| 1. |
- Nuñez Durán, Esther, et al.
(author)
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Serine/threonine protein kinase 25 antisense oligonucleotide treatment reverses glucose intolerance, insulin resistance, and nonalcoholic fatty liver disease in mice.
- 2018
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In: Hepatology communications. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 2:1, s. 69-83
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Journal article (peer-reviewed)abstract
- Nonalcoholic fatty liver disease (NAFLD) contributes to the pathogenesis of type 2 diabetes and cardiovascular disease, and patients with nonalcoholic steatohepatitis (NASH) are also at risk of developing cirrhosis, liver failure, and hepatocellular carcinoma. To date, no specific therapy exists for NAFLD/NASH, which has been recognized as one of the major unmet medical needs of the twenty-first century. We recently identified serine/threonine protein kinase (STK)25 as a critical regulator of energy homeostasis and NAFLD progression. Here, we investigated the effect of antisense oligonucleotides (ASOs) targeting Stk25 on the metabolic and molecular phenotype of mice after chronic exposure to dietary lipids. We found that Stk25 ASOs efficiently reversed high-fat diet-induced systemic hyperglycemia and hyperinsulinemia, improved whole-body glucose tolerance and insulin sensitivity, and ameliorated liver steatosis, inflammatory infiltration, apoptosis, hepatic stellate cell activation, and nutritional fibrosis in obese mice. Moreover, Stk25 ASOs suppressed the abundance of liver acetyl-coenzyme A carboxylase (ACC) protein, a key regulator of both lipid oxidation and synthesis, revealing the likely mechanism underlying repression of hepatic fat accumulation by ASO treatment. We also found that STK25 protein levels correlate significantly and positively with NASH development in human liver biopsies, and several common nonlinked single-nucleotide polymorphisms in the human STK25 gene are associated with altered liver fat, supporting a critical role of STK25 in the pathogenesis of NAFLD in humans. Conclusion: Preclinical validation for the metabolic benefit of pharmacologically inhibiting STK25 in the context of obesity is provided. Therapeutic intervention aimed at reducing STK25 function may provide a new strategy for the treatment of patients with NAFLD, type 2 diabetes, and related complex metabolic diseases. (Hepatology Communications 2018;2:69-83).
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| 2. |
- Al-Dury, Samer, et al.
(author)
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Obeticholic acid may increase the risk of gallstone formation in susceptible patients.
- 2019
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In: Journal of hepatology. - : Elsevier BV. - 1600-0641 .- 0168-8278. ; 71:5, s. 986-991
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Journal article (peer-reviewed)abstract
- The nuclear farnesoid X receptor (FXR) agonist obeticholic acid (OCA) has been developed for the treatment of liver diseases. We aimed to determine whether OCA treatment increases the risk of gallstone formation.Twenty patients awaiting laparoscopic cholecystectomy were randomized to treatment with OCA (25 mg/day) or placebo for three weeks before surgery. Serum bile acids (BAs), the BA synthesis marker C4 (7α-hydroxy-cholest-4-ene-3-one), and fibroblast growth factor 19 (FGF19) were measured before and after treatment. During surgery, biopsies from the liver and the whole bile-filled gallbladder were collected for analyses of gene expression, biliary lipids and FGF19.In serum, OCA increased FGF19 (from 95.0±8.5 to 234.4±35.6 ng/L) and decreased C4 (from 31.4±22.8 to 2.8±4.0 nmol/L) and endogenous BAs (from 1312.2±236.2 to 517.7±178.9 nmol/L; all p<0.05). At surgery, BAs in gallbladder bile were lower in OCA patients than controls (OCA, 77.9±53.6 mmol/L; placebo, 196.4±99.3 mmol/L; p<0.01), resulting in a higher cholesterol saturation index (OCA, 2.8±1.1; placebo, 1.8±0.8; p < 0.05). In addition, hydrophobic OCA conjugates accounted for 13.6±5.0% of gallbladder BAs after OCA treatment, resulting in a higher hydrophobicity index (OCA, 0.43±0.09; placebo, 0.34±0.07, p<0.05). Gallbladder FGF19 was three-fold higher in OCA patients than in controls (OCA, 40.3±16.5 ng/L; placebo, 13.5±13.1 ng/mL; p<0.005). Gene expression analysis indicated a mainly gallbladder epithelial origin of FGF19.Our results show for the first time an enrichment of FGF19 in human bile after OCA treatment. In accordance with its murine homolog FGF15, FGF19 might trigger relaxation and filling of the gallbladder which, in combination with increased cholesterol saturation and BA hydrophobicity, would enhance the risk for gallstone development.Obeticholic acid increased human gallbladder cholesterol saturation and bile acid hydrophobicity, both decreasing cholesterol solubility in bile. Together with increased hepatobiliary FGF19, our findings suggest that pharmacological FXR activation increases the risk of gallstone formation.
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| 3. |
- Al-Dury, Samer, et al.
(author)
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Pilot study with IBAT inhibitor A4250 for the treatment of cholestatic pruritus in primary biliary cholangitis
- 2018
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Journal article (peer-reviewed)abstract
- Pruritus is a common complication of cholestatic liver diseases. Inhibition of the ileal bile acid transporter (IBAT/ASBT) may emerge as treatment option. Our aim was to assess tolerability and effect on pruritus of the selective IBAT inhibitor A4250 in patients with primary biliary cholangitis (PBC). Ten patients with PBC and bile acid sequestrant treatment of cholestatic pruritus were after a two-week wash out of the bile acid sequestrant treated with either 0.75 mg (n = 4) or 1.5 mg (n = 5) of A4250 for four weeks. Patients' pruritus was assessed by Visual Analogue Scale (VAS), 5-D itch scale and the pruritus module of the PBC40 questionnaire. Plasma bile acids and 7 alpha-hydroxy-4-cholesten-3-one were measured by UPLC-MS/MS, plasma fibroblast growth factor 19 by ELISA, and serum autotaxin activity by homemade assay. All nine patients exposed to A4250 reported a remarkable improvement in pruritus, until none or mild according to 5-D itch, VAS and PBC40 pruritus. Five patients finished the study prematurely due to abdominal pain (5/5) and diarrhoea (4/5). The high incidence of probably bile acid malabsorption-related diarrhoea and abdominal pain in the bile acid sequestrant pre-treated population indicates that the start dose of A4250 may have been too high for adult patients.
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| 4. |
- Amrutkar, Manoj, et al.
(author)
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STK25 is a critical determinant in nonalcoholic steatohepatitis.
- 2016
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In: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 1530-6860. ; 30:10, s. 3628-3643
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Journal article (peer-reviewed)abstract
- Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and 10-20% of patients with NAFLD progress to nonalcoholic steatohepatitis (NASH) with a high risk of cirrhosis, liver failure, and hepatocellular carcinoma. Despite its high medical importance, the molecular mechanisms controlling progression from simple liver steatosis to NASH remain elusive. We recently identified serine/threonine protein kinase (STK)25 as a critical regulator of ectopic lipid deposition, systemic glucose, and insulin homeostasis. To elucidate the role of STK25 in the development of NASH, we challenged Stk25-knockout and transgenic mice with a methionine and choline-deficient (MCD) diet. We show that Stk25(-/-) mice are protected against MCD-diet-induced NASH, as evidenced by repressed liver steatosis, oxidative damage, inflammation, and fibrosis, whereas Stk25 transgenic mice developed a more severe NASH phenotype, compared with corresponding wild-type littermates. Consistently, NASH features were suppressed in STK25-deficient human hepatocytes cultured in MCD medium, and reciprocally enhanced in STK25-overexpressing cells. We also found a significant positive correlation in human liver biopsies between STK25 expression and NASH development. The study provides evidence for multiple roles of STK25 in NASH pathogenesis and future investigations to address the potential therapeutic relevance of pharmacological STK25 inhibitors in prevention and treatment of NASH are warranted.-Amrutkar, M., Chursa, U., Kern, M., Nuñez-Durán, E., Ståhlman, M., Sütt, S., Borén, J., Johansson, B. R., Marschall, H.-U., Blüher, M., Mahlapuu, M. STK25 is a critical determinant in nonalcoholic steatohepatitis.
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| 5. |
- Baghdasaryan, A., et al.
(author)
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Inhibition of intestinal bile acid absorption improves cholestatic liver and bile duct injury in a mouse model of sclerosing cholangitis
- 2016
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In: Journal of Hepatology. - : Elsevier BV. - 0168-8278. ; 64:3, s. 674-681
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Journal article (peer-reviewed)abstract
- Background and Aims: Approximately 95% of bile acids (BAs) excreted into bile are reabsorbed in the gut and circulate back to the liver for further biliary secretion. Therefore, pharmacological inhibition of the ileal apical sodium-dependent BA transporter (ASBT/SLC10A2) may protect against BA-mediated cholestatic liver and bile duct injury. Methods: Eight week old Mdr2(-/-) (Abcb4(-/-)) mice (model of cholestatic liver injury and sclerosing cholangitis) received either a diet supplemented with A4250 (0.01% w/w) - a highly potent and selective ASBT inhibitor - or a chow diet. Liver injury was assessed biochemically and histologically after 4 weeks of A4250 treatment. Expression profiles of genes involved in BA homeostasis, inflammation and fibrosis were assessed via RT-PCR from liver and ileum homogenates. Intestinal inflammation was assessed by RNA expression profiling and immunohistochemistry. Bile flow and composition, as well as biliary and fecal BA profiles were analyzed after 1 week of ASBT inhibitor feeding. Results: A4250 improved sclerosing cholangitis in Mdr2(-/-) mice and significantly reduced serum alanine aminotransferase, alkaline phosphatase and BAs levels, hepatic expression of proinflammatory (Tnf-alpha, Vcam1, Mcp-1) and pro-fibrogenic (Col1a1, Col1a2) genes and bile duct proliferation (mRNA and immunohistochemistry for cytokeratin 19 (CK19)). Furthermore, A4250 significantly reduced bile flow and biliary BA output, which correlated with reduced Bsep transcription, while Ntcp and Cyp7a1 were induced. Importantly A4250 significantly reduced biliary BA secretion but preserved HCO3- and biliary phospholipid secretion resulting in an increased HCO3-/BA and PL/BA ratio. In addition, A4250 profoundly increased fecal BA excretion without causing diarrhea and altered BA pool composition, resulting in diminished concentrations of primary BAs tauro-beta-muricholic acid and taurocholic acid. Conclusions: Pharmacological ASBT inhibition attenuates cholestatic liver and bile duct injury by reducing biliary BA concentrations in mice. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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| 6. |
- Cansby, Emmelie, 1984, et al.
(author)
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Depletion of protein kinase STK25 ameliorates renal lipotoxicity and protects against diabetic kidney disease.
- 2020
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In: JCI insight. - : American Society for Clinical Investigation. - 2379-3708. ; 5:24
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Journal article (peer-reviewed)abstract
- Diabetic kidney disease (DKD) is the most common cause of severe renal disease worldwide and the single strongest predictor of mortality in diabetes patients. Kidney steatosis has emerged as a critical trigger in the pathogenesis of DKD; however, the molecular mechanism of renal lipotoxicity remains largely unknown. Our recent studies in genetic mouse models, human cell lines, and well-characterized patient cohorts have identified serine/threonine protein kinase (STK)25 as a critical regulator of ectopic lipid storage in several metabolic organs prone to diabetic damage. Here, we demonstrate that overexpression of STK25 aggravates renal lipid accumulation and exacerbates structural and functional kidney injury in a mouse model of DKD. Reciprocally, inhibiting STK25 signaling in mice ameliorates diet-induced renal steatosis and alleviates the development of DKD-associated pathologies. Further, we find that STK25 silencing in human kidney cells protects against lipid deposition as well as oxidative and endoplasmic reticulum stress. Together, our results suggest that STK25 regulates a critical node governing susceptibility to renal lipotoxicity and that STK25 antagonism could mitigate DKD progression.
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| 7. |
- Cansby, Emmelie, 1984, et al.
(author)
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Protein kinase MST3 modulates lipid homeostasis in hepatocytes and correlates with nonalcoholic steatohepatitis in humans.
- 2019
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In: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 1530-6860. ; 33:9, s. 9974-9989
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Journal article (peer-reviewed)abstract
- Ectopic lipid storage in the liver is considered the main risk factor for nonalcoholic steatohepatitis (NASH). Understanding the molecular networks controlling hepatocellular lipid deposition is therefore essential for developing new strategies to effectively prevent and treat this complex disease. Here, we describe a new regulator of lipid partitioning in human hepatocytes: mammalian sterile 20-like (MST) 3. We found that MST3 protein coats lipid droplets in mouse and human liver cells. Knockdown of MST3 attenuated lipid accumulation in human hepatocytes by stimulating β-oxidation and triacylglycerol secretion while inhibiting fatty acid influx and lipid synthesis. We also observed that lipogenic gene expression and acetyl-coenzyme A carboxylase protein abundance were reduced in MST3-deficient hepatocytes, providing insight into the molecular mechanisms underlying the decreased lipid storage. Furthermore, MST3 expression was positively correlated with key features of NASH (i.e., hepatic lipid content, lobular inflammation, and hepatocellular ballooning) in human liver biopsies. In summary, our results reveal a role of MST3 in controlling the dynamic metabolic balance of liver lipid catabolism vs. lipid anabolism. Our findings highlight MST3 as a potential drug target for the prevention and treatment of NASH and related complex metabolic diseases.
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| 8. |
- Cansby, Emmelie, 1984, et al.
(author)
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STK25 Regulates Cardiovascular Disease Progression in a Mouse Model of Hypercholesterolemia
- 2018
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In: Arteriosclerosis Thrombosis and Vascular Biology. - : Ovid Technologies (Wolters Kluwer Health). - 1079-5642 .- 1524-4636. ; 38:8, s. 1723-1737
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Journal article (peer-reviewed)abstract
- Objective Recent cohort studies have shown that nonalcoholic fatty liver disease (NAFLD), and especially nonalcoholic steatohepatitis (NASH), associate with atherosclerosis and cardiovascular disease, independently of conventional cardiometabolic risk factors. However, the mechanisms underlying the pathophysiological link between NAFLD/NASH and cardiovascular disease still remain unclear. Our previous studies have identified STK25 (serine/threonine protein kinase 25) as a critical determinant in ectopic lipid storage, meta-inflammation, and progression of NAFLD/NASH. The aim of this study was to assess whether STK25 is also one of the mediators in the complex molecular network controlling the cardiovascular disease risk. Approach and Results Atherosclerosis was induced in Stk25 knockout and transgenic mice, and their wild-type littermates, by gene transfer of gain-of-function mutant of PCSK9 (proprotein convertase subtilisin/kexin type 9), which induces the downregulation of hepatic LDLR (low-density lipoprotein receptor), combined with an atherogenic western-type diet. We found that Stk25(-/-) mice displayed reduced atherosclerosis lesion area as well as decreased lipid accumulation, macrophage infiltration, collagen formation, and oxidative stress in aortic lesions compared with wild-type littermates, independently from alterations in dyslipidemia. Reciprocally, Stk25 transgenic mice presented aggravated plaque formation and maturation compared with wild-type littermates despite similar levels of fasting plasma cholesterol. We also found that STK25 protein was expressed in all layers of the aorta, suggesting a possible direct role in cardiovascular disease. Conclusions This study provides the first evidence that STK25 plays a critical role in regulation of cardiovascular disease risk and suggests that pharmacological inhibition of STK25 function may provide new possibilities for prevention/treatment of atherosclerosis.
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| 9. |
- Caputo, Mara, et al.
(author)
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Silencing of STE20-type kinase MST3 in mice with antisense oligonucleotide treatment ameliorates diet-induced nonalcoholic fatty liver disease
- 2021
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In: FASEB Journal. - 0892-6638. ; 35:5
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Journal article (peer-reviewed)abstract
- Nonalcoholic fatty liver disease (NAFLD) is emerging as a leading cause of chronic liver disease worldwide. Despite intensive nonclinical and clinical research in this field, no specific pharmacological therapy is currently approved to treat NAFLD, which has been recognized as one of the major unmet medical needs of the 21st century. Our recent studies have identified STE20-type kinase MST3, which localizes to intracellular lipid droplets, as a critical regulator of ectopic fat accumulation in human hepatocytes. Here, we explored whether treatment with Mst3-targeting antisense oligonucleotides (ASOs) can promote hepatic lipid clearance and mitigate NAFLD progression in mice in the context of obesity. We found that administration of Mst3-targeting ASOs in mice effectively ameliorated the full spectrum of high-fat diet-induced NAFLD including liver steatosis, inflammation, fibrosis, and hepatocellular damage. Mechanistically, Mst3 ASOs suppressed lipogenic gene expression, as well as acetyl-CoA carboxylase (ACC) protein abundance, and substantially reduced lipotoxicity-mediated oxidative and endoplasmic reticulum stress in the livers of obese mice. Furthermore, we found that MST3 protein levels correlated positively with the severity of NAFLD in human liver biopsies. In summary, this study provides the first in vivo evidence that antagonizing MST3 signaling is sufficient to mitigate NAFLD progression in conditions of excess dietary fuels and warrants future investigations to assess whether MST3 inhibitors may provide a new strategy for the treatment of patients with NAFLD.
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| 10. |
- Caputo, Mara, et al.
(author)
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STE20-Type Protein Kinase MST4 Controls NAFLD Progression by Regulating Lipid Droplet Dynamics and Metabolic Stress in Hepatocytes
- 2021
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In: Hepatology Communications. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 5:7, s. 1183-1200
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Journal article (peer-reviewed)abstract
- Nonalcoholic fatty liver disease (NAFLD) has emerged as a leading cause of chronic liver disease worldwide, primarily because of the massive global increase in obesity. Despite intense research efforts in this field, the factors that govern the initiation and subsequent progression of NAFLD are poorly understood, which hampers the development of diagnostic tools and effective therapies in this area of high unmet medical need. Here we describe a regulator in molecular pathogenesis of NAFLD: STE20-type protein kinase MST4. We found that MST4 expression in human liver biopsies was positively correlated with the key features of NAFLD (i.e., hepatic steatosis, lobular inflammation, and hepatocellular ballooning). Furthermore, the silencing of MST4 attenuated lipid accumulation in human hepatocytes by stimulating beta-oxidation and triacylglycerol secretion, while inhibiting fatty acid influx and lipid synthesis. Conversely, overexpression of MST4 in human hepatocytes exacerbated fat deposition by suppressing mitochondrial fatty acid oxidation and triacylglycerol efflux, while enhancing lipogenesis. In parallel to these reciprocal alterations in lipid storage, we detected substantially decreased or aggravated oxidative/endoplasmic reticulum stress in human hepatocytes with reduced or increased MST4 levels, respectively. Interestingly, MST4 protein was predominantly associated with intracellular lipid droplets in both human and rodent hepatocytes. Conclusion: Together, our results suggest that hepatic lipid droplet-decorating protein MST4 is a critical regulatory node governing susceptibility to NAFLD and warrant future investigations to address the therapeutic potential of MST4 antagonism as a strategy to prevent or mitigate the development and aggravation of this disease.
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