Abstract | BACKGROUND: Mechanism(s) connecting obstructive sleep apnoea syndrome (OSAS) to liver injury in paediatric non-alcoholic fatty liver disease ( NAFLD) are unknown. We hypothesised alterations in gut-liver axis and in the pool and phenotype of hepatic progenitor cells (HPCs) may be involved in OSAS-associated liver injury in NAFLD. METHODS: Eighty biopsy-proven NAFLD children (age, mean±SD, 11.4±2.0 years, 56% males, body mass index z-score 1.95±0.57) underwent a clinical-biochemical assessment, with measurement of insulin sensitivity, plasma cytokines, lipopolysaccharide (LPS), an intestinal permeability test and a standard polysomnography. Hepatic toll-like receptor (TLR)-4 expression by liver-resident cells and overall number and expression of resistin and adiponectin by HPCs were assessed by immunofluorescence and immunohistochemistry. OSAS was defined by an apnoea/hypopnoea index ≥1. RESULTS: OSAS was characterised by an increased intestinal permeability and endotoxemia, coupled with TLR-4 upregulation in hepatocytes, Kupffer and hepatic stellate cells (HSCs) and by an expansion of an adiponectin-deficient HPC pool, key features of steatohepatitis and fibrosis.The duration of haemoglobin desaturation (SaO2 <90%) independently predicted intestinal permeability (β: 0.396; p=0.026), plasma LPS (β: 0.358; p=0.008) and TLR-4 expression by hepatocytes (β: 0.332; p=0.009), Kupffer cells (β: 0.357; p=0.006) and HSCs (β:0.445; p=0.002).SaO2 <90% predicted also HPC number (β: 0.471; p=0.001) and impaired adiponectin expression by HPC pool (β: -0.532; p=0.0009).These relationships were observed in obese and non-obese children. CONCLUSIONS: In paediatric NAFLD, OSAS is associated with increased endotoxemia coupled with impaired gut barrier function, with increased TLR-4-mediated hepatic susceptibility to endotoxemia and with an expansion of an adiponectin-deficient HPC pool. These alterations may represent a novel pathogenic link and a potential therapeutic target for OSAS-associated liver injury in NAFLD.
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Authors | Valerio Nobili, Anna Alisi, Renato Cutrera, Guido Carpino, Cristiano De Stefanis, Valentina D'Oria, Rita De Vito, Salvatore Cucchiara, Eugenio Gaudio, Giovanni Musso |
Journal | Thorax
(Thorax)
Vol. 70
Issue 8
Pg. 769-81
(Aug 2015)
ISSN: 1468-3296 [Electronic] England |
PMID | 26069285
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions. |
Chemical References |
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Topics |
- Adiponectin
(biosynthesis)
- Apoptosis
- Biopsy
- Body Mass Index
- Cell Cycle
- Child
- Female
- Hepatocytes
(pathology)
- Humans
- Liver
(metabolism, pathology)
- Male
- Non-alcoholic Fatty Liver Disease
(complications, metabolism, pathology)
- Polysomnography
- Retrospective Studies
- Sleep Apnea, Obstructive
(complications, metabolism)
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