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4.
Skinmed ; 21(1): 44-46, 2023.
Article En | MEDLINE | ID: mdl-36987828

A 1-year-old girl presented with porcelain white fingernails, accidentally discovered when she was referred for an infantile hemangioma consultation. The family reported that the nails had been milky white since birth and her father had similar white finger and toenails. The father remembered that additional family members on his side of the family presented with white nails; however, he could not provide exact information about the number of other relatives affected by this nail abnormality. The girl and her father were the only available family members with white nails presented for this study (Figure 1). The girl presented with leukonychia totalis on all fingernails only, while the father had this abnormality on all finger and toenails (Figure 2). We were not aware of any association with other diseases or features in this family, except hemangioma in the girl. (SKINmed. 2023;21:44-46).


Hemangioma , Nail Diseases , Nails, Malformed , Female , Humans , Infant , Denmark , Nail Diseases/diagnosis , Nail Diseases/genetics , Nails , Phospholipase C delta , Male
5.
JAMA Dermatol ; 158(11): 1245-1253, 2022 11 01.
Article En | MEDLINE | ID: mdl-36044230

Importance: Uncombable hair syndrome (UHS) is a rare hair shaft anomaly that manifests during infancy and is characterized by dry, frizzy, and wiry hair that cannot be combed flat. Only about 100 known cases have been reported so far. Objective: To elucidate the genetic spectrum of UHS. Design, Setting, and Participants: This cohort study includes 107 unrelated index patients with a suspected diagnosis of UHS and family members who were recruited worldwide from January 2013 to December 2021. Participants of all ages, races, and ethnicities were recruited at referral centers or were enrolled on their own initiative following personal contact with the authors. Genetic analyses were conducted in Germany from January 2014 to December 2021. Main Outcomes and Measures: Clinical photographs, Sanger or whole-exome sequencing and array-based genotyping of DNA extracted from blood or saliva samples, and 3-dimensional protein modeling. Descriptive statistics, such as frequency counts, were used to describe the distribution of identified pathogenic variants and genotypes. Results: The genetic characteristics of patients with UHS were established in 80 of 107 (74.8%) index patients (82 [76.6%] female) who carried biallelic pathogenic variants in PADI3, TGM3, or TCHH (ie, genes that encode functionally related hair shaft proteins). Molecular genetic findings from 11 of these 80 individuals were previously published. In 76 (71.0%) individuals, the UHS phenotype were associated with pathogenic variants in PADI3. The 2 most commonly observed PADI3 variants account for 73 (48.0%) and 57 (37.5%) of the 152 variant PADI3 alleles in total, respectively. Two individuals carried pathogenic variants in TGM3, and 2 others carried pathogenic variants in TCHH. Haplotype analyses suggested a founder effect for the 4 most commonly observed pathogenic variants in the PADI3 gene. Conclusions and Relevance: This cohort study extends and gives an overview of the genetic variant spectrum of UHS based on molecular genetic analyses of the largest worldwide collective of affected individuals, to our knowledge. Formerly, a diagnosis of UHS could only be made by physical examination of the patient and confirmed by microscopical examination of the hair shaft. The discovery of pathogenic variants in PADI3, TCHH, and TGM3 may open a new avenue for clinicians and affected individuals by introducing molecular diagnostics for UHS.


Hair Diseases , Female , Male , Humans , Cohort Studies , Hair Diseases/diagnosis , Hair Diseases/genetics , Exome Sequencing , Hair/abnormalities , Transglutaminases
6.
Sci Rep ; 12(1): 14109, 2022 08 18.
Article En | MEDLINE | ID: mdl-35982095

Pyrimidine catabolism is implicated in hepatic steatosis. Dihydropyrimidine dehydrogenase (DPYD) is an enzyme responsible for uracil and thymine catabolism, and DPYD human genetic variability affects clinically observed toxicity following 5-Fluorouracil administration. In an in vitro model of fatty acid-induced steatosis, the pharmacologic inhibition of DPYD resulted in protection from lipid accumulation. Additionally, a gain-of-function mutation of DPYD, created through clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) engineering, led to an increased lipid burden, which was associated with altered mitochondrial functionality in a hepatocarcionma cell line. The studies presented herein describe a novel role for DPYD in hepatocyte metabolic regulation as a modulator of hepatic steatosis.


Dihydrouracil Dehydrogenase (NADP) , Fatty Acids , Dihydrouracil Dehydrogenase (NADP)/genetics , Fluorouracil/adverse effects , Humans , Uracil
7.
Regul Toxicol Pharmacol ; 115: 104697, 2020 Aug.
Article En | MEDLINE | ID: mdl-32590049

Romosozumab (EVENITY™ [romosozumab-aqqg in the US]) is a humanized monoclonal antibody that inhibits sclerostin and has been approved in several countries for the treatment of osteoporosis in postmenopausal women at high risk of fracture. Sclerostin is expressed in bone and aortic vascular smooth muscle (AVSM). Its function in AVSM is unclear but it has been proposed to inhibit vascular calcification, atheroprogression, and inflammation. An increased incidence of positively adjudicated serious cardiovascular adverse events driven by an increase in myocardial infarction and stroke was observed in romosozumab-treated subjects in a clinical trial comparing alendronate with romosozumab (ARCH; NCT01631214) but not in a placebo-controlled trial (FRAME; NCT01575834). To investigate the effects of sclerostin inhibition with sclerostin antibody on the cardiovascular system, a comprehensive nonclinical toxicology package with additional cardiovascular studies was conducted. Although pharmacodynamic effects were observed in the bone, there were no functional, morphological, or transcriptional effects on the cardiovascular system in animal models in the presence or absence of atherosclerosis. These nonclinical studies did not identify evidence that proves the association between sclerostin inhibition and adverse cardiovascular function, increased cardiovascular calcification, and atheroprogression.


Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Antibodies, Monoclonal/pharmacology , Bone Density Conservation Agents/pharmacology , Cardiovascular System/drug effects , Animals , Antibodies, Monoclonal/therapeutic use , Bone Density Conservation Agents/therapeutic use , Drug Evaluation, Preclinical , Female , Fractures, Bone/prevention & control , Humans , Macaca fascicularis , Male , Mice, Inbred C57BL , Mice, Knockout, ApoE , Osteoporosis/drug therapy , Rats, Sprague-Dawley , Risk
8.
Am J Hum Genet ; 107(1): 34-45, 2020 07 02.
Article En | MEDLINE | ID: mdl-32497488

IFAP syndrome is a rare genetic disorder characterized by ichthyosis follicularis, atrichia, and photophobia. Previous research found that mutations in MBTPS2, encoding site-2-protease (S2P), underlie X-linked IFAP syndrome. The present report describes the identification via whole-exome sequencing of three heterozygous mutations in SREBF1 in 11 unrelated, ethnically diverse individuals with autosomal-dominant IFAP syndrome. SREBF1 encodes sterol regulatory element-binding protein 1 (SREBP1), which promotes the transcription of lipogenes involved in the biosynthesis of fatty acids and cholesterols. This process requires cleavage of SREBP1 by site-1-protease (S1P) and S2P and subsequent translocation into the nucleus where it binds to sterol regulatory elements (SRE). The three detected SREBF1 mutations caused substitution or deletion of residues 527, 528, and 530, which are crucial for S1P cleavage. In vitro investigation of SREBP1 variants demonstrated impaired S1P cleavage, which prohibited nuclear translocation of the transcriptionally active form of SREBP1. As a result, SREBP1 variants exhibited significantly lower transcriptional activity compared to the wild-type, as demonstrated via luciferase reporter assay. RNA sequencing of the scalp skin from IFAP-affected individuals revealed a dramatic reduction in transcript levels of low-density lipoprotein receptor (LDLR) and of keratin genes known to be expressed in the outer root sheath of hair follicles. An increased rate of in situ keratinocyte apoptosis, which might contribute to skin hyperkeratosis and hypotrichosis, was also detected in scalp samples from affected individuals. Together with previous research, the present findings suggest that SREBP signaling plays an essential role in epidermal differentiation, skin barrier formation, hair growth, and eye function.


Arthrogryposis/genetics , Mutation/genetics , Sterol Regulatory Element Binding Protein 1/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Gene Expression Regulation/genetics , Humans , Keratosis/genetics , Male , Middle Aged , Pedigree , Phenotype , Young Adult
9.
Mol Biol Cell ; 27(8): 1346-57, 2016 Apr 15.
Article En | MEDLINE | ID: mdl-26864624

The coordination of cell cycle progression with the repair of DNA damage supports the genomic integrity of dividing cells. The function of many factors involved in DNA damage response (DDR) and the cell cycle depends on their Ran GTPase-regulated nuclear-cytoplasmic transport (NCT). The loading of Ran with GTP, which is mediated by RCC1, the guanine nucleotide exchange factor for Ran, is critical for NCT activity. However, the role of RCC1 or Ran⋅GTP in promoting cell proliferation or DDR is not clear. We show that RCC1 overexpression in normal cells increased cellular Ran⋅GTP levels and accelerated the cell cycle and DNA damage repair. As a result, normal cells overexpressing RCC1 evaded DNA damage-induced cell cycle arrest and senescence, mimicking colorectal carcinoma cells with high endogenous RCC1 levels. The RCC1-induced inhibition of senescence required Ran and exportin 1 and involved the activation of importin ß-dependent nuclear import of 53BP1, a large NCT cargo. Our results indicate that changes in the activity of the Ran⋅GTP-regulated NCT modulate the rate of the cell cycle and the efficiency of DNA repair. Through the essential role of RCC1 in regulation of cellular Ran⋅GTP levels and NCT, RCC1 expression enables the proliferation of cells that sustain DNA damage.


Cell Cycle Proteins/metabolism , Cell Cycle/physiology , DNA Repair/physiology , Guanine Nucleotide Exchange Factors/metabolism , Nuclear Proteins/metabolism , ran GTP-Binding Protein/metabolism , Cell Cycle Proteins/genetics , Cellular Senescence/physiology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , DNA Damage/physiology , Doxorubicin/pharmacology , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Gene Expression Regulation , Guanine Nucleotide Exchange Factors/genetics , Guanosine Triphosphate/metabolism , HCT116 Cells/drug effects , HeLa Cells , Humans , Karyopherins/metabolism , Nuclear Proteins/genetics , RNA Interference , Receptors, Cytoplasmic and Nuclear/metabolism , beta Karyopherins/metabolism , ran GTP-Binding Protein/genetics , Exportin 1 Protein
10.
Circulation ; 132(20): 1909-19, 2015 Nov 17.
Article En | MEDLINE | ID: mdl-26416809

BACKGROUND: Although vascular smooth muscle cell (VSMC) proliferation is implicated in atherogenesis, VSMCs in advanced plaques and cultured from plaques show evidence of VSMC senescence and DNA damage. In particular, plaque VSMCs show shortening of telomeres, which can directly induce senescence. Senescence can have multiple effects on plaque development and morphology; however, the consequences of VSMC senescence or the mechanisms underlying VSMC senescence in atherosclerosis are mostly unknown. METHODS AND RESULTS: We examined the expression of proteins that protect telomeres in VSMCs derived from human plaques and normal vessels. Plaque VSMCs showed reduced expression and telomere binding of telomeric repeat-binding factor-2 (TRF2), associated with increased DNA damage. TRF2 expression was regulated by p53-dependent degradation of the TRF2 protein. To examine the functional consequences of loss of TRF2, we expressed TRF2 or a TRF2 functional mutant (T188A) as either gain- or loss-of-function studies in vitro and in apolipoprotein E(-/-) mice. TRF2 overexpression bypassed senescence, reduced DNA damage, and accelerated DNA repair, whereas TRF2(188A) showed opposite effects. Transgenic mice expressing VSMC-specific TRF2(T188A) showed increased atherosclerosis and necrotic core formation in vivo, whereas VSMC-specific TRF2 increased the relative fibrous cap and decreased necrotic core areas. TRF2 protected against atherosclerosis independent of secretion of senescence-associated cytokines. CONCLUSIONS: We conclude that plaque VSMC senescence in atherosclerosis is associated with loss of TRF2. VSMC senes cence promotes both atherosclerosis and features of plaque vulnerability, identifying prevention of senescence as a potential target for intervention.


Atherosclerosis/metabolism , Cellular Senescence/physiology , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Plaque, Atherosclerotic/metabolism , Animals , Atherosclerosis/pathology , Cells, Cultured , Female , Humans , Male , Mice , Mice, Transgenic , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , Plaque, Atherosclerotic/pathology
11.
Circ Res ; 116(5): 816-26, 2015 Feb 27.
Article En | MEDLINE | ID: mdl-25524056

RATIONALE: DNA damage and the DNA damage response have been identified in human atherosclerosis, including in vascular smooth muscle cells (VSMCs). However, although double-stranded breaks (DSBs) are hypothesized to promote plaque progression and instability, in part, by promoting cell senescence, apoptosis, and inflammation, the direct effects of DSBs in VSMCs seen in atherogenesis are unknown. OBJECTIVE: To determine the presence and effect of endogenous levels of DSBs in VSMCs on atherosclerosis. METHODS AND RESULTS: Human atherosclerotic plaque VSMCs showed increased expression of multiple DNA damage response proteins in vitro and in vivo, particularly the MRE11/RAD50/NBS1 complex that senses DSB repair. Oxidative stress-induced DSBs were increased in plaque VSMCs, but DSB repair was maintained. To determine the effect of DSBs on atherosclerosis, we generated 2 novel transgenic mice lines expressing NBS1 or C-terminal deleted NBS1 only in VSMCs, and crossed them with apolipoprotein E(-/-) mice. SM22α-NBS1/apolipoprotein E(-/-) VSMCs showed enhanced DSB repair and decreased growth arrest and apoptosis, whereas SM22α-(ΔC)NBS1/apolipoprotein E(-/-) VSMCs showed reduced DSB repair and increased growth arrest and apoptosis. Accelerating or retarding DSB repair did not affect atherosclerosis extent or composition. However, VSMC DNA damage reduced relative fibrous cap areas, whereas accelerating DSB repair increased cap area and VSMC content. CONCLUSIONS: Human atherosclerotic plaque VSMCs show increased DNA damage, including DSBs and DNA damage response activation. VSMC DNA damage has minimal effects on atherogenesis, but alters plaque phenotype inhibiting fibrous cap areas in advanced lesions. Inhibiting DNA damage in atherosclerosis may be a novel target to promote plaque stability.


DNA Damage , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Plaque, Atherosclerotic/genetics , Animals , Aorta/cytology , Aorta/pathology , Aortic Diseases/genetics , Aortic Diseases/metabolism , Aortic Diseases/pathology , Apolipoproteins E/deficiency , Brachiocephalic Trunk/pathology , Carotid Arteries/cytology , Cell Cycle Proteins/biosynthesis , Cell Cycle Proteins/genetics , Cells, Cultured , Comet Assay , DNA Breaks, Double-Stranded , DNA Repair Enzymes/biosynthesis , DNA Repair Enzymes/genetics , DNA-Binding Proteins , Female , Gene Expression Profiling , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microfilament Proteins/biosynthesis , Microfilament Proteins/genetics , Muscle Proteins/biosynthesis , Muscle Proteins/genetics , Nuclear Proteins/biosynthesis , Nuclear Proteins/genetics , Oligonucleotide Array Sequence Analysis , Plaque, Atherosclerotic/metabolism , Plaque, Atherosclerotic/pathology , Up-Regulation
12.
Contemp Clin Dent ; 5(2): 150-4, 2014 Apr.
Article En | MEDLINE | ID: mdl-24963236

AIM: The aim of the study was to determine the clinical and histopathological effect on palatal hyperplasia caused by suction cups by different methods of management used for recovery of abused tissues. MATERIALS AND METHODS: A total of 35 subjects agreed for biopsy procedure, from 50 patients who gave consent for the study. Out of the 35 subjects, 20 were randomly selected for treatment with discontinuation of denture (Group I) and 15 selected for denture relined with tissue conditioner (COE-comfort) (Group II). Punch biopsy procedure was performed on these patients to study the histopathology of the lesion before the two modalities of treatment was administered on them. RESULTS: Inflammation caused by suction cup decreased considerably by both the treatment modalities, i.e., the use of tissue conditioner as well as discontinuation of denture (tissue rest) for a period of 2 weeks. CONCLUSION: It was concluded that wearing denture day and night considerably increased the severity of inflammatory papillary hyperplasia of palate. Healing was better with tissue conditioner when compared with tissue rest.

14.
Circulation ; 128(7): 702-12, 2013 Aug 13.
Article En | MEDLINE | ID: mdl-23841983

BACKGROUND: Mitochondrial DNA (mtDNA) damage occurs in both circulating cells and the vessel wall in human atherosclerosis. However, it is unclear whether mtDNA damage directly promotes atherogenesis or is a consequence of tissue damage, which cell types are involved, and whether its effects are mediated only through reactive oxygen species. METHODS AND RESULTS: mtDNA damage occurred early in the vessel wall in apolipoprotein E-null (ApoE(-/-)) mice, before significant atherosclerosis developed. mtDNA defects were also identified in circulating monocytes and liver and were associated with mitochondrial dysfunction. To determine whether mtDNA damage directly promotes atherosclerosis, we studied ApoE(-/-) mice deficient for mitochondrial polymerase-γ proofreading activity (polG(-/-)/ApoE(-/-)). polG(-/-)/ApoE(-/-) mice showed extensive mtDNA damage and defects in oxidative phosphorylation but no increase in reactive oxygen species. polG(-/-)/ApoE(-/-) mice showed increased atherosclerosis, associated with impaired proliferation and apoptosis of vascular smooth muscle cells, and hyperlipidemia. Transplantation with polG(-/-)/ApoE(-/-) bone marrow increased the features of plaque vulnerability, and polG(-/-)/ApoE(-/-) monocytes showed increased apoptosis and inflammatory cytokine release. To examine mtDNA damage in human atherosclerosis, we assessed mtDNA adducts in plaques and in leukocytes from patients who had undergone virtual histology intravascular ultrasound characterization of coronary plaques. Human atherosclerotic plaques showed increased mtDNA damage compared with normal vessels; in contrast, leukocyte mtDNA damage was associated with higher-risk plaques but not plaque burden. CONCLUSIONS: We show that mtDNA damage in vessel wall and circulating cells is widespread and causative and indicates higher risk in atherosclerosis. Protection against mtDNA damage and improvement of mitochondrial function are potential areas for new therapeutics.


Atherosclerosis/etiology , DNA Damage , DNA, Mitochondrial/chemistry , Mitochondria/pathology , Monocytes/pathology , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , Plaque, Atherosclerotic/pathology , Adiposity , Adult , Aged , Animals , Apolipoproteins E/genetics , Apoptosis , Atherosclerosis/genetics , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cells, Cultured , Cytokines/metabolism , DNA Adducts/analysis , DNA Polymerase gamma , DNA-Directed DNA Polymerase/deficiency , DNA-Directed DNA Polymerase/genetics , Electron Transport , Female , Humans , Hyperlipidemias/genetics , Leukocytes/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Mitochondria/chemistry , Mitochondria/physiology , Monocytes/metabolism , Muscle, Smooth, Vascular/metabolism , Oxygen Consumption , Radiation Chimera , Reactive Oxygen Species , Risk
15.
Niger J Clin Pract ; 16(2): 266-8, 2013.
Article En | MEDLINE | ID: mdl-23563476

Stenson's duct of parotid gland is a major duct which drains saliva into the oral cavity. Deep penetrating wound in the form of cut or crush injury to the buccal area carries the risk of parotid duct injury. It is in the form of ductal exposure, laceration, total severing, or crushing of the duct. These conditions are difficult to diagnose because of complex anatomy and variable nature of injury. Successful management of parotid duct injury depends on early diagnosis and appropriate intervention, failing of which may lead to complications like sialocele or salivary fistula. Many techniques have been proposed for diagnosis and management of parotid duct injuries. This article presents an easy and novel technique to diagnose and manage the parotid duct injuries using an "epidural catheter" which is often used for inducing spinal anesthesia. The technique of epidural catheter usage, its advantages, and limitation over other techniques proposed for the management of parotid duct injury are discussed.


Catheterization , Parotid Gland/surgery , Salivary Ducts/injuries , Salivary Ducts/surgery , Adult , Catheters , Humans , Male , Stents
16.
J Clin Diagn Res ; 7(1): 178-80, 2013 Jan.
Article En | MEDLINE | ID: mdl-23449967

Malnutrition affects the oral health and a poor oral health in turn, may lead to malnutrition. This interdependent relationship sees good nutritional health, thus promoting good oral health and vice versa. Malnutrition may alter the homeostasis, which can lead to disease progression of the oral cavity, reduce the resistance to the microbial biofilm and reduce the capacity of tissue healing. It may even affect the development of the oral cavity. Protein-energy malnutrition occurs when there is a deficiency of protein, energy foods or both, which are relative to a body's need. Studies have suggested that enamel hypoplasia, salivary gland hypofunction and saliva compositional changes may be the mechanisms through which the malnutrition is associated with caries, while an altered eruption timing may create a challenge in the analysis of the age specific caries rates. This paper gives an insight on the relationship of the malnutrition and the protein-energy malnutrition with the oral health status.

17.
Circulation ; 127(3): 386-96, 2013 Jan 22.
Article En | MEDLINE | ID: mdl-23224247

BACKGROUND: Vascular smooth muscle cells (VSMCs) in human atherosclerosis manifest extensive DNA damage and activation of the DNA damage response, a pathway that coordinates cell cycle arrest and DNA repair, or can trigger apoptosis or cell senescence. Sirtuin 1 deacetylase (SIRT1) regulates cell ageing and energy metabolism and regulates the DNA damage response through multiple targets. However, the direct role of SIRT1 in atherosclerosis and how SIRT1 in VSMCs might regulate atherosclerosis are unknown. METHODS AND RESULTS: SIRT1 expression was reduced in human atherosclerotic plaques and VSMCs both derived from plaques and undergoing replicative senescence. SIRT1 inhibition reduced DNA repair and induced apoptosis, in part, through reduced activation of the repair protein Nijmegen Breakage Syndrome-1 but not p53. Fat feeding reduced SIRT1 and induced DNA damage in VSMCs. VSMCs from mice expressing inactive truncated SIRT1 (Δex4) showed increased oxidized low-density lipoprotein-induced DNA damage and senescence. ApoE(-/-) mice expressing SIRT1(Δex4) only in smooth muscle cells demonstrated increased DNA damage response activation and apoptosis, increased atherosclerosis, reduced relative fibrous cap thickness, and medial degeneration. CONCLUSIONS: SIRT1 is reduced in human atherosclerosis and is a critical regulator of the DNA damage response and survival in VSMCs. VSMC SIRT1 protects against DNA damage, medial degeneration, and atherosclerosis.


Atherosclerosis/prevention & control , Atherosclerosis/physiopathology , DNA Damage/physiology , Muscle, Smooth, Vascular/metabolism , Sirtuin 1/metabolism , Animals , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Apoptosis/physiology , Cell Cycle/physiology , Cells, Cultured , DNA Repair/physiology , Disease Models, Animal , Down-Regulation/physiology , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/pathology , Rats , Rats, Wistar , Sirtuin 1/deficiency , Sirtuin 1/genetics
18.
Arterioscler Thromb Vasc Biol ; 32(10): 2461-7, 2012 Oct.
Article En | MEDLINE | ID: mdl-22859494

OBJECTIVE: Caffeine remains one of the most widely consumed drugs in the world. Caffeine has multiple actions, including inhibition of the DNA damage response, and its metabolites, 1-methylxanthine and 1-methyluric acid, are potent antioxidants. Combined, these properties can exert direct effects on cell proliferation, cell death, inflammation, and DNA repair, all important processes that occur in atherosclerosis. METHODS AND RESULTS: We first examined the effects of caffeine on mouse vascular smooth muscle cells. Caffeine inhibited activation of the DNA damage response regulator ataxia telangiectasia mutated protein and its downstream targets. Caffeine delayed DNA repair, had a concentration-dependent effect on cell proliferation, and protected against apoptosis. In vitro caffeine reduced oxygen consumption and decreased generation of reactive oxygen species. In vivo caffeine reduced DDR activation in vascular and nonvascular tissues, reduced reactive nitrogen species and serum levels of the DNA adduct 8-oxo-guanine, and inhibited atherogenesis in fat-fed ApoE(-/-) mice. Reduction in atherosclerosis was independent of the effects on blood pressure and serum lipids but associated with reduced cell proliferation and ataxia telangiectasia mutated protein activation. CONCLUSIONS: The Methyl Xanthine caffeine inhibits the DNA damage response in vitro and in vivo, regulates both cell proliferation and apoptosis after DNA damage, inhibits reactive species, and reduces atherogenesis in ApoE(-/-) mice.


Apolipoproteins E/deficiency , Atherosclerosis/prevention & control , Caffeine/pharmacology , DNA Damage/drug effects , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Xanthines/pharmacology , Animals , Apolipoproteins E/genetics , Apoptosis/drug effects , Atherosclerosis/genetics , Atherosclerosis/physiopathology , Caffeine/therapeutic use , Cell Proliferation/drug effects , Cells, Cultured , DNA Adducts/blood , DNA Damage/physiology , Disease Models, Animal , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Oxygen Consumption/drug effects , Signal Transduction/physiology , Xanthines/therapeutic use
19.
Int Immunol ; 22(9): 757-67, 2010 Sep.
Article En | MEDLINE | ID: mdl-20682547

Type-I IFN (IFN-I) are highly pleiotropic cytokines known to modulate immune responses and play an early central role in mediating antiviral defenses. We have shown that IFN-I mediate transient up-regulation of a distinct subset of lymphocyte surface activation markers on both B and T cells in vivo independent of cognate antigen: a state referred to as 'partial lymphocyte activation'. Here we investigated in vitro the possibility that partial lymphocyte activation may serve to lower the antigen-specific activation thresholds for T cells. We found that the kinetics of Ca(2+) flux in T cells responding to TCR cross-linking was not enhanced in partially activated T cells. Furthermore, following TCR stimulation with anti-cluster of differentiation (CD) 3 epsilon, a lower proportion of partially activated than naive T cells proliferated. In contrast, the proliferation of partially activated and naive ovalbumin peptide (OVAp, SIINFEKL) specific CD8(+) T cells (OT-I CD8(+) T cells) was similar when stimulated with OVAp. Surprisingly, using an enzyme-linked immunospot (ELISPOT) assay for IFN-gamma secretion, we found that a higher number of partially activated OT-I CD8(+) T cells expressed effector functions than did naive OT-I CD8(+) T cells. This is most readily explained by an increased survival of activated antigen-specific CD8(+) T cells from a pool of partially activated T cells than naive T cells. Overall, when examining the effects of early (Ca(2+) flux), intermediate (proliferation) or late events (IFN-gamma secretion) of T-cell activation, we found that partial activation promotes the survival but does not alter the antigen-specific activation thresholds of CD8(+) T cells.


CD8-Positive T-Lymphocytes/metabolism , Interferon Type I/metabolism , Receptors, Antigen, T-Cell/metabolism , T-Cell Antigen Receptor Specificity , T-Lymphocyte Subsets/metabolism , Animals , Antibodies, Monoclonal/pharmacology , Antigens/immunology , CD3 Complex/immunology , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Calcium Signaling/drug effects , Calcium Signaling/immunology , Cell Proliferation/drug effects , Cells, Cultured , Interferon Type I/immunology , Interferon-gamma/metabolism , Lymphocyte Activation/drug effects , Mice , Mice, Inbred C57BL , Mice, Transgenic , Ovalbumin/immunology , Receptors, Antigen, T-Cell/agonists , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , T-Lymphocyte Subsets/drug effects , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/pathology
20.
Cardiovasc Res ; 85(1): 28-37, 2010 Jan 01.
Article En | MEDLINE | ID: mdl-19633014

AIMS: The caspases are thought to be central mediators of the apoptotic program, but recent data indicate that apoptosis may also be mediated by caspase-independent mechanisms such as apoptosis-inducing factor (AIF). The role of AIF-induced apoptosis in heart, however, is currently not well understood. The aim of this study was to investigate the presence of and conditions for AIF-induced cardiac apoptosis in vitro. METHODS AND RESULTS: Hypertrophic cardiomyocyte (H-CM) cultures were prepared from the hearts of Dahl salt-sensitive rats fed a high salt diet. Apoptotic stimulation induced by hypoxia/reoxygenation or staurosporine (1 microM) enhanced AIF release in H-CMs compared with non-hypertrophic cardiomyocytes (N-CMs). Caspase inhibition using zVAD.fmk (25 microM) or overexpression of CrmA using recombinant adenovirus only partially protected N-CMs from apoptosis (63 +/- 0.93%) and provided no significant protection against apoptosis in hypertrophic cells (23 +/- 1.03%). On the other hand, poly-ADP-ribose polymerase inhibition using 4-AN (20 microM) during apoptotic stimulation blocked the release of AIF from mitochondria and significantly improved cell viability in hypertrophied cardiomyocytes (74 +/- 1.18%). CONCLUSION: A caspase-dependent, apoptotic pathway is important for N-CM death, whereas a caspase-independent, AIF-mediated pathway plays a critical role in H-CMs.


Apoptosis Inducing Factor/physiology , Apoptosis , Cardiomegaly/pathology , Myocytes, Cardiac/pathology , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Caspase Inhibitors , Caspases/physiology , Female , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerase Inhibitors , Rats , Rats, Inbred Dahl
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