1
|
Zarembska E, Ślusarczyk K, Wrzosek M. The Implication of a Polymorphism in the Methylenetetrahydrofolate Reductase Gene in Homocysteine Metabolism and Related Civilisation Diseases. Int J Mol Sci 2023; 25:193. [PMID: 38203363 PMCID: PMC10779094 DOI: 10.3390/ijms25010193] [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] [Received: 11/27/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the one-carbon cycle. This enzyme is essential for the metabolism of methionine, folate, and RNA, as well as for the production of proteins, DNA, and RNA. MTHFR catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to its active form, 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine. Numerous variants of the MTHFR gene have been recognised, among which the C677T variant is the most extensively studied. The C677T polymorphism, which results in the conversion of valine to alanine at codon 222, is associated with reduced activity and an increased thermolability of the enzyme. Impaired MTHFR efficiency is associated with increased levels of homocysteine, which can contribute to increased production of reactive oxygen species and the development of oxidative stress. Homocysteine is acknowledged as an independent risk factor for cardiovascular disease, while chronic inflammation serves as the common underlying factor among these issues. Many studies have been conducted to determine whether there is an association between the C677T polymorphism and an increased risk of cardiovascular disease, hypertension, diabetes, and overweight/obesity. There is substantial evidence supporting this association, although several studies have concluded that the polymorphism cannot be reliably used for prediction. This review examines the latest research on MTHFR polymorphisms and their correlation with cardiovascular disease, obesity, and epigenetic regulation.
Collapse
Affiliation(s)
- Emilia Zarembska
- Student Scientific Association “Farmakon”, Department of Biochemistry and Pharmacogenomics, Medical University of Warsaw, 1 Banacha St., 02-097 Warsaw, Poland
| | - Klaudia Ślusarczyk
- Student Scientific Association “Farmakon”, Department of Biochemistry and Pharmacogenomics, Medical University of Warsaw, 1 Banacha St., 02-097 Warsaw, Poland
- Department of Medical Genetics, Institute of Mother and Child, 17a Kasprzaka St., 01-211 Warsaw, Poland
| | - Małgorzata Wrzosek
- Department of Biochemistry and Pharmacogenomics, Medical University of Warsaw, 1 Banacha St., 02-097 Warsaw, Poland
- Centre for Preclinical Research, Medical University of Warsaw, 1B Banacha St., 02-097 Warsaw, Poland
| |
Collapse
|
2
|
Zhao R, Cao L, Gu WJ, Li L, Chen ZZ, Xiang J, Zhou ZY, Xu B, Zang WD, Zhou XY, Cao J, Sun K, Zhao JY. Gestational palmitic acid suppresses embryonic GATA-binding protein 4 signaling and causes congenital heart disease. Cell Rep Med 2023; 4:100953. [PMID: 36809766 PMCID: PMC10040382 DOI: 10.1016/j.xcrm.2023.100953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/13/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023]
Abstract
Dysregulated maternal fatty acid metabolism increases the risk of congenital heart disease (CHD) in offspring with an unknown mechanism, and the effect of folic acid fortification in preventing CHD is controversial. Using gas chromatography coupled to either a flame ionization detector or mass spectrometer (GC-FID/MS) analysis, we find that the palmitic acid (PA) concentration increases significantly in serum samples of pregnant women bearing children with CHD. Feeding pregnant mice with PA increased CHD risk in offspring and cannot be rescued by folic acid supplementation. We further find that PA promotes methionyl-tRNA synthetase (MARS) expression and protein lysine homocysteinylation (K-Hcy) of GATA4 and results in GATA4 inhibition and abnormal heart development. Targeting K-Hcy modification by either genetic ablation of Mars or using N-acetyl-L-cysteine (NAC) decreases CHD onset in high-PA-diet-fed mice. In summary, our work links maternal malnutrition and MARS/K-Hcy with the onset of CHD and provides a potential strategy in preventing CHD by targeting K-Hcy other than folic acid supplementation.
Collapse
Affiliation(s)
- Rui Zhao
- Institute for Developmental and Regenerative Cardiovascular Medicine, MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Li Cao
- Obstetrics & Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences, and Department of Materials Science, Fudan University, Shanghai 200438, China
| | - Wen-Jun Gu
- Obstetrics & Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences, and Department of Materials Science, Fudan University, Shanghai 200438, China
| | - Lei Li
- Department of Anatomy and Neuroscience Research Institute, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Zhong-Zhong Chen
- Urogenital Development Research Center, Department of Urology, Shanghai Children's Hospital School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Jie Xiang
- Obstetrics & Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences, and Department of Materials Science, Fudan University, Shanghai 200438, China
| | - Ze-Yu Zhou
- Obstetrics & Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences, and Department of Materials Science, Fudan University, Shanghai 200438, China
| | - Bo Xu
- Department of Anesthesiology, General Hospital of Southern Theatre Command of People's Liberation Army, Guangzhou 510030, China
| | - Wei-Dong Zang
- Department of Anatomy and Neuroscience Research Institute, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Xiang-Yu Zhou
- Obstetrics & Gynecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences, and Department of Materials Science, Fudan University, Shanghai 200438, China.
| | - Jing Cao
- Department of Anatomy and Neuroscience Research Institute, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
| | - Kun Sun
- Institute for Developmental and Regenerative Cardiovascular Medicine, MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
| | - Jian-Yuan Zhao
- Institute for Developmental and Regenerative Cardiovascular Medicine, MOE-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; Department of Anatomy and Neuroscience Research Institute, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China; International Human Phenome Institutes (Shanghai), Shanghai 200433, China.
| |
Collapse
|
3
|
Ravi R, Ragavachetty Nagaraj N, Subramaniam Rajesh B. Effect of advanced glycation end product on paraoxonase 2 expression: Its impact on endoplasmic reticulum stress and inflammation in HUVECs. Life Sci 2020; 246:117397. [DOI: 10.1016/j.lfs.2020.117397] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/31/2020] [Accepted: 02/02/2020] [Indexed: 12/23/2022]
|
4
|
Mei X, Qi D, Zhang T, Zhao Y, Jin L, Hou J, Wang J, Lin Y, Xue Y, Zhu P, Liu Z, Huang L, Nie J, Si W, Ma J, Ye J, Finnell RH, Saiyin H, Wang H, Zhao J, Zhao S, Xu W. Inhibiting MARSs reduces hyperhomocysteinemia-associated neural tube and congenital heart defects. EMBO Mol Med 2020; 12:e9469. [PMID: 32003121 PMCID: PMC7059139 DOI: 10.15252/emmm.201809469] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 12/16/2019] [Accepted: 12/19/2019] [Indexed: 02/05/2023] Open
Abstract
Hyperhomocysteinemia is a common metabolic disorder that imposes major adverse health consequences. Reducing homocysteine levels, however, is not always effective against hyperhomocysteinemia-associated pathologies. Herein, we report the potential roles of methionyl-tRNA synthetase (MARS)-generated homocysteine signals in neural tube defects (NTDs) and congenital heart defects (CHDs). Increased copy numbers of MARS and/or MARS2 were detected in NTD and CHD patients. MARSs sense homocysteine and transmit its signal by inducing protein lysine (N)-homocysteinylation. Here, we identified hundreds of novel N-homocysteinylated proteins. N-homocysteinylation of superoxide dismutases (SOD1/2) provided new mechanistic insights for homocysteine-induced oxidative stress, apoptosis and Wnt signalling deregulation. Elevated MARS expression in developing and proliferating cells sensitizes them to the effects of homocysteine. Targeting MARSs using the homocysteine analogue acetyl homocysteine thioether (AHT) reversed MARS efficacy. AHT lowered NTD and CHD onsets in retinoic acid-induced and hyperhomocysteinemia-induced animal models without affecting homocysteine levels. We provide genetic and biochemical evidence to show that MARSs are previously overlooked genetic determinants and key pathological factors of hyperhomocysteinemia, and suggest that MARS inhibition represents an important medicinal approach for controlling hyperhomocysteinemia-associated diseases.
Collapse
|
5
|
Shokri Y, Variji A, Nosrati M, Khonakdar-Tarsi A, Kianmehr A, Kashi Z, Bahar A, Bagheri A, Mahrooz A. Importance of paraoxonase 1 (PON1) as an antioxidant and antiatherogenic enzyme in the cardiovascular complications of type 2 diabetes: Genotypic and phenotypic evaluation. Diabetes Res Clin Pract 2020; 161:108067. [PMID: 32044348 DOI: 10.1016/j.diabres.2020.108067] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/13/2020] [Accepted: 02/06/2020] [Indexed: 12/12/2022]
Abstract
Oxidant-antioxidant imbalance is involved in the etiology of different diseases, including cardiovascular diseases (CVDs), liver disorders, kidney diseases, cancers and diabetes mellitus. Antioxidant enzymes play a key role in striking an oxidant-antioxidant balance. Moreover, paraoxonase 1 (PON1) is an antioxidant enzyme that binds with high-density lipoprotein (HDL) in the circulation, and antioxidant and antiaterogenic properties of this lipoprotein are significantly associated with PON1. Research suggests PON1 contributes to the pathogenesis of certain human diseases such as type 2 diabetes (T2D). The association between PON1 and T2D appear to be reciprocal so that the disease significantly decreases PON1 levels and in turn, the genetics of PON1 may have a role the risk of susceptibility to T2D. Several factors that reduce the activity and concentration of PON1 in patients with T2D include increased glycation and loss-of-function polymorphisms. The genotypic and phenotypic evaluations of PON1 are therefore crucial for assessing the risk of cardiovascular complications in these patients, and strategies for increasing or restoring PON1 levels are useful for reducing or preventing their cardiovascular complications as their main cause of mortality. The present review aimed at discussing and emphasizing the key role of PON1 in T2D as a silent and dangerous disease.
Collapse
Affiliation(s)
- Yasaman Shokri
- Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Atena Variji
- Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mani Nosrati
- Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abbas Khonakdar-Tarsi
- Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Anvarsadat Kianmehr
- Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran; Department of Medical Biotechnology, Faculty of Advanced Madical Technologies, Golestan University of Medical Sciences, Gorgan, Iran
| | - Zahra Kashi
- Diabetes Research Center, Imam Teaching Hospital, Mazandaran University of Medical Sciences, Sari, Iran
| | - Adele Bahar
- Diabetes Research Center, Imam Teaching Hospital, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abouzar Bagheri
- Department of Clinical Biochemistry and Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Abdolkarim Mahrooz
- Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Diabetes Research Center, Imam Teaching Hospital, Mazandaran University of Medical Sciences, Sari, Iran.
| |
Collapse
|
6
|
Trentini A, Bellini T, Bonaccorsi G, Cavicchio C, Hanau S, Passaro A, Cervellati C. Sex difference: an important issue to consider in epidemiological and clinical studies dealing with serum paraoxonase-1. J Clin Biochem Nutr 2019. [PMID: 31138960 DOI: 10.3164/jcbn.18.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the influence of sex on serum paraoxonase-1 (PON1) activities and on its relationship with cardiovascular disease risk factors such as overall and central obesity. Arylesterase and lactonase activities of PON1 were assessed in 374 women and 92 men. Both arylesterase and lactonase activities were significantly higher in women compared to men (p<0.001), irrespectively of confounders such as high density lipoprotein-cholesterol, age, smoking and body mass index or waist circumference. Sex also strongly influenced the interplay between PON1 and both fat measures, with only the arylesterase showing a significant and independent inverse correlation with the former parameter (r = -0.248, p<0.001) and the risk of overall obesity (odds ratio: 0.559, 95% confidence interval: 0.340-0.919) in women, but not in men; conversely, neither of the two activities remained associated with waist circumference in men or women after full adjustment. Noteworthy, the association between arylesterase and BMI in the female subsample was significant among women younger than forty-five years (r = -0.453, p<0.001, R 2 = 0.207). In conclusion, our study suggests that sex might chiefly influence PON1 activity and its contribution to cardiovascular disease risk. Further studies are needed to confirm and clarify our preliminary findings.
Collapse
Affiliation(s)
- Alessandro Trentini
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Tiziana Bellini
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy.,University Center for Studies on Gender Medicine, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Gloria Bonaccorsi
- University Center for Studies on Gender Medicine, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy.,Department of Morphology, Surgery and Experimental Medicine, Menopause and Osteoporosis Centre, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Carlotta Cavicchio
- Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Stefania Hanau
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Angelina Passaro
- Department of Medical Sciences, Internal Medicine and CardioRespiratory Section, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Carlo Cervellati
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| |
Collapse
|
7
|
AnandBabu K, Sen P, Angayarkanni N. Oxidized LDL, homocysteine, homocysteine thiolactone and advanced glycation end products act as pro-oxidant metabolites inducing cytokine release, macrophage infiltration and pro-angiogenic effect in ARPE-19 cells. PLoS One 2019; 14:e0216899. [PMID: 31086404 PMCID: PMC6516731 DOI: 10.1371/journal.pone.0216899] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/30/2019] [Indexed: 02/03/2023] Open
Abstract
Age-related Macular Degeneration (AMD) is one of the major vision-threatening diseases of the eye. Oxidative stress is one of the key factors in the onset and progression of AMD. In this study, metabolites associated with AMD pathology more so at the systemic level namely, oxidized LDL (oxLDL), homocysteine (Hcy), homocysteine thiolactone (HCTL), advanced glycation end product (AGE) were evaluated for their pro-oxidant nature in a localized ocular environment based on in vitro studies in human retinal pigment epithelial cells (ARPE-19 cells). Human ARPE-19 cells were treated with pro-oxidants 50 μg/mL oxLDL, 500 μM Hcy, 500 nM HCTL, 100 μg/mL AGE, 200 μM H2O2 and 200 μM H2O2 with and without pre-treatment of 5 mM N-acetyl cysteine (NAC). The cytokines IL-6, IL-8 and vascular endothelial growth factor (VEGF) secreted from ARPE-19 cells exposed to pro-oxidants were estimated by ELISA. In vitro angiogenesis assay was performed with conditioned media of the pro-oxidant treated ARPE-19 cells in Geltrex-Matrigel coated 96-well plate. The human acute monocytic leukemia cell line (THP-1) was differentiated into macrophages and its migration in response to conditioned media of ARPE-19 cells insulted with the pro-oxidants was studied by transwell migration assay. Western blot was performed to detect the protein expression of Bax, Bcl-2 and NF-κB to assess apoptotic changes. The compounds involved in the study showed a significant increase in reactive oxygen species (ROS) generation in ARPE-19 cells (oxLDL; Hcy; AGE: p < 0.001 and HCTL: p < 0.05). NAC pre-treatment significantly lowered the oxidative stress brought about by pro-oxidants as seen by lowered ROS and MDA levels in the cells. Treatment with pro-oxidants significantly increased the secretion of IL-6 (oxLDL: p < 0.05; Hcy, HCTL and AGE: p < 0.01) and IL-8 cytokines (oxLDL: p < 0.05; HCTL: p <. 001 and AGE: p < 0.01) in ARPE-19 cells. Serum samples of AMD patients (n = 23) revealed significantly higher IL-6 and IL-8 levels compared to control subjects (n = 23) (IL6: p < 0.01 and IL8: p < 0.05). The pro-oxidants also promoted VEGF secretion by ARPE-19 cells compared to untreated control (oxLDL: p < 0.001; Hcy: p < 0.01; HCTL and AGE: p < 0.05). In vitro angiogenesis assay showed that the conditioned media significantly increased the tube formation in RF/6A endothelial cells. Transwell migration assay revealed significant infiltration of macrophages in response to pro-oxidants. We further demonstrated that the pro-oxidants increased the Bax/Bcl-2 ratio and increased the NF-κB activation resulting in pro-apoptotic changes in ARPE-19 cells. Thus, oxLDL, Hcy, HCTL and AGE act as pro-oxidant metabolites in RPE that promote AMD through oxidative stress, inflammation, chemotaxis and neovascularization.
Collapse
Affiliation(s)
- Kannadasan AnandBabu
- R.S. Mehta Jain Department of Biochemistry and Cell Biology, KBIRVO, Vision Research Foundation, Sankara Nethralaya, Chennai, India
- School of Chemical and Biotechnology, SASTRA University, Thanjavur, India
| | - Parveen Sen
- Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, India
| | - Narayanasamy Angayarkanni
- R.S. Mehta Jain Department of Biochemistry and Cell Biology, KBIRVO, Vision Research Foundation, Sankara Nethralaya, Chennai, India
- * E-mail: ,
| |
Collapse
|
8
|
Jakubowski H. Homocysteine Modification in Protein Structure/Function and Human Disease. Physiol Rev 2019; 99:555-604. [PMID: 30427275 DOI: 10.1152/physrev.00003.2018] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B12, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.
Collapse
Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health , Newark, New Jersey ; and Department of Biochemistry and Biotechnology, Poznań University of Life Sciences , Poznań , Poland
| |
Collapse
|
9
|
Trentini A, Bellini T, Bonaccorsi G, Cavicchio C, Hanau S, Passaro A, Cervellati C. Sex difference: an important issue to consider in epidemiological and clinical studies dealing with serum paraoxonase-1. J Clin Biochem Nutr 2019; 64:250-256. [PMID: 31138960 PMCID: PMC6529704 DOI: 10.3164/jcbn.18-73] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/18/2018] [Indexed: 02/05/2023] Open
Abstract
The aim of this study was to evaluate the influence of sex on serum paraoxonase-1 (PON1) activities and on its relationship with cardiovascular disease risk factors such as overall and central obesity. Arylesterase and lactonase activities of PON1 were assessed in 374 women and 92 men. Both arylesterase and lactonase activities were significantly higher in women compared to men (p<0.001), irrespectively of confounders such as high density lipoprotein-cholesterol, age, smoking and body mass index or waist circumference. Sex also strongly influenced the interplay between PON1 and both fat measures, with only the arylesterase showing a significant and independent inverse correlation with the former parameter (r = −0.248, p<0.001) and the risk of overall obesity (odds ratio: 0.559, 95% confidence interval: 0.340–0.919) in women, but not in men; conversely, neither of the two activities remained associated with waist circumference in men or women after full adjustment. Noteworthy, the association between arylesterase and BMI in the female subsample was significant among women younger than forty-five years (r = −0.453, p<0.001, R2 = 0.207). In conclusion, our study suggests that sex might chiefly influence PON1 activity and its contribution to cardiovascular disease risk. Further studies are needed to confirm and clarify our preliminary findings.
Collapse
Affiliation(s)
- Alessandro Trentini
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Tiziana Bellini
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy.,University Center for Studies on Gender Medicine, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Gloria Bonaccorsi
- University Center for Studies on Gender Medicine, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy.,Department of Morphology, Surgery and Experimental Medicine, Menopause and Osteoporosis Centre, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Carlotta Cavicchio
- Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Stefania Hanau
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Angelina Passaro
- Department of Medical Sciences, Internal Medicine and CardioRespiratory Section, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| | - Carlo Cervellati
- Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy
| |
Collapse
|
10
|
Resveratrol exhibits an effect on attenuating retina inflammatory condition and damage of diabetic retinopathy via PON1. Exp Eye Res 2018; 181:356-366. [PMID: 30503749 DOI: 10.1016/j.exer.2018.11.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 11/07/2018] [Accepted: 11/25/2018] [Indexed: 12/18/2022]
Abstract
Diabetic retinopathy (DR), an obstacle of the visual microvascular system, is a serious complication of diabetic patients. Paraoxonase 1 (PON1) has been extensively evaluated as a genetic candidate for diabetic microvascular complications, and PON1 is associated with DR. In this study, the biological functions of PON1 and its related proteins were determined via gene ontology (GO) enrichment analysis; we demonstrated that treatment with resveratrol alleviated retinal inflammatory activities to evaluate its protective effects on streptozotocin (STZ)-induced diabetic rats and high-glucose (HG) stimulated rat retinal endothelial cells (RRECs). The GO enrichment analysis suggested that PON1 may regulate inflammatory responses and microvascular complications in DR. In an in vivo study, resveratrol significantly recovered the insulin level and PON1 expression and activity, as well as clearly reduced the retinal vascular permeability, retinal AGEs, LDL, Ox-LDL, caspase3 activity, retinal damage, IL-1β, IL-6, TNFα, VEGF, IFNγ and MCP-1 in STZ-diabetic rats. Moreover, resveratrol reduced the caspase3 activity and Ox-LDL expression in HG stimulated RRECs. However, its protective effect was a deficiency in PON1-silenced RRECs. PON1 is a pivotal modulator in the role of resveratrol in reversing the RREC damage induced by HG. Furthermore, we found that resveratrol exhibits an effect on attenuating the retinal inflammatory condition and damage of DR via PON1. Our study suggests that resveratrol-induced PON1 in the retina may be a promising therapeutic strategy to prevent diabetes-related retinopathy.
Collapse
|
11
|
Ramasamy K, Mishra C. Commentary: Role of hyperhomocysteinemia in proliferative diabetic retinopathy: A case-control study. Indian J Ophthalmol 2018; 66:1440. [PMID: 30249829 PMCID: PMC6173018 DOI: 10.4103/ijo.ijo_1442_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Kim Ramasamy
- Department of Vitreo Retina, Aravind Eye Hospital, Madurai, Tamil Nadu, India,Correspondence to: Prof. Kim Ramasamy, Department of Vitreo Retina, Aravind Eye Hospital, Madurai, Tamil Nadu, India. E-mail:
| | - Chitaranjan Mishra
- Department of Vitreo Retina, Aravind Eye Hospital, Madurai, Tamil Nadu, India
| |
Collapse
|
12
|
Gałczyński K, Bełtowski J, Nowakowski Ł, Vasilevska D, Rechberger T, Semczuk A. Serum paraoxonase 1 activity and protein N-homocysteinylation in primary human endometrial cancer. Tumour Biol 2018; 40:1010428318797869. [PMID: 30178714 DOI: 10.1177/1010428318797869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Paraoxonase 1 plays an important role in protection from oxidative stress and also decomposes homocysteine thiolactone, the toxic metabolite of homocysteine. A limited number of reports evaluated the role of paraoxonase 1 in women affected by female genital tract neoplasms, including endometrial cancer. This study aimed to analyze the paraoxonase activity in the group of endometrial cancer patients (n = 48) who underwent primary surgery and to compare the data available with a well-matched control group (n = 30). Due to the role of paraoxonase 1 in the metabolism of homocysteine (Hcy) thiolactone, the amount of Hcy-thiolactone as well as total serum Hcy concentrations was also measured. Serum paraoxonase 1 activity toward synthetic substrates, paraoxon and phenyl acetate, in the study group was significantly lower compared to the control one. The mean paraoxonase 1 activity toward homocysteine thiolactone tended to be lower in the endometrial cancer group but this difference was not significant. There was no relationship between endometrial cancer and Q192R polymorphism of PON1 assessed by the dual substrate method. No differences in paraoxonase 1 activity between endometrial cancer subgroups according to clinico-pathological features were detected. Total serum homocysteine and protein-bound homocysteine thiolactone did not differ between control and cancer groups. In conclusion, reduced paraoxonase 1 activity suggests diminished important antioxidant mechanisms during the development of primary endometrial cancers in humans. PON1 Q192R polymorphism is not associated with the risk of endometrial cancer. Despite lower paraoxonase 1 activity, homocysteine concentration, and protein N-homocysteinylation in endometrial cancers do not differ from matched controls.
Collapse
Affiliation(s)
| | - Jerzy Bełtowski
- 2 Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | - Łukasz Nowakowski
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
| | - Danuta Vasilevska
- 3 Centre of Obstetrics and Gynecology, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania
| | - Tomasz Rechberger
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
| | - Andrzej Semczuk
- 1 IInd Department of Gynecology, Medical University of Lublin, Lublin, Poland
| |
Collapse
|
13
|
Homme RP, Singh M, Majumder A, George AK, Nair K, Sandhu HS, Tyagi N, Lominadze D, Tyagi SC. Remodeling of Retinal Architecture in Diabetic Retinopathy: Disruption of Ocular Physiology and Visual Functions by Inflammatory Gene Products and Pyroptosis. Front Physiol 2018; 9:1268. [PMID: 30233418 PMCID: PMC6134046 DOI: 10.3389/fphys.2018.01268] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 08/21/2018] [Indexed: 02/06/2023] Open
Abstract
Diabetic patients suffer from a host of physiological abnormalities beyond just those of glucose metabolism. These abnormalities often lead to systemic inflammation via modulation of several inflammation-related genes, their respective gene products, homocysteine metabolism, and pyroptosis. The very nature of this homeostatic disruption re-sets the overall physiology of diabetics via upregulation of immune responses, enhanced retinal neovascularization, upregulation of epigenetic events, and disturbances in cells' redox regulatory system. This altered pathophysiological milieu can lead to the development of diabetic retinopathy (DR), a debilitating vision-threatening eye condition with microvascular complications. DR is the most prevalent cause of irreversible blindness in the working-age adults throughout the world as it can lead to severe structural and functional remodeling of the retina, decreasing vision and thus diminishing the quality of life. In this manuscript, we attempt to summarize recent developments and new insights to explore the very nature of this intertwined crosstalk between components of the immune system and their metabolic orchestrations to elucidate the pathophysiology of DR. Understanding the multifaceted nature of the cellular and molecular factors that are involved in DR could reveal new targets for effective diagnostics, therapeutics, prognostics, preventive tools, and finally strategies to combat the development and progression of DR in susceptible subjects.
Collapse
Affiliation(s)
- Rubens P. Homme
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Mahavir Singh
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Avisek Majumder
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY, United States
| | - Akash K. George
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Kavya Nair
- Eye and Vision Science Laboratory, Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Harpal S. Sandhu
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY, United States
- Kentucky Lions Eye Center, University of Louisville School of Medicine, Louisville, KY, United States
| | - Neetu Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - David Lominadze
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| | - Suresh C Tyagi
- Department of Physiology, University of Louisville School of Medicine, Louisville, KY, United States
| |
Collapse
|
14
|
Lactonase Activity and Lipoprotein-Phospholipase A 2 as Possible Novel Serum Biomarkers for the Differential Diagnosis of Autism Spectrum Disorders and Rett Syndrome: Results from a Pilot Study. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:5694058. [PMID: 29317982 PMCID: PMC5727786 DOI: 10.1155/2017/5694058] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/27/2017] [Accepted: 11/05/2017] [Indexed: 12/27/2022]
Abstract
Rett syndrome (RTT) and autism spectrum disorders (ASDs) are not merely expression of brain dysfunction but also reflect the perturbation of physiological/metabolic homeostasis. Accordingly, both disorders appear to be associated with increased vulnerability to toxicants produced by redox imbalance, inflammation, and pollution, and impairment of systemic-detoxifying agents could play a role in the exacerbation of these detrimental processes. To check this hypothesis, the activities of two mechanistically related blood-based enzymes, paraoxonase-1 (arylesterase, paraoxonase, and lactonase), and lipoprotein-associated phospholipase A2 (Lp-PLA2) were measured in the serum of 79 ASD and 95 RTT patients, and 77 controls. Lactonase and Lp-PLA2 showed a similar trend characterized by significantly lower levels of both activities in ASD compared to controls and RTT (p < 0.001 for all pairwise comparisons). Noteworthy, receiving operator curve (ROC) analysis revealed that lactonase and, mostly, Lp-PLA2 were able to discriminate between ASD and controls (lactonase: area under curve, AUC = 0.660; Lp-PLA2, AUC = 0.780), and, considering only females, between ASD and RTT (lactonase, AUC = 0.714; Lp-PLA2, AUC = 0.881). These results suggest that lactonase and, especially, Lp-PLA2 activities might represent novel candidate biomarkers for ASD.
Collapse
|
15
|
Cervellati C, Bonaccorsi G, Trentini A, Valacchi G, Sanz JM, Squerzanti M, Spagnolo M, Massari L, Crivellari I, Greco P, Parladori R, Passaro A, Ricci G. Paraoxonase, arylesterase and lactonase activities of paraoxonase-1 (PON1) in obese and severely obese women. Scandinavian Journal of Clinical and Laboratory Investigation 2017; 78:18-24. [PMID: 29168398 DOI: 10.1080/00365513.2017.1405274] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Obesity is independently associated with disturbances in lipid and lipoprotein metabolism, oxidative stress, and is a well-established independent risk factor for cardiovascular diseases (CVD). Human paraoxonase 1 (PON1) is a pleotropic high-density lipoprotein (HDL)-associated enzyme with antioxidant and anti-inflammatory proprieties that have been suggested to contribute to the athero-protective function of the lipoprotein. The aim of this study was to investigate whether obesity is associated with PON1 activity and whether this association is influenced by oxidative stress, inflammation and HDL cholesterol (HDL-C) concentration. The promiscuous activities, arylesterase and paraoxonase, and the putative physiological activity, lactonase, of PON1 were assessed in the serum of 214 obese and severely obese, 101 overweight and 129 normal-weight women. Levels of high-sensitivity C-reactive protein (hs-CRP), hydroperoxides (by-products of lipid oxidative damage) and lipid profiles were also evaluated. Arylesterase activity was the only activity that significantly differed across the groups (ANOVA, p < .01), with the greatest decrease observed in individuals with body mass index (BMI) > 40 kg/m2 compared to controls (p < .001). This activity was also inversely, although weakly (r = -0.160, p < .001) correlated with the BMI, and the association was independent of age and levels of oxidative stress and inflammation, but not of HDL-C concentration. In conclusion, our results suggest that the apparent obesity-associated decrement of PON1 activity might simply reflect the decrease in concentration of its plasmatic carrier.
Collapse
Affiliation(s)
- Carlo Cervellati
- a Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics , University of Ferrara , Ferrara , Italy
| | - Gloria Bonaccorsi
- b Department of Morphology, Surgery and Experimental Medicine, Menopause and Osteoporosis Centre , University of Ferrara , Ferrara , Italy.,c Department of Morphology, Surgery and Experimental Medicine, Section of Obstetrics and Gynecology , University of Ferrara , Ferrara , Italy
| | - Alessandro Trentini
- a Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics , University of Ferrara , Ferrara , Italy
| | - Giuseppe Valacchi
- d Department Life Sciences and Biotechnology , University of Ferrara , Ferrara , Italy.,e Department of Animal Sciences, Plants for Human Health Institute, NC Research Campus , NC State University , Kannapolis , NC , USA
| | - Juana M Sanz
- f Department of Medical Science, Section of Internal Medicine, Gerontology and Geriatrics , University of Ferrara , Ferrara , Italy
| | - Monica Squerzanti
- a Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics , University of Ferrara , Ferrara , Italy
| | - Manuela Spagnolo
- a Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics , University of Ferrara , Ferrara , Italy
| | - Leo Massari
- b Department of Morphology, Surgery and Experimental Medicine, Menopause and Osteoporosis Centre , University of Ferrara , Ferrara , Italy
| | - Ilaria Crivellari
- a Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics , University of Ferrara , Ferrara , Italy
| | - Pantaleo Greco
- b Department of Morphology, Surgery and Experimental Medicine, Menopause and Osteoporosis Centre , University of Ferrara , Ferrara , Italy.,c Department of Morphology, Surgery and Experimental Medicine, Section of Obstetrics and Gynecology , University of Ferrara , Ferrara , Italy
| | - Roberta Parladori
- g Department of Medical Sciences, Postgraduate School of Digestive Diseases , University of Ferrara , Ferrara , Italy
| | - Angelina Passaro
- f Department of Medical Science, Section of Internal Medicine, Gerontology and Geriatrics , University of Ferrara , Ferrara , Italy
| | - Giorgio Ricci
- g Department of Medical Sciences, Postgraduate School of Digestive Diseases , University of Ferrara , Ferrara , Italy
| |
Collapse
|
16
|
Bharathidevi SR, Babu KA, Jain N, Muthukumaran S, Umashankar V, Biswas J, Angayarkanni N. Ocular distribution of antioxidant enzyme paraoxonase & its alteration in cataractous lens & diabetic retina. Indian J Med Res 2017; 145:513-520. [PMID: 28862184 PMCID: PMC5663166 DOI: 10.4103/ijmr.ijmr_1284_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Background & objectives: The enzyme paraoxonase (PON), an antioxidant enzyme that has both arylesterase and thiolactonase activity, is well studied in cardiovascular diseases. Although a few studies have shown altered PON activity in ocular diseases such as age-related macular degeneration and diabetic retinopathy, but the tissue-wise expression of PON in its three gene forms has not been studied. This study was conducted to see the ocular distribution of PON for any altered expression in ocular pathologies such as in cataract and diabetes mellitus. Methods: Immunohistochemistry (IHC) of the ocular tissues was done for localizing all three forms of the PON in the human donor eyeballs. The PON arylesterase (PON-AREase) and thiolactonase (PON-HCTLase) activities were determined by spectrophotometry in kinetic mode, and the mRNA expression of the PON genes (PON1-3) was determined by reverse transcription-polymerase chain reaction. Results: IHC showed the presence of both PON1 and 2 in all the ocular tissues and PON3 was seen only in retina. The mRNA expression analysis showed that PON2 and PON3 were present in all the tissues, whereas PON1 was seen only in ciliary and retina. Both the PON-AREase and PON-HCTLase activities were detected in all ocular tissues and was in the order of lens>retina>choroid>ciliary body>iris. The expression and activity were studied in cataractous lens and in diabetic retina of the donor eyes. A significant decrease in PON-AREase activity was seen in cataractous lens (P<0.05) but not in diabetic retina, and there was an increase in PON- HCTLase activity (P<0.05) only in diabetic retina. Bioinformatic studies and in vitro experiments indicated that advanced glycation end products (AGE) such as carboxymethyl -lysine might decrease the PON- AREase activity of the PON. Interpretation & conclusions: Distribution of PON enzyme and its activity in ocular tissues is reported here. The study revealed maximal PON activity in lens and retina, which are prone to higher oxidative stress. Differential activities of PON were observed in the lens and retinal tissues from cataractous and diabetic patients, respectively.
Collapse
Affiliation(s)
| | - Kannadasan Anand Babu
- RS Mehta Jain Department of Biochemistry & Cell Biology, KBIRVO Block, Vision Research Foundation, Chennai, India
| | - Nishit Jain
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, India
| | | | - Vetrivel Umashankar
- Centre for Bioinformatics, KBIRVO Block, Vision Research Foundation, Chennai, India
| | - J Biswas
- Uveitis Services, Sankara Nethralaya, Chennai, India
| | - Narayanasamy Angayarkanni
- RS Mehta Jain Department of Biochemistry & Cell Biology, KBIRVO Block, Vision Research Foundation, Chennai, India
| |
Collapse
|
17
|
Arulkumar M, Vijayan R, Penislusshiyan S, Sathishkumar P, Angayarkanni J, Palvannan T. Alteration of paraoxonase, arylesterase and lactonase activities in people around fluoride endemic area of Tamil Nadu, India. Clin Chim Acta 2017; 471:206-215. [DOI: 10.1016/j.cca.2017.05.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 05/16/2017] [Accepted: 05/31/2017] [Indexed: 12/19/2022]
|
18
|
Brzović-Šarić V, Landeka I, Šarić B, Barberić M, Andrijašević L, Cerovski B, Oršolić N, Đikić D. Levels of selected oxidative stress markers in the vitreous and serum of diabetic retinopathy patients. Mol Vis 2015; 21:649-64. [PMID: 26120270 PMCID: PMC4462954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 06/10/2015] [Indexed: 10/30/2022] Open
Abstract
PURPOSE In diabetes, an impaired antioxidant defense system contributes to the development of diabetic retinopathy. The main objective of this paper was to find correlations of oxidative stress parameters within and between the vitreous and serum in patients with type 2 diabetes who had developed proliferative diabetic retinopathy. METHODS The study included and compared two groups of patients who underwent vitrectomy: 37 patients with type 2 diabetes and proliferative retinopathy (PDR), and 50 patients with non-diabetic eye disorders (NDED). Vascular endothelial growth factor (VEGF), advanced oxidized protein product (AOPP), and oxidative stress markers (direct lipid hydroperoxidation (LPO), malondialdehyde (MDA), total superoxide dismutase (SOD), and glutathione (GSH)) were measured in the vitreous and serum of both groups and correlated with one another, between humoral compartments and with gender, age, and serum glucose levels. RESULTS In the vitreous of PDR patients, VEGF, LPO, and MDA (p<0.05) were increased and SOD values were slightly lowered (p<0.05) than in NDED patients. Vitreous AOPP and GSH showed no differences between the groups. In the serum, AOPP, MDA, and SOD were increased (p<0.05) and VEGF was slightly increased (p<0.05) in the PDR group compared to NDED. With regard to gender, similar changes were recorded for both groups, except for the lower serum MDA in males than females in the NDED group. Advanced age showed no significant effect on changes of measured parameters in the vitreous. In the serum, VEGF was positively correlated (p<0.05) and MDA and SOD negatively correlated (p<0.05) with increasing age. Among measured parameters within and between the vitreous and serum, several correlative links occurred in the PDR group that were not present in the NDED group. The most prominent correlation changes were between serum LPO and vitreal LPO, serum SOD and vitreal LPO, serum LPO and serum SOD, and vitreal VEGF and serum SOD. CONCLUSIONS Among the selected oxidative stress markers, SOD and LPO were highly correlative in both the vitreous and serum in PDR compared to patients without metabolic disorders. Their correlations suggested that monitoring their mutual alterations might be informative during PDR development and should be considered in further research.
Collapse
Affiliation(s)
- Vlatka Brzović-Šarić
- Department of Ophthalmology, Sveti Duh Clinical Hospital, Sveti Duh 64, 10000 Zagreb, Croatia
| | - Irena Landeka
- Laboratory of Food Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
| | - Borna Šarić
- Department of Ophthalmology, Sveti Duh Clinical Hospital, Sveti Duh 64, 10000 Zagreb, Croatia
| | - Monika Barberić
- Medical Diagnostics Laboratory, Sveti Duh Clinical Hospital, Zagreb, Croatia
| | - Lidija Andrijašević
- Department of Ophthalmology, Sveti Duh Clinical Hospital, Sveti Duh 64, 10000 Zagreb, Croatia
| | | | - Nada Oršolić
- Department of Animal Physiology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Domagoj Đikić
- Department of Animal Physiology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| |
Collapse
|
19
|
Marsillach J, Suzuki SM, Richter RJ, McDonald MG, Rademacher PM, MacCoss MJ, Hsieh EJ, Rettie AE, Furlong CE. Human valacyclovir hydrolase/biphenyl hydrolase-like protein is a highly efficient homocysteine thiolactonase. PLoS One 2014; 9:e110054. [PMID: 25333274 PMCID: PMC4198189 DOI: 10.1371/journal.pone.0110054] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/08/2014] [Indexed: 11/29/2022] Open
Abstract
Homocysteinylation of lysine residues by homocysteine thiolactone (HCTL), a reactive homocysteine metabolite, results in protein aggregation and malfunction, and is a well-known risk factor for cardiovascular, autoimmune and neurological diseases. Human plasma paraoxonase-1 (PON1) and bleomycin hydrolase (Blmh) have been reported as the physiological HCTL detoxifying enzymes. However, the catalytic efficiency of HCTL hydrolysis by Blmh is low and not saturated at 20 mM HCTL. The catalytic efficiency of PON1 for HCTL hydrolysis is 100-fold lower than that of Blmh. A homocysteine thiolactonase (HCTLase) was purified from human liver and identified by mass spectrometry (MS) as the previously described human biphenyl hydrolase-like protein (BPHL). To further characterize this newly described HCTLase activity, BPHL was expressed in Escherichia coli and purified. The sequence of the recombinant BPHL (rBPHL) and hydrolytic products of the substrates HCTL and valacyclovir were verified by MS. We found that the catalytic efficiency (kcat/Km) of rBPHL for HCTL hydrolysis was 7.7 × 104 M−1s−1, orders of magnitude higher than that of PON1 or Blmh, indicating a more significant physiological role for BPHL in detoxifying HCTL.
Collapse
Affiliation(s)
- Judit Marsillach
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Stephanie M. Suzuki
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
| | - Rebecca J. Richter
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
| | - Matthew G. McDonald
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Peter M. Rademacher
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Edward J. Hsieh
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Allan E. Rettie
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Clement E. Furlong
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
- * E-mail:
| |
Collapse
|
20
|
Savu O, Serafinceanu C, Grajdeanu IV, Iosif L, Gaman L, Stoian I. Paraoxonase lactonase activity, inflammation and antioxidant status in plasma of patients with type 1 diabetes mellitus. J Int Med Res 2014; 42:523-9. [PMID: 24567352 DOI: 10.1177/0300060513516287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To investigate paraoxonase-1 (PON1) lactonase activity, myeloperoxidase (MPO) activity (as a marker of inflammation) and antioxidant status in plasma of patients with type 1 diabetes mellitus. METHODS Whole blood and plasma samples were collected from patients with diabetes and healthy control subjects. PON1 lactonase and MPO activities and total antioxidant capacity (TEAC) were determined in plasma. Glycosylated haemoglobin (HbA1c) was quantified in whole blood. RESULTS Plasma PON1 lactonase and MPO activities were significantly higher and TEAC was significantly lower in patients with diabetes (n = 18) compared with healthy control subjects (n = 20). There were significant positive correlations between PON1 lactonase activity and MPO activity and HbA1c level, and plasma MPO and HbA1c. There were significant negative correlations between PON1 lactonase activity and TEAC, and MPO activity and TEAC. CONCLUSIONS Increased lactonase activity may inefficiently compensate for the high level of chronic inflammation and low antioxidant capacity in the plasma of patients with type 1 diabetes mellitus.
Collapse
Affiliation(s)
- Octavian Savu
- N.C. Paulescu National Institute for Diabetes, Nutrition and Metabolic Diseases, Bucharest, Romania
| | | | | | | | | | | |
Collapse
|
21
|
Arora B, Narayanasamy A, Nirmal J, Halder N, Patnaik S, Ravi AK, Velpandian T. Development and validation of a LC-MS/MS method for homocysteine thiolactone in plasma and evaluation of its stability in plasma samples. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 944:49-54. [PMID: 24291720 DOI: 10.1016/j.jchromb.2013.11.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 11/02/2013] [Accepted: 11/06/2013] [Indexed: 11/26/2022]
Abstract
The present study demonstrates the development and validation of a sensitive method for the quantification of homocysteine thiolactone (HCTL) in human plasma using the technique of LC-MS/MS. The gradient elution of HCTL was achieved within 5min using ZIC HILIC column having acetonitrile with 0.1% formic acid and water with 0.1% formic acid. The method was validated for the linearity, sensitivity, accuracy, precision, recovery, matrix effect and stability. A good linearity was found within a range of 0.5-32.5nmol/ml. Quantification was performed using multiple reaction monitoring (MRM) mode based on the molecular/fragment ion transitions for HCTL (118/56) and homatropine (276.1/142.2) as internal standard. Generally, HCTL levels in plasma were found to be highly unstable. In order to verify the stability of the HCTL levels in plasma for a longer period, the samples were extracted immediately and stored at -86°C. Using the above method it was found to be stable for a period of 1 month. The method was well applied for quantification of HCTL in plasma of healthy human volunteers.
Collapse
Affiliation(s)
- Beauty Arora
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Angayarkanni Narayanasamy
- Department of Biochemistry and Cell Biology, Sankara Nethralaya, 18, College Road, Nungambakkam, Chennai 600006, TN, India
| | - Jayabalan Nirmal
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Nabanita Halder
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Santosh Patnaik
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Alok K Ravi
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Thirumurthy Velpandian
- High Precision Bio-analytical Facility, Department of Ocular Pharmacology and Pharmacy, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
| |
Collapse
|
22
|
Cholewa JM, Wyszczelska-Rokiel M, Glowacki R, Jakubowski H, Matthews T, Wood R, Craig SA, Paolone V. Effects of betaine on body composition, performance, and homocysteine thiolactone. J Int Soc Sports Nutr 2013; 10:39. [PMID: 23967897 PMCID: PMC3844502 DOI: 10.1186/1550-2783-10-39] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/09/2013] [Indexed: 11/17/2022] Open
Abstract
Background This study investigated the effects of long term betaine supplementation on body composition, performance, and homocysteine thiolactone (HCTL) in experienced strength trained men. Methods Twenty-three subjects were matched for training experience (4.8 ± 2.3 years) and body fat percentage (BF%: 16.9 ± 8.0%), randomly assigned to either a placebo (PL; n = 12) or betaine group (BET; n = 11; 2.5 g/day), and completed a 6 week periodized training program consisting of 3 two-week micro-cycles. Bench press and back squat training volumes were recorded and changes in training volume were assessed at each micro-cycle. Fasting urine was collected at baseline (BL), weeks 2, 4 and 6, and assayed for HCTL. Subjects were tested prior to and following 6 weeks of treatment. Arm and thigh cross sectional area (CSA) was estimated via girth and skin fold measurements. Body density was estimated via skin fold calipers and used to estimate BF%, fat mass (FM), and lean body mass (LBM). Performance was assessed via vertical jump (VJ), bench press 1 RM (BP), and back squat 1 RM (BS). Results Arm CSA increased significantly (p < .05) in BET but not PL. No differences existed between group and time for changes in thigh CSA. Back squat training volume increased significantly (p < .05) for both groups throughout training. Bench press training volume was significantly (p < .05) improved for BET compared to PL at microcycles one and three. Body composition (BF%, FM, LBM) improved significantly (p < .05) in BET but not PL. No differences were found in performance variables (BP, BS, VJ) between groups, except there was a trend (p = .07) for increased VJ power in BET versus PL. A significant interaction (p < .05) existed for HCTL, with increases from BL to week 2 in PL, but not BET. Additionally, HCTL remained elevated at week 4 in PL, but not BET. Conclusion Six-weeks of betaine supplementation improved body composition, arm size, bench press work capacity, attenuated the rise in urinary HCTL, and tended to improve power (p = .07) but not strength.
Collapse
Affiliation(s)
- Jason M Cholewa
- Department of Kinesiology, Recreation, and Sport Studies, Coastal Carolina University, Conway, SC, USA.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Bayrak T, Dursun P, Bayrak A, Gültekin M, Kolusarı A, Cakır E, Ozyurt M, Zeyneloğlu HB. Paraoxonase lactonase activity (PON-HTLase), asymmetric dimethylarginine (ADMA) and platelet activating factor-acetylhydrolase (PAF-AH) activity in non-obese women with PCOS. Gynecol Endocrinol 2012; 28:874-8. [PMID: 22621680 DOI: 10.3109/09513590.2012.683068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE Paraoxonase1 (PON1), exhibits both esterase activity (PON1-AREase) and homocysteine thiolactonase activity (PON1-HTLase) which respectively prevent LDL oxidation and detoxify homocysteine thiolactone (HTL). Platelet-activating factor-acetylhydrolase (PAF-AH) is an antioxidant enzyme preventing LDL oxidation by hydrolysis of oxidized phospholipids. Both of these enzymes exhibit a proatherogenic role. ADMA is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction. The aim was to compare non-obese PCOS patients with a BMI matched control group using the following characteristics: serum PON1-HTLase, ADMA, PAF-AH, and lipid and hormonal parameters. RESULTS 77 women with PCOS and 25 healthy subject were recruited for this study, The controls were non-obese BMI and age matched with the patients. There were no significant differences with respect to age, BMI, FSH, free testosterone, DHEA, androstenadion, total cholesterol, triglycerides, HDL, LDL, VLDL, fasting glucose/insulin ratio and HOMA-IR among the groups (p > 0.05). However, total testosterone and fasting glucose levels were significantly higher in the PCOS group (p < 0.05). On the other hand, PON1-HTLase levels (39.6 ± 5.77 vs. 33.8 ± 8.2, p = 0.02) were significantly lower in the PCOS group while ADMA levels (1.14 ± 0.6 vs. 3.37 ± 6.4, p = 0.004) were significantly higher in the PCOS group. However, there was no significant difference in PAF-AH activity among the groups. CONCLUSIONS Decreased PON1-HTLase and increased ADMA levels might be a relevant marker for the development of future atherosclerotic heart disease (AHD) in non-obese PCOS patients. Further studies are needed to confirm our results.
Collapse
Affiliation(s)
- Tulin Bayrak
- Department of Biochemistry, Hacettepe University Kastamonu School of Medicine, Ankara, Turkey
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Coral K, Madhavan J, Pukhraj R, Angayarkanni N. High glucose induced differential expression of lysyl oxidase and its isoform in ARPE-19 cells. Curr Eye Res 2012; 38:194-203. [PMID: 22966818 DOI: 10.3109/02713683.2012.720341] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE Lysyl oxidase (LOX) stabilizes the extracellular matrix (ECM) by cross-linking collagen and elastin molecules. In proliferative diabetic retinopathy (PDR), there is ECM remodeling with neovascularization and basement membrane changes. While protease activities are well reported, the role of LOX in the pathogenesis of diabetic retinopathy is less studied. This study was done to see the effect of high glucose on the activity and expression of LOX and its isoforms in ARPE-19 cells. MATERIALS AND METHODS ARPE-19 cells were exposed to high glucose up to 48 h, and LOX activity was determined by N-acetyl-3,7-dihydroxyphenoxazine assay. The mRNA expression of LOX and its isoforms was done by real-time PCR and the protein expression by ELISA. Immunohistochemistry for LOX was done in epiretinal membrane from PDR. RESULTS With an increase in glucose concentration LOX activity and protein was reduced significantly at 30 mM glucose at 48 h. mRNA expression of LOX, LOXL1, and LOXL2 varied with time and concentration of glucose. Vascular endothelial growth factor (VEGF) increased the LOX activity as well as the mRNA expression. Pigment epithelium-derived factor (PEDF) downregulated the mRNA expression of LOX, LOXL1, and LOXL2. The matrix metalloprotease (MMP) activity increased significantly with the increase in glucose concentration. The diabetic neovascular membrane showed increased immunostaining of LOX. CONCLUSIONS This study suggests that although the LOX activity, which is composite of all the isoforms, was reduced under high glucose conditions, there was a differential mRNA expression with increased LOX and LOXL1 and decreased LOXL2 expression.
Collapse
Affiliation(s)
- Karunakaran Coral
- Department of Biochemistry and Cell Biology, Vision and Medical Research Foundation, Chennai, India
| | | | | | | |
Collapse
|
25
|
Perła-Kaján J, Jakubowski H. Paraoxonase 1 and homocysteine metabolism. Amino Acids 2012; 43:1405-17. [PMID: 22643843 DOI: 10.1007/s00726-012-1321-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 05/04/2012] [Indexed: 01/23/2023]
Abstract
Paraoxonase 1 (PON1), a component of high-density lipoprotein (HDL), is a calcium-dependent multifunctional enzyme that connects metabolisms of lipoproteins and homocysteine (Hcy). Both PON1 and Hcy have been implicated in human diseases, including atherosclerosis and neurodegeneration. The involvement of Hcy in disease could be mediated through its interactions with PON1. Due to its ability to reduce oxidative stress, PON1 contributes to atheroprotective functions of HDL in mice and humans. Although PON1 has the ability to hydrolyze a variety of substrates, only one of them-Hcy-thiolactone-is known to occur naturally. In humans and mice, Hcy-thiolactonase activity of PON1 protects against N-homocysteinylation, which is detrimental to protein structure and function. PON1 also protects against neurotoxicity associated with hyperhomocysteinemia in mouse models. The links between PON1 and Hcy in relation to pathological states such as coronary artery disease, stroke, diabetic mellitus, kidney failure and Alzheimer's disease that emerge from recent studies are the topics of this review.
Collapse
Affiliation(s)
- Joanna Perła-Kaján
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Poznan, Poland.
| | | |
Collapse
|
26
|
Yilmaz N. Relationship between paraoxonase and homocysteine: crossroads of oxidative diseases. Arch Med Sci 2012; 8:138-53. [PMID: 22457688 PMCID: PMC3309450 DOI: 10.5114/aoms.2012.27294] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/17/2011] [Accepted: 04/07/2011] [Indexed: 01/14/2023] Open
Abstract
Homocysteine (Hcy) is an accepted independent risk factor for several major pathologies including cardiovascular disease, birth defects, osteoporosis, Alzheimer's disease, and renal failure. Interestingly, many of the pathologies associated with homocysteine are also linked to oxidative stress. The enzyme paraoxonase (PON1) - so named because of its ability to hydrolyse the toxic metabolite of parathion, paraoxon - was also shown early after its identification to manifest arylesterase activity. Although the preferred endogenous substrate of PON1 remains unknown, lactones comprise one possible candidate class. Homocysteine-thiolactone can be disposed of by enzymatic hydrolysis by the serum Hcy-thiolactonase/paraoxonase carried on high-density lipoprotein (HDL). In this review, Hcy and the PON1 enzyme family were scrutinized from different points of view in the literature and the recent articles on these subjects were examined to determine whether these two molecular groups are related to each other like a coin with two different sides, so close and yet so different and so opposite.
Collapse
Affiliation(s)
- Necat Yilmaz
- Central Laboratories of Antalya Education and Research Hospital of Ministry of Health, Antalya, Turkey
| |
Collapse
|
27
|
Chang HH, Lin DPC, Chen YS, Liu HJ, Lin W, Tsao ZJ, Teng MC, Chen BY. Intravitreal homocysteine-thiolactone injection leads to the degeneration of multiple retinal cells, including photoreceptors. Mol Vis 2011; 17:1946-56. [PMID: 21850169 PMCID: PMC3156793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 07/14/2011] [Indexed: 12/02/2022] Open
Abstract
PURPOSE Hyperhomocysteinemia is known to cause degeneration of retinal ganglion cells, but its influence on photoreceptors remains largely unknown. In particular, the role of homocysteine-thiolactone (Hcy-T)--the physiologic metabolite of homocysteine that has been proven to be more cytotoxic than homocysteine itself--as a factor that causes retinopathy, has not been defined. This study aimed to investigate the toxic effects of excessive Hcy-T in a mouse model. METHODS A total of 60 six-week-old female ICR mice were used in this study. The mice were divided into 3 experimental groups and 2 control groups. The mice in the experimental groups were subjected to intravitreal injections of Hcy-T to reach final estimated intravitreal concentrations at 5, 25, and 200 μM, respectively. Mice without injection (blank) and with 0.9 NaCl injections (sham injection) were used as controls. The mice with 200 μM Hcy-T were sacrificed at days 7, 15, 45, and 90 after injection and the mice with 5 or 25 μM Hcy-T were sacrificed at day 90, with the controls sacrificed at day 15 or 90 for comparison. Semi-quantitative dot-blot analysis was performed for confirmation of retinal homocysteinylation. The mouse retinas were evaluated microscopically, with the thickness of total and specific retinal layers determined. Immunohistochemical analysis was performed and the labeled cells were quantified to determine the effects of excessive Hcy-T on specific retinal cells. RESULTS Dose-dependent retinal homocysteinylation after Hcy-T injection was confirmed. The homocysteinylation was localized in the outer and inner segments of photoreceptors and the ganglion cell layer (GCL). Retinal cell degenerations were found in the GCL, inner nuclear layer, and outer nuclear layer at day 90 after 200 µM Hcy-T injection. Significant thickness reduction was found in the total retina, outer nuclear layer, and the outer and inner segment layers. A trend of thickness reduction was also found in the GCL and inner nuclear layer, although this was not statistically significant. The rhodopsin⁺ photoreceptors and the calbindin⁺ horizontal cells were significantly reduced at day 15, and were nearly ablated at day 90 after 200 μM Hcy-T injection (p<0.001 for both day 15 and day 90), which was not seen in the sham injection controls. The Chx-10⁺ or the Islet-1⁺ bipolar cells and the Pax-6⁺ amacrine cells were severely misarranged at day 90, but no significant reduction was found for both cell types. The GFAP⁺ Müller cells were activated at day 15, but were not significantly increased at day 90 after the injection. CONCLUSIONS Excessive retinal homocysteinylation by Hcy-T, a condition of hyperhomocysteinemia, could lead to degeneration of photoreceptors, which might lead to retinopathies associated with severe hyperhomocysteinemia or diabetes mellitus.
Collapse
Affiliation(s)
- Han-Hsin Chang
- School of Nutrition, Chung Shan Medical University, Taichung, Taiwan, ROC,Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC
| | - David Pei-Cheng Lin
- Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC,School of Optometry, Chung Shan Medical University, Taichung, Taiwan, ROC,School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan, ROC
| | - Ying-Shan Chen
- Department of Ophthalmology, Hsinchu Cathay General Hospital, Hsinchu, Taiwan, ROC
| | - Hsiang-Jui Liu
- Department of Optometry, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan, ROC
| | - Wei Lin
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, ROC
| | - Zih-Jay Tsao
- School of Nutrition, Chung Shan Medical University, Taichung, Taiwan, ROC,School of Optometry, Chung Shan Medical University, Taichung, Taiwan, ROC
| | - Mei-Ching Teng
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, ROC
| | - Bo-Yie Chen
- Department of Ophthalmology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC,School of Optometry, Chung Shan Medical University, Taichung, Taiwan, ROC
| |
Collapse
|