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Das MK, Savidge B, Pearl JE, Yates T, Miles G, Pareek M, Haldar P, Cooper AM. Altered hepatic metabolic landscape and insulin sensitivity in response to pulmonary tuberculosis. PLoS Pathog 2024; 20:e1012565. [PMID: 39331683 DOI: 10.1371/journal.ppat.1012565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 08/26/2024] [Indexed: 09/29/2024] Open
Abstract
Chronic inflammation triggers development of metabolic disease, and pulmonary tuberculosis (TB) generates chronic systemic inflammation. Whether TB induced-inflammation impacts metabolic organs and leads to metabolic disorder is ill defined. The liver is the master regulator of metabolism and to determine the impact of pulmonary TB on this organ we undertook an unbiased mRNA and protein analyses of the liver in mice with TB and reanalysed published data on human disease. Pulmonary TB led to upregulation of genes in the liver related to immune signalling and downregulation of genes encoding metabolic processes. In liver, IFN signalling pathway genes were upregulated and this was reflected in increased biochemical evidence of IFN signalling, including nuclear location of phosphorylated Stat-1 in hepatocytes. The liver also exhibited reduced expression of genes encoding the gluconeogenesis rate-limiting enzymes Pck1 and G6pc. Phosphorylation of CREB, a transcription factor controlling gluconeogenesis was drastically reduced in the livers of mice with pulmonary TB as was phosphorylation of other glucose metabolism-related kinases, including GSK3a, AMPK, and p42. In support of the upregulated IFN signalling being linked to the downregulated metabolic functions in the liver, we found suppression of gluconeogenic gene expression and reduced CREB phosphorylation in hepatocyte cell lines treated with interferons. The impact of reduced gluconeogenic gene expression in the liver was seen when infected mice were less able to convert pyruvate, a gluconeogenesis substrate, to the same extent as uninfected mice. Infected mice also showed evidence of reduced systemic and hepatic insulin sensitivity. Similarly, in humans with TB, we found that changes in a metabolite-based signature of insulin resistance correlates temporally with successful treatment of active TB and with progression to active TB following exposure. These data support the hypothesis that TB drives interferon-mediated alteration of hepatic metabolism resulting in reduced gluconeogenesis and drives systemic reduction of insulin sensitivity.
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Affiliation(s)
- Mrinal K Das
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
| | - Ben Savidge
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
| | - John E Pearl
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
| | - Thomas Yates
- Diabetes Research Centre, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, University of Leicester and University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Gareth Miles
- Leicester Cancer Research Centre, University of Leicester, Clinical Sciences Building, Leicester, United Kingdom
| | - Manish Pareek
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, University of Leicester and University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
- Department of Infection and HIV Medicine, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Pranabashis Haldar
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, University of Leicester and University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
- NIHR Respiratory Biomedical Research Centre, Leicester, Glenfield Hospital, Groby Road, Leicester, United Kingdom
| | - Andrea M Cooper
- Department of Respiratory Sciences, Leicester TB Research Group, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, University of Leicester and University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
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Yang T, Zhao G, Zhu W, Yu W, Jiang Y, Zhou Y, Li Y. Effect on the splenocyte function of weaned piglets induced by continuous lipopolysaccharide injections. J Vet Res 2024; 68:295-302. [PMID: 38947147 PMCID: PMC11210365 DOI: 10.2478/jvetres-2024-0024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 04/22/2024] [Indexed: 07/02/2024] Open
Abstract
Introduction When piglets are exposed to pathogens for a long period, the immune system organs, among them the spleen, play a major role in combating the stress caused by those pathogens. In the present study, the effect on splenocyte function was investigated in a model of weaned piglets in which stress was induced by multiple low doses of lipopolysaccharide (LPS). Material and Methods Forty-eight 28-day-old piglets were divided into two groups: the LPS group and the control group. During the experimental period of thirteen days, the LPS group was intraperitoneally injected with LPS (100 μg/kg) once per day, and the control group was injected with the same volume of 0.9% sterile saline. On the 1st, 5th, 9th and 13th days, the piglets' spleens were collected for isolating splenocytes. The proliferation ability of splenocytes was evaluated by the cell-counting-kit 8 method. Flow cytometry was used to detect cell cycle stage and apoptosis, and the nitric oxide level of cell supernatant was also tested. Results In the experimental group, the proliferation ability of splenocytes was enhanced, the proportion of cells in the G0/G1 phase was smaller, and cells were promoted to the S and G2/M phases. Meanwhile, apoptosis was suppressed and nitric oxide release upregulated. The results were significantly different between the LPS group and the control group on the 5th and 9th days. Conclusion The difference between the results of one group and those of the other suggest that after the 5th LPS injection, multiple low doses of LPS activated splenocytes and restored the number of splenocytes, which maintained and possibly enhanced the regulation of the immune function of the spleen.
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Affiliation(s)
- Tingyu Yang
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Guotong Zhao
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Wenlu Zhu
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Wanting Yu
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Yijie Jiang
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Yunxiao Zhou
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
| | - Yong Li
- College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang330045, Jiangxi, China
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Wang Y, Qing S, Yang J, Qian D. SCH772984 ameliorates lipopolysaccharide-induced hypoglycemia in mice through reversing MEK/ERK/Foxo1-mediated gluconeogenesis suppression. Can J Physiol Pharmacol 2024; 102:33-41. [PMID: 37944129 DOI: 10.1139/cjpp-2023-0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Lipopolysaccharide (LPS) results in a lethal hypoglycemic response. However, the main molecular mechanism involved in LPS-induced glucose metabolism disorder is poorly understood. This study intends to investigate the signaling pathways involved in LPS-induced hypoglycemia and potential efficacy of extracellular signal-regulated kinase (ERK) inhibitor SCH772984. The effects of LPS and SCH772984 on gluconeogenesis, glucose absorption, and glycogenolysis were evaluated by pyruvate tolerance test, oral glucose tolerance test, and glucagon test, respectively. After a single intraperitoneal injection of 0.5 mg/kg LPS, the mice's blood glucose levels and gluconeogenesis ability were significantly lower than that of control group. Besides, mRNA and protein expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) decreased significantly after LPS treatment. LPS induced the phosphorylation of ERK1/2, MEK1/2 (mitogen-activated protein kinase), and Foxo1 while inhibited Foxo1 expression in the nucleus, indicating an important role of the MEK/ERK/Foxo1 signaling in the inhibition of gluconeogenesis by LPS. Furthermore, SCH772984 elevated blood glucose, increased the G6Pase and PEPCK expression, and inhibited pERK1/2 and pFoxo1 expression in LPS-induced mice. In summary, LPS inhibited gluconeogenesis and induced hypoglycemia through the MEK/ERK/Foxo1 signal pathway, and ERK inhibitor could effectively reverse decreased blood glucose in mice with LPS treatment. These findings provide a novel therapeutic target for LPS-induced hypoglycemia.
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Affiliation(s)
- Yirong Wang
- Department of Pharmacy, The Third People's Hospital of Chengdu, The Second Affiliated Clinical College of Chongqing Medical University, Chengdu 610014, People's Republic of China
| | - Shuyun Qing
- Department of Pharmacy, The Third People's Hospital of Chengdu, The Second Affiliated Clinical College of Chongqing Medical University, Chengdu 610014, People's Republic of China
| | - Jing Yang
- Department of Pharmacy, The Third People's Hospital of Chengdu, The Second Affiliated Clinical College of Chongqing Medical University, Chengdu 610014, People's Republic of China
| | - Dehui Qian
- Department of Cardiology, The Second Affiliated Hospital of Army Medical University, Chongqing 400037, People's Republic of China
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Winn NC, Patel VS, Blair JA, Rodriguez A, Garcia JN, Yang TS, Hasty AH. Deletion of complement factor 5 amplifies glucose intolerance in obese male but not female mice. Am J Physiol Endocrinol Metab 2023; 325:E325-E335. [PMID: 37610411 PMCID: PMC10642989 DOI: 10.1152/ajpendo.00140.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/21/2023] [Accepted: 08/21/2023] [Indexed: 08/24/2023]
Abstract
Complement factor 5 of the innate immune system generates C5a and C5b ligands, which initiate inflammatory and cell lysis events, respectively. C5 activation has been linked with obesity-associated metabolic disorders; however, whether it has a causative role is unclear. We generated a C5 null (C5-/-) mouse using CRISPR-Cas9 gene editing to determine whether loss of C5 improves obesity-linked metabolic dysfunction. Generation of a new mouse model was prompted in part by the observation of off-target gene mutations in commercially available C5-/- lines. Male and female wild-type (WT), heterozygous (Het), and C5-/- mice were fed low-fat diet (LFD) or high-fat diet (HFD) for 22 wk. Body weight gain did not differ between genotypes on LFD or HFD. In lean animals, male C5-/- mice had similar glucose tolerance compared with WT controls; however, in obese conditions, glucose tolerance was worsened in C5-/- compared with controls. In contrast, female mice did not exhibit differences in glucose tolerance between genotypes under either dietary paradigm. Fasting insulin was not different between genotypes, whereas diet-induced obese male C5-/- mice had lower fed insulin concentrations compared with WT controls. No differences in adipose tissue inflammation or adipocyte size were identified between groups. Similarly, susceptibility to fatty liver and hepatic inflammation was similar between WT and C5-/- mice. However, the systemic cytokine response to acute endotoxin exposure was decreased in C5-/- mice. Together, these data suggest that loss of C5 worsens glucose tolerance in obese male but not female mice. Additional work is required to pinpoint the mechanisms by which loss of C5 amplifies glucose intolerance in obesity.NEW & NOTEWORTHY We generated a new mouse model of complement factor 5 deficiency. This work was prompted by a need for improved transgenic mouse lines of C5, due to off-target gene mutations. We find that loss of C5 worsens glucose tolerance in a sex-dependent manner. Though the mechanisms evoking glucose intolerance are not clear, we are confident this model will be useful in interrogating complement activation in obesity-associated diseases.
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Affiliation(s)
- Nathan C Winn
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Vitrag S Patel
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Joslin A Blair
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Alec Rodriguez
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Jamie N Garcia
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Tzushan S Yang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Alyssa H Hasty
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- VA Tennessee Valley Healthcare System, Nashville, Tennessee, United States
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Kinoshita A, Nagata T, Furuya F, Nishizawa M, Mukai E. White-skinned sweet potato (Ipomoea batatas L.) acutely suppresses postprandial blood glucose elevation by improving insulin sensitivity in normal rats. Heliyon 2023; 9:e14719. [PMID: 37025833 PMCID: PMC10070533 DOI: 10.1016/j.heliyon.2023.e14719] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 03/06/2023] [Accepted: 03/15/2023] [Indexed: 03/29/2023] Open
Abstract
Long-term administration of Ipomoea batatas L. (white-skinned sweet potato, WSSP) has been reported to help manage type 2 diabetes mellitus (T2DM) in humans and animals; however, the mechanisms of blood glucose regulation by WSSP remain unclear. Therefore, we aimed to investigate the acute effects of WSSP on blood glucose homeostasis under normal conditions and the underlying mechanisms. Three fractions of WSSP (≤10, 10-50, and >50 kDa) were obtained via ultracentrifugation. Rats were subjected to an oral glucose tolerance test (OGTT) after a single administration of WSSP. The insulin tolerance test (ITT) and pyruvate tolerance test (PTT) were performed to evaluate insulin sensitivity and gluconeogenesis, respectively. Single WSSP administration markedly reduced blood glucose levels as revealed by the OGTT. Serum insulin levels were not increased by WSSP treatment. Blood glucose levels during ITT were significantly reduced due to WSSP treatment. WSSP treatment activated the phosphorylation of Akt, thereby activating insulin signaling in the skeletal muscles and liver. The ≤10 kDa fraction considerably reduced blood glucose levels per the OGTT and ITT. In contrast, gluconeogenesis in PTT and the expression of key enzymes in hepatocytes were suppressed by the >50 kDa fraction. This study demonstrated that WSSP acutely reduced postprandial blood glucose levels by improving insulin sensitivity in skeletal muscles in normal rats, which was attributed to constituents with a molecular weight of ≤10 kDa. Moreover, WSSP treatment suppressed gluconeogenesis in the liver, for which constituents of >50 kDa were responsible. Thus, WSSP can acutely regulate blood glucose homeostasis via multiple mechanisms. Since postprandial hyperglycemia leads to the onset of T2DM, WSSP, as a functional food, may possess potential active compounds that prevent T2DM.
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Al-Yousif N, Rawal S, Jurczak M, Mahmud H, Shah FA. Endogenous Glucose Production in Critical Illness. Nutr Clin Pract 2021; 36:344-359. [PMID: 33682953 DOI: 10.1002/ncp.10646] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Regulation of endogenous glucose production (EGP) by hormonal, neuronal, and metabolic signaling pathways contributes to the maintenance of euglycemia under normal physiologic conditions. EGP is defined by the generation of glucose from substrates through glycogenolysis and gluconeogenesis, usually in fasted states, for local and systemic use. Abnormal increases in EGP are noted in patients with diabetes mellitus type 2, and elevated EGP may also impact the pathogenesis of nonalcoholic fatty liver disease and congestive heart failure. In this narrative review, we performed a literature search in PubMed to identify recently published English language articles characterizing EGP in critical illness. Evidence from preclinical and clinical studies demonstrates that critical illness can disrupt EGP through multiple mechanisms including increased systemic inflammation, counterregulatory hormone and catecholamine release, alterations in the hypothalamic-pituitary axis, insulin resistance, lactic acidosis, and iatrogenic insults such as vasopressors and glucocorticoids administered as part of clinical care. EGP contributes to hyperglycemia in critical illness when abnormally elevated and to hypoglycemia when abnormally depressed, each of which has been independently associated with increased mortality. Increased EGP may also promote protein catabolism that could worsen critical illness myopathy and impede recovery. Better understanding of the mechanisms and factors contributing to dysregulated EGP in critical illness may help in the development of therapeutic strategies that promote euglycemia, reduce intensive care unit-associated catabolism, and improve patient outcomes.
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Affiliation(s)
- Nameer Al-Yousif
- Department of Internal Medicine, UPMC Mercy Hospital, Pittsburgh, Pennsylvania, USA
| | - Sagar Rawal
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael Jurczak
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hussain Mahmud
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Faraaz Ali Shah
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA
- Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Abdelalim EM. Modeling different types of diabetes using human pluripotent stem cells. Cell Mol Life Sci 2021; 78:2459-2483. [PMID: 33242105 PMCID: PMC11072720 DOI: 10.1007/s00018-020-03710-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/19/2020] [Accepted: 11/11/2020] [Indexed: 12/22/2022]
Abstract
Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia as a result of progressive loss of pancreatic β cells, which could lead to several debilitating complications. Different paths, triggered by several genetic and environmental factors, lead to the loss of pancreatic β cells and/or function. Understanding these many paths to β cell damage or dysfunction could help in identifying therapeutic approaches specific for each path. Most of our knowledge about diabetes pathophysiology has been obtained from studies on animal models, which do not fully recapitulate human diabetes phenotypes. Currently, human pluripotent stem cell (hPSC) technology is a powerful tool for generating in vitro human models, which could provide key information about the disease pathogenesis and provide cells for personalized therapies. The recent progress in generating functional hPSC-derived β cells in combination with the rapid development in genomic and genome-editing technologies offer multiple options to understand the cellular and molecular mechanisms underlying the development of different types of diabetes. Recently, several in vitro hPSC-based strategies have been used for studying monogenic and polygenic forms of diabetes. This review summarizes the current knowledge about different hPSC-based diabetes models and how these models improved our current understanding of the pathophysiology of distinct forms of diabetes. Also, it highlights the progress in generating functional β cells in vitro, and discusses the current challenges and future perspectives related to the use of the in vitro hPSC-based strategies.
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Affiliation(s)
- Essam M Abdelalim
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), PO Box 34110, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Education City, Doha, Qatar.
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Anavi S, Tirosh O. iNOS as a metabolic enzyme under stress conditions. Free Radic Biol Med 2020; 146:16-35. [PMID: 31672462 DOI: 10.1016/j.freeradbiomed.2019.10.411] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 12/18/2022]
Abstract
Nitric oxide (NO) is a free radical acting as a cellular signaling molecule in many different biochemical processes. NO is synthesized from l-arginine through the action of the nitric oxide synthase (NOS) family of enzymes, which includes three isoforms: endothelial NOS (eNOS), neuronal NOS (nNOS) and inducible NOS (iNOS). iNOS-derived NO has been associated with the pathogenesis and progression of several diseases, including liver diseases, insulin resistance, obesity and diseases of the cardiovascular system. However, transient NO production can modulate metabolism to survive and cope with stress conditions. Accumulating evidence strongly imply that iNOS-derived NO plays a central role in the regulation of several biochemical pathways and energy metabolism including glucose and lipid metabolism during inflammatory conditions. This review summarizes current evidence for the regulation of glucose and lipid metabolism by iNOS during inflammation, and argues for the role of iNOS as a metabolic enzyme in immune and non-immune cells.
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Affiliation(s)
- Sarit Anavi
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel; Peres Academic Center, Rehovot, Israel
| | - Oren Tirosh
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel.
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Anti-Inflammatory and Antioxidant Properties of Black Mulberry ( Morus nigra L.) in a Model of LPS-Induced Sepsis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:5048031. [PMID: 30524657 PMCID: PMC6247390 DOI: 10.1155/2018/5048031] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/14/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022]
Abstract
Sepsis is a complex disease and is the cause of many deaths worldwide. Sepsis pathogenesis involves a dysregulated inflammatory response with consequent production of inflammatory mediators and reactive species. The production and excessive release of these substances into the systemic circulation trigger various cellular and metabolic alterations that are observed during the disease evolution. Thus, more studies have been carried out to investigate the therapeutic potential of plants such as Morus nigra L., popularly known as black mulberry. Studies have shown that plants belonging to the Morus genus are rich in secondary metabolites such as flavonoids which are associated with important biological activities as antioxidant and anti-inflammatory actions. Based on this context, the objective of our study was to evaluate the anti-inflammatory and antioxidant properties of Morus nigra L. in a sepsis model induced by LPS. Male C57BL/6 mice were distributed in four groups: control, sepsis, sepsis treated with leaf extract of mulberry, and sepsis treated with mulberry pulp. The animals were treated with 100 μL of their respective treatments for twenty-one days. Sepsis was induced at the 21st day with lipopolysaccharide (LPS) by intraperitoneal injection. The animals were euthanized 24 hours after receiving the LPS injection. The data obtained were analyzed in GraphPad Prism 6.0 software. Our results showed that treatment with either extract significantly decreased the number of leukocytes in the bronchoalveolar lavage fluid and serum levels of TNF in septic animals. Regarding the redox status, the treatments significantly decreased the antioxidant activity of the enzyme glutathione peroxidase. Regarding metalloproteinase type 2, it was observed that the treatment with black mulberry pulp was able to significantly reduce the activity of this enzyme concerning the sepsis group. Finally, these results together promoted an increase in the animal's survival that received the black mulberry leaf or pulp extract.
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Meidan E, Kolesnikov Y, Tirosh O. High Fat Diets Composed of Palm Stearin and Olive Oil Equally Exacerbate Liver Inflammatory Damage and Metabolic Stress in Mice. Mol Nutr Food Res 2018; 62:e1700915. [PMID: 29733507 DOI: 10.1002/mnfr.201700915] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 04/22/2018] [Indexed: 12/15/2022]
Abstract
SCOPE People with fatty liver could be subject to acute infections such as sepsis. The aim of the study is to evaluate the effect of high fat diets (HFD) of olive oil and palm stearin on liver inflammation induced by lipopolysaccharides (LPS). METHODS AND RESULTS C57BL/6J male mice were treated with high fat diets with different sources of oils: palm stearin and olive oil for 8 weeks followed by LPS injection. The proinflammatory effect of olive oil was also studied using gavage treatment and IP injection of LPS. Animals fed with HFDs showed an increase in body weight, elevated blood glucose levels, and fatty liver phenotype. HFDs aggravated the effect of LPS treatment to induce inflammatory response compared to low fat diet (LFD) effect. Following HFD supplementation, LPS induced hyperinsulinemia, more liver damage than in animals that consumed LFD. In addition, both gavage and long-term feeding with high lipids in the presence of LPS resulted in inhibition of gluconeogenic genes expression. CONCLUSION HFDs of both monounsaturated and saturated fat potentiated liver inflammation induced by LPS treatment indicate that the total amount of fat consumed is the main proinflammatory factor rather than the type of fat.
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Affiliation(s)
- Elena Meidan
- Institute of Biochemistry, Food Science and Nutrition, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Yula Kolesnikov
- Institute of Biochemistry, Food Science and Nutrition, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
| | - Oren Tirosh
- Institute of Biochemistry, Food Science and Nutrition, Hebrew University of Jerusalem, Rehovot, 7610001, Israel
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Maresin 1 attenuates mitochondrial dysfunction through the ALX/cAMP/ROS pathway in the cecal ligation and puncture mouse model and sepsis patients. J Transl Med 2018; 98:715-733. [PMID: 29467458 DOI: 10.1038/s41374-018-0031-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/31/2022] Open
Abstract
Inflammation always accompanies infection during sepsis. Mitochondrial dysfunction and the role of reactive oxygen species (ROS) produced by mitochondria have been proposed in the pathogenesis of sepsis. Maresins have protective and resolving effects in experimental models of infection. In the present study, we investigated the effects of maresin 1 (MaR1) on mitochondrial function in cecal ligation and puncture (CLP)-induced sepsis and sepsis patients to identify mechanisms underlying maresin 1-mediated stimulation of ROS in mitochondria. We found that treatment with MaR1 significantly inhibited production of cytokines, decreased bacterial load in the peritoneal lavage fluid, reduced the number of neutrophils, decreased lactic acid level and upregulated cyclic AMP (cAMP) concentration, with the outcome of decreased lung injury in CLP-induced sepsis in mice. The effects of MaR1 on downregulation nitric oxide (NOX) activity, improvement CAT and SOD activity to inhibit ROS production in mitochondria was dependent on lipoxin receptor (ALX) and cAMP. Survival rates were significantly increased after the treatment of mice with MaR1. In BMDM stimulated with LPS, MaR1 inhibited the ROS production, downregulated enzyme activity, reduced mtO2 production, increased mitochondrial membrane potential, improved adenosine triphosphate (ATP) content and mitochondrial DNA (mtDNA) copy number. Finally, the effects of MaR1 on ROS production in the blood of healthy volunteers stimulated with LPS or sepsis patients were associated with ALX and cAMP. Taken together, these data suggest that treatment with MaR1 could attenuate mitochondrial dysfunction during sepsis through regulating ROS production.
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Hypoxic Signaling and Cholesterol Lipotoxicity in Fatty Liver Disease Progression. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2548154. [PMID: 29955245 PMCID: PMC6000860 DOI: 10.1155/2018/2548154] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 04/30/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1α (HIF-1α), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1α activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.
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