The KLB rs17618244 gene variant is associated with fibrosing MAFLD by promoting hepatic stellate cell activation
Nadia Panera,
Marica Meroni,
Miriam Longo,
Annalisa Crudele,
Luca Valenti,
Emanuele Bellacchio,
Luca Miele,
Valentina D'Oria,
Erika Paolini,
Marco Maggioni,
Anna Ludovica Fracanzani,
Anna Alisi,
Paola Dongiovanni
Affiliations
Nadia Panera
Research Unit of Molecular Genetics of Complex Phenotypes, Bambino Gesù Children's Hospital, IRCCS, 4, Piazza Sant'Onofrio, Rome 00165, Italy
Marica Meroni
General Medicine and Metabolic Diseases, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35, Milan 20122, Italy
Miriam Longo
General Medicine and Metabolic Diseases, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35, Milan 20122, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milano 20122, Italy
Annalisa Crudele
Research Unit of Molecular Genetics of Complex Phenotypes, Bambino Gesù Children's Hospital, IRCCS, 4, Piazza Sant'Onofrio, Rome 00165, Italy
Luca Valenti
Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milano 20122, Italy; Translational Medicine – Department of Transfusion Medicine and Hematology, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
Emanuele Bellacchio
Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
Luca Miele
Area Medicina Interna, Gastroenterologia e Oncologia Medica, Fondazione Policlinico A. Gemelli IRCCS, Rome, Italy
Valentina D'Oria
Microscopy Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
Erika Paolini
General Medicine and Metabolic Diseases, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35, Milan 20122, Italy; Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano 20133, Italy
Marco Maggioni
Deparment of Pathology, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35 Milan 20122, Italy
Anna Ludovica Fracanzani
General Medicine and Metabolic Diseases, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35, Milan 20122, Italy; Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milano 20122, Italy
Anna Alisi
Research Unit of Molecular Genetics of Complex Phenotypes, Bambino Gesù Children's Hospital, IRCCS, 4, Piazza Sant'Onofrio, Rome 00165, Italy; Corresponding authors.
Paola Dongiovanni
General Medicine and Metabolic Diseases, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Pad. Granelli, via F Sforza 35, Milan 20122, Italy; Corresponding authors.
Background: The rs17618244 G>A β-Klotho (KLB) variant has been associated with increased risk of ballooning and inflammation in pediatric patients with metabolic associated fatty liver disease (MAFLD), by reducing KLB expression. In hepatocytes, KLB downregulation induced fat accumulation and the expression of inflammatory and lipotoxic genes. We aimed to examine firstly the impact of the KLB rs17618244 variation on liver damage in adult patients with MAFLD and secondly its effect on hepatic stellate cells (HSCs) activation. Methods: The impact of the KLB rs17618244 variant on histological liver damage was surveyed in a retrospective cohort of 1111 adult patients with MAFLD. Subgroup analysis was performed according to the presence of obesity (BMI>35; n = 708). Immortalized HSCs (LX-2) were transfected with the KLB wild type (LX-2_KLBwt), or with the mutant one carrying the rs17618244 (LX-2_KLBmut). Findings: At ordinal regression analysis the KLB rs17618244 variant was associated with hepatic fibrosis (OR 1.23, 95% C.I.1.004–1.51; p = 0.04), but not with steatosis, inflammation and ballooning. By stratifying patients according to the presence of obesity, the KLB A allele was further associated with lobular inflammation (OR 1.32, 95% C.I.1.02–1.72; p = 0.03) and cirrhosis (OR 2.51, 95% C.I.1.23–5.05; p = 0.01) Moreover, hepatic KLB expression correlated with that of fibrogenic genes. LX-2_KLBmut cells showed reduced KLB protein levels paralleled by an induction of pro-fibrogenic genes and enhanced proliferative rate. Interpretation: The KLB rs17618244 variant is associated with hepatic fibrosis, inflammation and cirrhosis mainly in obese patients with MAFLD and HSCs which carry this mutation are highly proliferative and acquire a myofibroblast-like phenotype. Funding: Ricerca Finalizzata Ministero della Salute GR-2019–12,370,172 (NP), Ricerca Corrente Fondazione IRCCS Cà Granda (PD and ALF), Ricerca Finalizzata Ministero della Salute RF-2013–02,358,319 (ALF), and Ricerca Corrente and 5 × 1000 Ministero della Salute (AA).
