Sergiy Sukhanov - Academia.edu (original) (raw)
Papers by Sergiy Sukhanov
Journal of Investigative Medicine, 2007
Apoptosis of smooth muscle cells (SMCs) is a prominent feature of advanced atherosclerotic plaque... more Apoptosis of smooth muscle cells (SMCs) is a prominent feature of advanced atherosclerotic plaque. We have previously shown that the proatherogenic molecule oxidized low-density lipoprotein (OxLDL) is associated with apoptotic SMCs in advanced plaques of human aorta and that OxLDL produces marked SMC apoptosis in vitro. In human aortic smooth muscle cells (HASMCs), the antioxidant Tiron (1 mM) suppressed superoxide production (by 18 ± 2%, DHE assay) and peroxide generation (by 88 ± 4%, CDC assay) induced by OxLDL (80 μg/mL, 16 hours) and completely blunted HASMC apoptosis (by 89 ± 2.6%, CELL DEATH ELISA), indicating that OxLDL-induced apoptosis was mediated by a redox-sensitive mechanism. The lipoxygenase (LOX) inhibitors AA-861, 5 μM and NDGA, 10 μM decreased OxLDL-induced superoxides (by 15 ± 2% and 25 ± 4%, respectively) and peroxides (by 48 ± 3% and 62 ± 6%, respectively) and NDGA completely blocked HASMC apoptosis (flow cytometry with annexin V staining). AA-861, 10 μM, another LOX inhibitor, Baicalein, 10 μM, and the NADPH oxidase-specific blocker apocynin, 100 μM suppressed OxLDL-induced HASMC apoptosis (by 93.0 ± 7%, 94 ± 0.4%, and 83 ± 3%, respectively) as was measured using cell death ELISA. To identify the oxidases involved in OxLDL-induced apoptosis, we studied the effect of OxLDL on SMC isolated from the aorta of 5-LOX- and 12/15-LOX-deficient and wild-type (WT) mice. 12/15-LOX deficiency markedly reduced OxLDL-induced superoxides and peroxides (by 31 ± 3% and 62 ± 7%, respectively, compared with WT). OxLDL-induced apoptosis was completely inhibited in 5-LOX- or 12/15-LOX-deficient SMC (by 82.6 ± 0.5% and 94.1 ± 0.7%, respectively); however, OxLDL produced 90.8 ± 4.4% apoptosis of WT SMC compared with control (0.5 μM staurosporine). In summary, we have identified 5-, 12/15-lipoxygenase and NADPH oxidase as key mediators of OxLDL-induced oxidative stress and SMC apoptosis. These data establish a novel functional relationship between different oxidases and together with our previous findings have major implications for understanding the mechanism of SMC depletion in advanced atherosclerotic plaque leading to plaque destabilization and acute coronary events.
Circulation, Nov 10, 2015
In arterial remodeling, smooth muscle cell (SMC) loss of contractile phenotype and increased prol... more In arterial remodeling, smooth muscle cell (SMC) loss of contractile phenotype and increased proliferation may result in vessel stenosis or a greater propensity for aneurysm formation and rupture. ...
Biochemical and Biophysical Research Communications, Jun 1, 2003
Oxidized low density lipoproteins (OxLDL) play a key role in atherogenesis and induce a wide rang... more Oxidized low density lipoproteins (OxLDL) play a key role in atherogenesis and induce a wide range of biological effects on smooth muscle cells. We used two commercially available cDNA microarray systems with a total of 35,932 human genes to determine differentially expressed genes in OxLDL-treated human aortic smooth muscle cells (HASMC) and to identify novel genes responsive to this agonist. We found a significant increase in expression of 180 and a significant decrease in expression of 192 named genes after treatment by OxLDL, compared with native LDL. Real time-PCR analysis confirmed microarray data for seven of eight tested genes. The differentially regulated genes were grouped into 16 classes based on the functions of the corresponding protein products. Our data demonstrate that OxLDL predominantly elevates expression of genes involved in cell-cell interactions, membrane transport, oncogenesis, apoptosis, and transcription and decreases expression of genes responsible for protein and nucleic acid biosynthesis, lipid metabolism, and humoral responses. Interestingly, we identify for the first time expression of metastasis-related protein (MB2) and novel scavenger receptor SREC-II in HASMC and these were upregulated 12- and 3-fold by OxLDL treatment, respectively. These findings have major implications for understanding atherogenic effect of OxLDL.
Biopolymers & Cell, Jan 20, 1994
Исследованы функциональные характеристики ДНК-зависимых ДНК-полимераз цианобактерии P. boryanum. ... more Исследованы функциональные характеристики ДНК-зависимых ДНК-полимераз цианобактерии P. boryanum. Установлено, что ДНК-полимераза II (ДЛИ) активно использует матрицы с различной структурой (наиболее активен фермент на ДНК P. boryanum и цианофага LPP-3, лизирующего данную цианобактерию), ДНК-поли мераза I (ДП1) менее активна на большинстве испытанных матриц, исключая цианобактериальную ДНК. Оба фермента нуждаются в праймировании синтетических рибонуклеиновых матриц и выявили разнию способность включать каждый из дезоксинуклеозидтрифосфатов. ДП1 и ДПП обладают З г-5''-экзонуклеазной актив ностью причем ДПП имеет более мощную ассоциированную экзонуклеазу. Только ДП1 способна к гидролизу фосфодиэфирных связей в направлении У-3'. Сделан вывод о возможной функциональной роли цианобактериальных ДП К-пол и мера з in vivo: ДПП является основным клеточным репликативным ферментом., а ДП1 ответственна за осиществление репаративных процессов и близка по свойствам ДНК-полимеразе I Escherichia со П.
Frontiers of Hormone Research, 2014
The process of vascular aging encompasses alterations in the function of endothelial (EC) and vas... more The process of vascular aging encompasses alterations in the function of endothelial (EC) and vascular smooth muscle cells (VSMCs) via oxidation, inflammation, cell senescence and epigenetic modifications, increasing the probability of atherosclerosis. Aged vessels exhibit decreased endothelial antithrombogenic properties, increased reactive oxygen species (ROS) generation and inflammatory signaling, increased migration of VSMCs to the subintimal space, impaired angiogenesis and increased elastin degradation. The key initiating step in atherogenesis is subendothelial accumulation of apolipoprotein-B containing low density lipoproteins resulting in activation of endothelial cells and recruitment of monocytes. Activated endothelial cells secrete “chemokines” that interact with cognate chemokine receptors on monocytes and promote directional migration. Recruitment of immune cells establishes a pro-inflammatory status, further causing elevated oxidative stress, which in turn triggers a series of events including apoptotic or necrotic death of vascular and non-vascular cells. Increased oxidative stress is also considered to be a key factor in mechanisms of aging-associated changes in tissue integrity and function. Experimental evidence indicates that insulin-like growth factor-1 (IGF-1) exerts anti-oxidant, anti-inflammatory and pro-survival effects on the vasculature, reducing atherosclerotic plaque burden and promoting features of atherosclerotic plaque stability.
Circulation, Nov 10, 2015
Impaired mitochondrial proliferation and function may lead to heart failure. Mitochondrial biogen... more Impaired mitochondrial proliferation and function may lead to heart failure. Mitochondrial biogenesis during postnatal cardiac development in rodents is accompanied by oxidative mitochondrial (mt) DNA damage and repair. How mtDNA damage is linked to mitochondrial biogenesis is unknown, but our previous data suggest that site-specific mtDNA oxidation is involved in regulation of mtDNA replication. Here we tested the hypothesis that modulation of Ogg1, a DNA glycosylase mediating the first step in the base excision repair of oxidative mtDNA damage, coordinately affects mitochondrial function and cardiac development. Wild type (WT) mice, Ogg1 knock-out (KO) mice and KO mice transgenically overexpressing mitochondria-targeted Ogg1 (KOTG) were analyzed for mtDNA damage and replication using Southern and slot-blot analyses; mitochondrial respiration using oxygraph; and cardiac function using echocardiography. Compared to WT, KO mice showed increased oxidative mtDNA damage in cardiac tissue, (0.18 ± 0.04 vs. 0.35 ± 0.04 lesions/104 bp respectively, p<0.05), 2-fold decrease in mtDNA copy number (p<0.05) and increased heart:body mass ratio (4.96 ± 0.11 vs. 5.70 ± 0.10 mg/g respectively, p<0.05). Conversely, KOTG mice showed decreased mtDNA oxidation, restored mtDNA copy number and blunted elevation in cardiac mass. Echocardiography confirmed increased cardiac mass in KO mice with a trend towards decrease of cardiac contractility. Compared to hearts from WT mice, KO animals displayed significant increase in mitochondrial oxygen flux at state III (54.0 ± 8.1 vs. 93.9 ± 9.2 pmol/sec/ml/10 mg respectively, p<0.05) with concurrent decrease in respiratory ratio (2.56 ± 0.42 vs. 1.46 ± 0.27 respectively), indicating constitutive uncoupling in the cardiac tissue. Mitochondrial bioenergetics of KOTG mice did not differ from WT animals. In summary, Ogg1 deficiency in mice leads to elevated oxidative mtDNA damage; decreased mtDNA copy number and respiration; and cardiac hypertrophy. Restored mtDNA repair completely eliminated these effects on mitochondrial function and cardiac development. These results suggest that abnormalities in mitochondrial function and cardiac development can be manipulated by altering mtDNA damage and repair.
Endocrinology, 1982
We have investigated the effects of monosodium glutamate (MSG) lesioning of the arcuate nucleus o... more We have investigated the effects of monosodium glutamate (MSG) lesioning of the arcuate nucleus on both central and peripheral components of the hypothalamo\x=req-\ pituitary-adrenocortical (HPA) axis under basal conditions and under acute and chronic stress. Plasma ACTH levels were lower in MSG-lesioned rats (27 \ m=+-\7 pg/ml) compared with controls (71 \ m=+-\18 pg/ml) while corticosterone levels were elevated (523 \ m=+-\ 84 ng/ml compared with 176 \ m=+-\34 ng/ml). Quantititative in situ hybridization histochemistry revealed that corticotrophin-releasing factor mRNA levels in the medial parvocellular part of the hypothalamic paraventricular nucleus were significantly lower in MSG-treated rats. MSG lesioning resulted in an enhanced response of corticosterone to restraint stress (1309 \m=+-\ 92 ng/ml compared with 628 \ m=+-\ 125 ng/ml in sham-lesioned animals), while ACTH responses to restraint stress in MSG-lesioned and sham-MSG groups were not significantly different (160 \m=+-\ 24 pg/ml and 167 \m=+-\ 24 pg/ml respectively). These data suggest that MSG-lesioned rats have an increased adrenocortical sensitivity. In rats subjected to the chronic osmotic stimulus of drinking 2% saline for 12 days, plasma ACTH levels were significantly reduced (15 \ m=+-\ 5 pg/ml) and the ACTH and corticosterone responses to restraint stress were eliminated. ACTH levels were also reduced in MSG-treated animals given 2% saline and the ACTH response to acute stress remained absent in these animals. However, a robust corticosterone response to restraint stress was observed in saline-treated MSG-lesioned rats. These data demonstrate that MSG lesioning results in elevated basal and stress\x=req-\ induced plasma corticosterone, and restores the adrenocortical response to stress which is absent in chronically osmotically stimulated rats. The evidence is consistent with the suggestion that MSG lesions a pathway involved in tonic inhibition of the HPA axis. In addition, the adrenocortical sensitivity to ACTH and other secretagogues may be increased in MSG-treated animals.
Circulation, 2017
Glyceraldehyde-3’-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme with a multiple glycolys... more Glyceraldehyde-3’-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme with a multiple glycolysis-unrelated functions. We have shown previously that GAPDH protected smooth muscle cells (SMC) agai...
JCI insight, Feb 22, 2023
Although murine models of coronary atherosclerotic disease have been used extensively to determin... more Although murine models of coronary atherosclerotic disease have been used extensively to determine mechanisms, limited new therapeutic options have emerged. Pigs with familial hypercholesterolemia (FH pigs) develop complex coronary atheromas that are almost identical to human lesions. We reported previously that insulin-like growth factor 1 (IGF-1) reduced aortic atherosclerosis and promoted features of stable plaque in a murine model. We administered human recombinant IGF-1 or saline (control) in atherosclerotic FH pigs for 6 months. IGF-1 decreased relative coronary atheroma in vivo (intravascular ultrasound) and reduced lesion cross-sectional area (postmortem histology). IGF-1 increased plaque's fibrous cap thickness, and reduced necrotic core, macrophage content, and cell apoptosis consistent with promotion of a stable plaque phenotype. IGF-1 reduced circulating triglycerides, markers of systemic oxidative stress and CXCL12 chemokine levels. We used spatial transcriptomics (ST) to identify global transcriptome changes in advanced plaque compartments and to obtain mechanistic insights into IGF-1 effects. ST analysis shows that IGF-1 suppressed FOS/FOSB factors and gene expression of MMP9 and CXCL14 in plaque macrophages, suggesting possible involvement of these molecules in IGF-1's effect on atherosclerosis. Thus, IGF-1 reduced coronary plaque burden and promoted features of stable plaque in a pig model, providing support for consideration of clinical trials.
Circulation, Nov 11, 2016
Collagen is a major constituent of the extracellular matrix in atherosclerotic plaques and suppor... more Collagen is a major constituent of the extracellular matrix in atherosclerotic plaques and supports plaque stability. La ribonucleoprotein domain family member 6 (LARP6) is an RNA binding protein, ...
The FASEB Journal, Apr 1, 2019
Circulation, Nov 14, 2017
Endothelial cells (ECs) provide a barrier function to the vasculature, which is supported by inte... more Endothelial cells (ECs) provide a barrier function to the vasculature, which is supported by intercellular junctions between ECs. Two types of endothelial cell intercellular junctions, namely tight...
Circulation, Nov 25, 2014
Introduction: Reactive oxygen species (ROS) play a key role in the development of atherosclerosis... more Introduction: Reactive oxygen species (ROS) play a key role in the development of atherosclerosis. Mitochondria are a main source of endogenous ROS in the cell. Mitochondrial DNA (mtDNA) is sensitive to oxidation and our previous results from cultured cell and intact animal models suggest that increasing mtDNA repair prevents both oxidative mtDNA damage and associated cytotoxicity and cellular dysfunction. Involvement of oxidative mtDNA damage in disorders characterized by chronic oxidative stress has been less thoroughly studied. Hypothesis: In the present study we tested the hypothesis that transgenic modulation of Ogg1, a DNA glycosylase mediating the first step in the base excision repair of oxidative mtDNA damage, coordinately regulates atherogenesis in mice fed a high fat diet. Methods: Wild type (WT) mice, Ogg1 knock-out (KO) mice and KO mice transgenically overexpressing mitochondria-targeted Ogg1 (KO-Tg) were fed pro-atherogenic Western type diet for 14 weeks and analyzed for mtDNA damage and signs of atherogenesis. Results: KO mice fed a high fat diet had increased oxidative mtDNA damage in cardiac tissue, whereas KO-Tg animals did not differ from WT mice (WT: 0.18 ± 0.04; KO: 0.35 ± 0.04; KO-Tg: 0.15 ± 0.01 lesions per 10 4 bp; n=3, P&lt;0.05; quantitative Southern blot analysis). We did not observe significant atherosclerotic plaque formation in the aortic valve of animals from any group; however appearance of fatty streaks, indicative of early plaque development, was more evident in KO mice (WT: 179 ± 20; KO: 384 ± 59 pixels, n=4, P&lt;0.05; immunohistochemistry for Fc receptor - general marker of inflammatory cells). This effect was completely blocked in KO-Tg mice. We found increased number of apoptotic cells in the aortic valve of KO, but not KO-Tg mice (WT: 2.00 ± 0.50; KO: 4.25 ± 0.48; KO-Tg: 2.14 ± 0.85 apoptotic cells, n=4, P&lt;0.05; TUNEL assay). Conclusion: Our data demonstrate that Ogg1 deficiency in mice fed a high fat diet leads to increased oxidative mtDNA damage, appearance of fatty streaks and cell apoptosis. In contrast, enhancement of mtDNA repair with mitochondria-targeted Ogg1 reduces fatty streaks formation and apoptosis induced by a high fat diet. These results suggest mtDNA damage and repair could be important targets for atheroprotection.
Circulation, Nov 11, 2016
Introduction: We have previously shown that smooth muscle cell (SMC)-specific IGF-1 receptor (IGF... more Introduction: We have previously shown that smooth muscle cell (SMC)-specific IGF-1 receptor (IGF1R) deficiency enhances plaque SMC apoptosis and increases atherosclerosis in Apoe-null mice, howeve...
Circulation, Nov 14, 2017
We have shown that IGF1 decreased atherosclerotic burden in high fat diet fed Apoe-null mice and ... more We have shown that IGF1 decreased atherosclerotic burden in high fat diet fed Apoe-null mice and we also demonstrated that decline in macrophage (MF) IGF1 signaling promoted murine atherogenesis. T...
American Journal of Physiology-heart and Circulatory Physiology, Oct 1, 2020
We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate ... more We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate cisplatin resistance in OSCC cells. However, the molecular mechanism underlying this role of TCRP1 remained to be elucidated. In this study, by using Human Toxicology and Drug Resistance Microarray, we identified 30 genes with significantly different expression levels between Tca/PYM and TCRP1 knockdown cell lines. Co-immunoprecipitation experiments and GST-pull down assays showed that metallothionein1X (MT1X) and Akt interact with TCRP1. siRNA-mediated knockdown of TCRP1 and MT1X was found to sensitize cells to cisplatin, leading to increased apoptosis and inhibition of cell proliferation. These functions of TCRP1 may be caused at least in part via activation of the PI3K/Akt/NF-kB signaling pathway. Taken together, our findings indicate that TCRP1 may be an important drug target for improvement of the treatment and survival of patients with oral squamous cell carcinoma.
The FASEB Journal, Apr 1, 2018
The FASEB Journal, Oct 3, 2018
Circulation, Nov 11, 2016
We have previously shown that IGF-1 reduces atherosclerosis in Apoe-null mice. We have now genera... more We have previously shown that IGF-1 reduces atherosclerosis in Apoe-null mice. We have now generated Apoe-null mice with SM22a promoter-driven IGF-1 receptor (IGF-1R) deficiency (22KI mice). IGF-1R...
Journal of Investigative Medicine, 2007
Apoptosis of smooth muscle cells (SMCs) is a prominent feature of advanced atherosclerotic plaque... more Apoptosis of smooth muscle cells (SMCs) is a prominent feature of advanced atherosclerotic plaque. We have previously shown that the proatherogenic molecule oxidized low-density lipoprotein (OxLDL) is associated with apoptotic SMCs in advanced plaques of human aorta and that OxLDL produces marked SMC apoptosis in vitro. In human aortic smooth muscle cells (HASMCs), the antioxidant Tiron (1 mM) suppressed superoxide production (by 18 ± 2%, DHE assay) and peroxide generation (by 88 ± 4%, CDC assay) induced by OxLDL (80 μg/mL, 16 hours) and completely blunted HASMC apoptosis (by 89 ± 2.6%, CELL DEATH ELISA), indicating that OxLDL-induced apoptosis was mediated by a redox-sensitive mechanism. The lipoxygenase (LOX) inhibitors AA-861, 5 μM and NDGA, 10 μM decreased OxLDL-induced superoxides (by 15 ± 2% and 25 ± 4%, respectively) and peroxides (by 48 ± 3% and 62 ± 6%, respectively) and NDGA completely blocked HASMC apoptosis (flow cytometry with annexin V staining). AA-861, 10 μM, another LOX inhibitor, Baicalein, 10 μM, and the NADPH oxidase-specific blocker apocynin, 100 μM suppressed OxLDL-induced HASMC apoptosis (by 93.0 ± 7%, 94 ± 0.4%, and 83 ± 3%, respectively) as was measured using cell death ELISA. To identify the oxidases involved in OxLDL-induced apoptosis, we studied the effect of OxLDL on SMC isolated from the aorta of 5-LOX- and 12/15-LOX-deficient and wild-type (WT) mice. 12/15-LOX deficiency markedly reduced OxLDL-induced superoxides and peroxides (by 31 ± 3% and 62 ± 7%, respectively, compared with WT). OxLDL-induced apoptosis was completely inhibited in 5-LOX- or 12/15-LOX-deficient SMC (by 82.6 ± 0.5% and 94.1 ± 0.7%, respectively); however, OxLDL produced 90.8 ± 4.4% apoptosis of WT SMC compared with control (0.5 μM staurosporine). In summary, we have identified 5-, 12/15-lipoxygenase and NADPH oxidase as key mediators of OxLDL-induced oxidative stress and SMC apoptosis. These data establish a novel functional relationship between different oxidases and together with our previous findings have major implications for understanding the mechanism of SMC depletion in advanced atherosclerotic plaque leading to plaque destabilization and acute coronary events.
Circulation, Nov 10, 2015
In arterial remodeling, smooth muscle cell (SMC) loss of contractile phenotype and increased prol... more In arterial remodeling, smooth muscle cell (SMC) loss of contractile phenotype and increased proliferation may result in vessel stenosis or a greater propensity for aneurysm formation and rupture. ...
Biochemical and Biophysical Research Communications, Jun 1, 2003
Oxidized low density lipoproteins (OxLDL) play a key role in atherogenesis and induce a wide rang... more Oxidized low density lipoproteins (OxLDL) play a key role in atherogenesis and induce a wide range of biological effects on smooth muscle cells. We used two commercially available cDNA microarray systems with a total of 35,932 human genes to determine differentially expressed genes in OxLDL-treated human aortic smooth muscle cells (HASMC) and to identify novel genes responsive to this agonist. We found a significant increase in expression of 180 and a significant decrease in expression of 192 named genes after treatment by OxLDL, compared with native LDL. Real time-PCR analysis confirmed microarray data for seven of eight tested genes. The differentially regulated genes were grouped into 16 classes based on the functions of the corresponding protein products. Our data demonstrate that OxLDL predominantly elevates expression of genes involved in cell-cell interactions, membrane transport, oncogenesis, apoptosis, and transcription and decreases expression of genes responsible for protein and nucleic acid biosynthesis, lipid metabolism, and humoral responses. Interestingly, we identify for the first time expression of metastasis-related protein (MB2) and novel scavenger receptor SREC-II in HASMC and these were upregulated 12- and 3-fold by OxLDL treatment, respectively. These findings have major implications for understanding atherogenic effect of OxLDL.
Biopolymers & Cell, Jan 20, 1994
Исследованы функциональные характеристики ДНК-зависимых ДНК-полимераз цианобактерии P. boryanum. ... more Исследованы функциональные характеристики ДНК-зависимых ДНК-полимераз цианобактерии P. boryanum. Установлено, что ДНК-полимераза II (ДЛИ) активно использует матрицы с различной структурой (наиболее активен фермент на ДНК P. boryanum и цианофага LPP-3, лизирующего данную цианобактерию), ДНК-поли мераза I (ДП1) менее активна на большинстве испытанных матриц, исключая цианобактериальную ДНК. Оба фермента нуждаются в праймировании синтетических рибонуклеиновых матриц и выявили разнию способность включать каждый из дезоксинуклеозидтрифосфатов. ДП1 и ДПП обладают З г-5''-экзонуклеазной актив ностью причем ДПП имеет более мощную ассоциированную экзонуклеазу. Только ДП1 способна к гидролизу фосфодиэфирных связей в направлении У-3'. Сделан вывод о возможной функциональной роли цианобактериальных ДП К-пол и мера з in vivo: ДПП является основным клеточным репликативным ферментом., а ДП1 ответственна за осиществление репаративных процессов и близка по свойствам ДНК-полимеразе I Escherichia со П.
Frontiers of Hormone Research, 2014
The process of vascular aging encompasses alterations in the function of endothelial (EC) and vas... more The process of vascular aging encompasses alterations in the function of endothelial (EC) and vascular smooth muscle cells (VSMCs) via oxidation, inflammation, cell senescence and epigenetic modifications, increasing the probability of atherosclerosis. Aged vessels exhibit decreased endothelial antithrombogenic properties, increased reactive oxygen species (ROS) generation and inflammatory signaling, increased migration of VSMCs to the subintimal space, impaired angiogenesis and increased elastin degradation. The key initiating step in atherogenesis is subendothelial accumulation of apolipoprotein-B containing low density lipoproteins resulting in activation of endothelial cells and recruitment of monocytes. Activated endothelial cells secrete “chemokines” that interact with cognate chemokine receptors on monocytes and promote directional migration. Recruitment of immune cells establishes a pro-inflammatory status, further causing elevated oxidative stress, which in turn triggers a series of events including apoptotic or necrotic death of vascular and non-vascular cells. Increased oxidative stress is also considered to be a key factor in mechanisms of aging-associated changes in tissue integrity and function. Experimental evidence indicates that insulin-like growth factor-1 (IGF-1) exerts anti-oxidant, anti-inflammatory and pro-survival effects on the vasculature, reducing atherosclerotic plaque burden and promoting features of atherosclerotic plaque stability.
Circulation, Nov 10, 2015
Impaired mitochondrial proliferation and function may lead to heart failure. Mitochondrial biogen... more Impaired mitochondrial proliferation and function may lead to heart failure. Mitochondrial biogenesis during postnatal cardiac development in rodents is accompanied by oxidative mitochondrial (mt) DNA damage and repair. How mtDNA damage is linked to mitochondrial biogenesis is unknown, but our previous data suggest that site-specific mtDNA oxidation is involved in regulation of mtDNA replication. Here we tested the hypothesis that modulation of Ogg1, a DNA glycosylase mediating the first step in the base excision repair of oxidative mtDNA damage, coordinately affects mitochondrial function and cardiac development. Wild type (WT) mice, Ogg1 knock-out (KO) mice and KO mice transgenically overexpressing mitochondria-targeted Ogg1 (KOTG) were analyzed for mtDNA damage and replication using Southern and slot-blot analyses; mitochondrial respiration using oxygraph; and cardiac function using echocardiography. Compared to WT, KO mice showed increased oxidative mtDNA damage in cardiac tissue, (0.18 ± 0.04 vs. 0.35 ± 0.04 lesions/104 bp respectively, p<0.05), 2-fold decrease in mtDNA copy number (p<0.05) and increased heart:body mass ratio (4.96 ± 0.11 vs. 5.70 ± 0.10 mg/g respectively, p<0.05). Conversely, KOTG mice showed decreased mtDNA oxidation, restored mtDNA copy number and blunted elevation in cardiac mass. Echocardiography confirmed increased cardiac mass in KO mice with a trend towards decrease of cardiac contractility. Compared to hearts from WT mice, KO animals displayed significant increase in mitochondrial oxygen flux at state III (54.0 ± 8.1 vs. 93.9 ± 9.2 pmol/sec/ml/10 mg respectively, p<0.05) with concurrent decrease in respiratory ratio (2.56 ± 0.42 vs. 1.46 ± 0.27 respectively), indicating constitutive uncoupling in the cardiac tissue. Mitochondrial bioenergetics of KOTG mice did not differ from WT animals. In summary, Ogg1 deficiency in mice leads to elevated oxidative mtDNA damage; decreased mtDNA copy number and respiration; and cardiac hypertrophy. Restored mtDNA repair completely eliminated these effects on mitochondrial function and cardiac development. These results suggest that abnormalities in mitochondrial function and cardiac development can be manipulated by altering mtDNA damage and repair.
Endocrinology, 1982
We have investigated the effects of monosodium glutamate (MSG) lesioning of the arcuate nucleus o... more We have investigated the effects of monosodium glutamate (MSG) lesioning of the arcuate nucleus on both central and peripheral components of the hypothalamo\x=req-\ pituitary-adrenocortical (HPA) axis under basal conditions and under acute and chronic stress. Plasma ACTH levels were lower in MSG-lesioned rats (27 \ m=+-\7 pg/ml) compared with controls (71 \ m=+-\18 pg/ml) while corticosterone levels were elevated (523 \ m=+-\ 84 ng/ml compared with 176 \ m=+-\34 ng/ml). Quantititative in situ hybridization histochemistry revealed that corticotrophin-releasing factor mRNA levels in the medial parvocellular part of the hypothalamic paraventricular nucleus were significantly lower in MSG-treated rats. MSG lesioning resulted in an enhanced response of corticosterone to restraint stress (1309 \m=+-\ 92 ng/ml compared with 628 \ m=+-\ 125 ng/ml in sham-lesioned animals), while ACTH responses to restraint stress in MSG-lesioned and sham-MSG groups were not significantly different (160 \m=+-\ 24 pg/ml and 167 \m=+-\ 24 pg/ml respectively). These data suggest that MSG-lesioned rats have an increased adrenocortical sensitivity. In rats subjected to the chronic osmotic stimulus of drinking 2% saline for 12 days, plasma ACTH levels were significantly reduced (15 \ m=+-\ 5 pg/ml) and the ACTH and corticosterone responses to restraint stress were eliminated. ACTH levels were also reduced in MSG-treated animals given 2% saline and the ACTH response to acute stress remained absent in these animals. However, a robust corticosterone response to restraint stress was observed in saline-treated MSG-lesioned rats. These data demonstrate that MSG lesioning results in elevated basal and stress\x=req-\ induced plasma corticosterone, and restores the adrenocortical response to stress which is absent in chronically osmotically stimulated rats. The evidence is consistent with the suggestion that MSG lesions a pathway involved in tonic inhibition of the HPA axis. In addition, the adrenocortical sensitivity to ACTH and other secretagogues may be increased in MSG-treated animals.
Circulation, 2017
Glyceraldehyde-3’-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme with a multiple glycolys... more Glyceraldehyde-3’-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme with a multiple glycolysis-unrelated functions. We have shown previously that GAPDH protected smooth muscle cells (SMC) agai...
JCI insight, Feb 22, 2023
Although murine models of coronary atherosclerotic disease have been used extensively to determin... more Although murine models of coronary atherosclerotic disease have been used extensively to determine mechanisms, limited new therapeutic options have emerged. Pigs with familial hypercholesterolemia (FH pigs) develop complex coronary atheromas that are almost identical to human lesions. We reported previously that insulin-like growth factor 1 (IGF-1) reduced aortic atherosclerosis and promoted features of stable plaque in a murine model. We administered human recombinant IGF-1 or saline (control) in atherosclerotic FH pigs for 6 months. IGF-1 decreased relative coronary atheroma in vivo (intravascular ultrasound) and reduced lesion cross-sectional area (postmortem histology). IGF-1 increased plaque's fibrous cap thickness, and reduced necrotic core, macrophage content, and cell apoptosis consistent with promotion of a stable plaque phenotype. IGF-1 reduced circulating triglycerides, markers of systemic oxidative stress and CXCL12 chemokine levels. We used spatial transcriptomics (ST) to identify global transcriptome changes in advanced plaque compartments and to obtain mechanistic insights into IGF-1 effects. ST analysis shows that IGF-1 suppressed FOS/FOSB factors and gene expression of MMP9 and CXCL14 in plaque macrophages, suggesting possible involvement of these molecules in IGF-1's effect on atherosclerosis. Thus, IGF-1 reduced coronary plaque burden and promoted features of stable plaque in a pig model, providing support for consideration of clinical trials.
Circulation, Nov 11, 2016
Collagen is a major constituent of the extracellular matrix in atherosclerotic plaques and suppor... more Collagen is a major constituent of the extracellular matrix in atherosclerotic plaques and supports plaque stability. La ribonucleoprotein domain family member 6 (LARP6) is an RNA binding protein, ...
The FASEB Journal, Apr 1, 2019
Circulation, Nov 14, 2017
Endothelial cells (ECs) provide a barrier function to the vasculature, which is supported by inte... more Endothelial cells (ECs) provide a barrier function to the vasculature, which is supported by intercellular junctions between ECs. Two types of endothelial cell intercellular junctions, namely tight...
Circulation, Nov 25, 2014
Introduction: Reactive oxygen species (ROS) play a key role in the development of atherosclerosis... more Introduction: Reactive oxygen species (ROS) play a key role in the development of atherosclerosis. Mitochondria are a main source of endogenous ROS in the cell. Mitochondrial DNA (mtDNA) is sensitive to oxidation and our previous results from cultured cell and intact animal models suggest that increasing mtDNA repair prevents both oxidative mtDNA damage and associated cytotoxicity and cellular dysfunction. Involvement of oxidative mtDNA damage in disorders characterized by chronic oxidative stress has been less thoroughly studied. Hypothesis: In the present study we tested the hypothesis that transgenic modulation of Ogg1, a DNA glycosylase mediating the first step in the base excision repair of oxidative mtDNA damage, coordinately regulates atherogenesis in mice fed a high fat diet. Methods: Wild type (WT) mice, Ogg1 knock-out (KO) mice and KO mice transgenically overexpressing mitochondria-targeted Ogg1 (KO-Tg) were fed pro-atherogenic Western type diet for 14 weeks and analyzed for mtDNA damage and signs of atherogenesis. Results: KO mice fed a high fat diet had increased oxidative mtDNA damage in cardiac tissue, whereas KO-Tg animals did not differ from WT mice (WT: 0.18 ± 0.04; KO: 0.35 ± 0.04; KO-Tg: 0.15 ± 0.01 lesions per 10 4 bp; n=3, P&lt;0.05; quantitative Southern blot analysis). We did not observe significant atherosclerotic plaque formation in the aortic valve of animals from any group; however appearance of fatty streaks, indicative of early plaque development, was more evident in KO mice (WT: 179 ± 20; KO: 384 ± 59 pixels, n=4, P&lt;0.05; immunohistochemistry for Fc receptor - general marker of inflammatory cells). This effect was completely blocked in KO-Tg mice. We found increased number of apoptotic cells in the aortic valve of KO, but not KO-Tg mice (WT: 2.00 ± 0.50; KO: 4.25 ± 0.48; KO-Tg: 2.14 ± 0.85 apoptotic cells, n=4, P&lt;0.05; TUNEL assay). Conclusion: Our data demonstrate that Ogg1 deficiency in mice fed a high fat diet leads to increased oxidative mtDNA damage, appearance of fatty streaks and cell apoptosis. In contrast, enhancement of mtDNA repair with mitochondria-targeted Ogg1 reduces fatty streaks formation and apoptosis induced by a high fat diet. These results suggest mtDNA damage and repair could be important targets for atheroprotection.
Circulation, Nov 11, 2016
Introduction: We have previously shown that smooth muscle cell (SMC)-specific IGF-1 receptor (IGF... more Introduction: We have previously shown that smooth muscle cell (SMC)-specific IGF-1 receptor (IGF1R) deficiency enhances plaque SMC apoptosis and increases atherosclerosis in Apoe-null mice, howeve...
Circulation, Nov 14, 2017
We have shown that IGF1 decreased atherosclerotic burden in high fat diet fed Apoe-null mice and ... more We have shown that IGF1 decreased atherosclerotic burden in high fat diet fed Apoe-null mice and we also demonstrated that decline in macrophage (MF) IGF1 signaling promoted murine atherogenesis. T...
American Journal of Physiology-heart and Circulatory Physiology, Oct 1, 2020
We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate ... more We recently reported that TCRP1, a novel multidrug-resistance associated human gene, can mediate cisplatin resistance in OSCC cells. However, the molecular mechanism underlying this role of TCRP1 remained to be elucidated. In this study, by using Human Toxicology and Drug Resistance Microarray, we identified 30 genes with significantly different expression levels between Tca/PYM and TCRP1 knockdown cell lines. Co-immunoprecipitation experiments and GST-pull down assays showed that metallothionein1X (MT1X) and Akt interact with TCRP1. siRNA-mediated knockdown of TCRP1 and MT1X was found to sensitize cells to cisplatin, leading to increased apoptosis and inhibition of cell proliferation. These functions of TCRP1 may be caused at least in part via activation of the PI3K/Akt/NF-kB signaling pathway. Taken together, our findings indicate that TCRP1 may be an important drug target for improvement of the treatment and survival of patients with oral squamous cell carcinoma.
The FASEB Journal, Apr 1, 2018
The FASEB Journal, Oct 3, 2018
Circulation, Nov 11, 2016
We have previously shown that IGF-1 reduces atherosclerosis in Apoe-null mice. We have now genera... more We have previously shown that IGF-1 reduces atherosclerosis in Apoe-null mice. We have now generated Apoe-null mice with SM22a promoter-driven IGF-1 receptor (IGF-1R) deficiency (22KI mice). IGF-1R...