| 1. |
- Cansby, Emmelie, 1984, et al.
(författare)
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Silencing of STE20-type kinase STK25 in human aortic endothelial and smooth muscle cells is atheroprotective
- 2022
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 5, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies highlight the importance of lipotoxic damage in aortic cells as the major pathogenetic contributor to atherosclerotic disease. Since the STE20-type kinase STK25 has been shown to exacerbate ectopic lipid storage and associated cell injury in several metabolic organs, we here investigate its role in the main cell types of vasculature. We depleted STK25 by small interfering RNA in human aortic endothelial and smooth muscle cells exposed to oleic acid and oxidized LDL. In both cell types, the silencing of STK25 reduces lipid accumulation and suppresses activation of inflammatory and fibrotic pathways as well as lowering oxidative and endoplasmic reticulum stress. Notably, in smooth muscle cells, STK25 inactivation hinders the shift from a contractile to a synthetic phenotype. Together, we provide several lines of evidence that antagonizing STK25 signaling in human aortic endothelial and smooth muscle cells is atheroprotective, highlighting this kinase as a new potential therapeutic target for atherosclerotic disease.
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| 2. |
- Caputo, Mara, et al.
(författare)
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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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Ingår i: FASEB Journal. - 0892-6638. ; 35:5
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Caputo, Mara, et al.
(författare)
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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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Ingår i: Hepatology Communications. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 5:7, s. 1183-1200
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Kumar Anand, Sumit, et al.
(författare)
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Inhibition of MAP4K4 signaling initiates metabolic reprogramming to protect hepatocytes from lipotoxic damage
- 2022
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Ingår i: Journal of Lipid Research. - : Elsevier BV. - 0022-2275. ; 63:7
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Tidskriftsartikel (refereegranskat)abstract
- The primary hepatic consequence of obesity is non-alcoholic fatty liver disease (NAFLD), affecting about 25% of the global adult population. Non-alcoholic steatohepatitis (NASH) is a severe form of NAFLD characterized by liver lipid accumulation, inflammation, and hepatocyte ballooning, with a different degree of hepatic fibrosis. In the light of rapidly increasing prevalence of NAFLD and NASH, there is an urgent need for improved understanding of the molecular pathogenesis of these diseases. The aim of this study was to decipher the possible role of STE20-type kinase MAP4K4 in the regulation of he-patocellular lipotoxicity and susceptibility to NAFLD. We found that MAP4K4 mRNA expression in human liver biopsies was positively correlated with key hallmarks of NAFLD (i.e., liver steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis). We also found that the silencing of MAP4K4 suppressed lipid deposition in human he-patocytes by stimulating beta-oxidation and tri-acylglycerol secretion, while attenuating fatty acid influx and lipid synthesis. Furthermore, down -regulation of MAP4K4 markedly reduced the glycolysis rate and lowered incidences of oxidative/ endoplasmic reticulum stress. In parallel, we observed suppressed JNK and ERK and increased AKT phosphorylation in MAP4K4-deficient hep-atocytes. Together, these results provide the first experimental evidence supporting the potential involvement of STE20-type kinase MAP4K4 as a component of the hepatocellular lipotoxic milieu promoting NAFLD susceptibility.
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| 5. |
- Kurhe, Yeshwant, et al.
(författare)
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Antagonizing STK25 Signaling Suppresses the Development of Hepatocellular Carcinoma Through Targeting Metabolic, Inflammatory, and Pro-Oncogenic Pathways
- 2022
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Ingår i: Cellular and Molecular Gastroenterology and Hepatology. - : Elsevier BV. - 2352-345X. ; 13:2, s. 405-423
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Tidskriftsartikel (refereegranskat)abstract
- Y BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is one of the most fatal and fastest-growing cancers. Recently, nonalcoholic steatohepatitis (NASH) has been recognized as a major catalyst for HCC. Thus, additional research is critically needed to identify mechanisms involved in NASHinduced hepatocarcinogenesis, to advance the prevention and treatment of NASH-driven HCC. Because the sterile 20-type kinase serine/threonine kinase 25 (STK25) exacerbates NASH-related phenotypes, we investigated its role in HCC development and aggravation in this study. METHODS: Hepatocarcinogenesis was induced in the context of NASH in Stk25 knockout and wild-type mice by combining chemical procarcinogens and a dietary challenge. In the first cohort, a single injection of diethylnitrosamine was combined with a high-fat diet-feeding. In the second cohort, chronic administration of carbon tetrachloride was combined with a choline-deficient L-amino-acid-defined diet. To study the cell-autonomous mode of action of STK25, we silenced this target in the human hepatocarcinoma cell line HepG2 by small interfering RNA. RESULTS: In both mouse models of NASH-driven HCC, the livers from Stk25(-/-) mice showed a markedly lower tumor burden compared with wild-type controls. We also found that genetic depletion of STK25 in mice suppressed liver tumor growth through reduced hepatocellular apoptosis and decreased compensatory proliferation, by a mechanism that involves protection against hepatic lipotoxicity and inactivation of STAT3, ERK1/2, and p38 signaling. Consistently, silencing of STK25 suppressed proliferation, apoptosis, migration, and invasion in HepG2 cells, which was accompanied by lower expression of the markers of epithelial-mesenchymal transition and autophagic flux. CONCLUSIONS: This study provides evidence that antagonizing STK25 signaling hinders the development of NASH-related HCC and provides an impetus for further analysis of STK25 as a therapeutic target for NASH-induced HCC treatment in human beings.
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| 6. |
- Sarma, Partha Pratim, et al.
(författare)
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Pharmacologically active chemical composite of Musa balbisiana ameliorates oxidative stress, mitochondrial cellular respiration, and thereby metabolic dysfunction
- 2022
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Ingår i: JOURNAL OF FOOD BIOCHEMISTRY. - : Hindawi Limited. - 0145-8884 .- 1745-4514. ; 46:9
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Tidskriftsartikel (refereegranskat)abstract
- The ripe fruit pulp of different Musa species is known for its excellent source of nutrient contents. Musa balbisiana (MB) is one such variety of Musa species, mainly found in the southern part of Asia, especially in the North-eastern part of India, remains unexplored despite its continuous use by the local traditional healers. The present study focuses on identifying and quantifying the active chemicals present in the ripe fruit pulp of Musa balbisiana (RFPMB) to understand its combined efficacy and nutritional benefit to control human metabolic complications specially related to diabetes and cardiovascular disorder. Characterization and confirmation through targeted LC-MS and HPLC-PDA based assays followed by quantitative analysis led us to identify the major bioactive compounds in RFPMB as shikimic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, sinapic acid, caffeic acid, syringic acid, chlorogenic acid, trans-cinnamic acid, and two essential fatty acids; linolenic acid and linoleic acid. The ripe fruit pulp is further analyzed to understand the nutritional and mineral content and found a substantial presence of calcium and potassium (15.74 +/- 0.43 and 395.20 +/- 9.5 mg/100 g of raw pulp, respectively) compared to other reported varieties. The active portion of RFPMB reduces the production of ROS, the expression of inflammatory marker genes TNF-alpha and TGF-beta, and accelerates the mitochondrial oxygen consumption rate (OCR) by enhancing the basal respiration, maximal respiration, and ATP production capacity of the targeted cells. The present study concluded that, a particular phytopharmaceutical composition of RFPMB with 11-biomarker compounds might be an efficacious formulation for developing a value-added nutraceutical product in managing metabolic complications and its related oxidative stress. Practical applications This study has provided the prior information regarding the potential nutraceutical and phytochemical advantages of Musa balbisiana (MB) fruit pulp over other reported banana varieties. The HPLC-based quantification will give a clear understanding of the food values in comparison of bioactive compounds present in the active fraction of RFPMB, which can be an effective phytopharmaceutical in combating metabolic disorders and oxidative stress. Overall this study will help to commercialize a value-added product from this variety of banana with proper scientific validation.
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| 7. |
- Xia, Ying, et al.
(författare)
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Silencing of STE20-type kinase TAOK1 confers protection against hepatocellular lipotoxicity through metabolic rewiring
- 2023
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Ingår i: Hepatology communications.. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: NAFLD has become the leading cause of chronic liver disease worldwide afflicting about one quarter of the adult population. NASH is a severe subtype of NAFLD, which in addition to hepatic steatosis connotes liver inflammation and hepatocyte ballooning. In light of the exponentially increasing prevalence of NAFLD, it is imperative to gain a better understanding of its molecular pathogenesis. The aim of this study was to examine the potential role of STE20-type kinase TAOK1 -a hepatocellular lipid droplet-associated protein-in the regulation of liver lipotoxicity and NAFLD etiology. Methods: The correlation between TAOK1 mRNA expression in liver biopsies and the severity of NAFLD was evaluated in a cohort of 62 participants. Immunofluorescence microscopy was applied to describe the subcellular localization of TAOK1 in human and mouse hepatocytes. Metabolic reprogramming and oxidative/endoplasmic reticulum stress were investigated in immortalized human hepatocytes, where TAOK1 was overexpressed or silenced by small interfering RNA, using functional assays, immunofluorescence microscopy, and colorimetric analysis. Migration, invasion, and epithelial-mesenchymal transition were examined in TAOK1-deficient human hepatoma-derived cells. Alterations in hepatocellular metabolic and pro-oncogenic signaling pathways were assessed by immunoblotting. Results: We observed a positive correlation between the TAOK1 mRNA abundance in human liver biopsies and key hallmarks of NAFLD (i.e., hepatic steatosis, inflammation, and ballooning). Furthermore, we found that TAOK1 protein fully colocalized with intracellular lipid droplets in human and mouse hepatocytes. The silencing of TAOK1 alleviated lipotoxicity in cultured human hepatocytes by accelerating lipid catabolism (mitochondrial beta-oxidation and triacylglycerol secretion), suppressing lipid anabolism (fatty acid influx and lipogenesis), and mitigating oxidative/endoplasmic reticulum stress, and the opposite changes were detected in TAOK1-overexpressing cells. We also found decreased proliferative, migratory, and invasive capacity, as well as lower epithelial-mesenchymal transition in TAOK1-deficient human hepatoma-derived cells. Mechanistic studies revealed that TAOK1 knockdown inhibited ERK and JNK activation and repressed acetyl-CoA carboxylase (ACC) protein abundance in human hepatocytes. Conclusions: Together, we provide the first experimental evidence supporting the role of hepatic lipid droplet-decorating kinase TAOK1 in NAFLD development through mediating fatty acid partitioning between anabolic and catabolic pathways, regulating oxidative/endoplasmic reticulum stress, and modulating metabolic and pro-oncogenic signaling.
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