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Kwon YS, Cho YE, Kim Y, Koh M, Hwang S. Dimethyloxalylglycine Suppresses SREBP1c and Lipogenic Gene Expressions in Hepatocytes Independently of HIF1A. Curr Issues Mol Biol 2024; 46:2386-2397. [PMID: 38534767 DOI: 10.3390/cimb46030151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
Dimethyloxalylglycine (DMOG) is a representative inhibitor of the prolyl hydroxylase domain (PHD), which mediates the degradation of hypoxia-inducible factor-1-alpha (HIF1A). DMOG exerts its pharmacological effects via the canonical pathway that involves PHD inhibition; however, it remains unclear whether DMOG affects lipogenic gene expression in hepatocytes. We aimed to elucidate the effects of DMOG on sterol regulatory element-binding protein-1c (SREBP1c), a master regulator of fatty acid synthesis in hepatocytes. DMOG treatment inhibited SREBP1c mRNA and protein expression in HepG2 and AML12 hepatocytes and reduced the transcript levels of SREBP1c-regulated lipogenic genes. A luciferase reporter assay revealed that DMOG inhibited the transcriptional activity of SREBP1c. Moreover, DMOG suppressed SREBP1c expression in mice liver. Mechanistically, treatment with DMOG enhanced the expression of HIF1A and insulin-induced gene 2 (INSIG2), which inhibits the activation of SREBP1c. However, HIF1A or INSIG2 knockdown failed to reverse the inhibitory effect of DMOG on SREBP1c expression, suggesting a redundant role of HIF1A and INSIG2 in terms of repressing SREBP1c. DMOG did not function through the canonical pathway involving inhibition of SREBP1c by PHD, highlighting the presence of non-canonical pathways that mediate its anti-lipogenic effect.
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Affiliation(s)
- Yong Seong Kwon
- College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea
| | - Ye Eun Cho
- College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea
| | - Yeonsoo Kim
- College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea
| | - Minseob Koh
- Department of Chemistry, Pusan National University, Busan 46241, Republic of Korea
| | - Seonghwan Hwang
- College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea
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2
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Xie D, Liu M, Lin Y, Liu X, Yan H. Silencing of topical proline hydroxylase domain 2 promotes the healing of rat diabetic wounds by phosphorylating AMPK. PLoS One 2023; 18:e0294566. [PMID: 38039326 PMCID: PMC10691724 DOI: 10.1371/journal.pone.0294566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 11/04/2023] [Indexed: 12/03/2023] Open
Abstract
BACKGROUND For diabetic ulcers, the impaired response to hypoxia is a key feature associated with delayed healing. In the early phase of hypoxia, hypoxic signaling activates the AMPK system through direct phosphorylation of the PHD2 pathway, producing a significant endogenous hypoxic protective effect. METHODS Twenty Sprague-Dawley (SD) rats were randomly divided into two groups: treatment (sh-PHD2) and control (sh-Control). Using lentiviral encapsulation of PHD2-shRNA and transfection, the silencing efficiency of PHD2 expression was verified in rat dermal fibroblasts (RDF) and in rat aortic endothelial cells (RAECs). Changes in the ability of RDF and RAECs to proliferate, migrate, and in the rate of ATP production were observed and then tested after inhibition of AMPK phosphorylation using dorsomorphin. The lentiviral preparation was injected directly into the wounds of rats and wound healing was recorded periodically to calculate the healing rate. Wounded tissues were excised after 14 days and the efficiency of PHD2 silencing, as well as the expression of growth factors, was examined using molecular biology methods. Histological examination was performed to assess CD31 expression and therefore determine effects on angiogenesis. RESULTS Lentiviral-encapsulated PHD2-sh-RNA effectively suppressed PHD2 expression and improved the proliferation, migration, and ATP production rate of RDF and RAEC, which were restored to their previous levels after inhibition of AMPK. The rate of wound healing, vascular growth, and expression of growth factors were significantly improved in diabetic-model rats after local silencing of PHD2 expression. CONCLUSION Silencing of PHD2 promoted wound healing in diabetic-model SD rats by activating AMPK phosphorylation.
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Affiliation(s)
- Defu Xie
- Southwest Medical University, No. 1 Section 1, Xianglin Road, Luzhou City, Sichuan Province, 646000, China
- National Key Clinical Construction Specialty, Wound Repair & Regeneration Laboratory, Department of Plastic & Burn Surgery, Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Jiangyang District, Luzhou,Sichuan Province, 646000, China
| | - Mengchang Liu
- Southwest Medical University, No. 1 Section 1, Xianglin Road, Luzhou City, Sichuan Province, 646000, China
- National Key Clinical Construction Specialty, Wound Repair & Regeneration Laboratory, Department of Plastic & Burn Surgery, Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Jiangyang District, Luzhou,Sichuan Province, 646000, China
| | - Yingxi Lin
- Southwest Medical University, No. 1 Section 1, Xianglin Road, Luzhou City, Sichuan Province, 646000, China
- National Key Clinical Construction Specialty, Wound Repair & Regeneration Laboratory, Department of Plastic & Burn Surgery, Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Jiangyang District, Luzhou,Sichuan Province, 646000, China
| | - Xingke Liu
- Southwest Medical University, No. 1 Section 1, Xianglin Road, Luzhou City, Sichuan Province, 646000, China
- National Key Clinical Construction Specialty, Wound Repair & Regeneration Laboratory, Department of Plastic & Burn Surgery, Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Jiangyang District, Luzhou,Sichuan Province, 646000, China
| | - Hong Yan
- Southwest Medical University, No. 1 Section 1, Xianglin Road, Luzhou City, Sichuan Province, 646000, China
- National Key Clinical Construction Specialty, Wound Repair & Regeneration Laboratory, Department of Plastic & Burn Surgery, Affiliated Hospital of Southwest Medical University, No. 25 Taiping Street, Jiangyang District, Luzhou,Sichuan Province, 646000, China
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3
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Wu Z, Xu C, Zheng T, Li Q, Yang S, Shao J, Guan W, Zhang S. A critical role of AMP-activated protein kinase in regulating intestinal nutrient absorption, barrier function, and intestinal diseases. J Cell Physiol 2022; 237:3705-3716. [PMID: 35892164 DOI: 10.1002/jcp.30841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/12/2022] [Accepted: 07/15/2022] [Indexed: 02/06/2023]
Abstract
As one of the most important organs in animals, the intestine is responsible for nutrient absorption and acts as a barrier between the body and the environment. Intestinal physiology and function require the participation of energy. 5'-adenosine monophosphate-activated protein kinase (AMPK), a classical and highly expressed energy regulator in intestinal cells, regulates the process of nutrient absorption and barrier function and is also involved in the therapy of intestinal diseases. Studies have yielded findings that AMPK regulates the absorption of glucose, amino acids, and fatty acids in the intestine primarily by regulating transportation systems, as we detailed here. Moreover, AMPK is involved in the regulation of the intestinal mechanical barrier and immune barrier through manipulating the expression of tight junctions, antimicrobial peptides, and secretory immunoglobulins. In addition, AMPK also participates in the regulation of intestinal diseases, which indicates that AMPK is a promising therapeutic target for intestinal diseases and cancer. In this review, we summarized the current understanding regarding how AMPK regulates intestinal nutrient absorption, barrier function, and intestinal diseases.
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Affiliation(s)
- Zhihui Wu
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Chengfei Xu
- School of Clinical Medicine, Chengdu Medical College, Chengdu, China
| | - Tenghui Zheng
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Qihui Li
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Siwang Yang
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jiayuan Shao
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Wutai Guan
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China.,College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China
| | - Shihai Zhang
- Guangdong Province Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, China.,College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, China
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4
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AMPK-mTOR Signaling and Cellular Adaptations in Hypoxia. Int J Mol Sci 2021; 22:ijms22189765. [PMID: 34575924 PMCID: PMC8465282 DOI: 10.3390/ijms22189765] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/02/2021] [Accepted: 09/06/2021] [Indexed: 12/14/2022] Open
Abstract
Cellular energy is primarily provided by the oxidative degradation of nutrients coupled with mitochondrial respiration, in which oxygen participates in the mitochondrial electron transport chain to enable electron flow through the chain complex (I-IV), leading to ATP production. Therefore, oxygen supply is an indispensable chapter in intracellular bioenergetics. In mammals, oxygen is delivered by the bloodstream. Accordingly, the decrease in cellular oxygen level (hypoxia) is accompanied by nutrient starvation, thereby integrating hypoxic signaling and nutrient signaling at the cellular level. Importantly, hypoxia profoundly affects cellular metabolism and many relevant physiological reactions induce cellular adaptations of hypoxia-inducible gene expression, metabolism, reactive oxygen species, and autophagy. Here, we introduce the current knowledge of hypoxia signaling with two-well known cellular energy and nutrient sensing pathways, AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin complex 1 (mTORC1). Additionally, the molecular crosstalk between hypoxic signaling and AMPK/mTOR pathways in various hypoxic cellular adaptions is discussed.
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5
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Hutami IR, Izawa T, Khurel-Ochir T, Sakamaki T, Iwasa A, Tanaka E. Macrophage Motility in Wound Healing Is Regulated by HIF-1α via S1P Signaling. Int J Mol Sci 2021; 22:ijms22168992. [PMID: 34445695 PMCID: PMC8396560 DOI: 10.3390/ijms22168992] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 12/20/2022] Open
Abstract
Accumulating evidence indicates that the molecular pathways mediating wound healing induce cell migration and localization of cytokines to sites of injury. Macrophages are immune cells that sense and actively respond to disturbances in tissue homeostasis by initiating, and subsequently resolving, inflammation. Hypoxic conditions generated at a wound site also strongly recruit macrophages and affect their function. Hypoxia inducible factor (HIF)-1α is a transcription factor that contributes to both glycolysis and the induction of inflammatory genes, while also being critical for macrophage activation. For the latter, HIF-1α regulates sphingosine 1-phosphate (S1P) to affect the migration, activation, differentiation, and polarization of macrophages. Recently, S1P and HIF-1α have received much attention, and various studies have been performed to investigate their roles in initiating and resolving inflammation via macrophages. It is hypothesized that the HIF-1α/S1P/S1P receptor axis is an important determinant of macrophage function under inflammatory conditions and during disease pathogenesis. Therefore, in this review, biological regulation of monocytes/macrophages in response to circulating HIF-1α is summarized, including signaling by S1P/S1P receptors, which have essential roles in wound healing.
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Affiliation(s)
- Islamy Rahma Hutami
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
- Department of Orthodontics, Faculty of Dentistry, Sultan Agung Islamic University, Semarang 50112, Indonesia
| | - Takashi Izawa
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan
- Correspondence: ; Tel.: +81-86-235-6691; Fax: +81-88-235-6694
| | - Tsendsuren Khurel-Ochir
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Takuma Sakamaki
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Akihiko Iwasa
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
| | - Eiji Tanaka
- Department of Orthodontics and Dentofacial Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8504, Japan; (I.R.H.); (T.K.-O.); (T.S.); (A.I.); (E.T.)
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6
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Liu L, Liu X, Liu M, Xie D, Yan H. Proline hydroxylase domain-containing enzymes regulate calcium levels in cardiomyocytes by TRPA1 ion channel. Exp Cell Res 2021; 407:112777. [PMID: 34389294 DOI: 10.1016/j.yexcr.2021.112777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/01/2021] [Accepted: 08/07/2021] [Indexed: 11/15/2022]
Abstract
The proline hydroxylase domain-containing enzymes (PHDs) acts as cellular oxygen sensors, inducing a series of responses to hypoxia, especially during the regulation of metabolism and energy homeostasis. The increase of Ca2+ in cardiomyocytes, induced by the opening of PHD signaling pathway, is the key initiation signal necessary for the PHD-mediated regulation of the energy metabolism pathway, but the underlying molecular mechanism remains incompletely understood. This study used PHD inhibitors (PHIs) and PHD2-specific RNA interference (PHD2shRNA) to inhibit PHD signals in cardiomyocytes to explore whether transient receptor potential ankyrin 1 (TRPA1) is involved in the regulation of calcium ion influx in the PHD activation pathway associated with to AMP-activated protein kinase (AMPK). The Fluo-3AM probe was used to measure changes in free intracellular calcium ion concentrations, and western blot analysis was used to detect the levels of phosphorylated (P)-AMPK, TRPA1, and P-Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) levels. The PHI-mediated inhibition of PHD resulted in an increase in free Ca2+ fluorescence in cardiomyocytes, which activated AMPK, TRPA1, and CaMKⅡ. The TRPA1 inhibitor HC030031, the CaMKII inhibitor KN93, and a ryanodine inhibitor (Ryanodine) were all able to inhibit the PHI-induced increase in intracellular Ca2+ and AMPK activation. Both PHIs and PHD2shRNA were able to effectively activate CaMKII and TRPA1. However, an inositol 1,4,5-triphosphate receptor (IP3R) inhibitor and the protein kinase A (PKA) inhibitor H89 did not significantly inhibit the PHI-induced increase in intracellular Ca2+ and AMPK activation. These results indicated that PHD might activate the CaMKⅡ pathway through the TRPA1 ion channel, inducing the release of calcium from the sarcoplasmic reticulum through ryanodine receptor 2 (RyR2), activating AMPK to initiate the protective effects of hypoxia in cardiomyocytes.
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Affiliation(s)
- Lan Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Xingke Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Mengchang Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Defu Xie
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Hong Yan
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China.
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7
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Zhao Q, Song P, Zou MH. AMPK and Pulmonary Hypertension: Crossroads Between Vasoconstriction and Vascular Remodeling. Front Cell Dev Biol 2021; 9:691585. [PMID: 34169079 PMCID: PMC8217619 DOI: 10.3389/fcell.2021.691585] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Pulmonary hypertension (PH) is a debilitating and life-threatening disease characterized by increased blood pressure within the pulmonary arteries. Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase that contributes to the regulation of metabolic and redox signaling pathways. It has key roles in the regulation of cell survival and proliferation. The role of AMPK in PH is controversial because both inhibition and activation of AMPK are preventive against PH development. Some clinical studies found that metformin, the first-line antidiabetic drug and the canonical AMPK activator, has therapeutic efficacy during treatment of early-stage PH. Other study findings suggest the use of metformin is preferentially beneficial for treatment of PH associated with heart failure with preserved ejection fraction (PH-HFpEF). In this review, we discuss the "AMPK paradox" and highlight the differential effects of AMPK on pulmonary vasoconstriction and pulmonary vascular remodeling. We also review the effects of AMPK activators and inhibitors on rescue of preexisting PH in animals and include a discussion of gender differences in the response to metformin in PH.
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Affiliation(s)
| | | | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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8
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Poloznikov AA, Nersisyan SA, Hushpulian DM, Kazakov EH, Tonevitsky AG, Kazakov SV, Vechorko VI, Nikulin SV, Makarova JA, Gazaryan IG. HIF Prolyl Hydroxylase Inhibitors for COVID-19 Treatment: Pros and Cons. Front Pharmacol 2021; 11:621054. [PMID: 33584306 PMCID: PMC7878396 DOI: 10.3389/fphar.2020.621054] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
The review analyzes the potential advantages and problems associated with using HIF prolyl hydroxylase inhibitors as a treatment for COVID-19. HIF prolyl hydroxylase inhibitors are known to boost endogenous erythropoietin (Epo) and activate erythropoiesis by stabilizing and activating the hypoxia inducible factor (HIF). Recombinant Epo treatment has anti-inflammatory and healing properties, and thus, very likely, will be beneficial for moderate to severe cases of COVID-19. However, HIF PHD inhibition may have a significantly broader effect, in addition to stimulating the endogenous Epo production. The analysis of HIF target genes reveals that some HIF-targets, such as furin, could play a negative role with respect to viral entry. On the other hand, HIF prolyl hydroxylase inhibitors counteract ferroptosis, the process recently implicated in vessel damage during the later stages of COVID-19. Therefore, HIF prolyl hydroxylase inhibitors may serve as a promising treatment of COVID-19 complications, but they are unlikely to aid in the prevention of the initial stages of infection.
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Affiliation(s)
| | | | - Dmitry M Hushpulian
- P. A. Hertsen Moscow Oncology Research Center, Branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia.,School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Eliot H Kazakov
- Department of Anatomy and Cell Biology, New York Medical College, Valhalla, NY, United States
| | | | - Sergey V Kazakov
- Department of Chemistry and Physical Sciences, Dyson College of Arts and Sciences, Pace University, Pleasantville, NY, United States
| | - Valery I Vechorko
- City Clinical Hospital No 15 Named After O. M. Filatov, Moscow, Russia
| | - Sergey V Nikulin
- Faculty of Biology and Biotechnology, HSE University, Moscow, Russia
| | - Julia A Makarova
- Faculty of Biology and Biotechnology, HSE University, Moscow, Russia
| | - Irina G Gazaryan
- P. A. Hertsen Moscow Oncology Research Center, Branch of the National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia.,Department of Anatomy and Cell Biology, New York Medical College, Valhalla, NY, United States.,Department of Chemistry and Physical Sciences, Dyson College of Arts and Sciences, Pace University, Pleasantville, NY, United States.,Chemical Enzymology Department, M. V. Lomonosov Moscow State University, Moscow, Russia
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9
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Dengler F. Activation of AMPK under Hypoxia: Many Roads Leading to Rome. Int J Mol Sci 2020; 21:ijms21072428. [PMID: 32244507 PMCID: PMC7177550 DOI: 10.3390/ijms21072428] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is known as a pivotal cellular energy sensor, mediating the adaptation to low energy levels by deactivating anabolic processes and activating catabolic processes in order to restore the cellular ATP supply when the cellular AMP/ATP ratio is increased. Besides this well-known role, it has also been shown to exert protective effects under hypoxia. While an insufficient supply with oxygen might easily deplete cellular energy levels, i.e., ATP concentration, manifold other mechanisms have been suggested and are heavily disputed regarding the activation of AMPK under hypoxia independently from cellular AMP concentrations. However, an activation of AMPK preceding energy depletion could induce a timely adaptation reaction preventing more serious damage. A connection between AMPK and the master regulator of hypoxic adaptation via gene transcription, hypoxia-inducible factor (HIF), has also been taken into account, orchestrating their concerted protective action. This review will summarize the current knowledge on mechanisms of AMPK activation under hypoxia and its interrelationship with HIF.
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Affiliation(s)
- Franziska Dengler
- Institute of Veterinary Physiology, University of Leipzig, D-04103 Leipzig, Germany
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10
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Dengler F, Gäbel G. The Fast Lane of Hypoxic Adaptation: Glucose Transport Is Modulated via A HIF-Hydroxylase-AMPK-Axis in Jejunum Epithelium. Int J Mol Sci 2019; 20:ijms20204993. [PMID: 31601024 PMCID: PMC6834319 DOI: 10.3390/ijms20204993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 12/21/2022] Open
Abstract
The intestinal epithelium is able to adapt to varying blood flow and, thus, oxygen availability. Still, the adaptation fails under pathologic situations. A better understanding of the mechanisms underlying the epithelial adaptation to hypoxia could help to improve the therapeutic approach. We hypothesized that the short-term adaptation to hypoxia is mediated via AMP-activated protein kinase (AMPK) and that it is coupled to the long-term adaptation by a common regulation mechanism, the HIF-hydroxylase enzymes. Further, we hypothesized the transepithelial transport of glucose to be part of this short-term adaptation. We conducted Ussing chamber studies using isolated lagomorph jejunum epithelium and cell culture experiments with CaCo-2 cells. The epithelia and cells were incubated under 100% and 21% O2, respectively, with the panhydroxylase inhibitor dimethyloxalylglycine (DMOG) or under 1% O2. We showed an activation of AMPK under hypoxia and after incubation with DMOG by Western blot. This could be related to functional effects like an impairment of Na+-coupled glucose transport. Inhibitor studies revealed a recruitment of glucose transporter 1 under hypoxia, but not after incubation with DMOG. Summing up, we showed an influence of hydroxylase enzymes on AMPK activity and similarities between hypoxia and the effects of hydroxylase inhibition on functional changes.
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Affiliation(s)
- Franziska Dengler
- Institute of Veterinary Physiology, University of Leipzig, 04103 Leipzig, Germany.
| | - Gotthold Gäbel
- Institute of Veterinary Physiology, University of Leipzig, 04103 Leipzig, Germany.
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11
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Wang Z, Chen Z, Jiang Z, Luo P, Liu L, Huang Y, Wang H, Wang Y, Long L, Tan X, Liu D, Jin T, Wang Y, Wang Y, Liao F, Zhang C, Chen L, Gan Y, Liu Y, Yang F, Huang C, Miao H, Chen J, Cheng T, Fu X, Shi C. Cordycepin prevents radiation ulcer by inhibiting cell senescence via NRF2 and AMPK in rodents. Nat Commun 2019; 10:2538. [PMID: 31182708 PMCID: PMC6557849 DOI: 10.1038/s41467-019-10386-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 05/08/2019] [Indexed: 12/13/2022] Open
Abstract
The pathological mechanisms of radiation ulcer remain unsolved and there is currently no effective medicine. Here, we demonstrate that persistent DNA damage foci and cell senescence are involved in radiation ulcer development. Further more, we identify cordycepin, a natural nucleoside analogue, as a potent drug to block radiation ulcer (skin, intestine, tongue) in rats/mice by preventing cell senescence through the increase of NRF2 nuclear expression (the assay used is mainly on skin). Finally, cordycepin is also revealed to activate AMPK by binding with the α1 and γ1 subunit near the autoinhibitory domain of AMPK, then promotes p62-dependent autophagic degradation of Keap1, to induce NRF2 dissociate from Keap1 and translocate to the nucleus. Taken together, our findings identify cordycepin prevents radiation ulcer by inhibiting cell senescence via NRF2 and AMPK in rodents, and activation of AMPK or NRF2 may thus represent therapeutic targets for preventing cell senescence and radiation ulcer.
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Affiliation(s)
- Ziwen Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Zelin Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Zhongyong Jiang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Peng Luo
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Lang Liu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
- Department of Toxicology, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, 550025, Guiyang, China
| | - Yu Huang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
- Department of Toxicology, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, 550025, Guiyang, China
| | - Huilan Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
- Institute of Clinical Medicine, Southwest Medical University, 646000, Luzhou, China
| | - Yu Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Lei Long
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Xu Tan
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Dengqun Liu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Taotao Jin
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Yawei Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Yang Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Fengying Liao
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Chi Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Long Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Yibo Gan
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Yunsheng Liu
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Fan Yang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Chunji Huang
- College of Basic Medical Sciences, Third Military Medical University, 400038, Chongqing, China
| | - Hongming Miao
- College of Basic Medical Sciences, Third Military Medical University, 400038, Chongqing, China
| | - Jieping Chen
- Department of Hematology, Southwest Hospital, Third Military Medical University, 40038, Chongqing, China
| | - Tianmin Cheng
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China
| | - Xiaobing Fu
- Wound Healing and Cell Biology Laboratory, the First Affiliated Hospital, Chinese PLA General Hospital, Trauma Center of Postgraduate Medical College, 100000, Beijing, China.
| | - Chunmeng Shi
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Rocket Force Medicine, Third Military Medical University (Army Medical University), 400038, Chongqing, China.
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12
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Cheng C, Zhuo S, Zhang B, Zhao X, Liu Y, Liao C, Quan J, Li Z, Bode AM, Cao Y, Luo X. Treatment implications of natural compounds targeting lipid metabolism in nonalcoholic fatty liver disease, obesity and cancer. Int J Biol Sci 2019; 15:1654-1663. [PMID: 31360108 PMCID: PMC6643217 DOI: 10.7150/ijbs.33837] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/19/2019] [Indexed: 01/23/2023] Open
Abstract
Metabolic disorders can lead to a scarcity or excess of certain metabolites such as glucose, lipids, proteins, purines, and metal ions, which provide the biochemical foundation and directly contribute to the etiology of metabolic diseases. Nonalcoholic fatty liver disease, obesity, and cancer are common metabolic disorders closely associated with abnormal lipid metabolism. In this review, we first describe the regulatory machinery of lipid metabolism and its deregulation in metabolic diseases. Next, we enumerate and integrate the mechanism of action of some natural compounds, including terpenoids and flavonoids, to ameliorate the development of metabolic diseases by targeting lipid metabolism. Medicinal natural products have an established history of use in health care and therapy. Natural compounds might provide a good source of potential therapeutic agents for treating or preventing metabolic diseases with lipid metabolic abnormalities.
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Affiliation(s)
- Can Cheng
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China
| | - Songming Zhuo
- Department of Respiratory Medicine, Shenzhen Longgang Center Hospital, Shenzhen, Guangdong 518116, PR China
| | - Bo Zhang
- Department of Ultrasound Imaging,Xiangya Hospital,Central South University, Changsha, Hunan 410078, PR China
| | - Xu Zhao
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China
| | - Ying Liu
- Department of Medicine, Hunan Traditional Chinese Medical College, Zhuzhou, Hunan 412000, China
| | - Chaoliang Liao
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China
| | - Jing Quan
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China
| | - Zhenzhen Li
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Ya Cao
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China.,Molecular Imaging Research Center of Central South University, Changsha, Hunan 410078, China
| | - Xiangjian Luo
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Xiangya Hospital, Central South University, Changsha, Hunan 410078, PR China.,Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, Hunan 410078, PR China.,Key Laboratory of Carcinogenesis, Chinese Ministry of Health, Changsha, Hunan 410078,PR China.,Molecular Imaging Research Center of Central South University, Changsha, Hunan 410078, China
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13
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Ren Y, Geng Y, Chen H, Lu ZM, Shi JS, Xu Z. Polysaccharide peptides from Coriolus versicolor: A multi-targeted approach for the protection or prevention of alcoholic liver disease. J Funct Foods 2018. [DOI: 10.1016/j.jff.2017.11.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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14
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Wu J, Guo S, Chen X, Liu W, Zhao M, Zhang L, Su Z, Zhang Y. Yiqi Huoxue prescription can prevent and treat post-MI myocardial remodeling through promoting the expression of AMPK signal pathway. JOURNAL OF TRADITIONAL CHINESE MEDICAL SCIENCES 2017. [DOI: 10.1016/j.jtcms.2017.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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15
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Stoehr A, Yang Y, Patel S, Evangelista AM, Aponte A, Wang G, Liu P, Boylston J, Kloner PH, Lin Y, Gucek M, Zhu J, Murphy E. Prolyl hydroxylation regulates protein degradation, synthesis, and splicing in human induced pluripotent stem cell-derived cardiomyocytes. Cardiovasc Res 2016; 110:346-58. [PMID: 27095734 DOI: 10.1093/cvr/cvw081] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/12/2016] [Indexed: 12/12/2022] Open
Abstract
AIMS Protein hydroxylases are oxygen- and α-ketoglutarate-dependent enzymes that catalyse hydroxylation of amino acids such as proline, thus linking oxygen and metabolism to enzymatic activity. Prolyl hydroxylation is a dynamic post-translational modification that regulates protein stability and protein-protein interactions; however, the extent of this modification is largely uncharacterized. The goals of this study are to investigate the biological consequences of prolyl hydroxylation and to identify new targets that undergo prolyl hydroxylation in human cardiomyocytes. METHODS AND RESULTS We used human induced pluripotent stem cell-derived cardiomyocytes in combination with pulse-chase amino acid labelling and proteomics to analyse the effects of prolyl hydroxylation on protein degradation and synthesis. We identified 167 proteins that exhibit differences in degradation with inhibition of prolyl hydroxylation by dimethyloxalylglycine (DMOG); 164 were stabilized. Proteins involved in RNA splicing such as serine/arginine-rich splicing factor 2 (SRSF2) and splicing factor and proline- and glutamine-rich (SFPQ) were stabilized with DMOG. DMOG also decreased protein translation of cytoskeletal and sarcomeric proteins such as α-cardiac actin. We searched the mass spectrometry data for proline hydroxylation and identified 134 high confidence peptides mapping to 78 unique proteins. We identified SRSF2, SFPQ, α-cardiac actin, and cardiac titin as prolyl hydroxylated. We identified 29 prolyl hydroxylated proteins that showed a significant difference in either protein degradation or synthesis. Additionally, we performed next-generation RNA sequencing and showed that the observed decrease in protein synthesis was not due to changes in mRNA levels. Because RNA splicing factors were prolyl hydroxylated, we investigated splicing ± inhibition of prolyl hydroxylation and detected 369 alternative splicing events, with a preponderance of exon skipping. CONCLUSIONS This study provides the first extensive characterization of the cardiac prolyl hydroxylome and demonstrates that inhibition of α-ketoglutarate hydroxylases alters protein stability, translation, and splicing.
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Affiliation(s)
- Andrea Stoehr
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yanqin Yang
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sajni Patel
- Proteomics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Alicia M Evangelista
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Angel Aponte
- Proteomics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Guanghui Wang
- Proteomics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Poching Liu
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Boylston
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Philip H Kloner
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yongshun Lin
- iPS Cell Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Marjan Gucek
- Proteomics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jun Zhu
- DNA Sequencing and Genomics Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Elizabeth Murphy
- Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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16
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Zhdanov AV, Okkelman IA, Collins FW, Melgar S, Papkovsky DB. A novel effect of DMOG on cell metabolism: direct inhibition of mitochondrial function precedes HIF target gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1254-66. [DOI: 10.1016/j.bbabio.2015.06.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/11/2015] [Accepted: 06/30/2015] [Indexed: 12/17/2022]
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17
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Townley-Tilson WHD, Pi X, Xie L. The Role of Oxygen Sensors, Hydroxylases, and HIF in Cardiac Function and Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:676893. [PMID: 26491535 PMCID: PMC4600863 DOI: 10.1155/2015/676893] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 03/26/2015] [Accepted: 04/10/2015] [Indexed: 12/14/2022]
Abstract
Ischemic heart disease is the leading cause of death worldwide. Oxygen-sensing proteins are critical components of the physiological response to hypoxia and reperfusion injury, but the role of oxygen and oxygen-mediated effects is complex in that they can be cardioprotective or deleterious to the cardiac tissue. Over 200 oxygen-sensing proteins mediate the effects of oxygen tension and use oxygen as a substrate for posttranslational modification of other proteins. Hydroxylases are an essential component of these oxygen-sensing proteins. While a major role of hydroxylases is regulating the transcription factor HIF, we investigate the increasing scope of hydroxylase substrates. This review discusses the importance of oxygen-mediated effects in the heart as well as how the field of oxygen-sensing proteins is expanding, providing a more complete picture into how these enzymes play a multifaceted role in cardiac function and disease. We also review how oxygen-sensing proteins and hydroxylase function could prove to be invaluable in drug design and therapeutic targets for heart disease.
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Affiliation(s)
- W. H. Davin Townley-Tilson
- Department of Medicine, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xinchun Pi
- Department of Medicine, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Liang Xie
- Department of Medicine, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
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18
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Zheng L, Kelly CJ, Colgan SP. Physiologic hypoxia and oxygen homeostasis in the healthy intestine. A Review in the Theme: Cellular Responses to Hypoxia. Am J Physiol Cell Physiol 2015; 309:C350-60. [PMID: 26179603 DOI: 10.1152/ajpcell.00191.2015] [Citation(s) in RCA: 295] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent years, the intestinal mucosa has proven to be an intriguing organ to study tissue oxygenation. The highly vascularized lamina propria juxtaposed to an anaerobic lumen containing trillions of metabolically active microbes results in one of the most austere tissue microenvironments in the body. Studies to date have determined that a healthy mucosa contains a steep oxygen gradient along the length of the intestine and from the lumen to the serosa. Advances in technology have allowed multiple independent measures and indicate that, in the healthy mucosa of the small and large intestine, the lumen-apposed epithelia experience Po2 conditions of <10 mmHg, so-called physiologic hypoxia. This unique physiology results from a combination of factors, including countercurrent exchange blood flow, fluctuating oxygen demands, epithelial metabolism, and oxygen diffusion into the lumen. Such conditions result in the activation of a number of hypoxia-related signaling processes, including stabilization of the transcription factor hypoxia-inducible factor. Here, we review the principles of mucosal oxygen delivery, metabolism, and end-point functional responses that result from this unique oxygenation profile.
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Affiliation(s)
- Leon Zheng
- Department of Medicine and Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
| | - Caleb J Kelly
- Department of Medicine and Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
| | - Sean P Colgan
- Department of Medicine and Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado
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19
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Burns TA, Watts MR, Weber PS, McCutcheon LJ, Geor RJ, Belknap JK. Effect of dietary nonstructural carbohydrate content on activation of 5'-adenosine monophosphate-activated protein kinase in liver, skeletal muscle, and digital laminae of lean and obese ponies. J Vet Intern Med 2014; 28:1280-8. [PMID: 24750267 PMCID: PMC4857936 DOI: 10.1111/jvim.12356] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/13/2013] [Accepted: 03/05/2014] [Indexed: 01/16/2023] Open
Abstract
Background In EMS‐associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5′‐Adenosine‐monophosphate‐activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR. Hypothesis/Objectives To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge. Animals Twenty‐two mixed‐breed ponies. Methods Immunohistochemistry and immunoblotting for total AMPK and phospho(P)‐AMPK and RT‐qPCR for AMPK‐responsive genes were performed on laminar, liver, and skeletal muscle samples collected after a 7‐day feeding protocol in which ponies stratified on body condition score (BCS; obese or lean) were fed either a low‐CHO diet (ESC + starch, approximately 7% DM; n = 5 obese, 5 lean) or a high‐CHO diet (ESC + starch, approximately 42% DM; n = 6 obese, 6 lean). Results 5′‐Adenosine‐monophosphate‐activated protein kinase was immunolocalized to laminar keratinocytes, dermal constituents, and hepatocytes. A high‐CHO diet resulted in significantly decreased laminar [P‐AMPK] in lean ponies (P = .03), but no changes in skeletal muscle (lean, P = .33; obese, P = .43) or liver (lean, P = .84; obese, P = .13) [P‐AMPK]. An inverse correlation existed between [blood glucose] and laminar [P‐AMPK] in obese ponies on a high‐CHO diet. Conclusions and Clinical Importance Laminar tissue exhibited a normal response to a high‐CHO diet (decreased [P‐AMPK]), whereas this response was not observed in liver and skeletal muscle in both lean (skeletal muscle, P = .33; liver, P = .84) and obese (skeletal muscle, P = .43; liver, P = .13) ponies.
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Affiliation(s)
- T A Burns
- The Ohio State University College of Veterinary Medicine, Columbus, OH
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20
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Ward JBJ, Keely SJ, Keely SJ. Oxygen in the regulation of intestinal epithelial transport. J Physiol 2014; 592:2473-89. [PMID: 24710059 DOI: 10.1113/jphysiol.2013.270249] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The transport of fluid, nutrients and electrolytes to and from the intestinal lumen is a primary function of epithelial cells. Normally, the intestine absorbs approximately 9 l of fluid and 1 kg of nutrients daily, driven by epithelial transport processes that consume large amounts of cellular energy and O2. The epithelium exists at the interface of the richly vascularised mucosa, and the anoxic luminal environment and this steep O2 gradient play a key role in determining the expression pattern of proteins involved in fluid, nutrient and electrolyte transport. However, the dynamic nature of the splanchnic circulation necessitates that the epithelium can evoke co-ordinated responses to fluctuations in O2 availability, which occur either as a part of the normal digestive process or as a consequence of several pathophysiological conditions. While it is known that hypoxia-responsive signals, such as reactive oxygen species, AMP-activated kinase, hypoxia-inducible factors, and prolyl hydroxylases are all important in regulating epithelial responses to altered O2 supply, our understanding of the molecular mechanisms involved is still limited. Here, we aim to review the current literature regarding the role that O2 plays in regulating intestinal transport processes and to highlight areas of research that still need to be addressed.
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Affiliation(s)
- Joseph B J Ward
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Simon J Keely
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle NSW, Australia
| | - Stephen J Keely
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
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21
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Wu C, Guo Y, Su Y, Zhang X, Luan H, Zhang X, Zhu H, He H, Wang X, Sun G, Sun X, Guo P, Zhu P. Cordycepin activates AMP-activated protein kinase (AMPK) via interaction with the γ1 subunit. J Cell Mol Med 2013; 18:293-304. [PMID: 24286368 PMCID: PMC3930416 DOI: 10.1111/jcmm.12187] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 10/11/2013] [Indexed: 12/22/2022] Open
Abstract
Cordycepin is a bioactive component of the fungus Cordyceps militaris. Previously, we showed that cordycepin can alleviate hyperlipidemia through enhancing the phosphorylation of AMP-activated protein kinase (AMPK), but the mechanism of this stimulation is unknown. Here, we investigated the potential mechanisms of cordycepin-induced AMPK activation in HepG2 cells. Treatment with cordycepin largely reduced oleic acid (OA)-elicited intracellular lipid accumulation and increased AMPK activity in a dose-dependent manner. Cordycepin-induced AMPK activation was not accompanied by changes in either the intracellular levels of AMP or the AMP/ATP ratio, nor was it influenced by calmodulin-dependent protein kinase kinase (CaMKK) inhibition; however, this activation was significantly suppressed by liver kinase B1 (LKB1) knockdown. Molecular docking, fluorescent and circular dichroism measurements showed that cordycepin interacted with the γ1 subunit of AMPK. Knockdown of AMPKγ1 by siRNA substantially abolished the effects of cordycepin on AMPK activation and lipid regulation. The modulating effects of cordycepin on the mRNA levels of key lipid regulatory genes were also largely reversed when AMPKγ1 expression was inhibited. Together, these data suggest that cordycepin may inhibit intracellular lipid accumulation through activation of AMPK via interaction with the γ1 subunit.
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Affiliation(s)
- Chongming Wu
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
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22
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Zhang GG, Cai HQ, Li YH, Sui YB, Zhang JS, Chang JR, Ning M, Wu Y, Tang CS, Qi YF, Yin XH. Ghrelin protects heart against ERS-induced injury and apoptosis by activating AMP-activated protein kinase. Peptides 2013; 48:156-65. [PMID: 23994559 DOI: 10.1016/j.peptides.2013.08.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/12/2013] [Accepted: 08/12/2013] [Indexed: 12/29/2022]
Abstract
Ghrelin, the endogenous ligand of growth hormone secretagogue receptor (GHS-R), is a cardioprotective peptide. In our previous work, we have revealed that ghrelin could protect heart against ischemia/reperfusion (I/R) injury by inhibiting endoplasmic reticulum stress (ERS), which contributes to many heart diseases. In current study, using both in vivo and in vitro models, we investigated how ghrelin inhibits myocardial ERS. In the in vivo rat heart injury model induced by isoproterenol (ISO), we found that exogenous ghrelin could alleviate heart dysfunction, reduce myocardial injury and apoptosis and inhibit the excessive myocardial ERS induced by ISO. More importantly, the activation of AMP-activated protein kinase (AMPK) was observed. To explore the role of AMPK activation in ERS inhibition by ghrelin, we set up two in vitro ERS models by exposing cultured rat cardiomyocytes to tunicamycin(Tm) or dithiothreitol (DTT). In both models, compared with Tm or DTT treatment alone, pre-incubation cardiomyocytes with ghrelin significantly activated AMPK, reversed the upregulation of the ERS markers, C/EBP-homologous protein (CHOP) and cleaved caspase-12, and reduced apoptosis of cardiomyocytes. Further, we found that the ERS inhibitory and anti-apoptotic actions induced by ghrelin were blocked by an AMPK inhibitor. To investigate how ghrelin activates AMPK, selective antagonist of GHS-R1a and inhibitor of Ca(2+)/Calmodulin-dependent protein kinase kinase (CaMKK) were added, respectively, before ghrelin pre-incubation, and we found that AMPK activation was prevented and the ERS inhibitory and anti-apoptotic actions of ghrelin were blocked. In conclusion, ghrelin could protect heart against ERS-induced injury and apoptosis, at least partially through a GHS-R1a/CaMKK/AMPK pathway.
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Affiliation(s)
- Gai-Gai Zhang
- Department of Geriatrics and Gerontology, Beijing Huaxin Hospital, the First Affiliated Hospital of Tsinghua University, Beijing 100016, China.
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Shizu R, Shindo S, Yoshida T, Numazawa S. Cross-talk between constitutive androstane receptor and hypoxia-inducible factor in the regulation of gene expression. Toxicol Lett 2013; 219:143-50. [PMID: 23528251 DOI: 10.1016/j.toxlet.2013.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 03/12/2013] [Accepted: 03/15/2013] [Indexed: 11/24/2022]
Abstract
Hypoxia inducible factor (HIF) and 5'-AMP-activated protein kinase are often activated under similar physiological conditions. Constitutive androstane receptor (CAR) translocates into the nucleus in accordance with 5'-AMP-activated protein kinase and thus confers transactivation. The aim of the present study was to investigate a possible link between CAR and HIFα. Phenobarbital (PB), a typical CAR activator, increased the gene expression of HIF-target genes in the livers of mice, including erythropoietin, heme oxygenase-1 and vascular endothelial growth factor-a. PB induced an accumulation of nuclear HIF-1α and an increase in the HIF-responsive element-mediated transactivation in HepG2 cells. Cobalt chloride, a typical HIF activator, induced the gene expression of CAR-target genes, including cyp2b9 and cyp2b10, an accumulation of nuclear CAR and an increase in the PB-responsive enhancer module-mediated transactivation in the mouse liver. Immunoprecipitation-immunoblot and chromatin immunoprecipitation analyses suggest that CAR binds to the PB-responsive enhancer module with HIF-1α in the liver of untreated mice and that the complex dissociates upon PB treatment. Taken together these results suggest that CAR and HIF-α interact and reciprocally modulate the functions of each other.
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Affiliation(s)
- Ryota Shizu
- Division of Toxicology, Department of Pharmacology, Toxicology and Therapeutics, Showa University School of Pharmacy, Tokyo, Japan
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24
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Zou L, Zhu-Mauldin X, Marchase RB, Paterson AJ, Liu J, Yang Q, Chatham JC. Glucose deprivation-induced increase in protein O-GlcNAcylation in cardiomyocytes is calcium-dependent. J Biol Chem 2012; 287:34419-31. [PMID: 22908225 PMCID: PMC3464547 DOI: 10.1074/jbc.m112.393207] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 08/16/2012] [Indexed: 11/06/2022] Open
Abstract
The posttranslational modification of nuclear and cytosolic proteins by O-linked β-N-acetylglucosamine (O-GlcNAc) has been shown to play an important role in cellular response to stress. Although increases in O-GlcNAc levels have typically been thought to be substrate-driven, studies in several transformed cell lines reported that glucose deprivation increased O-GlcNAc levels by a number of different mechanisms. A major goal of this study therefore was to determine whether in primary cells, such as neonatal cardiomyocytes, glucose deprivation increases O-GlcNAc levels and if so by what mechanism. Glucose deprivation significantly increased cardiomyocyte O-GlcNAc levels in a time-dependent manner and was associated with decreased O-GlcNAcase (OGA) but not O-GlcNAc transferase (OGT) protein. This response was unaffected by either the addition of pyruvate as an alternative energy source or by the p38 MAPK inhibitor SB203580. However, the response to glucose deprivation was blocked completely by glucosamine, but not by inhibition of OGA with 2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate. Interestingly, the CaMKII inhibitor KN93 also significantly reduced the response to glucose deprivation. Lowering extracellular Ca(2+) with EGTA or blocking store operated Ca(2+) entry with SKF96365 also attenuated the glucose deprivation-induced increase in O-GlcNAc. In C2C12 and HEK293 cells both glucose deprivation and heat shock increased O-GlcNAc levels, and CaMKII inhibitor KN93 attenuated the response to both stresses. These results suggest that increased intracellular calcium and subsequent activation of CaMKII play a key role in regulating the stress-induced increase in cellular O-GlcNAc levels.
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Affiliation(s)
- Luyun Zou
- From the Division of Molecular and Cellular Pathology, Department of Pathology
| | | | | | - Andrew J. Paterson
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and
| | - Jian Liu
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019
| | - Qinglin Yang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019
| | - John C. Chatham
- From the Division of Molecular and Cellular Pathology, Department of Pathology
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