative stimuli, such as electric shocks. We investigated if young rats can learn to associate the presence of an odour with the experience of being tickled (i.e. using an experimenter’s hand to mimic rough-and-tumble play), shown to elicit 50 kHz ultrasonic vocalisations (USVs), which are indicative of positive affect. Male, pair-housed Wistar rats (N = 24) were all exposed to two neutral odours (A and B) presented in a perforated container on alternate days in a test arena. Following 60s of exposure, the rats were either tickled on days when odour A (n = 8) or odour B (n = 8) was present, or never tickled (n = 8). When tickled, rats produced significantly more 50 kHz USVs compared to the days when not being tickled, and compared to control rats. The level of anticipatory 50 kHz USVs in the 60s prior to tickling did not differ significantly between the tickled and control rats. As a retrieval test following the odour conditioning, rats were exposed successively in the same arena to three odours: an unknown neutral odour, extract of fox faeces, and either odours A or B. Compared to controls, 50 kHz USVs of tickled rats increased when exposed to the odour they had previously experienced when tickled, indicating that these rats had learned to associate the odour with the positive experience of being tickled. In a test with free access for 5 min to both arms of a T-maze, each containing one of the odours, rats tickled with odour A spent more time in the arm with this odour. This work is the first to test in a fully balanced design whether rats can learn to associate an odour with tickling, and indicates that positive odour conditioning has potential to be used as an alternative to negative conditioning tests.
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7
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SEXRAT MALE: A smartphone and tablet application to annotate and process live sexual behavior in male rodents. J Neurosci Methods 2019; 320:9-15. [DOI: 10.1016/j.jneumeth.2019.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 11/18/2022]
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8
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Koszegi S, Molnar A, Lenart L, Hodrea J, Balogh DB, Lakat T, Szkibinszkij E, Hosszu A, Sparding N, Genovese F, Wagner L, Vannay A, Szabo AJ, Fekete A. RAAS inhibitors directly reduce diabetes-induced renal fibrosis via growth factor inhibition. J Physiol 2018; 597:193-209. [PMID: 30324679 PMCID: PMC6312411 DOI: 10.1113/jp277002] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/15/2018] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Increased activation of the renin-angiotensin-aldosterone system (RAAS) and elevated growth factor production are of crucial importance in the development of renal fibrosis leading to diabetic kidney disease. The aim of this study was to provide evidence for the antifibrotic potential of RAAS inhibitor (RAASi) treatment and to explore the exact mechanism of this protective effect. We found that RAASi ameliorate diabetes-induced renal interstitial fibrosis and decrease profibrotic growth factor production. RAASi prevents fibrosis by acting directly on proximal tubular cells, and inhibits hyperglycaemia-induced growth factor production and thereby fibroblast activation. These results suggest a novel therapeutic indication and potential of RAASi in the treatment of renal fibrosis. ABSTRACT In diabetic kidney disease (DKD) increased activation of renin-angiotensin-aldosterone system (RAAS) contributes to renal fibrosis. Although RAAS inhibitors (RAASi) are the gold standard therapy in DKD, the mechanism of their antifibrotic effect is not yet clarified. Here we tested the antifibrotic and renoprotective action of RAASi in a rat model of streptozotocin-induced DKD. In vitro studies on proximal tubular cells and renal fibroblasts were also performed to further clarify the signal transduction pathways that are directly altered by hyperglycaemia. After 5 weeks of diabetes, male Wistar rats were treated for two more weeks per os with the RAASi ramipril, losartan, spironolactone or eplerenone. Proximal tubular cells were cultured in normal or high glucose (HG) medium and treated with RAASi. Platelet-derived growth factor (PDGF) or connective tissue growth factor (CTGF/CCN2)-induced renal fibroblasts were also treated with various RAASi. In diabetic rats, reduced renal function and interstitial fibrosis were ameliorated and elevated renal profibrotic factors (TGFβ1, PDGF, CTGF/CCN2, MMP2, TIMP1) and alpha-smooth muscle actin (αSMA) levels were decreased by RAASi. HG increased growth factor production of HK-2 cells, which in turn induced activation and αSMA production of fibroblasts. RAASi decreased tubular PDGF and CTGF expression and reduced production of extracellular matrix (ECM) components in fibroblasts. In proximal tubular cells, hyperglycaemia-induced growth factor production increased renal fibroblast transformation, contributing to the development of fibrosis. RAASi, even in non-antihypertensive doses, decreased the production of profibrotic factors and directly prevented fibroblast activation. All these findings suggest a novel therapeutic role for RAASi in the treatment of renal fibrosis.
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Affiliation(s)
- Sandor Koszegi
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Agnes Molnar
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,1st Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Lilla Lenart
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Judit Hodrea
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Dora Bianka Balogh
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,1st Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Tamas Lakat
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Edgar Szkibinszkij
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Adam Hosszu
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,1st Department of Paediatrics, Semmelweis University, Budapest, Hungary
| | - Nadja Sparding
- Nordic Bioscience, Biomarkers & Research, Herlev, Denmark.,Biomedical Sciences, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Laszlo Wagner
- Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary
| | - Adam Vannay
- MTA-SE Paediatrics and Nephrology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Attila J Szabo
- 1st Department of Paediatrics, Semmelweis University, Budapest, Hungary.,MTA-SE Paediatrics and Nephrology Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Andrea Fekete
- MTA-SE "Lendület" Diabetes Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,1st Department of Paediatrics, Semmelweis University, Budapest, Hungary
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