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Mbikay M, Chrétien M. The Biological Relevance of PCSK9: When Less Is Better…. Biochem Cell Biol 2022; 100:189-198. [PMID: 35263196 DOI: 10.1139/bcb-2021-0540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Proprotein Convertase Subtilisin/Kexin-type 9 (PCSK9) is a circulating negative regulator of hepatic low-density lipoprotein receptor (LDLR) which clears cholesterol from blood. Gain-of-function genetic mutations which amplify PCSK9 activity have been found to cause potentially lethal familial hypercholesterolemia. Inversely, reduction of its activity through loss-of-function genetics or with pharmaceuticals was shown to increase hepatic LDLR, to lower blood cholesterol, and to protect against cardiovascular diseases. New epidemiological and experimental evidence suggests that this reduction could also attenuate inflammation, reinforce cancer immunity, provide resistance to infections, and protect against liver pathologies. In this review, we question the relevance of this protein under normal physiology. We propose that PCSK9 is an important, but non-essential, modulator of cholesterol metabolism and immunity, and that its pathogenicity results from its chronic overexpression.
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Affiliation(s)
- Majambu Mbikay
- Institut de recherches cliniques de Montréal, 5598, Functional Endoproteolysis, Montreal, Quebec, Canada;
| | - Michel Chrétien
- Institut de recherches cliniques de Montreal, 5598, Functional Endoproteolysis, Montreal, Quebec, Canada;
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Rannikko J, Jacome Sanz D, Ortutay Z, Seiskari T, Aittoniemi J, Huttunen R, Syrjänen J, Pesu M. Reduced plasma PCSK9 response in patients with bacteraemia is associated with mortality. J Intern Med 2019; 286:553-561. [PMID: 31166632 DOI: 10.1111/joim.12946] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme controls blood cholesterol levels by downregulating the expression of the low-density lipoprotein receptor (LDLR). Pathogenic lipids (e.g. lipopolysaccharide) are removed from the circulation by an LDLR/PCSK9-dependent mechanism; thus, it has been suggested that PCSK9 inhibitors may be beneficial in the treatment of infections. We measured plasma PCSK9 levels in patients with culture-positive bacteraemia and explored pathogen-dependent and infection site-dependent effects as well as correlations between patient characteristics and outcome. METHODS Proprotein convertase subtilisin/kexin type 9 in the plasma was measured with an enzyme-linked immunosorbent assay from 481 patients with blood culture-positive infection on days 0 to 4 after admission to the emergency department. Patient outcome and clinical and laboratory data were gathered retrospectively from patient records. RESULTS The plasma PCSK9 level was elevated equally in patients with Gram-positive or Gram-negative bacterial infections; particularly high levels were seen in patients with a lower respiratory tract infection and Streptococcus pneumoniae bacteraemia. PCSK9 levels showed a significant positive correlation with C-reactive protein (CRP) level. Bacteraemia patients with liver disease or a history of alcohol abuse had significantly lower levels of plasma PCSK9. Reduced PCSK9 plasma responses in patients were significantly associated with mortality at days 7, 28 and 90. CONCLUSION Proprotein convertase subtilisin/kexin type 9 is upregulated in blood culture-positive infections. Plasma PCSK9 resembles acute-phase proteins; its expression is induced during an infection, reduced in liver disease and correlates positively with CRP level. We have shown that PCSK9 levels are lower in patients with a fatal prognosis.
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Affiliation(s)
- J Rannikko
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland.,Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - D Jacome Sanz
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Z Ortutay
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - T Seiskari
- Department of Clinical Microbiology, Fimlab Laboratories Ltd, Tampere, Finland
| | - J Aittoniemi
- Department of Clinical Microbiology, Fimlab Laboratories Ltd, Tampere, Finland
| | - R Huttunen
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
| | - J Syrjänen
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
| | - M Pesu
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Department of Dermatology, Tampere University Hospital, Tampere, Finland
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Druce I, Abujrad H, Chaker S, Meggison H, Hill A, Raymond A, Mayne J, Ooi TC. Circulating PCSK9 is lowered acutely following surgery. J Clin Lab Anal 2017; 32:e22358. [PMID: 29148099 DOI: 10.1002/jcla.22358] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/21/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND A decrease in serum low-density lipoprotein cholesterol (LDL-C) is well documented after acute stress. Plasma proprotein convertase subtilisin kexin 9 (PCSK9), which promotes degradation of low-density lipoprotein receptor (LDL-R) resulting in reduced plasma clearance of low-density lipoproteins (LDL) and an increase in serum LDL-C, would be predicted to decrease. Yet, a few studies have demonstrated an increase 1-8 days after acute stress. Our objective was to assess the earlier status of plasma PCSK9, within the first 24 hours of onset of stress. METHODS We measured serum lipids and plasma PCSK9 in 39 patients before and soon after an elective surgical procedure (abdominal aortic aneurysm (AAA) repair). RESULTS We observed an early decrease in PCSK9 following surgery, as well as a decrease in total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) and triglycerides (TG). CONCLUSION Unlike other studies which showed an increase in PCSK9 after the onset of stress, our study detected a fall in PCSK9 following acute surgical stress. The observed difference is likely due to the earlier timing of PCSK9 measurement in our study. Further studies involving serial poststress measurements for several days are needed to determine whether PCSK9 behaves as an acute-phase reactant, whether it displays a biphasic response to acute stress, and whether changes in circulating PCSK9 are responsible for lipoprotein changes observed after surgical stress. (Clinical Trial Registration: ClinicalTrials.gov study ID NCT00493389).
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Affiliation(s)
- Irena Druce
- Clinical Research Laboratory, Division of Endocrinology and Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Hussein Abujrad
- Clinical Research Laboratory, Division of Endocrinology and Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON, Canada.,Chronic Disease Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada
| | - Seham Chaker
- Clinical Research Laboratory, Division of Endocrinology and Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Hilary Meggison
- Department of Critical Care Medicine, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada
| | - Andrew Hill
- Division of Vascular Surgery, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada
| | - Angela Raymond
- Clinical Research Laboratory, Division of Endocrinology and Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Janice Mayne
- Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Teik Chye Ooi
- Clinical Research Laboratory, Division of Endocrinology and Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON, Canada.,Chronic Disease Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON, Canada
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