1
|
Salazar-Villatoro L, Chávez-Munguía B, Guevara-Estrada CE, Lagunes-Guillén A, Hernández-Martínez D, Castelan-Ramírez I, Omaña-Molina M. Taurine, a Component of the Tear Film, Exacerbates the Pathogenic Mechanisms of Acanthamoeba castellanii in the Ex Vivo Amoebic Keratitis Model. Pathogens 2023; 12:1049. [PMID: 37624009 PMCID: PMC10458499 DOI: 10.3390/pathogens12081049] [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: 07/29/2023] [Revised: 08/13/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
Acanthamoeba spp. is the etiological agent of amoebic keratitis. In this study, the effect of taurine in physiological concentrations in tears (195 μM) on trophozoites of Acanthamoeba castellanii through the ex vivo amoebic keratitis model was evaluated. Trophozoites were coincubated with the Syrian golden hamster cornea (Mesocricetus auratus) for 3 and 6 h. Group 1: Control (-). Corneas coincubated with amoebic culture medium and taurine. Group 2: Control (+). Corneas coincubated with trophozoites without taurine. Group 3: Corneas coincubated with taurine 15 min before adding trophozoites. Group 4: Trophozoites coincubated 15 min with taurine before placing them on the cornea. Group 5: Corneas coincubated for 15 min with trophozoites; subsequently, taurine was added. Results are similar for both times, as evaluated by scanning electron microscopy. As expected, in the corneas of Group 1, no alterations were observed in the corneal epithelium. In the corneas of Group 2, few adhered trophozoites were observed on the corneal surface initiating migrations through cell junctions as previously described; however, in corneas of Groups 3, 4 and 5, abundant trophozoites were observed, penetrating through different corneal cell areas, emitting food cups and destabilizing corneal surface in areas far from cell junctions. Significant differences were confirmed in trophozoites adherence coincubated with taurine (p < 0.05). Taurine does not prevent the adhesion and invasion of the amoebae, nor does it favor its detachment once these have adhered to the cornea, suggesting that taurine in the physiological concentrations found in tears stimulates pathogenic mechanisms of A. castellanii.
Collapse
Affiliation(s)
- Lizbeth Salazar-Villatoro
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de Mexico 07360, Mexico; (L.S.-V.); (B.C.-M.); (A.L.-G.)
| | - Bibiana Chávez-Munguía
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de Mexico 07360, Mexico; (L.S.-V.); (B.C.-M.); (A.L.-G.)
| | - Celia Esther Guevara-Estrada
- Laboratorio de Amibas Anfizóicas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla 54090, Mexico; (C.E.G.-E.); (D.H.-M.); (I.C.-R.)
| | - Anel Lagunes-Guillén
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Ciudad de Mexico 07360, Mexico; (L.S.-V.); (B.C.-M.); (A.L.-G.)
| | - Dolores Hernández-Martínez
- Laboratorio de Amibas Anfizóicas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla 54090, Mexico; (C.E.G.-E.); (D.H.-M.); (I.C.-R.)
| | - Ismael Castelan-Ramírez
- Laboratorio de Amibas Anfizóicas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla 54090, Mexico; (C.E.G.-E.); (D.H.-M.); (I.C.-R.)
| | - Maritza Omaña-Molina
- Laboratorio de Amibas Anfizóicas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla 54090, Mexico; (C.E.G.-E.); (D.H.-M.); (I.C.-R.)
| |
Collapse
|
2
|
Teng PY, Liu G, Choi J, Yadav S, Wei F, Kim WK. Effects of levels of methionine supplementations in forms of L or DL-methionine on the performance, intestinal development, immune response, and antioxidant system in broilers challenged with Eimeria spp. Poult Sci 2023; 102:102586. [PMID: 36966644 PMCID: PMC10064433 DOI: 10.1016/j.psj.2023.102586] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/23/2023] Open
Abstract
The study was conducted to investigate the effects of 2 isoforms of methionine on growth performance and intestinal health induced by methionine (Met) deficiency and Eimeria infection in broilers. A total of 720 one-day old male chicks (Cobb500) were randomly allocated to 10 groups in a 2 × 5 factorial arrangement (6 reps/group, 12 birds/cage) with diets and Eimeria challenge as the main factors. Hundred percent DL-Met, 100% L-Met, 80% DL-Met, and 80% L-Met diets were formulated to meet approximately 100 or 80% of the total sulfur amino acid (TSAA) requirement with DL-Met or L-Met as Met supplementation sources. The 60% TSAA basal diet (60% Met) was formulated without Met supplementation. At d14, the challenge groups were gavaged with mixed Eimeria spp. Growth performance was recorded on d7, 14, 20 (6-day postinfection [DPI]), and 26 (12 DPI). The gut permeability was measured on 5 and 11 DPI. Antioxidant status and gene expression of immune cytokines and tight junction proteins were measured on 6 and 12 DPI. Data were analyzed by 1-way and 2-way ANOVA before and after the challenge, respectively. Orthogonal polynomial contrasts were used for post hoc comparison. Overall, the Eimeria challenge and 60% Met diet significantly reduced growth performance, antioxidant status, and mRNA expression of tight junction genes and immune cytokines. For other Met treatments, the L-Met groups had significantly higher BWG and lower FCR than the DL-Met group from d 1 to 20. The L-Met groups had less gut permeability than the DL-Met groups on 5 DPI. Compared to the 80% Met groups, the 100% Met groups reduced gut permeability. At 6 DPI, the 80% Met groups showed higher ZO1 expression than the 100% Met groups. The challenge groups had higher Muc2 expression and GSH/GSSG compared to the nonchallenge groups, and SOD activity was lower in the L-Met groups compared to the DL-Met groups at 6 DPI. The 100% Met groups had higher GPx activity than the 80% Met groups at 12 DPI. In conclusion, during coccidiosis, the 100% Met groups had better gut integrity and antioxidant status. Met supplementation in the form of L-Met improved growth performance in the starter phase and gut permeability in the challenge phase.
Collapse
Affiliation(s)
- Po-Yun Teng
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - Guanchen Liu
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - Janghan Choi
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - Sudhir Yadav
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - Fengxian Wei
- Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou, Henan, China
| | - Woo K Kim
- Department of Poultry Science, University of Georgia, Athens, GA, USA.
| |
Collapse
|
3
|
Zuo F, Wei H, Peng J, Li S, Zhou Y. Effects on the Cell Barrier Function of L-Met and DL-HMTBA Is Related to Metabolic Characteristics and m 6A Modification. Front Nutr 2022; 9:836069. [PMID: 35464013 PMCID: PMC9020446 DOI: 10.3389/fnut.2022.836069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/07/2022] [Indexed: 11/15/2022] Open
Abstract
Methionine is a substrate for protein synthesis and participates in many other biological events via its metabolism. We have previously demonstrated significant differences in the metabolism of L-methionine (L-Met) and its precursor DL-2-hydroxy-4-methylthiobutyric acid (DL-HMTBA) in IPEC-J2 cells. When DL–HMTBA is added to the diet, intracellular methionine (Met) sources also contain the natural form of L-Met. Then, what is the effect on Met metabolism when these two Met sources exist simultaneously? Moreover, the effects of metabolic differences on cell function remain unclear. In this study, it was found that when the proportion of L-Met to DL–HMTBA was ≤ 40%:60%, Met transmethylation was promoted and when the proportion of L-Met to DL-HMTBA was ≤ 85%:15%, Met trans-sulfuration and regeneration were improved. In addition, DL-HMTBA improved the cell barrier function when the ratio of L-Met to DL-HMTBA was ≤ 40%:60%. This finding may be due to the decrease in the proportion of S-adenosylmethionine to S-adenosylhomocysteine and mRNA N6-methyladenosine (m6A) levels, which increase the mRNA stability and protein expression of tight junction zona occludens-1. To sum up, the effects of L-Met and DL–HMTBA on Met metabolism, especially transmethylation, suggest that DL–HMTBA has the potential to influence the intestinal barrier function of animals through epigenetic processes.
Collapse
Affiliation(s)
- Fangrui Zuo
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.,Wuhan Sun HY Biology Co., Ltd, Wuhan, China
| | - Hongkui Wei
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jian Peng
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shengqing Li
- State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan, China
| | - Yuanfei Zhou
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
4
|
Ren B, Wang L, Mulati A, Liu Y, Liu Z, Liu X. Methionine Restriction Improves Gut Barrier Function by Reshaping Diurnal Rhythms of Inflammation-Related Microbes in Aged Mice. Front Nutr 2022; 8:746592. [PMID: 35004799 PMCID: PMC8733897 DOI: 10.3389/fnut.2021.746592] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/03/2021] [Indexed: 12/25/2022] Open
Abstract
Age-related gut barrier dysfunction and dysbiosis of the gut microbiome play crucial roles in human aging. Dietary methionine restriction (MR) has been reported to extend lifespan and reduce the inflammatory response; however, its protective effects on age-related gut barrier dysfunction remain unclear. Accordingly, we focus on the effects of MR on inflammation and gut function. We found a 3-month methionine-restriction reduced inflammatory factors in the serum of aged mice. Moreover, MR reduced gut permeability in aged mice and increased the levels of the tight junction proteins mRNAs, including those of occludin, claudin-1, and zona occludens-1. MR significantly reduced bacterial endotoxin lipopolysaccharide concentration in aged mice serum. By using 16s rRNA sequencing to analyze microbiome diurnal rhythmicity during 24 h, we found MR moderately recovered the cyclical fluctuations of the gut microbiome which was disrupted in aged mice, leading to time-specific enhancement of the abundance of short-chain fatty acid-producing and lifespan-promoting microbes. Moreover, MR dampened the oscillation of inflammation-related TM7-3 and Staphylococcaceae. In conclusion, the effects of MR on the gut barrier were likely related to alleviation of the oscillations of inflammation-related microbes. MR can enable nutritional intervention against age-related gut barrier dysfunction.
Collapse
Affiliation(s)
- Bo Ren
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China.,School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Luanfeng Wang
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Aiziguli Mulati
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Yan Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Zhigang Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| | - Xuebo Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, China
| |
Collapse
|
5
|
Wang L, Ren B, Hui Y, Chu C, Zhao Z, Zhang Y, Zhao B, Shi R, Ren J, Dai X, Liu Z, Liu X. Methionine Restriction Regulates Cognitive Function in High-Fat Diet-Fed Mice: Roles of Diurnal Rhythms of SCFAs Producing- and Inflammation-Related Microbes. Mol Nutr Food Res 2020; 64:e2000190. [PMID: 32729963 DOI: 10.1002/mnfr.202000190] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/15/2020] [Indexed: 12/11/2022]
Abstract
SCOPE Methionine restriction (MR) is known to potently alleviate inflammation and improve gut microbiome in obese mice. The gut microbiome exhibits diurnal rhythmicity in composition and function, and this, in turn, drives oscillations in host metabolism. High-fat diet (HFD) strongly altered microbiome diurnal rhythmicity, however, the role of microbiome diurnal rhythmicity in mediating the improvement effects of MR on obesity-related metabolic disorders remains unclear. METHODS AND RESULTS 10-week-old male C57BL/6J mice are fed a low-fat diet or HFD for 4 weeks, followed with a full diet (0.86% methionine, w/w) or a methionine-restricted diet (0.17% methionine, w/w) for 8 weeks. Analyzing microbiome diurnal rhythmicity at six time points, the results show that HFD disrupts the cyclical fluctuations of the gut microbiome in mice. MR partially restores these cyclical fluctuations, which lead to time-specifically enhance the abundance of short-chain fatty acids producing bacteria, increases the acetate and butyric, and dampens the oscillation of inflammation-related Desulfovibrionales and Staphylococcaceae over the course of 1 day. Notably, MR, which protects against systemic inflammation, influences brain function and synaptic plasticity. CONCLUSION MR could serve as a potential nutritional intervention for attenuating obesity-induced cognitive impairments by balancing the circadian rhythm in microbiome-gut-brain homeostasis.
Collapse
Affiliation(s)
- Luanfeng Wang
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Bo Ren
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yan Hui
- BGI Institute of Applied Agriculture, BGI-Shenzhen, Shenzhen, 518120, China.,Department of Food Science, University of Copenhagen, Copenhagen, 1958, Denmark
| | - Chuanqi Chu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhenting Zhao
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yuyu Zhang
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Beita Zhao
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Renjie Shi
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Junli Ren
- BGI Institute of Applied Agriculture, BGI-Shenzhen, Shenzhen, 518120, China
| | - Xiaoshuang Dai
- BGI Institute of Applied Agriculture, BGI-Shenzhen, Shenzhen, 518120, China
| | - Zhigang Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xuebo Liu
- Laboratory of Functional Chemistry and Nutrition of Food, College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| |
Collapse
|
6
|
Miousse IR, Tobacyk J, Melnyk S, James SJ, Cheema AK, Boerma M, Hauer-Jensen M, Koturbash I. One-carbon metabolism and ionizing radiation: a multifaceted interaction. Biomol Concepts 2018; 8:83-92. [PMID: 28574375 DOI: 10.1515/bmc-2017-0003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/03/2017] [Indexed: 01/20/2023] Open
Abstract
Ionizing radiation (IR) is a ubiquitous component of our environment and an important tool in research and medical treatment. At the same time, IR is a potent genotoxic and epigenotoxic stressor, exposure to which may lead to negative health outcomes. While the genotoxocity is well described and characterized, the epigenetic effects of exposure to IR and their mechanisms remain under-investigated. In this conceptual review, we propose the IR-induced changes to one-carbon metabolism as prerequisites to alterations in the cellular epigenome. We also provide evidence from both experimental and clinical studies describing the interactions between IR and one-carbon metabolism. We further discuss the potential for the manipulation of the one-carbon metabolism in clinical applications for the purpose of normal tissue protection and for increasing the radiosensitivity of cancerous cells.
Collapse
|
7
|
Cooke D, Ouattara A, Ables GP. Dietary methionine restriction modulates renal response and attenuates kidney injury in mice. FASEB J 2018; 32:693-702. [PMID: 28970255 DOI: 10.1096/fj.201700419r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Methionine restriction (MR) extends the lifespan across several species, such as rodents, fruit flies, roundworms, and yeast. MR studies have been conducted on various rodent organs, such as liver, adipose tissue, heart, bones, and skeletal muscle, to elucidate its benefits to the healthspan; however, studies of the direct effect of MR on kidneys are lacking. To investigate the renal effects of MR, we used young and aged unilateral nephrectomized and 5/6 nephrectomized (5/6Nx) mice. Our studies indicated that MR mice experienced polydipsia and polyuria compared with control-fed counterparts. Urine albumin, creatinine, albumin-to-creatinine ratio, sulfur amino acids, and electrolytes were reduced in MR mice. Kidneys of MR mice up-regulated genes that are involved in ion transport, such as Aqp2, Scnn1a, and Slc6a19, which indicated a response to maintain osmotic balance. In addition, we identified renoprotective biomarkers that are affected by MR, such as clusterin and cystatin C. Of importance, MR attenuated kidney injury in 5/6Nx mice by down-regulating inflammation and fibrosis mechanisms. Thus, our studies in mice show the important role of kidneys during MR in maintaining osmotic homeostasis. Moreover, our studies also show that the MR diet delays the progression of kidney disease.-Cooke, D., Ouattara, A., Ables, G. P. Dietary methionine restriction modulates renal response and attenuates kidney injury in mice.
Collapse
Affiliation(s)
- Diana Cooke
- Orentreich Foundation for the Advancement of Science, Cold Spring, New York, USA
| | - Amadou Ouattara
- Orentreich Foundation for the Advancement of Science, Cold Spring, New York, USA
| | - Gene P Ables
- Orentreich Foundation for the Advancement of Science, Cold Spring, New York, USA
| |
Collapse
|
8
|
Abstract
Methionine restriction (MR) extends lifespan across different species. The main responses of rodent models to MR are well-documented in adipose tissue (AT) and liver, which have reduced mass and improved insulin sensitivity, respectively. Recently, molecular mechanisms that improve healthspan have been identified in both organs during MR. In fat, MR induced a futile lipid cycle concomitant with beige AT accumulation, producing elevated energy expenditure. In liver, MR upregulated fibroblast growth factor 21 and improved glucose metabolism in aged mice and in response to a high-fat diet. Furthermore, MR also reduces mitochondrial oxidative stress in various organs such as liver, heart, kidneys, and brain. Other effects of MR have also been reported in such areas as cardiac function in response to hyperhomocysteinemia (HHcy), identification of molecular mechanisms in bone development, and enhanced epithelial tight junction. In addition, rodent models of cancer responded positively to MR, as has been reported in colon, prostate, and breast cancer studies. The beneficial effects of MR have also been documented in a number of invertebrate model organisms, including yeast, nematodes, and fruit flies. MR not only promotes extended longevity in these organisms, but in the case of yeast has also been shown to improve stress tolerance. In addition, expression analyses of yeast and Drosophila undergoing MR have identified multiple candidate mediators of the beneficial effects of MR in these models. In this review, we emphasize other in vivo effects of MR such as in cardiovascular function, bone development, epithelial tight junction, and cancer. We also discuss the effects of MR in invertebrates.
Collapse
|
9
|
Ables GP, Hens JR, Nichenametla SN. Methionine restriction beyond life-span extension. Ann N Y Acad Sci 2016; 1363:68-79. [DOI: 10.1111/nyas.13014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 01/06/2016] [Accepted: 01/11/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Gene P. Ables
- Orentreich Foundation for the Advancement of Science; Cold Spring New York
| | - Julie R. Hens
- Orentreich Foundation for the Advancement of Science; Cold Spring New York
| | | |
Collapse
|
10
|
Ouattara A, Cooke D, Gopalakrishnan R, Huang TH, Ables GP. Methionine restriction alters bone morphology and affects osteoblast differentiation. Bone Rep 2016; 5:33-42. [PMID: 28326345 PMCID: PMC4926829 DOI: 10.1016/j.bonr.2016.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/20/2016] [Accepted: 02/08/2016] [Indexed: 12/22/2022] Open
Abstract
Methionine restriction (MR) extends the lifespan of a wide variety of species, including rodents, drosophila, nematodes, and yeasts. MR has also been demonstrated to affect the overall growth of mice and rats. The objective of this study was to evaluate the effect of MR on bone structure in young and aged male and female C57BL/6J mice. This study indicated that MR affected the growth rates of males and young females, but not aged females. MR reduced volumetric bone mass density (vBMD) and bone mineral content (BMC), while bone microarchitecture parameters were decreased in males and young females, but not in aged females compared to control-fed (CF) mice. However, when adjusted for bodyweight, the effect of MR in reducing vBMD, BMC and microarchitecture measurements was either attenuated or reversed suggesting that the smaller bones in MR mice is appropriate for its body size. In addition, CF and MR mice had similar intrinsic strength properties as measured by nanoindentation. Plasma biomarkers suggested that the low bone mass in MR mice could be due to increased collagen degradation, which may be influenced by leptin, IGF-1, adiponectin and FGF21 hormone levels. Mouse preosteoblast cell line cultured under low sulfur amino acid growth media attenuated gene expression levels of Col1al, Runx2, Bglap, Alpl and Spp1 suggesting delayed collagen formation and bone differentiation. Collectively, our studies revealed that MR altered bone morphology which could be mediated by delays in osteoblast differentiation. MR affected the growth rates of males and young females, but not aged females. CF and MR mice had similar intrinsic strength properties. Low methionine media attenuated bone differentiation genes in MC3T3-E1 preosteoblast cells. The lower bone mass in MR mice is appropriate for its smaller body size.
Collapse
Key Words
- Aged mice
- BMC, bone mineral content
- BS, bone surface
- BV, bone volume
- CF, control-fed
- CTX-1, C-terminal telopeptide of type 1 collagen
- Conn.Dn., connectivity density
- FGF21, fibroblast growth factor-21
- HFD, high-fat diet
- HHCy, hyperhomocysteinemia
- IDI, indentation depth increase
- IGF-1, insulin-like growth factor-1
- Imax, maximal MOI
- Imin, minimal MOI
- LPD, low protein diet
- MC3T3-E1 subclone 4
- MOI, moment of inertia
- MR, methionine restriction
- Methionine restriction
- Micro-computed tomography
- Nanoindentation
- OC, osteocalcin
- OPG, osteoprotegerin
- P1NP, N-terminal propeptide of type 1 procollagen
- RANKL, receptor activator for nuclear factor κB ligand
- SMI, structure model index
- TV, total volume
- Tb.N, trabecular number
- Tb.Sp, trabecular separation
- Tb.Th, trabecular thickness
- pMOI, polar MOI
- vBMD, volumetric bone mass density
- μCT, micro-computed tomography
Collapse
Affiliation(s)
- Amadou Ouattara
- Orentreich Foundation for the Advancement of Science, Inc, 855 Route 301, Cold Spring, NY 10516, USA
| | - Diana Cooke
- Orentreich Foundation for the Advancement of Science, Inc, 855 Route 301, Cold Spring, NY 10516, USA
| | - Raj Gopalakrishnan
- School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tsang-hai Huang
- Institute of Physical Education, Health and Leisure Studies, National Cheng Kung University, Tainan City, Taiwan
| | - Gene P. Ables
- Orentreich Foundation for the Advancement of Science, Inc, 855 Route 301, Cold Spring, NY 10516, USA
- Corresponding author at: Orentreich Foundation for the Advancement of Science, Inc., 855 Route 301, Cold Spring, NY 10516, USA.Orentreich Foundation for the Advancement of Science, Inc.855 Route 301Cold SpringNY10516USA
| |
Collapse
|
11
|
Mullin JM, Skrovanek SM, Ramalingam A, DiGuilio KM, Valenzano MC. Methionine restriction fundamentally supports health by tightening epithelial barriers. Ann N Y Acad Sci 2015; 1363:59-67. [PMID: 26646941 DOI: 10.1111/nyas.12955] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/16/2015] [Accepted: 10/16/2015] [Indexed: 12/21/2022]
Abstract
Dietary methionine restriction (MR) has been found to affect one of the most primary tissue-level functions of an organism: the efficiency with which the epithelial linings of major organs separate the fluid compartments that they border. This process, epithelial barrier function, is basic for proper function of all organs, including the lung, liver, gastrointestinal tract, reproductive tract, blood-brain barrier, and kidney. Specifically, MR has been found to modify the protein composition of tight junctional complexes surrounding individual epithelial cells in a manner that renders the complexes less leaky. This has been observed in both a renal epithelial cell culture model and in gastrointestinal tissue. In both cases, MR increased the transepithelial electrical resistance across the epithelium, while decreasing passive leak of small nonelectrolytes. However, the specific target protein modifications involved were unique to each case. Overall, this provides an example of the primary level on which MR functions to modify, and improve, an organism.
Collapse
Affiliation(s)
- James M Mullin
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania.,Division of Gastroenterology, Lankenau Medical Center, Wynnewood, Pennsylvania
| | | | | | | | - Mary C Valenzano
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| |
Collapse
|
12
|
Beutheu S, Ghouzali I, Galas L, Déchelotte P, Coëffier M. Glutamine and arginine improve permeability and tight junction protein expression in methotrexate-treated Caco-2 cells. Clin Nutr 2013; 32:863-9. [DOI: 10.1016/j.clnu.2013.01.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/23/2012] [Accepted: 01/27/2013] [Indexed: 12/16/2022]
|
13
|
Wang X, Valenzano MC, Mercado JM, Zurbach EP, Flounders CJ, Mullin JM. Zinc enhancement of LLC-PK(1) renal epithelial barrier function. Clin Nutr 2013; 33:280-6. [PMID: 23755840 DOI: 10.1016/j.clnu.2013.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 04/02/2013] [Accepted: 05/01/2013] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND AIMS Earlier work by our group and others has documented improvement of epithelial barrier function in human gastrointestinal models. Here we tested zinc's ability to improve a renal epithelial model. Our aim was to compare the functional and structural effects of zinc on the tight junctional (TJ) complexes of these two very distinct epithelial cell types. Zinc's ability to achieve barrier enhancement in very different epithelial cell types by action upon distinct molecular targets in each epithelial model may suggest a fundamental general role for supplemental zinc in epithelial barrier improvement throughout the body. METHODS Cell layers were exposed to 50 or 100 μM zinc on both cell surfaces for 48 h followed by measurement of transepithelial electrical resistance (Rt) and transepithelial (14)C-mannitol flux (Jm). TJ proteins in cell layers were analyzed by Western immunoblot. RESULTS AND CONCLUSIONS Zinc supplementation improved the basal TJ barrier function of LLC-PK1 renal cell layers, exemplified by increased Rt and decreased Jm. These zinc-induced changes were also accompanied by decreased NaCl dilution potentials. Of the tight junctional proteins that were tested (occludin, claudins 1, 2, 3, 4, and 5, and tricellulin), we did not observe a zinc-induced change in abundance of any of them, in detergent-soluble fractions of lysates of confluent differentiated cell layers. However, examination of cytosolic fractions showed concentration-dependent increases in the levels of claudins -2 and -4 in this compartment as a result of supplemental zinc. The effects of supplemental zinc on the tight junctional complexes and barrier properties of this renal epithelial model are contrasted with zinc effects on the CACO-2 gastrointestinal model.
Collapse
Affiliation(s)
- Xuexuan Wang
- Lankenau Institute for Medical Research, Wynnewood, PA 19096, USA
| | | | - Joanna M Mercado
- Lankenau Institute for Medical Research, Wynnewood, PA 19096, USA
| | - E Peter Zurbach
- Department of Chemistry, Saint Joseph's University, 5600 City Avenue, Philadelphia, PA 19131, USA
| | - Christopher J Flounders
- School of Biomedical Engineering Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
| | - James M Mullin
- Lankenau Institute for Medical Research, Wynnewood, PA 19096, USA; Division of Gastroenterology, Lankenau Medical Center, Wynnewood, PA 19096, USA.
| |
Collapse
|
14
|
Wang X, Valenzano MC, Mercado JM, Zurbach EP, Mullin JM. Zinc supplementation modifies tight junctions and alters barrier function of CACO-2 human intestinal epithelial layers. Dig Dis Sci 2013; 58:77-87. [PMID: 22903217 DOI: 10.1007/s10620-012-2328-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 07/17/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND Zinc deficiency is known to result in epithelial barrier leak in the GI tract. Precise effects of zinc on epithelial tight junctions (TJs) are only beginning to be described and understood. Along with nutritional regimens like methionine-restriction and compounds such as berberine, quercetin, indole, glutamine and rapamycin, zinc has the potential to function as a TJ modifier and selective enhancer of epithelial barrier function. AIMS The purpose of this study was to determine the effects of zinc-supplementation on the TJs of a well-studied in vitro GI model, CACO-2 cells. METHODS Barrier function was assessed electrophysiologically by measuring transepithelial electrical resistance (Rt), and radiochemically, by measuring transepithelial (paracellular) diffusion of 14C-D-mannitol and 14C-polyethyleneglycol. TJ composition was studied by Western immunoblot analyses of occludin, tricellulin and claudins-1 to -5 and -7. RESULTS Fifty- and 100-μM zinc concentrations (control medium is 2 μM) significantly increase Rt but simultaneously increase paracellular leak to D-mannitol. Claudins 2 and 7 are downregulated in total cell lysates, while occludin, tricellulin and claudins-1, -3, -4 and -5 are unchanged. Claudins-2 and -7 as well as tricellulin exhibit decreased cytosolic content as a result of zinc supplementation. CONCLUSIONS Zinc alters CACO-2 TJ composition and modifies TJ barrier function selectively. Zinc is one of a growing number of "nutraceutical" substances capable of enhancing epithelial barrier function, and may find use in countering TJ leakiness induced in various disease states.
Collapse
Affiliation(s)
- Xuexuan Wang
- Lankenau Institute for Medical Research, 100 W Lancaster Ave, Wynnewood, PA 19096, USA
| | | | | | | | | |
Collapse
|
15
|
Overgaard CE, Daugherty BL, Mitchell LA, Koval M. Claudins: control of barrier function and regulation in response to oxidant stress. Antioxid Redox Signal 2011; 15:1179-93. [PMID: 21275791 PMCID: PMC3144428 DOI: 10.1089/ars.2011.3893] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Claudins are a family of nearly two dozen transmembrane proteins that are a key part of the tight junction barrier that regulates solute movement across polarized epithelia. Claudin family members interact with each other, as well as with other transmembrane tight junction proteins (such as occludin) and cytosolic scaffolding proteins (such as zonula occludens-1 (ZO-1)). Although the interplay between all of these different classes of proteins is critical for tight junction formation and function, claudin family proteins are directly responsible for forming the equivalent of paracellular ion selective channels (or pores) with specific permeability and thus are essential for barrier function. In this review, we summarize current progress in identifying structural elements of claudins that regulate their transport, assembly, and function. The effects of oxidant stress on claudins are also examined, with particular emphasis on lung epithelial barrier function and oxidant stress induced by chronic alcohol abuse.
Collapse
Affiliation(s)
- Christian E Overgaard
- Division of Pulmonary, Allergy and Critical Care Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | |
Collapse
|
16
|
Tang X, Yang Y, Shi Y, Le G. Comparative in vivo antioxidant capacity of DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) and DL-methionine in male mice fed a high-fat diet. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2011; 91:2166-2172. [PMID: 21567412 DOI: 10.1002/jsfa.4434] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/14/2011] [Accepted: 03/14/2011] [Indexed: 05/30/2023]
Abstract
BACKGROUND In animal diets, methionine (Met) is considered to be the first limiting amino acid, and the activity of synthetic Met is typically added either as DL-methionine (DLM) or as DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA). It has been demonstrated that HMTBA exhibits a higher antioxidant capability in vitro as compared to DLM. However, the difference in antioxidant capability between DLM and HMTBA in vivo is unknown. METHODS In the present study, 60 male C57BL/6 mice were randomly divided into six groups and fed either a normal diet (NFD, 5.37% fat) or a high-fat diet (HFD, 19.7% fat) in conjunction with 0.2% DLM, 0.2% HMTBA or 0.1% DLM and 0.1% HMTBA for 4 weeks. RESULTS HFD supplemented with 2% DLM and NFD with 2% HMTBA both induced adverse affects in relation to serum lipid parameters and depressed antioxidant defense systems in the digestive system. However, these changes were restored in the 0.2% HMTBA-treated HFD group. Furthermore, no significant differences were found in the lipid parameters and antioxidant status in the NFD and HFD group supplemented with 0.1% DLM and 0.1% HMTBA. CONCLUSION HMTBA restored oxidative redox status under OS conditions and its antioxidant properties were positively correlated with the dosage included in diet.
Collapse
Affiliation(s)
- Xue Tang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, Jiangsu Province, PR China
| | | | | | | |
Collapse
|
17
|
Nakatsukasa M, Sotozono C, Shimbo K, Ono N, Miyano H, Okano A, Hamuro J, Kinoshita S. Amino Acid profiles in human tear fluids analyzed by high-performance liquid chromatography and electrospray ionization tandem mass spectrometry. Am J Ophthalmol 2011; 151:799-808.e1. [PMID: 21310375 DOI: 10.1016/j.ajo.2010.11.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 10/29/2010] [Accepted: 11/01/2010] [Indexed: 11/29/2022]
Abstract
PURPOSE To identify the 23 amino acid profiles in human tear fluids, and to evaluate whether the ocular disease conditions reflect the amino acid profiles. DESIGN Laboratory investigation. METHODS We evaluated the concentrations and relative composition of 23 amino acids in tear fluids obtained from 31 healthy volunteers using reversed-phase high-performance liquid chromatography and electrospray ionization tandem mass spectrometry, and compared them with those in plasma and aqueous humor. We also evaluated the tear-fluid amino acid profiles from 33 affected subjects. RESULTS The amino acid profiles of the basal tear and reflex tear were found to be similar, and 4 distinct groups of healthy volunteers (male, female, young, and elderly) showed similar profiles. Absolute concentrations of taurine (Tau) and L-glutamine were significantly dominant in these tear fluids. The relative compositions of Tau, L-glutamic acid, L-arginine (Arg), and citrulline in the tear fluid were significantly higher than those in the plasma and aqueous humor. Analysis of the hierarchical clustering of the amino acid profiles clearly distinguished severe ocular surface diseases from non-ocular surface diseases. The relative compositions of Tau, L-methionine, and Arg decreased in severe ocular surface disease subjects compared with non-ocular surface disease subjects. CONCLUSIONS Tear-fluid amino acid profiles differ from those in plasma and aqueous humor. Steady-state tear-fluid amino acid profiles might reflect ocular-surface homeostasis and the observed changes of amino acids might have a close relation with the disease conditions on the ocular surface.
Collapse
Affiliation(s)
- Mina Nakatsukasa
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Ramalingam A, Wang X, Gabello M, Valenzano MC, Soler AP, Ko A, Morin PJ, Mullin JM. Dietary methionine restriction improves colon tight junction barrier function and alters claudin expression pattern. Am J Physiol Cell Physiol 2010; 299:C1028-35. [PMID: 20739626 DOI: 10.1152/ajpcell.00482.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The beneficial effects of caloric restriction in increasing longevity and forestalling age-related diseases are well known. Dietary restriction of methionine also renders similar benefits. We recently showed in a renal epithelial cell culture system that reduction of culture medium methionine by 80% resulted in altered tight junctional (TJ) claudin composition and also improved epithelial barrier function (51). In the current study, we examined the effect of dietary restriction of methionine on TJ barrier function in rat gastrointestinal tissue to see whether this phenomenon also holds true in a tissue model and for a different epithelial cell type. After 28 days on methionine-restricted (MR) diet, rats showed small but significant reductions in the plasma and (intracellular) colonocyte levels of methionine. Colon mucosal sheets from rats on the MR diet showed increased transepithelial electrical resistance with concomitant decrease in paracellular diffusion of (14)C-D-mannitol, suggesting improved barrier function relative to rats on control diet. This improved barrier function could not be explained by changes in colon crypt length or frequency. Neither was the colonocyte mitotic index nor the apoptotic frequency altered significantly. However, TJ composition/structure was being altered by the MR diet. RT-PCR and Western blot analysis showed an increase in the abundance of claudin-3 and an apparent change in the posttranslational modification of occludin, data reinforcing a paracellular barrier alteration. Overall, our data suggest that reduction in dietary intake of methionine results in improved epithelial barrier function by inducing altered TJ protein composition.
Collapse
|
19
|
D'Souza T, Sherman-Baust CA, Poosala S, Mullin JM, Morin PJ. Age-related changes of claudin expression in mouse liver, kidney, and pancreas. J Gerontol A Biol Sci Med Sci 2009; 64:1146-53. [PMID: 19692671 DOI: 10.1093/gerona/glp118] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Tight junctions (TJs) play crucial roles in tissue homeostasis and inflammation through their roles in the control of paracellular transport and barrier function. There is evidence that these functions are compromised in older organisms, but the exact mechanisms leading to TJ deterioration are not well understood. Claudin proteins are a family of membrane proteins that constitute the structural barrier elements of TJs and therefore play a major role in their formation and function. Using immunohistochemistry and immunoblotting, we have studied the expression of six different claudin proteins (claudin-1, -2, -3, -4, -5, and -7) in three tissues (liver, kidney, and pancreas) of aging male and female mice. In general, we find an age-dependent decrease in the expression of several claudin proteins in all three tissues observed, although the exact changes are tissue specific. Our findings provide a possible basis for the decrease in tissue barrier function in older organisms.
Collapse
Affiliation(s)
- Theresa D'Souza
- Laboratory of Cellular and Molecular Biology, National Institute on Aging, NIH Biomedical Research Center, Baltimore, MD 21224, USA
| | | | | | | | | |
Collapse
|
20
|
Walter JK, Rueckert C, Voss M, Mueller SL, Piontek J, Gast K, Blasig IE. The oligomerization of the coiled coil-domain of occludin is redox sensitive. Ann N Y Acad Sci 2009; 1165:19-27. [PMID: 19538283 DOI: 10.1111/j.1749-6632.2009.04058.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The transmembrane tight junction protein occludin is sensitive to oxidative stress. Occludin oligomerizes; however, its function in the tight junction is unknown. The cytosolic C-terminal tail contains a coiled coil-domain and forms dimers contributing to the oligomerization. The regulation of the oligomerization remains unclear. As the domain area contains sulfhydryl residues, we tested the hypothesis that the dimerization of the coiled coil-domain depends on these residues. We showed that the dimerization is modulated by the thiol concentration in the low-millimolar range, which is relevant both for physiological and pathophysiological conditions. Masking the sulfhydryl residues in the fragment by covalent binding of 4-vinyl pyridine prevented the dimerization but did not affect its helical structure and cylindric shape. The data demonstrate, for the first time, that disulfide bridge formation of murine cystein 408 is involved in the dimerization. This process is redox-sensitive but the secondary structure of the domain is not. It is concluded that the dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.
Collapse
Affiliation(s)
- Juliane K Walter
- Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
21
|
Mullin JM, Skrovanek SM, Valenzano MC. Modification of Tight Junction Structure and Permeability by Nutritional Means. Ann N Y Acad Sci 2009; 1165:99-112. [DOI: 10.1111/j.1749-6632.2009.04028.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
22
|
Martin TA, Jiang WG. Loss of tight junction barrier function and its role in cancer metastasis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:872-91. [DOI: 10.1016/j.bbamem.2008.11.005] [Citation(s) in RCA: 313] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 10/29/2008] [Accepted: 11/06/2008] [Indexed: 12/23/2022]
|
23
|
Claudin-3 gene silencing with siRNA suppresses ovarian tumor growth and metastasis. Proc Natl Acad Sci U S A 2009; 106:3426-30. [PMID: 19208807 DOI: 10.1073/pnas.0813348106] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Claudin-3 (CLDN3) is a tight junction protein that is overexpressed in 90% of ovarian tumors. Previous in vitro studies have indicated that CLDN3 overexpression promotes the migration, invasion, and survival of ovarian cancer cells. Here, we investigated the efficacy of lipidoid-formulated CLDN3 siRNA in 3 different ovarian cancer models. Intratumoral injection of lipidoid/CLDN3 siRNA into OVCAR-3 xenografts resulted in dramatic silencing of CLDN3, significant reduction in cell proliferation, reduction in tumor growth, and a significant increase in the number of apoptotic cells. Intraperitoneal injection of lipidoid-formulated CLDN3 siRNA resulted in a substantial reduction in tumor burden in MISIIR/TAg transgenic mice and mice bearing tumors derived from mouse ovarian surface epithelial cells. Ascites development was reduced in CLDN3 siRNA-treated mice, suggesting the treatment effectively suppressed metastasis. Toxicity was not observed after multiple i.p. injections. Importantly, treatment of mice with nonimmunostimulatory 2'-OMe modified CLDN3 siRNA was as effective in suppressing tumor growth as unmodifed siRNA. These results suggest that lipidoid-formulated CLDN3 siRNA has potential as a therapeutic for ovarian cancer.
Collapse
|